Contribution of diffusion weighted MRI to diagnosis and staging in gastric tumors and comparison with multi-detector computed tomography.

PubMed

Arslan, Harun; Fatih Özbay, Mehmet; Çallı, İskan; Doğan, Erkan; Çelik, Sebahattin; Batur, Abdussamet; Bora, Aydın; Yavuz, Alpaslan; Bulut, Mehmet Deniz; Özgökçe, Mesut; Çetin Kotan, Mehmet

2017-03-01

Diagnostic performance of Diffusion-Weighted magnetic resonance Imaging (DWI) and Multi-Detector Computed Tomography (MDCT) for TNM (Tumor, Lymph node, Metastasis) staging of gastric cancer was compared. We used axial T2-weighted images and DWI (b-0,400 and b-800 s/mm2) protocol on 51 pre-operative patients who had been diagnosed with gastric cancer. We also conducted MDCT examinations on them. We looked for a signal increase in the series of DWI images. The depth of tumor invasion in the stomach wall (tumor (T) staging), the involvement of lymph nodes (nodal (N) staging), and the presence or absence of metastases (metastatic staging) in DWI and CT images according to the TNM staging system were evaluated. In each diagnosis of the tumors, sensitivity, specificity, positive and negative accuracy rates of DWI and MDCT examinations were found through a comparison with the results of the surgical pathology, which is the gold standard method. In addition to the compatibilities of each examination with surgical pathology, kappa statistics were used. Sensitivity and specificity of DWI and MDCT in lymph node staging were as follows: N1: DWI: 75.0%, 84.6%; MDCT: 66.7%, 82%;N2: DWI: 79.3%, 77.3%; MDCT: 69.0%, 68.2%; N3: DWI: 60.0%, 97.6%; MDCT: 50.0%, 90.2%. The diagnostic tool DWI seemed more compatible with the gold standard method (surgical pathology), especially in the staging of lymph node, when compared to MDCT. On the other hand, in T staging, the results of DWI and MDCT were better than the gold standard when the T stage increased. However, DWI did not demonstrate superiority to MDCT. The sensitivity and specificity of both imaging techniques for detecting distant metastasis were 100%. The diagnostic accuracy of DWI for TNM staging in gastric cancer before surgery is at a comparable level with MDCT and adding DWI to routine protocol of evaluating lymph nodes metastasis might increase diagnostic accuracy.

64-slice MDCT angiography of upper extremity in assessment of native hemodialysis access.

PubMed

Wasinrat, Jitladda; Siriapisith, Thanongchai; Thamtorawat, Somrach; Tongdee, Trongtum

2011-01-01

To compare multidetector row computed tomographic (MDCT) angiography with conventional digital subtraction angiography (DSA) in the evaluation of vascular access stenoses in hemodialysis patients. Twenty-one consecutive patients were imaged with MDCT angiography and subsequent DSA. The superficial vein of leg was used as the route for intravenous administration. The vascular stenosis was assessed in not significant (<50% stenosis), moderate stenosis (50%-74% stenosis), severe stenosis (75%-99%), and total occlusion (100%). The accuracy, sensitivity, specificity, positive, and negative predictive values were calculated for significant vascular stenosis using DSA as the standard reference. The sensitivity and specificity of MDCT angiography for the detection of significant hemodialysis vascular access were 100% (95% CI, 89.3%-100%) and 94.8% (95% CI, 89.1%-97.6%), respectively. The positive and negative predictive values were 84.2% (95% CI, 68.1%-93.4%) and 100% (95% CI, 95.8%-100%), respectively. The accuracy of MDCT angiography for detection of significant stenoses was 95.9% (95% CI, 91.4%-97.0%). MDCT angiography provides excellent correlation in vascular stenosis as compared with DSA in hemodialysis access. Complete assessment of entire vascular segments could be performing with MDCT angiography in planning before endovascular intervention or surgical correction.

Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

PubMed

Norris, Joseph M; Kishikova, Lyudmila; Avadhanam, Venkata S; Koumellis, Panos; Francis, Ian S; Liu, Christopher S C

2015-08-01

To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems.

PubMed

Avanesov, Maxim; Weinrich, Julius M; Kraus, Thomas; Derlin, Thorsten; Adam, Gerhard; Yamamura, Jin; Karul, Murat

2016-11-01

The purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. In this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48-64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. In neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p=0.25; mCTSI: 4.0 vs. 4.0, p=0.10; EPIC: 2.0 vs. 2.0, p=0.41; NP: CTSI: 8.0 vs. 7.0, p=0.64; mCTSI: 8.0 vs. 8.0, p=0.10; EPIC: 3.0 vs. 3.0, p=0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. An initial dual-phase abdominal CT after ≥72h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a single-phase protocol. Copyright © 2016. Published by Elsevier Ireland Ltd.

Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

PubMed Central

Falcão, João L. A. A.; Falcão, Breno A. A.; Gurudevan, Swaminatha V.; Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A.

2015-01-01

Background The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. Results At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques. PMID:25993595

Small (≤ 2 cm) hepatocellular carcinoma in patients with chronic liver disease: comparison of gadoxetic acid-enhanced 3.0 T MRI and multiphasic 64-multirow detector CT.

PubMed

Hwang, J; Kim, S H; Lee, M W; Lee, J Y

2012-07-01

To compare the diagnostic performance of gadoxetic acid-enhanced MRI using 3.0 T with that of multiphasic 64-multirow detector CT (MDCT) for the detection of small (≤2 cm) hepatocellular carcinoma (HCC) in patients with chronic liver disease. A total of 54 patients (44 men, 10 women; age range, 33-81 years) with 59 HCCs (≤2 cm in diameter) who underwent both multiphasic (arterial, portal venous, equilibrium) 64-MDCT and gadoxetic acid-enhanced 3.0 T MRI were enrolled in this study. Two observers independently and randomly reviewed the MR and CT images on a lesion-by-lesion basis. The diagnostic performance of these techniques for the detection of HCC was assessed by alternative free-response receiver operating characteristic (ROC) analysis, in addition to evaluating the sensitivity and positive predictive value. For each observer, the areas under the ROC curve were 0.874 and 0.863 for MRI, respectively, as opposed to 0.660 and 0.687 for CT, respectively. The differences between the two techniques were statistically significant for each observer (p<0.001). The sensitivities (89.8% and 86.4%) of MRI for both observers were significantly higher than those (57.6% and 61.0% for each observer, respectively) of MDCT. No significant difference was seen between the positive predictive values for the two techniques (p>0.05). Gadoxetic acid-enhanced 3.0 T MRI shows a better diagnostic performance than that of 64-MDCT for the detection of small (≤2 cm) HCCs in patients with chronic liver disease.

Application of MPVR and TL-VR with 64-row MDCT in neonates with congenital EA and distal TEF.

PubMed

Wen, Yang; Peng, Yun; Zhai, Ren-You; Li, Ying-Zi

2011-03-28

To assess the application of multiple planar volume reconstruction (MPVR) and three-dimensional (3D) transparency lung volume rendering (TL-VR) with 64-row multidetector-row computed tomography (MDCT) in neonates with congenital esophageal atresia (EA) and distal tracheoesophageal fistula (TEF). Twenty neonates (17 boys, 3 girls) with EA and distal TEF at a mean age of 4.6 d (range 1-16 d) were enrolled in this study. A helical scan of 64-row MDCT was performed at the 64 mm × 0.625 mm collimation. EA and TEF were reconstructed with MPVR and TL-VR, respectively. Initial diagnosis of EA was made by chest radiography showing the inserted catheter in the proximal blind-ended esophageal pouch. Manifestations of MDCT images were compared with the findings at surgery. MDCT showed the proximal and distal esophageal pouches in 20 cases. No significant difference was observed in gaps between the proximal and distal esophageal pouches detected by MPVR and TL-VR. The lengths of gaps between the proximal and distal esophageal pouches detected by MPVR and TL-VR correlated well with the findings at surgery (R = 0.87, P < 0.001). The images of MPVR revealed the orifice of TEF in 13 cases, while TL-VR images showed the orifice of TEF in 4 cases. EA and distal TEF can be reconstructed using MPVR and TL-VR of 64-row MDCT, which is a noninvasive technique to demonstrate the distal esophageal pouches and inter-pouch distance in neonates with EA and distal TEF.

Multidetector computed tomographic morphology of ovaries in cynomolgus macaques (Macaca fascicularis).

PubMed

Jones, Jeryl C; Appt, Susan E; Bourland, J Daniel; Hoyer, Patricia B; Clarkson, Thomas B; Kaplan, Jay R

2007-09-01

Macaques are important models for menopause and associated diseases in women. A sensitive, noninvasive technique for quantifying changes in ovarian morphology would facilitate longitudinal studies focused on the health-related sequelae of naturally occurring or experimentally induced alterations in ovarian structure and function. Multidetector computed tomography (MDCT) is a fast, non-invasive imaging technique that uses X-rays, multiple rows of detectors, and computers to generate detailed slice images of structures. The purpose of this study was to describe the utility of MDCT for reliably characterizing ovarian morphology in macaques. Five macaques were scanned using contrast-enhanced MDCT. The following characteristics were described: 1) appearance of ovaries and adjacent landmarks, 2) effects of varying technical protocols on ovarian image quality, 3) radiation doses delivered to the pelvic region during scanning, and 4) MDCT estimates of ovarian volume and antral follicle counts versus those measured directly in ovarian tissue. Ovaries were distinguishable in all MDCT scans and exhibited heterogeneous contrast enhancement. Antral follicles appeared as focal areas of nonenhancement. Ovarian image quality with 5 pediatric scanning protocols was sufficient for discriminating ovarian margins. Pelvic region radiation doses ranged from 0.5 to 0.7 rad. Antral follicles counted using MDCT ranged from 3 to 5 compared with 3 to 4 counted using histology. Ovarian volumes measured using MDCT ranged from 0.41 to 0.67 ml compared with 0.40 to 0.65 ml by water displacement. MDCT is a promising technique for measuring longitudinal changes in macaque ovarian morphology reliably and noninvasively.

Accuracy of percutaneous soft-tissue interventions using a multi-axis, C-arm CT system and 3D laser guidance.

PubMed

Kostrzewa, Michael; Rathmann, Nils; Kara, Kerim; Schoenberg, Stefan O; Diehl, Steffen J

2015-10-01

Purpose of this phantom study was to compare the accuracy of needle placement using a multi-axis, C-arm-based, flat-panel, cone-beam computed tomography system (CBCT guidance) with that under multi-detector computed tomography guidance (MDCT guidance). In an abdominal phantom, eight lesions (six lesions in the liver and two in the renal pelvises, respectively) were each punctured in-plane and off-plane with a 20G needle under CBCT and MDCT guidance. Access paths were initially defined and reproduced identically on the two systems. In total, 32 interventions were conducted. CBCT and MDCT guidance was compared prospectively with respect to technical success, accuracy, and overall procedural time. All 32 interventions were technically successful in that it was possible to hit the respective lesion in each procedure. When comparing the accuracy of MDCT to CBCT guidance there was no significant difference in absolute, angular, and longitudinal deviation for either in- or off-plane interventions. Overall procedural duration was significantly longer under CBCT guidance for in-plane interventions (888 vs 527s, p=0.00005), whereas, for off-plane procedures there was no significant difference between CBCT and MDCT guidance (920 vs 701s, p=0.08). Off-plane interventions took significantly longer than in-plane interventions under MDCT guidance (701 vs 527s, p=0.03), whereas under CBCT guidance no significant difference could be found between off- and in-plane procedures (920 vs. 888s, p=0.2). In this phantom study, we could show that percutaneous soft-tissue interventions under CBCT guidance can be conducted with an accuracy comparable to that under MDCT guidance. Although overall procedural duration is in general shorter using MDCT guidance, CBCT-guided interventions offer the advantage of more degrees of freedom, which is of particular importance for off-plane procedures. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Comparison of radiation dose reduction of prospective ECG-gated one beat scan using 320 area detector CT coronary angiography and prospective ECG-gated helical scan with high helical pitch (FlashScan) using 64 multidetector-row CT coronary angiography].

PubMed

Matsutani, Hideyuki; Sano, Tomonari; Kondo, Takeshi; Fujimoto, Shinichiro; Sekine, Takako; Arai, Takehiro; Morita, Hitomi; Takase, Shinichi

2010-12-20

A high radiation dose associated with 64 multidetector-row computed tomography (64-MDCT) is a major concern for physicians and patients alike. A new 320 row area detector computed tomography (ADCT) can obtain a view of the entire heart with one rotation (0.35 s) without requiring the helical method. As such, ADCT is expected to reduce the radiation dose. We studied image quality and radiation dose of ADCT compared to that of 64-MDCT in patients with a low heart rate (HR≤60). Three hundred eighty-five consecutive patients underwent 64-MDCT and 379 patients, ADCT. Patients with an arrhythmia were excluded. Prospective ECG-gated helical scan with high HP (FlashScan) in 64 was used for MDCT and prospective ECG-gated conventional one beat scan, for 320-ADCT. Image quality was visually evaluated by an image quality score. Radiation dose was estimated by DLP (mGy･cm) for 64-MDCT and DLP.e (mGy･cm) for 320-ADCT. Radiation dose of 320-ADCT (208±48 mGy･cm) was significantly (P<0.0001) lower than that of 64-MDCT (484±112 mGy･cm), and image quality score of 320-ADCT (3.0±0.2) was significantly (P=0.0011) higher than that of 64-MDCT (2.9±0.4). Scan time of 320-ADCT (1.4±0.1 s) was also significantly (P<0.0001) shorter than that of 64-MDCT (6.8±0.6 s). 320-ADCT can achieve not only a reduction in radiation dose but also a superior image quality and shortening of scan time compared to 64-MDCT.

Optimisation of coronary vascular territorial 3D echocardiographic strain imaging using computed tomography: a feasibility study using image fusion.

PubMed

de Knegt, Martina Chantal; Fuchs, A; Weeke, P; Møgelvang, R; Hassager, C; Kofoed, K F

2016-12-01

Current echocardiographic assessments of coronary vascular territories use the 17-segment model and are based on general assumptions of coronary vascular distribution. Fusion of 3D echocardiography (3DE) with multidetector computed tomography (MDCT) derived coronary anatomy may provide a more accurate assessment of left ventricular (LV) territorial function. We aimed to test the feasibility of MDCT and 3DE fusion and to compare territorial longitudinal strain (LS) using the 17-segment model and a MDCT-guided vascular model. 28 patients underwent 320-slice MDCT and transthoracic 3DE on the same day followed by invasive coronary angiography. MDCT (Aquilion ONE, ViSION Edition, Toshiba Medical Systems) and 3DE apical full-volume images (Artida, Toshiba Medical Systems) were fused offline using a dedicated workstation (prototype fusion software, Toshiba Medical Systems). 3DE/MDCT image alignment was assessed by 3 readers using a 4-point scale. Territorial LS was assessed using the 17-segment model and the MDCT-guided vascular model in territories supplied by significantly stenotic and non-significantly stenotic vessels. Successful 3DE/MDCT image alignment was obtained in 86 and 93 % of cases for reader one, and reader two and three, respectively. Fair agreement on the quality of automatic image alignment (intra-class correlation = 0.40) and the success of manual image alignment (Fleiss' Kappa = 0.40) among the readers was found. In territories supplied by non-significantly stenotic left circumflex arteries, LS was significantly higher in the MDCT-guided vascular model compared to the 17-segment model: -15.00 ± 7.17 (mean ± standard deviation) versus -11.87 ± 4.09 (p < 0.05). Fusion of MDCT and 3DE is feasible and provides physiologically meaningful displays of myocardial function.

Stenosis detection in native hemodialysis fistulas with MDCT angiography.

PubMed

Heye, Sam; Maleux, Geert; Claes, Kathleen; Kuypers, Dirk; Oyen, Raymond

2009-04-01

The objective of our study was to assess the diagnostic value of 64-MDCT angiography in the evaluation of failing hemodialysis arteriovenous fistulas (AVFs) in comparison with conventional digital subtraction angiography (DSA). Thirty-six patients (22 men; mean age +/- SD, 65 +/- 15 years) with hemodialysis fistula dysfunction underwent MDCT angiography before DSA. Linear weighted kappa was used to calculate interobserver agreement for stenosis for both MDCT angiography and DSA on a 5-point scale. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the detection of >/= 50% stenosis or occlusion on MDCT angiography was calculated using DSA as the standard of reference. Wilcoxon's signed rank test and Mann-Whitney U test were used to compare differences in image quality between MDCT angiography and DSA and between MDCT angiography with the patient's arm stretched overhead or alongside the body, respectively. Interobserver agreement for detecting stenosis was excellent for both DSA (kappa = 0.86; 95% CI, 0.81-0.91) and MDCT angiography (kappa = 0.82; 95% CI, 0.77-0.87). Accuracy, sensitivity, specificity, PPV, and NPV of MDCT angiography for detecting >/= 50% stenosis or occlusion was 92.0% (95% CI, 86.8-95.3%), 90.2% (77.8-96.3%), 92.8% (85.9-96.6%), 85.2% (72.3-92.9%), and 95.4% (89.0-98.3%), respectively. No significant difference in image quality was seen between MDCT angiography and DSA (p = 0.3008) or between MDCT angiography with the patient's arm stretched overhead or alongside the body (p = 0.2912). MDCT angiography is a reproducible and reliable imaging technique for detection of >/= 50% stenosis or occlusion in dysfunctional hemodialysis fistulas.

The diagnostic performance and added value of (18)F-FDG PET/CT in the detection of liver metastases in recurrent colorectal carcinoma patients.

PubMed

Odalovic, Strahinja; Artiko, Vera; Sobic-Saranovic, Dragana; Stojiljkovic, Milica; Petrovic, Milorad; Petrovic, Nebojsa; Kozarevic, Nebojsa; Grozdic-Milojevic, Isidora; Obradovic, Vladimir

2015-01-01

The aim of this study was to assess the value of (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT in detection of liver metastases in patients with suspected recurrent colorectal carcinoma, as well as to compare diagnostic performance of (18)F-FDG PET/CT with conventional imaging methods (MDCT). This study included 73 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013, with suspicion of recurrence. The patients underwent (18)F-FDG PET/CT examination on a 64-slice hybrid PET/CT scanner (Biograph, TruePoint64, Siemens Medical Solutions, Inc. USA). Prior to (18)F-FDG PET/CT all patients underwent contrast-enhanced MDCT. Findings of (18)F-FDG PET/CT and MDCT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up over at least six months. Final diagnosis of liver metastases of colorectal cancer was made either by histopathological examination of specimen after biopsy or surgery, or based on clinical, laboratory and imaging evaluation during first six months after PET/CT scan. In detection of liver metastases (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 83.3%, 95.3%, 92.6%, 89.1% and 90.4%, respectively. In addition, MDCT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy in detection of liver metastases of 60%, 88.4%, 78.3%, 76% and 76.7%, respectively. There was significant difference in sensitivity (83.3% vs 60%; P=0.045) between these two methods. In addition, significant difference was observed in accuracy between PET/CT and MDCT (90.4% vs 76.7%; P=0.016). The higher specificity in visualization of liver metastases was also achieved by (18)F-FDG PET/CT compared to MDCT (95.3% vs 88.4%), but this difference was not significant (P=0.37). (18)F-FDG PET/CT was highly sensitive, specific and accurate method in detection of liver metastases in patients with suspected recurrent colorectal carcinoma in our study. This hybrid imaging showed superior diagnostic performance in evaluation of suspected colorectal cancer liver metastases compared to conventional imaging.

The role of mobile computed tomography in mass fatality incidents.

PubMed

Rutty, Guy N; Robinson, Claire E; BouHaidar, Ralph; Jeffery, Amanda J; Morgan, Bruno

2007-11-01

Mobile multi-detector computed tomography (MDCT) scanners are potentially available to temporary mortuaries and can be operational within 20 min of arrival. We describe, to our knowledge, the first use of mobile MDCT for a mass fatality incident. A mobile MDCT scanner attended the disaster mortuary after a five vehicle road traffic incident. Five out of six bodies were successfully imaged by MDCT in c. 15 min per body. Subsequent full radiological analysis took c. 1 h per case. The results were compared to the autopsy examinations. We discuss the advantages and disadvantages of imaging with mobile MDCT in relation to mass fatality work, illustrating the body pathway process, and its role in the identification of the pathology, personal effects, and health and safety hazards. We propose that the adoption of a single modality of mobile MDCT could replace the current use of multiple radiological sources within a mass fatality mortuary.

Quantitative imaging of peripheral trabecular bone microarchitecture using MDCT.

PubMed

Chen, Cheng; Zhang, Xiaoliu; Guo, Junfeng; Jin, Dakai; Letuchy, Elena M; Burns, Trudy L; Levy, Steven M; Hoffman, Eric A; Saha, Punam K

2018-01-01

Osteoporosis associated with reduced bone mineral density (BMD) and microarchitectural changes puts patients at an elevated risk of fracture. Modern multidetector row CT (MDCT) technology, producing high spatial resolution at increasingly lower dose radiation, is emerging as a viable modality for trabecular bone (Tb) imaging. Wide variation in CT scanners raises concerns of data uniformity in multisite and longitudinal studies. A comprehensive cadaveric study was performed to evaluate MDCT-derived Tb microarchitectural measures. A human pilot study was performed comparing continuity of Tb measures estimated from two MDCT scanners with significantly different image resolution features. Micro-CT imaging of cadaveric ankle specimens (n=25) was used to examine the validity of MDCT-derived Tb microarchitectural measures. Repeat scan reproducibility of MDCT-based Tb measures and their ability to predict mechanical properties were examined. To assess multiscanner data continuity of Tb measures, the distal tibias of 20 volunteers (age:26.2±4.5Y,10F) were scanned using the Siemens SOMATOM Definition Flash and the higher resolution Siemens SOMATOM Force scanners with an average 45-day time gap between scans. The correlation of Tb measures derived from the two scanners over 30% and 60% peel regions at the 4% to 8% of distal tibia was analyzed. MDCT-based Tb measures characterizing bone network area density, plate-rod microarchitecture, and transverse trabeculae showed good correlations (r∈0.85,0.92) with the gold standard micro-CT-derived values of matching Tb measures. However, other MDCT-derived Tb measures characterizing trabecular thickness and separation, erosion index, and structure model index produced weak correlation (r<0.8) with their micro-CT-derived values. Most MDCT Tb measures were found repeatable (ICC∈0.94,0.98). The Tb plate-width measure showed a strong correlation (r = 0.89) with experimental yield stress, while the transverse trabecular measure produced the highest correlation (r = 0.81) with Young's modulus. The data continuity experiment showed that, despite significant differences in image resolution between two scanners (10% MTF along xy-plane and z-direction - Flash: 16.2 and 17.9 lp/cm; Force: 24.8 and 21.0 lp/cm), most Tb measures had high Pearson correlations (r > 0.95) between values estimated from the two scanners. Relatively lower correlation coefficients were observed for the bone network area density (r = 0.91) and Tb separation (r = 0.93) measures. Most MDCT-derived Tb microarchitectural measures are reproducible and their values derived from two scanners strongly correlate with each other as well as with bone strength. This study has highlighted those MDCT-derived measures which show the greatest promise for characterization of bone network area density, plate-rod and transverse trabecular distributions with a good correlation (r ≥ 0.85) compared with their micro-CT-derived values. At the same time, other measures representing trabecular thickness and separation, erosion index, and structure model index produced weak correlations (r < 0.8) with their micro-CT-derived values, failing to accurately portray the projected trabecular microarchitectural features. Strong correlations of Tb measures estimated from two scanners suggest that image data from different scanners can be used successfully in multisite and longitudinal studies with linear calibration required for some measures. In summary, modern MDCT scanners are suitable for effective quantitative imaging of peripheral Tb microarchitecture if care is taken to focus on appropriate quantitative metrics. © 2017 American Association of Physicists in Medicine.

Evaluation of three imaging techniques for the detection of vertical root fractures in the absence and presence of gutta-percha root fillings.

PubMed

Khedmat, S; Rouhi, N; Drage, N; Shokouhinejad, N; Nekoofar, M H

2012-11-01

To compare the accuracy of digital radiography (DR), multidetector computed tomography (MDCT) and cone beam computed tomography (CBCT) in detecting vertical root fractures (VRF) in the absence and presence of gutta-percha root filling. The root canals of 100 extracted human single-rooted teeth were prepared and randomly divided into four groups: two experimental groups with artificially fractured root and two intact groups as controls. In one experimental and one control group, a size 40, 0.04 taper gutta-percha cone was inserted in the root canals. Then DR, MDCT and CBCT were performed and the images evaluated. Statistical analyses of sensitivity, specificity and accuracy of each imaging technique in the presence and absence of gutta-percha were calculated and compared. In the absence of gutta-percha, the specificity of DR, MDCT and CBCT was similar. CBCT was the most accurate and sensitive imaging technique (P < 0 .05). In the presence of gutta-percha, the accuracy of MDCT was higher than the other imaging techniques (P < 0.05). The sensitivity of CBCT and MDCT was significantly higher than that of DR (P < 0.05), whereas CBCT was the least specific technique. Under the conditions of this ex vivo study, CBCT was the most sensitive imaging technique in detecting vertical root fracture. The presence of gutta-percha reduced the accuracy, sensitivity and specificity of CBCT but not MDCT. The sensitivity of DR was reduced in the presence of gutta-percha. The use of MDCT as an alternative technique may be recommended when VRF are suspected in root filled teeth. However, as the radiation dose of MDCT is higher than CBCT, the technique could be considered at variance with the principles of ALARA. © 2012 International Endodontic Journal.

Use of multidetector computed tomography in the assessment of dogs with pericardial effusion.

PubMed

Scollan, K F; Bottorff, B; Stieger-Vanegas, S; Nemanic, S; Sisson, D

2015-01-01

Contrast-enhanced multidetector computed tomography (MDCT) allows high spatial and temporal resolution imaging of cardiac, thoracic, and abdominal structures. Accurate determination of the cause of pericardial effusion (PE) is essential to providing appropriate treatment and prognosis. Echocardiography and pericardial fluid analysis may not differentiate between causes of PE and cannot identify extracardiac metastasis. Describe the thoracic and abdominal MDCT findings and evaluate the utility of MDCT to differentiate between neoplastic and nonneoplastic causes of PE in dogs. Eleven client-owned dogs with PE diagnosed by echocardiography. Prospective observational study. Transthoracic echocardiography (TTE), 3-view thoracic radiography, and contrast-enhanced thoracic and abdominal MDCT images were evaluated for the presence of cardiac masses, pulmonary metastases, and abdominal masses. Histopathology in 5 dogs and survival analysis in all dogs were evaluated. A neoplastic cause was identified in 6/11 dogs and a nonneoplastic cause was identified in 5/11. Cardiac MDCT findings were consistent with TTE findings in all dogs with right atrial (5/5) and heart base masses (1/1). Pulmonary metastases were identified in 1/11 dogs by thoracic radiography and in 2/11 dogs by MDCT. MDCT identified splenic or hepatic lesions consistent with neoplasia in 6/11 and 5/11 dogs, respectively. Focal MDCT pericardial changes at the pericardiocentesis site were noted in 3/11 dogs. Multidetector computed tomography did not improve the detection of cardiac masses in dogs with PE over echocardiography. The benefit of MDCT was primarily in the detection of pulmonary metastases and extracardiac lesions using a single imaging modality. Copyright © 2014 by the American College of Veterinary Internal Medicine.

Blunt trauma of bone structures of the chest--computed tomography vs multidetector computed tomography.

PubMed

Petrović, Kosta; Turkalj, Ivan; Stojanović, Sanja; Vucaj-Cirilović, Viktorija; Nikolić, Olivera; Stojiljković, Dragana

2013-08-01

Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists inde pendently and separately described the findings for 5-mm-thick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thin-slice examination together which was ultimately considered as a real, true finding. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.

Potential benefit of a simultaneous, side-by-side display of contrast MDCT and echocardiography over routine sequential imaging for assessment of adult congenital heart disease: A preliminary study.

PubMed

Oe, Hiroki; Watanabe, Nobuhisa; Miyoshi, Toru; Osawa, Kazuhiro; Akagi, Teiji; Kanazawa, Susumu; Ito, Hiroshi

2018-06-18

Management of adult congenital heart disease (ACHD) patients requires understanding of its complex morphology and functional features. An innovative imaging technique has been developed to display a virtual multi-planar reconstruction obtained from contrast-enhanced multidetector-computed tomography (MDCT) corresponding to the same cross-sectional image from transthoracic echocardiography (TTE). The aim of this study is to assess the usefulness of this imaging technology in ACHD patients. This study consisted of 46 consecutive patients (30 women; mean age, 52±18 years old) with ACHD who had undergone contrast MDCT. All patients underwent TTE within a week of MDCT. An experienced sonographer who did not know the results of MDCT conducted a diagnosis using TTE and, then, using the new imaging technology. We studied whether this imaging technology provided additional or unexpected findings or makes more accurate diagnosis. In this imaging technology, MDCT cross-section provides higher-resolution image to the deep compared to corresponding TTE image. Depending on the MDCT section which can be arbitrarily set under the echo guide, we can diagnose unexpected or incremental lesions or more accurately assess the severity of the lesion in 27 patients (59%) compared to TTE study alone. This imaging technology was useful in the following situations: CONCLUSIONS: This integrated imaging technology provides incremental role over TTE in complex anatomy, and allows functional information in ACHD patients. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

The role of follow-up ultrasound and clinical parameters after abdominal MDCT in patients with multiple trauma.

PubMed

Geyer, Lucas L; Körner, M; Linsenmaier, U; Wirth, S; Reiser, M F; Meindl, T

2014-05-01

Beside its value during the initial trauma work-up (focused assessment with sonography for trauma), ultrasound (US) is recommended for early follow-up examinations of the abdomen in multiple injured patients. However, multidetector CT (MDCT) has proven to reliably diagnose traumatic lesions of abdominal organs, to depict their extent, and to assess their clinical relevance. To evaluate the diagnostic impact of follow-up US studies after MDCT of the abdomen and to identify possible clinical parameters indicating the need of a follow-up US. During a 30-month period, patients with suspected multiple trauma were allocated. Patients with admission to the ICU, an initial abdominal MDCT scan, and an US follow-up examination after 6 and 24 h were included. Two patient cohorts were defined: patients with normal abdominal MDCT (group 1), patients with trauma-related pathologic abdominal MDCT (group 2). In all patients, parameters indicating alteration of vital functions or hemorrhage within the first 24 h were obtained by reviewing the medical charts. Forty-four of 193 patients were included: 24 were categorized in group 1 (mean age, 41.1 years; range, 21-90 years), 20 in group 2 (mean age, 36.6 years; range, 16-71 years). In group 1, US did not provide new information compared to emergency MDCT. In group 2, there were no contradictory 6- and 24-h follow-up US findings. In patients with positive MDCT findings and alterations of clinical parameters, US did not detect progression of a previously diagnosed pathology or any late manifestation of such a lesion. In none of the patients with negative abdominal MDCT and pathological clinical parameters US indicated an abdominal injury. Routine US follow-up does not yield additional information after abdominal trauma. In patients with MDCT-proven organ lesions, follow-up MDCT should be considered if indicated by abnormal clinical and/or laboratory findings.

MDCT assessment of resectability in hilar cholangiocarcinoma.

PubMed

Ni, Qihong; Wang, Haolu; Zhang, Yunhe; Qian, Lijun; Chi, Jiachang; Liang, Xiaowen; Chen, Tao; Wang, Jian

2017-03-01

The purpose of this study is to investigate the value of multidetector computed tomography (MDCT) assessment of resectability in hilar cholangiocarcinoma, and to identify the factors associated with unresectability and accurate evaluation of resectability. From January 2007 to June 2015, a total of 77 consecutive patients were included. All patients had preoperative MDCT (with MPR and MinIP) and surgical treatment, and were pathologically proven with hilar cholangiocarcinoma. The MDCT images were reviewed retrospectively by two senior radiologists and one hepatobiliary surgeon. The surgical findings and pathologic results were considered to be the gold standard. The Chi square test was used to identify factors associated with unresectability and accurate evaluation of resectability. The sensitivity, specificity, and overall accuracy of MDCT assessment were 83.3 %, 75.9 %, and 80.5 %, respectively. The main causes of inaccuracy were incorrect evaluation of N2 lymph node metastasis (4/15) and distant metastasis (4/15). Bismuth type IV tumor, main or bilateral hepatic artery involvement, and main or bilateral portal vein involvement were highly associated with unresectability (P < 0.001). Patients without biliary drainage had higher accuracy of MDCT evaluation of resectability compared to those with biliary drainage (P < 0.001). MDCT is reliable for preoperative assessment of resectability in hilar cholangiocarcinoma. Bismuth type IV tumor and main or bilateral vascular involvement highly suggest the unresectability of hilar cholangiocarcinoma. Patients without biliary drainage have a more accurate MDCT evaluation of resectability. We suggest MDCT should be performed before biliary drainage to achieve an accurate evaluation of resectability in hilar cholangiocarcinoma.

Comparison of eye lens dose on neuroimaging protocols between 16- and 64-section multidetector CT: achieving the lowest possible dose.

PubMed

Tan, J S P; Tan, K-L; Lee, J C L; Wan, C-M; Leong, J-L; Chan, L-L

2009-02-01

To our knowledge, there has been no study that compares the radiation dose delivered to the eye lens by 16- and 64-section multidetector CT (MDCT) for standard clinical neuroimaging protocols. Our aim was to assess radiation-dose differences between 16- and 64-section MDCT from the same manufacturer, by using near-identical neuroimaging protocols. Three cadaveric heads were scanned on 16- and 64-section MDCT by using standard neuroimaging CT protocols. Eye lens dose was measured by using thermoluminescent dosimeters (TLD), and each scanning was repeated to reduce random error. The dose-length product, volume CT dose index (CTDI(vol)), and TLD readings for each imaging protocol were averaged and compared between scanners and protocols, by using the paired Student t test. Statistical significance was defined at P < .05. The radiation dose delivered and eye lens doses were lower by 28.1%-45.7% (P < .000) on the 64-section MDCT for near-identical imaging protocols. On the 16-section MDCT, lens dose reduction was greatest (81.1%) on a tilted axial mode, compared with a nontilted helical mode for CT brain scans. Among the protocols studied, CT of the temporal bone delivered the greatest radiation dose to the eye lens. Eye lens radiation doses delivered by the 64-section MDCT are significantly lower, partly due to improvements in automatic tube current modulation technology. However, where applicable, protection of the eyes from the radiation beam by either repositioning the head or tilting the gantry remains the best way to reduce eye lens dose.

Proximal pulmonary vein stenosis detection in pediatric patients: value of multiplanar and 3-D VR imaging evaluation.

PubMed

Lee, Edward Y; Jenkins, Kathy J; Muneeb, Muhammad; Marshall, Audrey C; Tracy, Donald A; Zurakowski, David; Boiselle, Phillip M

2013-08-01

One of the important benefits of using multidetector computed tomography (MDCT) is its capability to generate high-quality two-dimensional (2-D) multiplanar (MPR) and three-dimensional (3-D) images from volumetric and isotropic axial CT data. However, to the best of our knowledge, no results have been published on the potential diagnostic role of multiplanar and 3-D volume-rendered (VR) images in detecting pulmonary vein stenosis, a condition in which MDCT has recently assumed a role as the initial noninvasive imaging modality of choice. The purpose of this study was to compare diagnostic accuracy and interpretation time of axial, multiplanar and 3-D VR images for detection of proximal pulmonary vein stenosis in children, and to assess the potential added diagnostic value of multiplanar and 3-D VR images. We used our hospital information system to identify all consecutive children (< 18 years of age) with proximal pulmonary vein stenosis who had both a thoracic MDCT angiography study and a catheter-based conventional angiography within 2 months from June 2005 to February 2012. Two experienced pediatric radiologists independently reviewed each MDCT study for the presence of proximal pulmonary vein stenosis defined as ≥ 50% of luminal narrowing on axial, multiplanar and 3-D VR images. Final diagnosis was confirmed by angiographic findings. Diagnostic accuracy was compared using the z-test. Confidence level of diagnosis (scale 1-5, 5 = highest), perceived added diagnostic value (scale 1-5, 5 = highest), and interpretation time of multiplanar or 3-D VR images were compared using paired t-tests. Interobserver agreement was measured using the chance-corrected kappa coefficient. The final study population consisted of 28 children (15 boys and 13 girls; mean age: 5.2 months). Diagnostic accuracy based on 116 individual pulmonary veins for detection of proximal pulmonary vein stenosis was 72.4% (84 of 116) for axial MDCT images, 77.5% (90 of 116 cases) for multiplanar MDCT images, and 93% (108 of 116 cases) for 3-D VR images with significantly higher accuracy with 3-D VR compared to axial (z = 4.17, P < 0.001) and multiplanar (z = 3.34, P < 0.001) images. Confidence levels for detection of proximal pulmonary vein stenosis were significantly higher with 3-D VR images (mean level: 4.6) compared to axial MDCT images (mean level: 1.7) and multiplanar MDCT images (mean level: 2.0) (paired t-tests, P < 0.001). Thus, 3-D VR images (mean added diagnostic value: 4.7) were found to provide added diagnostic value for detecting proximal pulmonary vein stenosis (paired t-test, P < 0.001); however, multiplanar MDCT images did not provide added value (paired t-test, P = 0.89). Interpretation time was significantly longer and interobserver agreement was higher when using 3-D VR images than using axial MDCT images or MPR MDCT images for diagnosing proximal pulmonary vein stenosis (paired t-tests, P < 0.001). Use of 3-D VR images in the diagnosis of proximal pulmonary vein stenosis in children significantly increases accuracy, confidence level, added diagnostic value and interobserver agreement. Thus, the routine use of this technique should be encouraged despite its increased interpretation time.

Assessment of Gd-EOB-DTPA-enhanced MRI for HCC and dysplastic nodules and comparison of detection sensitivity versus MDCT.

PubMed

Inoue, Tatsuo; Kudo, Masatoshi; Komuta, Mina; Hayaishi, Sosuke; Ueda, Taisuke; Takita, Masahiro; Kitai, Satoshi; Hatanaka, Kinuyo; Yada, Norihisa; Hagiwara, Satoru; Chung, Hobyung; Sakurai, Toshiharu; Ueshima, Kazuomi; Sakamoto, Michiie; Maenishi, Osamu; Hyodo, Tomoko; Okada, Masahiro; Kumano, Seishi; Murakami, Takamichi

2012-09-01

We aimed to evaluate gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for the detection of hepatocellular carcinomas (HCCs) and dysplastic nodules (DNs) compared with dynamic multi-detector row computed tomography (MDCT), and to discriminate between HCCs and DNs. Eighty-six nodules diagnosed as HCC or DNs were retrospectively investigated. Gd-EOB-DTPA-enhanced MRI and dynamic MDCT were compared with respect to their diagnostic ability for hypervascular HCCs and detection sensitivity for hypovascular tumors. The ability of hepatobiliary images of Gd-EOB-DTPA-enhanced MRI to discriminate between these nodules was assessed. We also calculated the EOB enhancement ratio of the tumors. For hypervascular HCCs, the diagnostic ability of Gd-EOB-DTPA-enhanced MRI was significantly higher than that of MDCT for tumors less than 2 cm (p = 0.048). There was no difference in the detection of hypervascular HCCs between hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI (43/45: 96%) and dynamic MDCT (40/45: 89%), whereas the detection sensitivity of hypovascular tumors by Gd-EOB-DTPA-enhanced MRI was significantly higher than that by dynamic MDCT (39/41: 95% vs. 25/41: 61%, p = 0.001). EOB enhancement ratios were decreased in parallel with the degree of differentiation in DNs and HCCs, although there was no difference between DNs and hypovascular well-differentiated HCCs. The diagnostic ability of Gd-EOB-DTPA-enhanced MRI for hypervascular HCCs less than 2 cm was significantly higher than that of MDCT. For hypovascular tumors, the detection sensitivity of hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was significantly higher than that of dynamic Gd-EOB-DTPA-enhanced MRI and dynamic MDCT. It was difficult to distinguish between DNs and hypovascular well-differentiated HCCs based on the EOB enhancement ratio.

The value of dual-source multidetector-row computed tomography in determining pulmonary blood supply in patients with pulmonary atresia with ventricular septal defect.

PubMed

Chaosuwannakit, N; Makarawate, P

2018-01-01

Primary evaluation of patients with pulmonary atresia with ventricular septal defect (PA-VSD) traditionally relies upon echocardiography and conventional cardiac angiography (CCA). Cardiac angiography is considered the gold standard for delineation of anatomy in children with PA-VSD. Data comparing CCA and dual-source multidetector-row computed tomography angiography (MDCT) in PA-VSD patients is limited. The objective of this study was to test the hypothesis that MDCT is equivalent to CCA for anatomic delineation in these patients. Twenty-eight patients with PA-VSD underwent CCA and MDCT in close proximity to each other without interval therapy. A retrospective review of these 28 patients was performed. All MDCT data of pulmonary artery morphology, major aortopulmonary collateral arteries (MAPCAs) and type of blood supply (dual vs. single supply) were evaluated by blinded experts and results were compared with CCA. Twenty-eight patients had adequate size right and left pulmonary arteries (21 confluent and 7 non-confluent). Seven patients had complete absence of native pulmonary artery and 3 patients had stenosis of distal branches of pulmonary arteries; all had MAPCAs from descending thoracic aorta and/or subclavian arteries. Sensitivity, specificity, positive and negative predictive value of MDCT for detecting confluent of pulmonary arteries, absence of native pulmonary artery and stenosis of pulmonary arteries were all 100%. Moreover, accuracy of detecting MAPCAs was excellent. These results suggest that MDCT and CCA are equivalent in their ability to delineate pulmonary artery anatomy and MAPCAs. Dual source MDCT provides high diagnostic accuracy in evaluation of pulmonary blood supply in patients with PA-VSD and allows precise characterisation of the condition of pulmonary arteries and MAPCAs which is of paramount importance in managing patients with PA-VSD. (Folia Morphol 2018; 77, 1: 116-122).

Usefulness of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI): assessment of morphology and diameter of the superior mesenteric artery (SMA) on multi-planar reconstructed (MPR) images.

PubMed

Woodhams, Reiko; Nishimaki, Hiroshi; Fujii, Kaoru; Kakita, Satoko; Hayakawa, Kazushige

2010-10-01

The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI. Four patients who were diagnosed with NOMI were retrospectively analyzed. All patients had 8-row MDCT followed by laparotomy. Two of them underwent angiography after MDCT. The morphology and diameter of SMA of these cases was analyzed on multi-planar reconstructed (MPR) images. The mean diameter of SMA of NOMI cases was compared to that of 13 control cases. MPR images of all NOMI cases showed irregular narrowing of the SMA, spasm of the arcades of SMA, and poor demonstration of intramural vessels. MPR images of two patients who had angiography were concordant with their angiograms. The mean diameter of SMA of NOMI patients was 3.4±1.1mm, which was statistically smaller than that of 13 control patients, 6.0±1.5mm (P<0.05, Wilcoxon rank sum tests). Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Multidetector computed tomography for preoperative evaluation of vascular anatomy in living renal donors.

PubMed

Türkvatan, Aysel; Akinci, Serkan; Yildiz, Sener; Olçer, Tülay; Cumhur, Turhan

2009-04-01

Currently, multidetector computed tomographic (MDCT) angiography has become a noninvasive alternative imaging modality to catheter renal angiography for the evaluation of renal vascular anatomy in living renal donors. In this study, we investigated the diagnostic accuracy of 16-slice MDCT in the preoperative assessment of living renal donors. Fifty-nine consecutive living renal donors (32 men, 27 women) underwent MDCT angiography followed by open donor nephrectomy. All MDCT studies were performed by using a 16-slice MDCT scanner with the same protocol consisting of arterial and nephrographic phases followed by conventional abdominal radiography. The MDCT images were assessed retrospectively for the number and branching pattern of the renal arteries and for the number and presence of major or minor variants of the renal veins. The results were compared with open surgical results. The sensitivity and specificity of MDCT for the detection of anatomic variants of renal arteries including the accessory arteries (n = 9), early arterial branching (n = 7) and major renal venous anomalies including the accessory renal veins (n = 3), late venous confluence (n = 4), circumaortic (n = 2) or retroaortic (n = 3) left renal veins were 100%. However, the sensitivity for identification of minor venous variants was 79%. All of three ureteral duplications were correctly identified at excretory phase conventional abdominal radiography. Sixteen-slice MDCT is highly accurate for the identification of anatomic variants of renal arteries and veins. Dual-phase MDCT angiography including arterial and nephrographic phases followed by conventional abdominal radiography enables complete assessment of renal donors without significant increase of radiation dose. However, the evaluation of minor venous variants may be problematic because of their small diameters and poor opacification.

One-stop-shop preoperative evaluation for living liver donors with gadoxetic acid disodium-enhanced magnetic resonance imaging: efficiency and additional benefit.

PubMed

Xie, Shuangshuang; Liu, Chenhao; Yu, Zichuan; Ren, Tao; Hou, Jiancun; Chen, Lihua; Huang, Lixiang; Cheng, Yue; Ji, Qian; Yin, Jianzhong; Zhang, Longjiang; Shen, Wen

2015-12-01

To explore the efficiency, cost, and time for examination of one-stop-shop gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in preoperative evaluation for parent donors by comparing with multidetector computer tomography combined with conventional MR cholangiopancreatography (MDCT-MRCP). Forty parent donors were evaluated with MDCT-MRCP, and the other 40 sex-, age-, and weight-matched donors with Gd-EOB-DTPA-enhanced MRI. Anatomical variations and graft volume determined by pre- and intra-operative findings, costs and time for imaging were recorded. Image quality was ranked on a 4-point scale and compared between both groups. Gd-EOB-DTPA-enhanced MRI provided better image quality than MDCT-MRCP for the depiction of portal veins and bile ducts by both reviewers (p < 0.05), hepatic veins by one reviewer (p < 0.05), rather hepatic arteries by both reviewers (p < 0.01). Sixty-nine living donors proceeded to liver donation with all anatomical findings accurately confirmed by intra-operative findings. The "in-room" time of Gd-EOB-DTPA-enhanced MRI was 12 min longer than MDCT-MRCP. Gd-EOB-DTPA-enhanced MRI was cheaper than MDCT-MRCP (US$519.72 vs. US$631.85). One-stop-shop Gd-EOB-DTPA-enhanced MRI has similar diagnostic accuracy as MDCT-MRCP and can provide additional benefit in terms of costs and convenience in preoperative evaluation for parent donors. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

C-arm flat-panel CT arthrography of the shoulder: Radiation dose considerations and preliminary data on diagnostic performance.

PubMed

Guggenberger, Roman; Ulbrich, Erika J; Dietrich, Tobias J; Scholz, Rosemarie; Kaelin, Pascal; Köhler, Christoph; Elsässer, Thilo; Le Corroller, Thomas; Pfammatter, Thomas; Alkadhi, Hatem; Andreisek, Gustav

2017-02-01

To investigate radiation dose and diagnostic performance of C-arm flat-panel CT (FPCT) versus standard multi-detector CT (MDCT) shoulder arthrography using MRI-arthrography as reference standard. Radiation dose of two different FPCT acquisitions (5 and 20 s) and standard MDCT of the shoulder were assessed using phantoms and thermoluminescence dosimetry. FPCT arthrographies were performed in 34 patients (mean age 44 ± 15 years). Different joint structures were quantitatively and qualitatively assessed by two independent radiologists. Inter-reader agreement and diagnostic performance were calculated. Effective radiation dose was markedly lower in FPCT 5 s (0.6 mSv) compared to MDCT (1.7 mSv) and FPCT 20 s (3.4 mSv). Contrast-to-noise ratios (CNRs) were significantly (p < 0.05) higher in FPCT 20-s versus 5-s protocols. Inter-reader agreements of qualitative ratings ranged between к = 0.47-1.0. Sensitivities for cartilage and rotator cuff pathologies were low for FPCT 5-s (40 % and 20 %) and moderate for FPCT 20-s protocols (75 % and 73 %). FPCT showed high sensitivity (81-86 % and 89-99 %) for bone and acromioclavicular-joint pathologies. Using a 5-s protocol FPCT shoulder arthrography provides lower radiation dose compared to MDCT but poor sensitivity for cartilage and rotator cuff pathologies. FPCT 20-s protocol is moderately sensitive for cartilage and rotator cuff tendon pathology with markedly higher radiation dose compared to MDCT. • FPCT shoulder arthrography is feasible with fluoroscopy and CT in one workflow. • A 5-s FPCT protocol applies a lower radiation dose than MDCT. • A 20-s FPCT protocol is moderately sensitive for cartilage and tendon pathology.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

PubMed

Yuceler, Zeyneb; Kantarci, Mecit; Yuce, Ihsan; Kizrak, Yesim; Bayraktutan, Ummugulsum; Ogul, Hayri; Kiris, Adem; Celik, Omer; Pirimoglu, Berhan; Genc, Berhan; Gundogdu, Fuat

2014-01-01

Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

PubMed

Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

2013-04-01

There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P < 0.001 for each). On review by expert radiologists, the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (κ = 0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

Myocardial Fibrosis in Hypertrophic Cardiomyopathy: Volumetric Assessment of Late Enhancement Provided by Cardiac Computed Tomography.

PubMed

Langer, Christoph; Schaefer, Philipp; Lutz, Matthias; Eden, Matthias; Hohnhorst, Mirko; Harders, Hauke; Faber, Lothar; Jansen, Olav; Both, Marcus; Frey, Norbert

2015-01-01

With subgroups of patients with hypertrophic cardiomyopathy (HCM) confers a 4% to 5% risk for adverse prognosis. Besides left-ventricular muscle mass (LV-MM) myocardial fibrosis (MF) assessable by late gadolinium enhancement in cardiovascular magnetic resonance (LGE-CMR) has been related to that. Myocardial fibrosis can also be demonstrated by late enhancement (LE) in late-enhanced multislice computed tomography (leMDCT). This analysis investigates leMDCT whether to enable quantification of LE load in terms of LE mass by percent LV-MM in HCM. In a prospective validation study, we included 30 consecutive patients with HCM who underwent leMDCT (64 slice) and LGE-CMR (1.5 T). The leMDCT scan was performed 7 minutes after injection of iodine contrast (Iopromid). Endocardial and epicardial planimetry served for the assessment of LV-MM. Visually detectable LE was quantified using the manual quantification method resulting in LE by percent LV-MM (%LE). The LGE-CMR data served for validation. Mean (SD) age was 64.1 (13.9) years. Myocardial fibrosis prevalence was 63.3% (19/30 patients indentified by both leMDCT and LGE-CMR). In leMDCT, tissue density in LE areas compared with normal myocardium was higher (138.2 [23.9] HU vs 98.4 [16.5] HU, P < 0.001) but lower than in the LV cavity (138.2 [23.9] HU vs 169.2 [35.9] HU, P < 0.001). Late enhancement mass in leMDCT seemed to be 7.9 (8.5) g LE versus 8.6 [11] g LGE in CMR (P = 0.497, r = 0.95) resulting in a leMDCT/LGE-CMR relation of 1.2. Referring LE mass to LV-MM gave an LE proportion measured by leMDCT of 4 (3.9) %LE versus 3.9 (4.1) %LGE in LGE-CMR (r = 0.88, P = 0.75). Intraobserver/interobserver reliability of LE mass assessment showed an intraclass correlation coefficient of 0.99 and 0.97. In patients with HCM, leMDCT provides volumetric assessment of LE mass-absolutely and by percent LV-MM.

Spectrum of Abdominal Aortic Disease in a Tertiary Health Care Setup: MDCT Based Observational Study

PubMed Central

Kumar, DG Santosh; Gadabanahalli, Karthik; Kalyanpur, Arjun

2016-01-01

Introduction Abdominal aortic disease is an important cause of clinical disability that requires early detection by imaging methods for prompt and effective management. Understanding regional disease pattern and prevalence has a bearing on healthcare management and resource planning. Non-invasive, conclusive imaging strategy plays an important role in the detection of disease. Multi-Detector Computed Tomography (MDCT) with its technological developments provides affordable, accurate and comprehensive imaging solution. Aim To evaluate regional demography of abdominal aortic disease spectrum detected using MDCT imaging data in a tertiary hospital. Materials and Methods A descriptive study was conducted based on MDCT imaging data of patients who were investigated with clinical diagnosis of abdominal aortic disease, from March 2008-2010, over a period of 24 months. Patients were examined with the contrast-enhanced MDCT examination. Morphological diagnosis of the aortic disease was based on changes in relative aortic caliber, luminal irregularity, presence of wall calcification, dissection or thrombus and evidence of major branch occlusion. Patients were categorized into four groups based on imaging findings. MDCT information and associated clinical parameters were examined and correlated to management of patient. Descriptive statistical data, namely mean, standard deviation and frequency of disease were evaluated. Results A total of 90 out of 210 patients (43%) were detected with the abdominal aortic abnormality defined by imaging criteria. Group I, comprising of patients with atherosclerosis –including those with complications, constituted 65.5% of the patients. Group II represented patients with aneurysms (45.5%). Group III, consisting of 32.2% of the patients, contained those with dissections. The rest of the patients, including patients with aorto-arteritis, were classified as group IV. Eight patients with aneurysm and one patient with aorto-arteritis were considered for surgical treatment. Ten patients with dissection underwent endovascular procedure. Rest of the patients was managed conservatively. Conclusion Aortic disease was observed in 43% of investigated patients. Atherosclerosis with and without aortic aneurysm constituted the largest group. MDCT provided comprehensive information about the lesion and associated complications. In view of the wider availability and desired imaging qualities, MDCT provided optimal information for diagnosis and management of aortic pathology. Majority of our patients (90%) were treated conservatively. PMID:28050476

Fat-suppressed 3D spoiled gradient-echo MRI and MDCT arthrography of articular cartilage in patients with hip dysplasia.

PubMed

Nishii, Takashi; Tanaka, Hisashi; Nakanishi, Katsuyuki; Sugano, Nobuhiko; Miki, Hidenobu; Yoshikawa, Hideki

2005-08-01

Our objective was to assess the diagnostic ability of MDCT arthrography for acetabular and femoral cartilage lesions in patients with hip dysplasia. A disorder of the articular cartilage was evaluated in 20 hips of 18 patients with acetabular dysplasia who did not have osteoarthritis or who had early stage osteoarthritis before undergoing pelvic osteotomy surgery. The findings on fat-suppressed 3D fast spoiled gradient-echo MRI and MDCT arthrography of the hip were evaluated by two independent observers, and sensitivity, specificity, and accuracy were determined using arthroscopic findings as the standard of reference. Kappa values were calculated to quantify the level of interobserver agreement. The sensitivity and specificity for the detection of any cartilage disorder (grade 1 or higher) were (observer 1/observer 2) 49%/67% and 89%/76%, respectively, on MRI, and 67%/67% and 89%/82%, respectively, on CT arthrography. The sensitivity and specificity for the detection of cartilage lesions with substance loss (grade 2 or higher) were (observer 1/observer 2) 47%/53% and 92%/87%, respectively, on MRI, and 70%/79% and 93%/94%, respectively, on CT arthrography. CT arthrography provided significantly higher sensitivity in the detection of grade 2 or higher lesions than MRI for both observers. Interobserver agreement in the detection of grade 2 or higher cartilage lesions was moderate (kappa = 0.53) on MRI and substantial (kappa = 0.78) on CT. MDCT arthrography is a sensitive and reproducible method for assessing articular cartilage lesions with substance loss in patients with hip dysplasia.

Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

PubMed Central

Yi, Ji Sook; Han, Jong Kyu; Kim, Hyun-Joo

2015-01-01

Objective To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. Results The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Conclusion Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI. PMID:26175589

Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging and Multidetector-Row Computed Tomography for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.

PubMed

Ye, Feng; Liu, Jun; Ouyang, Han

2015-08-01

The purpose of this meta-analysis was to compare the diagnostic accuracy of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) for hepatocellular carcinoma (HCC).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until July 4, 2014, using combinations of the following terms: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrast-enhanced computed tomography, and magnetic resonance imaging. Inclusion criteria were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy specimen; comparative study of MRI using Gd-EOB-DTPA and MDCT for diagnosis of HCC; and studies that provided quantitative outcome data. The pooled sensitivity and specificity of the 2 methods were compared, and diagnostic accuracy was assessed with alternative-free response receiver-operating characteristic analysis.Nine studies were included in the meta-analysis, and a total of 1439 lesions were examined. The pooled sensitivity and specificity for 1.5T MRI were 0.95 and 0.96, respectively, for 3.0T MRI were 0.91 and 0.96, respectively, and for MDCT were 0.74 and 0.93, respectively. The pooled diagnostic odds ratio for 1.5T and 3.0T MRI was 242.96, respectively, and that of MDCT was 33.47. To summarize, Gd-EOB-DTPA-enhanced MRI (1.5T and 3.0T) has better diagnostic accuracy for HCC than MDCT.

Surface radiation dose comparison of a dedicated extremity cone beam computed tomography (CBCT) device and a multidetector computed tomography (MDCT) machine in pediatric ankle and wrist phantoms

PubMed Central

Nagy, Eszter; Apfaltrer, Georg; Riccabona, Michael; Singer, Georg; Stücklschweiger, Georg; Guss, Helmuth; Sorantin, Erich

2017-01-01

Objectives To evaluate and compare surface doses of a cone beam computed tomography (CBCT) and a multidetector computed tomography (MDCT) device in pediatric ankle and wrist phantoms. Methods Thermoluminescent dosimeters (TLD) were used to measure and compare surface doses between CBCT and MDCT in a left ankle and a right wrist pediatric phantom. In both modalities adapted pediatric dose protocols were utilized to achieve realistic imaging conditions. All measurements were repeated three times to prove test-retest reliability. Additionally, objective and subjective image quality parameters were assessed. Results Average surface doses were 3.8 ±2.1 mGy for the ankle, and 2.2 ±1.3 mGy for the wrist in CBCT. The corresponding surface doses in optimized MDCT were 4.5 ±1.3 mGy for the ankle, and 3.4 ±0.7 mGy for the wrist. Overall, mean surface dose was significantly lower in CBCT (3.0 ±1.9 mGy vs. 3.9 ±1.2 mGy, p<0.001). Subjectively rated general image quality was not significantly different between the study protocols (p = 0.421), whereas objectively measured image quality parameters were in favor of CBCT (p<0.001). Conclusions Adapted extremity CBCT imaging protocols have the potential to fall below optimized pediatric ankle and wrist MDCT doses at comparable image qualities. These possible dose savings warrant further development and research in pediatric extremity CBCT applications. PMID:28570626

Health economic assessment of Gd-EOB-DTPA MRI versus ECCM-MRI and multi-detector CT for diagnosis of hepatocellular carcinoma in China

PubMed Central

He, Xiaoning; Holtorf, Anke-Peggy; Rinde, Harald; Xie, Shuangshuang; Shen, Wen; Hou, Jiancun; Li, Xuehua; Li, Ziping; Lai, Jiaming; Wang, Yuting; Zhang, Lin; Wang, Jian; Li, Xuesong; Ma, Kuansheng; Ye, Feng; Ouyang, Han; Zhao, Hong

2018-01-01

Limited data exists in China on the comparative cost of gadolinium ethoxybenzyl diethylenetriamine magnetic resonance imaging (Gd-EOB-DTPA-MRI) with other imaging techniques. This study compared the total cost of Gd-EOB-DTPA-MRI with multidetector computed tomography (MDCT) and extracellular contrast media–enhanced MRI (ECCM-MRI) as initial imaging procedures in patients with suspected hepatocellular carcinoma (HCC). We developed a decision-tree model on the basis of the Chinese clinical guidelines for HCC, which was validated by clinical experts from China. The model compared the diagnostic accuracy and costs of alternative initial imaging procedures. Compared with MDCT and ECCM-MRI, Gd-EOB-DTPA-MRI imaging was associated with higher rates of diagnostic accuracy, i.e. higher proportions of true positives (TP) and true negatives (TN) with lower false positives (FP). Total diagnosis and treatment cost per patient after the initial Gd-EOB-DTPA-MRI evaluation was similar to MDCT (¥30,360 vs. ¥30,803) and lower than that reported with ECCM-MRI (¥30,360 vs. ¥31,465). Lower treatment cost after initial Gd-EOB-DTPA-MRI was driven by reduced utilization of confirmatory diagnostic procedures and unnecessary treatments. The findings reported that Gd-EOB-DTPA-MRI offered higher diagnostic accuracy compared with MDCT and ECCM-MRI at a comparable cost, which indicates Gd-EOB-DTPA-MRI could be the preferred initial imaging procedure for the diagnosis of HCC in China. PMID:29324837

Role of Multi Detector Computed Tomography (MDCT) in Preoperative Staging of Pancreatic Carcinoma.

PubMed

Singhal, Soumil; Prabhu, Nirmal Kumar; Sethi, Pulkit; Moorthy, Srikanth

2017-05-01

Pancreatic carcinoma is one of the leading causes of cancer related death in advanced countries and has shown rising trends in developing countries like India. Increase in the incidence has been linked to risk factors like lifestyle modification associated with increased alcohol consumption and rapid urbanization. Most patients at the time of diagnosis present with an advanced condition. Surgical resection offers the only chance for cure in them and imaging plays a crucial role in the early diagnosis of the condition. To compare the staging of pancreatic carcinoma by MDCT (Multi Detector Computed Tomography) with surgery in a preoperative setting in a tertiary referral centre in Kerala. A cross-sectional observational study was performed between November 2014 and October 2016, 25 patients (12 men, 13 women), with a mean age of 54.2 years, were evaluated. MDCT was performed using 16 slice, 64 slice and 256 slice multi detector CT machines. The gold standard for diagnosis was histopathology and operative data. All statistical analysis was done using IBM SPSS version 20.0. Validity parameters like sensitivity, specificity, accuracy and Positive Predictive Value (PPV) / Negative Predictive Value (NPV) were computed for MDCT with respect to surgery. Of the 25 patients who were evaluated for surgery, 15 (60%) cases were classified as resectable tumours, 3 (12%) as borderline resectable and 7 (28%) as unresectable tumours. CT showed a sensitivity of 82.3% with a specificity of 87.5%. However, for assessing vascular invasion, CT showed sensitivity and specificity of 100% and 93.3% respectively. Three (12%) patients in the study who were classified as borderline resectable pancreatic tumours underwent surgery. Contrast-enhanced multiphase pancreatic imaging using MDCT plays a pivotal role in diagnosing and assessing resectability and vascular invasion of pancreatic tumours. It is very useful for determining borderline resectable tumours pre-operatively, which aids for better treatment planning.

Sixty-Four-Section Cardiac Computed Tomography in Mechanical Prosthetic Heart Valve Dysfunction: Thrombus or Pannus.

PubMed

Gündüz, Sabahattin; Özkan, Mehmet; Kalçik, Macit; Gürsoy, Ozan Mustafa; Astarcioğlu, Mehmet Ali; Karakoyun, Süleyman; Aykan, Ahmet Çağri; Biteker, Murat; Gökdeniz, Tayyar; Kaya, Hasan; Yesin, Mahmut; Duran, Nilüfer Ekşi; Sevinç, Deniz; Güneysu, Tahsin

2015-12-01

Distinguishing pannus and thrombus in patients with prosthetic valve dysfunction is essential for the selection of proper treatment. We have investigated the utility of 64-slice multidetector computed tomography (MDCT) in distinguishing between pannus and thrombus, the latter amenable to thrombolysis. Sixty-two (23 men, mean age 44±14 years) patients with suspected mechanical prosthetic valve dysfunction assessed by transesophageal echocardiography were included in this prospective observational trial. Subsequently, MDCT was performed before any treatment was started. Periprosthetic masses were detected by MDCT in 46 patients, and their attenuation values were measured as Hounsfield Units (HU). Patients underwent thrombolysis unless contraindicated, and those with a contraindication or failed thrombolysis underwent surgery. A mass which was completely lysed or surgically detected as a clot was classified as thrombus, whereas a mass which was surgically detected as tissue overgrowth was classified as pannus. A definitive diagnosis could be achieved in 37 patients with 39 MDCT masses (22 thrombus and 17 pannus). The mean attenuation value of 22 thrombotic masses was significantly lower than that in 17 pannus (87±59 versus 322±122; P<0.001). Area under the receiver operating characteristic curve was 0.96 (95% confidence interval: 0.91-0.99; P<0.001), and a cutoff point of HU≥145 provided high sensitivity (87.5%) and specificity (95.5%) in discriminating pannus from thrombus. Complete lysis was more common for masses with HU<90 compared with those with HU 90 to 145 (100% versus 42.1%; P=0.007). Sixty-four slice MDCT is helpful in identifying masses amenable to thrombolysis in patients with prosthetic valve dysfunction. A high (HU≥145) attenuation suggests pannus overgrowth, whereas a lower value is associated with thrombus formation. A higher attenuation (HU>90) is associated with reduced lysis rates. © 2015 American Heart Association, Inc.

SENSITIVITY OF ENDOSCOPIC ULTRASOUND, MULTIDETECTOR COMPUTER TOMOGRAPHY AND MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY IN THE DIAGNOSIS OF PANCREAS DIVISUM: A TERTIARY CENTER EXPERIENCE

PubMed Central

Kushnir, Vladimir M.; Wani, Sachin B.; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris; Mullady, Daniel; Jonnalagadda, Sreenivasa S.; Early, Dayna S.; Edmundowicz, Steven A.; Azar, Riad R.

2014-01-01

OBJECTIVES There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: 1. Evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP) and multi-detector computed tomography (MDCT) for pancreas divisum. 2. Assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. METHODS For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography (ERP) who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent ERP and cross-sectional imaging. RESULTS The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) [p<0.001 for each]. On review by expert radiologists the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (қ=0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (қ=0.43). CONCLUSIONS EUS is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum. PMID:23211370

Computer-based route-definition system for peripheral bronchoscopy.

PubMed

Graham, Michael W; Gibbs, Jason D; Higgins, William E

2012-04-01

Multi-detector computed tomography (MDCT) scanners produce high-resolution images of the chest. Given a patient's MDCT scan, a physician can use an image-guided intervention system to first plan and later perform bronchoscopy to diagnostic sites situated deep in the lung periphery. An accurate definition of complete routes through the airway tree leading to the diagnostic sites, however, is vital for avoiding navigation errors during image-guided bronchoscopy. We present a system for the robust definition of complete airway routes suitable for image-guided bronchoscopy. The system incorporates both automatic and semiautomatic MDCT analysis methods for this purpose. Using an intuitive graphical user interface, the user invokes automatic analysis on a patient's MDCT scan to produce a series of preliminary routes. Next, the user visually inspects each route and quickly corrects the observed route defects using the built-in semiautomatic methods. Application of the system to a human study for the planning and guidance of peripheral bronchoscopy demonstrates the efficacy of the system.

The Role of Multidetector Computed Tomography in the Early Diagnosis of Invasive Pulmonary Aspergillosis in Patients with Febrile Neutropenia Undergoing Hematopoietic Stem Cell Transplantation

PubMed Central

Çiledağ, Nazan; Arda, Kemal; Arıbaş, Bilgin Kadri; Tekgündüz, Ali Irfan Emre; Altuntaş, Fevzi

2012-01-01

Objective: To evaluate vessel involvement and the role of multidetector computed tomography (MDCT) in the earlydiagnosis of invasive pulmonary aspergillosis (IPA) in patients with febrile neutropenia and antibiotic-resistant feverundergoing autologous bone morrow transplantation. Material and Methods: In all, 74 pulmonary MDCT examinations in 37 consecutive hematopoietic stem celltransplantation patients with febrile neutropenia and clinically suspected IPA were retrospectively evaluated. Results: Diagnosis of IPA was based on Fungal Infections Cooperative Group, and National Institute of Allergy andInfectious Diseases Mycoses Study Consensus Group criteria. In all, 0, 14, and 11 patients were diagnosed as proven,probable, and possible IPA, respectively. Among the 25 patients accepted as probable and possible IPA, all had pulmonaryMDCT findings consistent with IPA. The remaining 12 patients were accepted as having fever of unknown origin (FUO)and had patent vessels based on MDCT findings.In the patients with probable and possible IPA, 72 focal pulmonary lesions were observed; in 41 of the 72 (57%) lesionsvascular occlusion was noted and the CT halo sign was observed in 25 of these 41 (61%) lesions. Resolution of feveroccurred following antifungal therapy in 19 (76%) of the 25 patients with probable and possible IPA. In all, 6 (25%)of the patients diagnosed as IPA died during follow-up. Transplant-related mortality 100 d post transplant in patientswith IPA and FUO was 24% and 0%, respectively. Conclusion: In conclusion, MDCT has a potential role in the early diagnosis of IPA via detection of vessel occlusion. PMID:24744620

Paradigm of pretest risk stratification before coronary computed tomography.

PubMed

Jensen, Jesper Møller; Ovrehus, Kristian A; Nielsen, Lene H; Jensen, Jesper K; Larsen, Henrik M; Nørgaard, Bjarne L

2009-01-01

The optimal method of determining the pretest risk of coronary artery disease as a patient selection tool before coronary multidetector computed tomography (MDCT) is unknown. We investigated the ability of 3 different clinical risk scores to predict the outcome of coronary MDCT. This was a retrospective study of 551 patients consecutively referred for coronary MDCT on a suspicion of coronary artery disease. Diamond-Forrester, Duke, and Morise risk models were used to predict coronary artery stenosis (>50%) as assessed by coronary MDCT. The models were compared by receiver operating characteristic analysis. The distribution of low-, intermediate-, and high-risk persons, respectively, was established and compared for each of the 3 risk models. Overall, all risk prediction models performed equally well. However, the Duke risk model classified the low-risk patients more correctly than did the other models (P < 0.01). In patients without coronary artery calcification (CAC), the predictive value of the Duke risk model was superior to the other risk models (P < 0.05). Currently available risk prediction models seem to perform better in patients without CAC. Between the risk prediction models, there was a significant discrepancy in the distribution of patients at low, intermediate, or high risk (P < 0.01). The 3 risk prediction models perform equally well, although the Duke risk score may have advantages in subsets of patients. The choice of risk prediction model affects the referral pattern to MDCT. Copyright (c) 2009 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

MDCT evaluation of potential living renal donor, prior to laparoscopic donor nephrectomy: What the transplant surgeon wants to know?

PubMed Central

Ghonge, Nitin P; Gadanayak, Satyabrat; Rajakumari, Vijaya

2014-01-01

As Laparoscopic Donor Nephrectomy (LDN) offers several advantages for the donor such as lesser post-operative pain, fewer cosmetic concerns and faster recovery time, there is growing global trend towards LDN as compared to open nephrectomy. Comprehensive pre-LDN donor evaluation includes assessment of renal morphology including pelvi-calyceal and vascular system. Apart from donor selection, evaluation of the regional anatomy allows precise surgical planning. Due to limited visualization during laparoscopic renal harvesting, detailed pre-transplant evaluation of regional anatomy, including the renal venous anatomy is of utmost importance. MDCT is the modality of choice for pre-LDN evaluation of potential renal donors. Apart from appropriate scan protocol and post-processing methods, detailed understanding of surgical techniques is essential for the Radiologist for accurate image interpretation during pre-LDN MDCT evaluation of potential renal donors. This review article describes MDCT evaluation of potential living renal donor, prior to LDN with emphasis on scan protocol, post-processing methods and image interpretation. The article laid special emphasis on surgical perspectives of pre-LDN MDCT evaluation and addresses important points which transplant surgeons want to know. PMID:25489130

Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.

PubMed

Zink, Stephen I; Ohki, Stephen K; Stein, Barry; Zambuto, Domenic A; Rosenberg, Ronald J; Choi, Jenny J; Tubbs, Daniel S

2008-10-01

The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding. Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location. Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative. Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.

Approach to interpret images produced by new generations of multidetector CT scanners in post-operative spine.

PubMed

Zeitoun, Rania; Hussein, Manar

2017-11-01

To reach a practical approach to interpret MDCT findings in post-operative spine cases and to change the false belief of CT failure in the setting of instruments secondary to related artefacts. We performed observational retrospective analysis of premier, early and late MDCT scans in 68 post-operative spine patients, with emphasis on instruments related complications and osseous fusion status. We used a grading system for assessment of osseous fusion in 35 patients and we further analysed the findings in failure of fusion, grade (D). We observed a variety of instruments related complications (mostly screws medially penetrating the pedicle) and osseous fusion status in late scans. We graded 11 interbody and 14 posterolateral levels as osseous fusion failure, showing additional instruments related complications, end plates erosive changes, adjacent segments spondylosis and malalignment. Modern MDCT scanners provide high quality images and are strongly recommended in assessment of the instruments and status of osseous fusion. In post-operative imaging of the spine, it is essential to be aware for what you are looking for, in relevance to the date of surgery. Advances in knowledge: Modern MDCT scanners allow assessment of instruments position and integrity and osseous fusion status in post-operative spine. We propose a helpful algorithm to simplify interpreting post-operative spine imaging.

Influence of the Quantity of Aortic Valve Calcium on the Agreement Between Automated 3-Dimensional Transesophageal Echocardiography and Multidetector Row Computed Tomography for Aortic Annulus Sizing.

PubMed

Podlesnikar, Tomaz; Prihadi, Edgard A; van Rosendael, Philippe J; Vollema, E Mara; van der Kley, Frank; de Weger, Arend; Ajmone Marsan, Nina; Naji, Franjo; Fras, Zlatko; Bax, Jeroen J; Delgado, Victoria

2018-01-01

Accurate aortic annulus sizing is key for selection of appropriate transcatheter aortic valve implantation (TAVI) prosthesis size. The present study compared novel automated 3-dimensional (3D) transesophageal echocardiography (TEE) software and multidetector row computed tomography (MDCT) for aortic annulus sizing and investigated the influence of the quantity of aortic valve calcium (AVC) on the selection of TAVI prosthesis size. A total of 83 patients with severe aortic stenosis undergoing TAVI were evaluated. Maximal and minimal aortic annulus diameter, perimeter, and area were measured. AVC was assessed with computed tomography. The low and high AVC burden groups were defined according to the median AVC score. Overall, 3D TEE measurements slightly underestimated the aortic annulus dimensions as compared with MDCT (mean differences between maximum, minimum diameter, perimeter, and area: -1.7 mm, 0.5 mm, -2.7 mm, and -13 mm 2 , respectively). The agreement between 3D TEE and MDCT on aortic annulus dimensions was superior among patients with low AVC burden (<3,025 arbitrary units) compared with patients with high AVC burden (≥3,025 arbitrary units). The interobserver variability was excellent for both methods. 3D TEE and MDCT led to the same prosthesis size selection in 88%, 95%, and 81% of patients in the total population, the low, and the high AVC burden group, respectively. In conclusion, the novel automated 3D TEE imaging software allows accurate and highly reproducible measurements of the aortic annulus dimensions and shows excellent agreement with MDCT to determine the TAVI prosthesis size, particularly in patients with low AVC burden. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

PubMed

Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

2016-01-01

We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

"Silent" kidney stones in "asymptomatic" primary hyperparathyroidism-a comparison of multidetector computed tomography and ultrasound.

PubMed

Selberherr, Andreas; Hörmann, Marcus; Prager, Gerhard; Riss, Philipp; Scheuba, Christian; Niederle, Bruno

2017-03-01

The purpose of this study was to demonstrate the high number of kidney stones in primary hyperparathyroidism (PHPT) and the low number of in fact "asymptomatic" patients. Forty patients with PHPT (28 female, 12 male; median age 58 (range 33-80) years; interquartile range 17 years [51-68]) without known symptoms of kidney stones prospectively underwent multidetector computed tomography (MDCT) and ultrasound (US) examinations of the urinary tract prior to parathyroid surgery. Images were evaluated for the presence and absence of stones, as well as for the number of stones and sizes in the long axis. The MDCT and US examinations were interpreted by two experienced radiologists who were blinded to all clinical and biochemical data. Statistical analysis was performed using the Wilcoxon signed-rank test. US revealed a total of 4 kidney stones in 4 (10 %) of 40 patients (median size 6.5 mm, interquartile range 11.5 mm). MDCT showed a total of 41 stones (median size was 3 mm, interquartile range 2.25 mm) in 15 (38 %) of 40 patients. The number of kidney stones detected with MDCT was significantly higher compared to US (p = 0.00124). MDCT is a highly sensitive method for the detection of "silent" kidney stones in patients with PHPT. By widely applying this method, the number of asymptomatic courses of PHPT may be substantially reduced. MDCT should be used primarily to detect kidney stones in PHPT and to exclude asymptomatic PHPT.

Comparison of dosimetric properties among four commercial multi-detector computed tomography scanners.

PubMed

Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hatemura, Masahiro; Shimonobou, Toshiaki; Sakamoto, Takashi; Okumura, Shuichiro; Ideguchi, Daichi; Honda, Keiichi; Kawata, Kenji

2017-03-01

This study compared dosimetric properties among four commercial multi-detector CT (MDCT) scanners. The X-ray beam characteristics were obtained from photon intensity attenuation curves of aluminum and off-center ratio (OCR) profiles in air, which were measured with four commercial MDCT scanners. The absorbed dose for MDCT scanners was evaluated with Farmer ionization chamber measurements at the center and four peripheral points in the body- and head-type cylindrical water phantoms. Measured collected charge was converted to absorbed dose using a 60 Co absorbed dose-to-water calibration factor and Monte Carlo (MC)-calculated correction factors. Four MDCT scanners were modeled to correspond with measured X-ray beam characteristics using GMctdospp (IMPS, Germany) software. Al half-value layers (Al-HVLs) with a body-bowtie filter determined from measured Al-attenuation curves ranged 7.2‒9.1mm at 120kVp and 6.1‒8.0mm at 100kVp. MC-calculated Al-HVLs and OCRs in air were in acceptable agreement within 0.5mm and 5% of measured values, respectively. The percentage difference between nominal and actual beam width was greater with decreasing collimation width. The absorbed doses for MDCT scanners at 120kVp ranged 5.1‒7.1mGy and 10.8‒17.5mGy per 100mAs at the center in the body- and head-type water phantoms, respectively. Measured doses at four peripheral points were within 5% agreement of MC-calculated values. The absorbed dose at the center in both water phantoms increased with decreasing Al-HVL for the same charge on the focus. In this study the X-ray beam characteristics and the absorbed dose were measured and compared with calculated values for four MDCT scanners. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Virtual modeling of robot-assisted manipulations in abdominal surgery.

PubMed

Berelavichus, Stanislav V; Karmazanovsky, Grigory G; Shirokov, Vadim S; Kubyshkin, Valeriy A; Kriger, Andrey G; Kondratyev, Evgeny V; Zakharova, Olga P

2012-06-27

To determine the effectiveness of using multidetector computed tomography (MDCT) data in preoperative planning of robot-assisted surgery. Fourteen patients indicated for surgery underwent MDCT using 64 and 256-slice MDCT. Before the examination, a specially constructed navigation net was placed on the patient's anterior abdominal wall. Processing of MDCT data was performed on a Brilliance Workspace 4 (Philips). Virtual vectors that imitate robotic and assistant ports were placed on the anterior abdominal wall of the 3D model of the patient, considering the individual anatomy of the patient and the technical capabilities of robotic arms. Sites for location of the ports were directed by projection on the roentgen-positive tags of the navigation net. There were no complications observed during surgery or in the post-operative period. We were able to reduce robotic arm interference during surgery. The surgical area was optimal for robotic and assistant manipulators without any need for reinstallation of the trocars. This method allows modeling of the main steps in robot-assisted intervention, optimizing operation of the manipulator and lowering the risk of injuries to internal organs.

MDCT diagnosis of post-traumatic hepatic arterio-portal fistulas.

PubMed

Nguyen, Cuong T; Nguyen, Coung; Saksobhavivat, Nitima; Saksobahavivat, Nitima; Shanmuganathan, Kathirkamanathan; Steenburg, Scott D; Steenburg, Scott; Moeslein, Fred M; Moeslein, Fred; Mirvis, Stuart E; Chiu, William

2013-06-01

The purpose of this study is to evaluate the performance of multidetector computed tomography (MDCT) in diagnosing arterioportal fistulas (APF) in high-grade liver injury. A retrospective analysis of catheter-based hepatic angiograms performed for major penetrating and blunt liver injuries identified 11 patients with APFs. Using the trauma registry, two additional demographically matched groups with and without liver injury were formed. A randomized qualitative consensus review of 33 MDCTs was performed by three trauma radiologists for the following MDCT findings of APF: transient hepatic parenchymal attenuation differences (THPAD), early increased attenuation of a peripheral or central portal vein compared with the main portal vein, and the "double-barrel" or "rail tract" signs. THPAD was the most sensitive finding and also had a high specificity for diagnosing APF. Both the early increased attenuation of a peripheral or central portal vein compared with the main portal vein and the double-barrel or rail tract signs had a100% specificity and a sensitivity of 64% and 36%, respectively. Measurement of differences in attenuation values between the APF and the contralateral central portal vein was most sensitive and specific in diagnosing APF. Traumatic APF of the liver can be optimally diagnosed with arterial phase imaging of solid organ using MDCT.

Low-tube voltage 100 kVp MDCT in screening of cocaine body packing: image quality and radiation dose compared to 120 kVp MDCT.

PubMed

Aissa, Joel; Rubbert, Christian; Boos, Johannes; Schleich, Christoph; Thomas, Christoph; Kröpil, Patric; Antoch, Gerald; Miese, Falk

2015-10-01

The aim of this study was to evaluate the impact of a reduced tube potential (100 kVp) for non-enhanced abdominal low-dose CT on radiation dose and image quality (IQ) in the detection of body packing. This retrospective study was approved by the local research ethics committee of our clinic. From March 2012 to July 2014, 99 subjects were referred to our institute with suspected body packing. 50 CT scans were performed using a 120 kVp protocol (group A), and 49 CTs were performed using a low-dose protocol with a tube voltage of 100 kVp (group B). Subjective and objective IQ were assessed. DLP and CTDIvol were analyzed. All examinations were of diagnostic IQ. Objective IQ was not significantly different between the 120 kVp and 100 kVp protocol. Mean density of solid and liquid body packets was 210 ± 60.2 HU at 120 kVp and 250.6 ± 29.7 HU at 100 kVp. Radiation dose was significantly lower in group B as compared to group A (p < 0.05). In group A, body packs were detected in 16 (32%) of the 50 patients. In group B, packets were observed in 15 (31%) of 49 patients. Laboratory analysis detected cocaine in all smuggled body packs. Low-tube voltage 100 kVp MDCT with automated tube current modulation in screening of illegal drugs leads to a diagnostic IQ and significant dose reduction compared to 120 kVp low-tube voltage protocols. Despite lower radiation dose, liquid and solid cocaine containers retain high attenuation and are easily detected.

The diagnostic performance of coronary artery angiography with 64-MSCT and post 64-MSCT: systematic review and meta-analysis.

PubMed

Li, Min; Du, Xiang-Min; Jin, Zhi-Tao; Peng, Zhao-Hui; Ding, Juan; Li, Li

2014-01-01

To comprehensively investigate the diagnostic performance of coronary artery angiography with 64-MDCT and post 64-MDCT. PubMed was searched for all published studies that evaluated coronary arteries with 64-MDCT and post 64-MDCT. The clinical diagnostic role was evaluated by applying the likelihood ratios (LRs) to calculate the post-test probability based on Bayes' theorem. 91 studies that met our inclusion criteria were ultimately included in the analysis. The pooled positive and negative LRs at patient level were 8.91 (95% CI, 7.53, 10.54) and 0.02 (CI, 0.01, 0.03), respectively. For studies that did not claim that non-evaluable segments were included, the pooled positive and negative LRs were 11.16 (CI, 8.90, 14.00) and 0.01 (CI, 0.01, 0.03), respectively. For studies including uninterruptable results, the diagnostic performance decreased, with the pooled positive LR 7.40 (CI, 6.00, 9.13) and negative LR 0.02 (CI, 0.01, 0.03). The areas under the summary ROC curve were 0.98 (CI, 0.97 to 0.99) for 64-MDCT and 0.96 (CI, 0.94 to 0.98) for post 64-MDCT, respectively. For references explicitly stating that the non-assessable segments were included during analysis, a post-test probability of negative results >95% and a positive post-test probability <95% could be obtained for patients with a pre-test probability of <73% for coronary artery disease (CAD). On the other hand, when the pre-test probability of CAD was >73%, the diagnostic role was reversed, with a positive post-test probability of CAD >95% and a negative post-test probability of CAD <95%. The diagnostic performance of post 64-MDCT does not increase as compared with 64-MDCT. CTA, overall, is a test of exclusion for patients with a pre-test probability of CAD<73%, while for patients with a pre-test probability of CAD>73%, CTA is a test used to confirm the presence of CAD.

Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms.

PubMed

Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

2014-08-01

To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8%) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2%) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47%), celiomesenteric trunk (CMT) (51 patients, 3.4%) and splenomesenteric trunk (18 patients, 1.2%). An evaluation of CMT was classified as long (34 patients, 66.7%) or short (17 patients, 33.3%) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1%); subtype II, 5 patients (10.2%); subtype III, 15 patients (30.6%); subtype IV, 3 patients (6.1%). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. • Aortic origins of CA, SMA and their major branches were investigated. • Celiomesenteric trunk includes several different subtypes and configurations. • Probable embryological mechanisms of origin variants in these observed arteries were discussed. • Origin variants in these observed arteries have wide-ranging health implications.

Multidetector computed tomography sizing of aortic annulus prior to transcatheter aortic valve replacement (TAVR): Variability and impact of observer experience.

PubMed

Le Couteulx, S; Caudron, J; Dubourg, B; Cauchois, G; Dupré, M; Michelin, P; Durand, E; Eltchaninoff, H; Dacher, J-N

2018-05-01

To evaluate intra- and inter-observer variability of multidetector computed tomography (MDCT) sizing of the aortic annulus before transcatheter aortic valve replacement (TAVR) and the effect of observer experience, aortic valve calcification and image quality. MDCT examinations of 52 consecutive patients with tricuspid aortic valve (30 women, 22 men) with a mean age of 83±7 (SD) years (range: 64-93 years) were evaluated retrospectively. The maximum and minimum diameters, area and circumference of the aortic annulus were measured twice at diastole and systole with a standardized approach by three independent observers with different levels of experience (expert [observer 1]; resident with intensive 6 months practice [observer 2]; trained resident with starting experience [observer 3]). Observers were requested to recommend the valve prosthesis size. Calcification volume of the aortic valve and signal to noise ratio were evaluated. Intra- and inter-observer reproducibility was excellent for all aortic annulus dimensions, with an intraclass correlation coefficient ranging respectively from 0.84 to 0.98 and from 0.82 to 0.97. Agreement for selection of prosthesis size was almost perfect between the two most experienced observers (k=0.82) and substantial with the inexperienced observer (k=0.67). Aortic valve calcification did not influence intra-observer reproducibility. Image quality influenced reproducibility of the inexperienced observer. Intra- and inter-observer variability of aortic annulus sizing by MDCT is low. Nevertheless, the less experienced observer showed lower reliability suggesting a learning curve. Copyright © 2017. Published by Elsevier Masson SAS.

Reproducibility of Abdominal Aortic Aneurysm Diameter Measurement and Growth Evaluation on Axial and Multiplanar Computed Tomography Reformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dugas, Alexandre; Therasse, Eric; Kauffmann, Claude

2012-08-15

Purpose: To compare different methods measuring abdominal aortic aneurysm (AAA) maximal diameter (Dmax) and its progression on multidetector computed tomography (MDCT) scan. Materials and Methods: Forty AAA patients with two MDCT scans acquired at different times (baseline and follow-up) were included. Three observers measured AAA diameters by seven different methods: on axial images (anteroposterior, transverse, maximal, and short-axis views) and on multiplanar reformation (MPR) images (coronal, sagittal, and orthogonal views). Diameter measurement and progression were compared over time for the seven methods. Reproducibility of measurement methods was assessed by intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results: Dmax, as measuredmore » on axial slices at baseline and follow-up (FU) MDCTs, was greater than that measured using the orthogonal method (p = 0.046 for baseline and 0.028 for FU), whereas Dmax measured with the orthogonal method was greater those using all other measurement methods (p-value range: <0.0001-0.03) but anteroposterior diameter (p = 0.18 baseline and 0.10 FU). The greatest interobserver ICCs were obtained for the orthogonal and transverse methods (0.972) at baseline and for the orthogonal and sagittal MPR images at FU (0.973 and 0.977). Interobserver ICC of the orthogonal method to document AAA progression was greater (ICC = 0.833) than measurements taken on axial images (ICC = 0.662-0.780) and single-plane MPR images (0.772-0.817). Conclusion: AAA Dmax measured on MDCT axial slices overestimates aneurysm size. Diameter as measured by the orthogonal method is more reproducible, especially to document AAA progression.« less

Assessment of liver ablation using cone beam computed tomography.

PubMed

Abdel-Rehim, Mohamed; Ronot, Maxime; Sibert, Annie; Vilgrain, Valérie

2015-01-14

To investigate the feasibility and accuracy of cone beam computed tomography (CBCT) in assessing the ablation zone after liver tumor ablation. Twenty-three patients (17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasound-guided percutaneous tumor ablation [radiofrequency (n = 14), microwave (n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography (MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the non-parametric paired Wilcoxon t-test. Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient (4%). The ablation zone was identified in 21/23 (91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage (at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2 (9%), 8 (35%), and 13 (56%), patients respectively. Registration quality between peri-procedural CBCT and post-procedural MDCT images was good to excellent in 17/23 (74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm(3) (range: 4-95 cm(3)) and 30 cm(3) (range: 4-124 cm(3)), respectively (P-value > 0.2). There was a good correlation (r = 0.79) between the volumes of the two techniques. Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.

Health economic evaluation of Gd-EOB-DTPA MRI vs ECCM-MRI and multi-detector computed tomography in patients with suspected hepatocellular carcinoma in Thailand and South Korea.

PubMed

Lee, Jeong-Min; Kim, Myeong-Jin; Phongkitkarun, Sith; Sobhonslidsuk, Abhasnee; Holtorf, Anke-Peggy; Rinde, Harald; Bergmann, Karsten

2016-08-01

The effectiveness of treatment decisions and economic outcomes of using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) were compared with extracellular contrast media-enhanced MRI (ECCM-MRI) and multi-detector computed tomography (MDCT) as initial procedures in patients with suspected hepatocellular carcinoma (HCC) in South Korea and Thailand. A decision-tree model simulated the clinical pathway for patients with suspected HCC from the first imaging procedure to a confirmed treatment decision. Input data (probabilities and resource consumptions) were estimated and validated by clinical experts. Costs for diagnostic alternatives and related treatment options were derived from published sources, taking into account both payer's and hospital's perspectives. All experts from Korea and Thailand agreed that Gd-EOB-DTPA-MRI yields the highest diagnostic certainty and minimizes the need for additional confirmatory diagnostic procedures in HCC. In Korea, from the payer's perspective, total cost was USD $3087/patient to reach a confirmed treatment decision using Gd-EOB-DTPA-MRI (vs $3205/patient for MDCT and $3403/patient for ECCM-MRI). From the hospital's perspective, Gd-EOB-DTPA-MRI incurred the lowest cost ($2289/patient vs $2320/patient and $2528/patient, respectively). In Thailand, Gd-EOB-DTPA-MRI was the least costly alternative for the payer ($702/patient vs $931/patient for MDCT and $873/patient for ECCM-MRI). From the hospital's perspective, costs were $1106/patient, $1178/patient, and $1087/patient for Gd-EOB-DTPA-MRI, MDCT, and ECCM-MRI, respectively. Gd-EOB-DTPA-MRI as an initial imaging procedure in patients with suspected HCC provides better diagnostic certainty and relevant statutory health insurance cost savings in Thailand and Korea, compared with ECCM-MRI and MDCT.

Usefulness and limitations of postmortem computed tomography in forensic analysis of gunshot injuries: Three case reports.

PubMed

Usui, Akihito; Kawasumi, Yusuke; Hosokai, Yoshiyuki; Kozakai, Masataka; Saito, Haruo; Funayama, Masato

2016-01-01

Gunshot injury has always been an important field of investigation in postmortem forensic radiology. The localization and retrieval of the bullet and of potentially important fragments are vital to these cases. Using postmortem multidetector-row computed tomography (MDCT) prior to forensic autopsy, we sought to illustrate the importance of this modality in the noninvasive characterization of gunshot wounds. We obtained and analyzed MDCT images in three cases of gunshot wounds (accidental close-range shotgun shooting, suicidal contact gunshot to the head and accidental long-range buckshot shooting). We discuss the value of postmortem MDCT findings in gunshot wound cases by comparing with forensic autopsy findings in Japan, a developing country with miserably low autopsy rate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Detection of attenuated plaque in stable angina with 64-multidetector computed tomography: a comparison with intravascular ultrasound.

PubMed

Jinzaki, Masahiro; Okabe, Teruo; Endo, Ayaka; Kawamura, Akio; Koga, Seiko; Yamada, Minoru; Fukuda, Keiichi; Kuribayashi, Sachio

2012-01-01

To clarify multidetector computed tomography (MDCT) findings of attenuated plaque detected by intravascular ultrasound (IVUS). One hundred and fifty-four patients with stable angina underwent MDCT before IVUS. The attenuated plaque was identified in the targeted artery with IVUS, and the same artery was analyzed with MDCT for the presence of a high density area (HDA) >130 Hounsfield units (HU), and a low density area (LDA) <30 HU. A HDA in attenuated plaque was compared with that in calcified plaque. Ten attenuated plaques and 15 calcified plaques were identified in 9 of 154 patients (males=9, 66.2 ± 9.5 years). Eight of the 10 attenuated plaques and all 15 calcified plaques were accompanied with a HDA on MDCT. The HDA ranged from 174 to 667 HU (mean 389.0 ± 148.3 HU) in the 8 attenuated plaques, and from 545 to 1,205 HU (mean 920.9 ± 215.9 HU) in 15 calcified plaques. There was a significant difference in CT density of the HDA between the attenuated and calcified plaque (P<0.001). All attenuated plaques contained LDA <30 HU in the portions without HDA. MDCT has the ability to demonstrate attenuated plaque as the combination of HDA (approximately 400 HU on average) and LDA <30 HU. The HDA can be differentiated from calcified plaque by its lower CT density value.

An intelligent framework for medical image retrieval using MDCT and multi SVM.

PubMed

Balan, J A Alex Rajju; Rajan, S Edward

2014-01-01

Volumes of medical images are rapidly generated in medical field and to manage them effectively has become a great challenge. This paper studies the development of innovative medical image retrieval based on texture features and accuracy. The objective of the paper is to analyze the image retrieval based on diagnosis of healthcare management systems. This paper traces the development of innovative medical image retrieval to estimate both the image texture features and accuracy. The texture features of medical images are extracted using MDCT and multi SVM. Both the theoretical approach and the simulation results revealed interesting observations and they were corroborated using MDCT coefficients and SVM methodology. All attempts to extract the data about the image in response to the query has been computed successfully and perfect image retrieval performance has been obtained. Experimental results on a database of 100 trademark medical images show that an integrated texture feature representation results in 98% of the images being retrieved using MDCT and multi SVM. Thus we have studied a multiclassification technique based on SVM which is prior suitable for medical images. The results show the retrieval accuracy of 98%, 99% for different sets of medical images with respect to the class of image.

Automated cortical bone segmentation for multirow-detector CT imaging with validation and application to human studies

PubMed Central

Li, Cheng; Jin, Dakai; Chen, Cheng; Letuchy, Elena M.; Janz, Kathleen F.; Burns, Trudy L.; Torner, James C; Levy, Steven M.; Saha, Punam K

2015-01-01

Purpose: Cortical bone supports and protects human skeletal functions and plays an important role in determining bone strength and fracture risk. Cortical bone segmentation at a peripheral site using multirow-detector CT (MD-CT) imaging is useful for in vivo assessment of bone strength and fracture risk. Major challenges for the task emerge from limited spatial resolution, low signal-to-noise ratio, presence of cortical pores, and structural complexity over the transition between trabecular and cortical bones. An automated algorithm for cortical bone segmentation at the distal tibia from in vivo MD-CT imaging is presented and its performance and application are examined. Methods: The algorithm is completed in two major steps—(1) bone filling, alignment, and region-of-interest computation and (2) segmentation of cortical bone. After the first step, the following sequence of tasks is performed to accomplish cortical bone segmentation—(1) detection of marrow space and possible pores, (2) computation of cortical bone thickness, detection of recession points, and confirmation and filling of true pores, and (3) detection of endosteal boundary and delineation of cortical bone. Effective generalizations of several digital topologic and geometric techniques are introduced and a fully automated algorithm is presented for cortical bone segmentation. Results: An accuracy of 95.1% in terms of volume of agreement with manual outlining of cortical bone was observed in human MD-CT scans, while an accuracy of 88.5% was achieved when compared with manual outlining on postregistered high resolution micro-CT imaging. An intraclass correlation coefficient of 0.98 was obtained in cadaveric repeat scans. A pilot study was conducted to describe gender differences in cortical bone properties. This study involved 51 female and 46 male participants (age: 19–20 yr) from the Iowa Bone Development Study. Results from this pilot study suggest that, on average after adjustment for height and weight differences, males have thicker cortex (mean difference 0.33 mm and effect size 0.92 at the anterior region) with lower bone mineral density (mean difference −28.73 mg/cm3 and effect size 1.35 at the posterior region) as compared to females. Conclusions: The algorithm presented is suitable for fully automated segmentation of cortical bone in MD-CT imaging of the distal tibia with high accuracy and reproducibility. Analysis of data from a pilot study demonstrated that the cortical bone indices allow quantification of gender differences in cortical bone from MD-CT imaging. Application to larger population groups, including those with compromised bone, is needed. PMID:26233184

Non-contrast MDCT for Ureteral Calculi and Alternative Diagnoses: Yield in Adult Women vs in Adult Men.

PubMed

Fani, Parisa; Patlas, Michael N; Monteiro, Sandra; Katz, Douglas S

2018-02-02

To determine the yield of non-contrast multi-detector computed tomography (MDCT) of the abdomen and pelvis in diagnosing ureteral calculi as well as other alternative acute conditions in male vs in female adult patients presenting to the emergency department with new onset of symptoms. Our institutional review board approved a retrospective review of the official reports of the non-contrast MDCT examinations of the abdomen and pelvis performed on adults (18 years and older) presenting to our emergency department with a suspected ureteral calculus from October 1, 2011 to October 30, 2013. Patients with recently documented ureteral calculi, known urinary tract infection, malignancy, and trauma were excluded from the study. From a total of 1097 non-contrast MDCT examinations of the abdomen and pelvis over the 2-year period, 400 randomly selected examinations were reviewed (approximately one-third of all the examinations). We compared the prevalence of ureteral calculi between the male and female population. P values and confidence intervals were determined using software Stata 14. Other acute intra-abdominal and intra-pelvic findings amenable to prompt medical care were also documented and analyzed separately. The mean patient age was 55.2 years, with a range of 19-90 years. This included 170 female (mean age 56.8 years) and 230 male patients (mean age 54.2 years). Ureteral calculi were detected in 170 (42.5%) of the patients [111 males (48%) and 59 females (34.7%)] with a prevalence which was statistically significantly higher in the male patients compared to in the female patients (P < 0.01, confidence level of 95% and CI of 13.2-13.4). An alternative diagnosis was made based on the MDCT findings in 49 patient cases (12.25 %), including 26 females (15.29%) and 23 males (10.00%). There was no statistically significant difference in alternative acute findings in male compared to in female patients (P > 0.05). This was with the exception of acute pyelonephritis, which was statistically significantly higher in the female patients (P < 0.01). The likelihood of making the diagnosis of a ureteral calculus on non-contrast MDCT of the abdomen and pelvis was statistically significantly higher in male patients compared with female patients presenting to our emergency department. However, there was no statistically significant difference in the alternative diagnoses, with the exception of pyelonephritis, which was more common in women. Copyright © 2018 Elsevier Inc. All rights reserved.

Latest generation of flat detector CT as a peri-interventional diagnostic tool: a comparative study with multidetector CT.

PubMed

Leyhe, Johanna Rosemarie; Tsogkas, Ioannis; Hesse, Amélie Carolina; Behme, Daniel; Schregel, Katharina; Papageorgiou, Ismini; Liman, Jan; Knauth, Michael; Psychogios, Marios-Nikos

2017-12-01

Flat detector CT (FDCT) has been used as a peri-interventional diagnostic tool in numerous studies with mixed results regarding image quality and detection of intracranial lesions. We compared the diagnostic aspects of the latest generation FDCT with standard multidetector CT (MDCT). 102 patients were included in our retrospective study. All patients had undergone interventional procedures. FDCT was acquired peri-interventionally and compared with postinterventional MDCT regarding depiction of ventricular/subarachnoidal spaces, detection of intracranial hemorrhage, and delineation of ischemic lesions using an ordinal scale. Ischemic lesions were quantified with the Alberta Stroke Program Early CT Scale (ASPECTS) on both examinations. Two neuroradiologists with varying grades of experience and a medical student scored the anonymized images separately, blinded to the clinical history. The two methods were of equal diagnostic value regarding evaluation of the ventricular system and the subarachnoidal spaces. Subarachnoidal, intraventricular, and parenchymal hemorrhages were detected with a sensitivity of 95%, 97%, and 100% and specificity of 97%, 100%, and 99%, respectively, using FDCT. Gray-white differentiation was feasible in the majority of FDCT scans, and ischemic lesions were detected with a sensitivity of 71% on FDCT, compared with MDCT scans. The mean difference in ASPECTS values on FDCT and MDCT was 0.5 points (95% CI 0.12 to 0.88). The latest generation of FDCT is a reliable and accurate tool for the detection of intracranial hemorrhage. Gray-white differentiation is feasible in the supratentorial region. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with ¹⁵O-H₂O PET.

PubMed

Kikuchi, Yasuka; Oyama-Manabe, Noriko; Naya, Masanao; Manabe, Osamu; Tomiyama, Yuuki; Sasaki, Tsukasa; Katoh, Chietsugu; Kudo, Kohsuke; Tamaki, Nagara; Shirato, Hiroki

2014-07-01

This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H₂O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.

Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans.

PubMed

Shokri, Abbas; Ramezani, Leila; Bidgoli, Mohsen; Akbarzadeh, Mahdi; Ghazikhanlu-Sani, Karim; Fallahi-Sichani, Hamed

2018-03-01

This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes ( P <.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

3D noise power spectrum applied on clinical MDCT scanners: effects of reconstruction algorithms and reconstruction filters

NASA Astrophysics Data System (ADS)

Miéville, Frédéric A.; Bolard, Gregory; Benkreira, Mohamed; Ayestaran, Paul; Gudinchet, François; Bochud, François; Verdun, Francis R.

2011-03-01

The noise power spectrum (NPS) is the reference metric for understanding the noise content in computed tomography (CT) images. To evaluate the noise properties of clinical multidetector (MDCT) scanners, local 2D and 3D NPSs were computed for different acquisition reconstruction parameters. A 64- and a 128-MDCT scanners were employed. Measurements were performed on a water phantom in axial and helical acquisition modes. CT dose index was identical for both installations. Influence of parameters such as the pitch, the reconstruction filter (soft, standard and bone) and the reconstruction algorithm (filtered-back projection (FBP), adaptive statistical iterative reconstruction (ASIR)) were investigated. Images were also reconstructed in the coronal plane using a reformat process. Then 2D and 3D NPS methods were computed. In axial acquisition mode, the 2D axial NPS showed an important magnitude variation as a function of the z-direction when measured at the phantom center. In helical mode, a directional dependency with lobular shape was observed while the magnitude of the NPS was kept constant. Important effects of the reconstruction filter, pitch and reconstruction algorithm were observed on 3D NPS results for both MDCTs. With ASIR, a reduction of the NPS magnitude and a shift of the NPS peak to the low frequency range were visible. 2D coronal NPS obtained from the reformat images was impacted by the interpolation when compared to 2D coronal NPS obtained from 3D measurements. The noise properties of volume measured in last generation MDCTs was studied using local 3D NPS metric. However, impact of the non-stationarity noise effect may need further investigations.

Relative threshold of detection of active arterial bleeding: in vitro comparison of MDCT and digital subtraction angiography.

PubMed

Roy-Choudhury, Shuvro H; Gallacher, David J; Pilmer, John; Rankin, Sheila; Fowler, Geoff; Steers, Jeff; Dourado, Renato; Woodburn, Paul; Adam, Andreas

2007-11-01

The objective of our study was to determine the relative sensitivity and the lowest threshold of bleeding detectable with digital subtraction angiography (DSA) and with MDCT using an in vitro physiologic system. A closed pulsatile cardiopulmonary bypass circuit was connected to tubes traversing a water bath to simulate the abdominal aorta and inferior vena cava. Three smaller interconnecting acrylic plastic tubes were connected as branches to the aortic tubing to simulate branch vessels. One of the three tubes, the control, had no holes in it, one had a 100-microm hole, and one had a 280-microm hole. The leakage rates were predetermined with a cardiac output of 2 and 4 L/min and with a mean arterial pressure (MAP) ranging from 30 to 100 mm Hg for each hole size. The following studies were performed for each of the predetermined leakage rates. For study 1, 16-MDCT was performed using bolus tracking after 35 mL of contrast medium had been injected into a simulated peripheral vein. For study 2, DSA was performed using a 4-French straight catheter placed 10 cm proximal to the holes (selective first aortic branch cannulation). For study 3, DSA was performed with a catheter placed in the small branch at the site of the hole (highly superselective). For study 4, 16-MDCT was performed with a catheter placed as in study 2, 10 cm proximal to the holes, for the detection of lower leakage rates. Cine loops of MDCT and DSA images were examined by two blinded observers to detect extravasation from the holes in the tubes (i.e., the branch arteries). Interobserver agreement was studied using Cohen's kappa statistic. The threshold to detect bleeding was as follows for each study: For IV contrast-enhanced MDCT (study 1), it was 0.35 mL/min; DSA with a catheter 10 cm proximal to the holes (study 2), 0.96 mL/min; DSA with a catheter at the holes (study 3), 0.05 mL/min [corrected] or lower; and intraarterial selective MDCT (study 4), 0.05 mL/min [corrected] or lower. The ease of detection improved with increasing MAPs and larger volumes of leakage. Interobserver correlation was excellent. In vitro, i.v. contrast-enhanced MDCT is more sensitive than first-order aortic branch-selective DSA in detecting active hemorrhage unless the catheter position is highly superselective and is close to the bleeding artery. These results suggest that MDCT can be used as the initial imaging technique in the diagnosis of active hemorrhage if the clinical condition of the patient allows.

Vertebral and femoral bone mineral density and bone strength in prostate cancer patients assessed in phantomless PET/CT examinations.

PubMed

Schwaiger, Benedikt J; Kopperdahl, David L; Nardo, Lorenzo; Facchetti, Luca; Gersing, Alexandra S; Neumann, Jan; Lee, Kwang J; Keaveny, Tony M; Link, Thomas M

2017-08-01

Bone fracture risk assessed ancillary to positron emission tomography with computed tomography co-registration (PET/CT) could provide substantial clinical value to oncology patients with elevated fracture risk without introducing additional radiation dose. The purpose of our study was to investigate the feasibility of obtaining valid measurements of bone mineral density (BMD) and finite element analysis-derived bone strength of the hip and spine using PET/CT examinations of prostate cancer patients by comparing against values obtained using routine multidetector-row computed tomography (MDCT) scans-as validated in previous studies-as a reference standard. Men with prostate cancer (n=82, 71.6±8.3 years) underwent Fluorine-18 NaF PET/CT and routine MDCT within three months. Femoral neck and total hip areal BMD, vertebral trabecular BMD and femur and vertebral strength based on finite element analysis were assessed in 63 paired PET/CT and MDCT examinations using phantomless calibration and Biomechanical-CT analysis. Men with osteoporosis or fragile bone strength identified at either the hip or spine (vertebral trabecular BMD ≤80mg/cm 3 , femoral neck or total hip T-score ≤-2.5, vertebral strength ≤6500N and femoral strength ≤3500N, respectively) were considered to be at high risk of fracture. PET/CT- versus MDCT-based BMD and strength measurements were compared using paired t-tests, linear regression and by generating Bland-Altman plots. Agreement in fracture-risk classification was assessed in a contingency table. All measurements from PET/CT versus MDCT were strongly correlated (R 2 =0.93-0.97; P<0.0001 for all). Mean differences for total hip areal BMD (0.001g/cm 2 , 1.1%), femoral strength (-60N, 1.3%), vertebral trabecular BMD (2mg/cm 3 , 2.6%) and vertebral strength (150N; 1.7%) measurements were not statistically significant (P>0.05 for all), whereas the mean difference in femoral neck areal BMD measurements was small but significant (-0.018g/cm 2 ; -2.5%; P=0.007). The agreement between PET/CT and MDCT for fracture-risk classification was 97% (0.89 kappa for repeatability). Ancillary analyses of BMD, bone strength, and fracture risk agreed well between PET/CT and MDCT, suggesting that PET/CT can be used opportunistically to comprehensively assess bone integrity. In subjects with high fracture risk such as cancer patients this may serve as an additional clinical tool to guide therapy planning and prevention of fractures. Copyright © 2017 Elsevier Inc. All rights reserved.

Cumulative doses analysis in young trauma patients: a single-centre experience.

PubMed

Salerno, Sergio; Marrale, Maurizio; Geraci, Claudia; Caruso, Giuseppe; Lo Re, Giuseppe; Lo Casto, Antonio; Midiri, Massimo

2016-02-01

Multidetector computed tomography (MDCT) represents the main source of radiation exposure in trauma patients. The radiation exposure of young patients is a matter of considerable medical concern due to possible long-term effects. Multiple MDCT studies have been observed in the young trauma population with an increase in radiation exposure. We have identified 249 young adult patients (178 men and 71 women; age range 14-40 years) who had received more than one MDCT study between June 2010 and June 2014. According to the International Commission on Radiological Protection publication, we have calculated the cumulative organ dose tissue-weighting factors by using CT-EXPO software(®). We have observed a mean cumulative dose of about 27 mSv (range from 3 to 297 mSv). The distribution analysis is characterised by low effective dose, below 20 mSv, in the majority of the patients. However, in 29 patients, the effective dose was found to be higher than 20 mSv. Dose distribution for the various organs analysed (breasts, ovaries, testicles, heart and eye lenses) shows an intense peak for lower doses, but in some cases high doses were recorded. Even though cumulative doses may have long-term effects, which are still under debate, high doses are observed in this specific group of young patients.

MDCT in the evaluation of skeletal trauma: principles, protocols, and clinical applications.

PubMed

Geijer, Mats; El-Khoury, Georges Y

2006-10-01

Multidetector computed tomography (MDCT) scanners have made volume imaging possible and are used extensively to study polytrauma patients, especially in the evaluation of the spine and peripheral skeleton. An MDCT scanner coupled with a modern workstation has become an essential diagnostic tool for any emergency department. Familiarity with the basic physical principles of MDCT such as projection data, section collimation, and beam collimation is important to achieve high-quality imaging while keeping unnecessary radiation to a minimum. After a polytrauma MDCT examination, images can be reconstructed to obtain different slice thickness, slice interval, fields of view, or reconstruction kernels. No additional scanning is needed for imaging the thoracolumbar spine or bony pelvis. High-quality multiplanar reformation (MPR) and three-dimensional (3-D) images can be created at the workstation using the volumetric data. However, MDCT is a high-dose examination, and care should be taken to use as low a dose as possible. In the musculoskeletal system, MDCT has long been used for evaluation of spinal and pelvic trauma; however, the frequency of its use in extremity trauma has been low. In the extremities, radiography seems to underestimate the extent and severity of injury, especially in complex areas such as the shoulder, elbow, wrist, knee, and ankle. MDCT in the extremities is helpful in fracture detection, evaluation, characterization, and treatment planning. The MPR images give excellent structural detail, and the 3-D images help in understanding the spatial relations, which is important for fracture classification and for preoperative planning. MDCT is also helpful in the follow-up of postoperative results, even in the presence of hardware. Tendon injuries can also be evaluated with MDCT.

Role of whole-body 64-slice multidetector computed tomography in treatment planning for multiple myeloma.

PubMed

Razek, Ahmed Abdel Khalek Abdel; Ezzat, Amany; Azmy, Emad; Tharwat, Nehal

2013-08-01

The authors evaluated the role of whole-body 64-slice multidetector computed tomography (WB-MDCT) in treatment planning for multiple myeloma. This was a prospective study of 28 consecutive patients with multiple myeloma (19 men, nine women; age range, 51-73 years; mean age, 60 years) who underwent WB-MDCT and conventional radiography (CR) of the skeleton. The images were interpreted for the presence of bony lesions, medullary lesions, fractures and extraosseous lesions. We evaluated any changes in treatment planning as a result of WB-MDCT findings. WB-MDCT was superior to CR for detecting bony lesions (p=0.001), especially of the spine (p=0.001) and thoracic cage (p=0.006). WB-MDCT upstaged 14 patients, with a significant difference in staging (p=0.002) between WB-MDCT and CR. Medullary involvement either focal (n=6) or diffuse (n=3) had a positive correlation with the overall score (r=0.790) and stage (r=0.618) of disease. Spine fractures were better detected at WB-MDCT (n=4) than at CR (n=2). Extraosseous soft tissue lesions (n=7) were detected only at WB-MDCT. Findings detected at the WB-MDCT led to changes in the patient's treatment plan in 39% of cases. Upstaging of seven patients (25%) altered the medical treatment plan, and four of 28 (14%) patients required additional radiotherapy (7%) and vertebroplasty (7%). We conclude that WB-MDCT has an impact on treatment planning and prognosis in patients with multiple myeloma, as it has high rate of detecting cortical and medullary bone lesions, spinal fracture and extraosseous lesions. This information may alter treatment planning in multiple myeloma due to disease upstaging and detection of spine fracture and extraosseous spinal lesions.

Accuracy of Monte Carlo simulations compared to in-vivo MDCT dosimetry.

PubMed

Bostani, Maryam; Mueller, Jonathon W; McMillan, Kyle; Cody, Dianna D; Cagnon, Chris H; DeMarco, John J; McNitt-Gray, Michael F

2015-02-01

The purpose of this study was to assess the accuracy of a Monte Carlo simulation-based method for estimating radiation dose from multidetector computed tomography (MDCT) by comparing simulated doses in ten patients to in-vivo dose measurements. MD Anderson Cancer Center Institutional Review Board approved the acquisition of in-vivo rectal dose measurements in a pilot study of ten patients undergoing virtual colonoscopy. The dose measurements were obtained by affixing TLD capsules to the inner lumen of rectal catheters. Voxelized patient models were generated from the MDCT images of the ten patients, and the dose to the TLD for all exposures was estimated using Monte Carlo based simulations. The Monte Carlo simulation results were compared to the in-vivo dose measurements to determine accuracy. The calculated mean percent difference between TLD measurements and Monte Carlo simulations was -4.9% with standard deviation of 8.7% and a range of -22.7% to 5.7%. The results of this study demonstrate very good agreement between simulated and measured doses in-vivo. Taken together with previous validation efforts, this work demonstrates that the Monte Carlo simulation methods can provide accurate estimates of radiation dose in patients undergoing CT examinations.

Assessment of In-Stent Restenosis Using 64-MDCT: Analysis of the CORE-64 Multicenter International Trial

PubMed Central

Wykrzykowska, Joanna J.; Arbab-Zadeh, Armin; Godoy, Gustavo; Miller, Julie M.; Lin, Shezhang; Vavere, Andrea; Paul, Narinder; Niinuma, Hiroyuki; Hoe, John; Brinker, Jeffrey; Khosa, Faisal; Sarwar, Sheryar; Lima, Joao; Clouse, Melvin E.

2012-01-01

OBJECTIVE Evaluations of stents by MDCT from studies performed at single centers have yielded variable results with a high proportion of unassessable stents. The purpose of this study was to evaluate the accuracy of 64-MDCT angiography (MDCTA) in identifying in-stent restenosis in a multicenter trial. MATERIALS AND METHODS The Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography Using 64 Detectors (CORE-64) Multicenter Trial and Registry evaluated the accuracy of 64-MDCTA in assessing 405 patients referred for coronary angiography. A total of 75 stents in 52 patients were assessed: 48 of 75 stents (64%) in 36 of 52 patients (69%) could be evaluated. The prevalence of in-stent restenosis by quantitative coronary angiography (QCA) in this subgroup was 23% (17/75). Eighty percent of the stents were ≤ 3.0 mm in diameter. RESULTS The overall sensitivity, specificity, positive predictive value, and negative predictive value to detect 50% in-stent stenosis visually using MDCT compared with QCA was 33.3%, 91.7%, 57.1%, and 80.5%, respectively, with an overall accuracy of 77.1% for the 48 assessable stents. The ability to evaluate stents on MDCTA varied by stent type: Thick-strut stents such as Bx Velocity were assessable in 50% of the cases; Cypher, 62.5% of the cases; and thinner-strut stents such as Taxus, 75% of the cases. We performed quantitative assessment of in-stent contrast attenuation in Hounsfield units and correlated that value with the quantitative percentage of stenosis by QCA. The correlation coefficient between the average attenuation decrease and ≥ 50% stenosis by QCA was 0.25 (p = 0.073). Quantitative assessment failed to improve the accuracy of MDCT over qualitative assessment. CONCLUSION The results of our study showed that 64-MDCT has poor ability to detect in-stent restenosis in small-diameter stents. Evaluability and negative predictive value were better in large-diameter stents. Thus, 64-MDCT may be appropriate for stent assessment in only selected patients. PMID:20028909

Diagnostic accuracy of 64-slice multidetector CT angiography for detection of in-stent restenosis of vertebral artery ostium stents: comparison with conventional angiography.

PubMed

Lee, Youn Joo; Lim, Yeon Soo; Lim, Hyun Wook; Yoo, Won Jong; Choi, Byung Gil; Kim, Bum Soo

2014-10-01

There are very few reports assessing in-stent restenosis (ISR) after vertebral artery ostium (VAO) stents using multidetector computed tomography (MDCT). To compare the diagnostic accuracy of computed tomography angiography (CTA) using 64-slice MDCT with digital subtraction angiography (DSA) for detection of significant ISR after VAO stenting. The study evaluated 57 VAO stents in 57 patients (39 men, 18 women; mean age 64 years [range, 48-90 years]). All stents were scanned with a 64-slice MDCT scanner. Three sets of images were reconstructed with three different convolution kernels. Two observers who were blinded to the results of DSA assessed the diagnostic accuracy of CTA for detecting significant ISR (≥50% diameter narrowing) of VAO stents in comparison with DSA as the reference standard. The sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. Of the 57 stents, 46 (81%) were assessable using CTA, while 11 (19%) were not. No stents with diameters ≤2.75 mm were assessable. DSA revealed 13 cases of significant ISR in all stents. The respective sensitivity, specificity, positive and negative predictive values, and accuracy were 92%, 82%, 60%, 97%, and 84% for all stents. On excluding the 11 non-assessable stents, the respective values were 88%, 95%, 78%, 97%, and 93%. Of the 46 CTA assessable stents, eight significant ISRs were diagnosed on DSA. Seven of eight patients with significant ISR by DSA were diagnosed correctly with CTA. The area under the receiver-operating characteristic curve (AUC) was 0.87 for all stents and 0.91 for assessable stents, indicating good to excellent agreement between CTA and DSA for detecting significant ISR after VAO stenting. Sixty-four-slice MDCT is a promising non-invasive method of assessing stent patency and can exclude significant ISR with high diagnostic values after VAO stenting. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Improving the performances of autofocus based on adaptive retina-like sampling model

NASA Astrophysics Data System (ADS)

Hao, Qun; Xiao, Yuqing; Cao, Jie; Cheng, Yang; Sun, Ce

2018-03-01

An adaptive retina-like sampling model (ARSM) is proposed to balance autofocusing accuracy and efficiency. Based on the model, we carry out comparative experiments between the proposed method and the traditional method in terms of accuracy, the full width of the half maxima (FWHM) and time consumption. Results show that the performances of our method are better than that of the traditional method. Meanwhile, typical autofocus functions, including sum-modified-Laplacian (SML), Laplacian (LAP), Midfrequency-DCT (MDCT) and Absolute Tenengrad (ATEN) are compared through comparative experiments. The smallest FWHM is obtained by the use of LAP, which is more suitable for evaluating accuracy than other autofocus functions. The autofocus function of MDCT is most suitable to evaluate the real-time ability.

Journal Club: Comparison of assessment of preoperative pulmonary vasculature in patients with non-small cell lung cancer by non-contrast- and 4D contrast-enhanced 3-T MR angiography and contrast-enhanced 64-MDCT.

PubMed

Ohno, Yoshiharu; Nishio, Mizuho; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Seki, Shinichiro; Sugimura, Kazuro

2014-03-01

The purpose of this article is to prospectively and directly compare the capabilities of non-contrast-enhanced MR angiography (MRA), 4D contrast-enhanced MRA, and contrast-enhanced MDCT for assessing pulmonary vasculature in patients with non-small cell lung cancer (NSCLC) before surgical treatment. A total of 77 consecutive patients (41 men and 36 women; mean age, 71 years) with pathologically proven and clinically assessed stage I NSCLC underwent thin-section contrast-enhanced MDCT, non-contrast-enhanced and contrast-enhanced MRA, and surgical treatment. The capability for anomaly assessment of the three methods was independently evaluated by two reviewers using a 5-point visual scoring system, and final assessment for each patient was made by consensus of the two readers. Interobserver agreement for pulmonary arterial and venous assessment was evaluated with the kappa statistic. Then, sensitivity, specificity, and accuracy for the detection of anomalies were directly compared among the three methods by use of the McNemar test. Interobserver agreement for pulmonary artery and vein assessment was substantial or almost perfect (κ=0.72-0.86). For pulmonary arterial and venous variation assessment, there were no significant differences in sensitivity, specificity, and accuracy among non-contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 50%; specificity, 98.5%; accuracy, 93.2%), 4D contrast-enhanced MRA (pulmonary arteries: sensitivity, 77.1%; specificity, 97.4%; accuracy, 87.7%; pulmonary veins: sensitivity, 62.5%; specificity, 100.0%; accuracy, 95.9%), and thin-section contrast-enhanced MDCT (pulmonary arteries: sensitivity, 91.4%; specificity, 89.5%; accuracy, 90.4%; pulmonary veins: sensitivity, 50%; specificity, 100.0%; accuracy, 95.9%) (p>0.05). Pulmonary vascular assessment of patients with NSCLC before surgical resection by non-contrast-enhanced MRA can be considered equivalent to that by 4D contrast-enhanced MRA and contrast-enhanced MDCT.

Pulmonary involvement in rheumatoid arthritis: multidetector computed tomography findings.

PubMed

Yuksekkaya, Ruken; Celikyay, Fatih; Yilmaz, Ayse; Arslan, Sule; Inanir, Ahmet; Inonu, Handan; Deniz, Caglar

2013-12-01

Pulmonary involvement in rheumatoid arthritis (RA) is common and encompasses a large spectrum of disease with different treatment options and prognoses. Therefore, assessment of these patients with multidetector computed tomography (MDCT) is vital. To evaluate the MDCT pulmonary findings of patients with RA and to compare these findings with the clinical status. Chest MDCT scans of 85 patients with RA between 2006-2012 were assessed. One patient with a pulmonary infection was excluded from the study. MDCT findings and distribution of the CT findings were examined, and patients were classified according to the predominant CT pattern. The pulmonary function test (PFT) results and categories, demographic characteristics, and clinical status of some of the patients for whom the results were obtained were evaluated, and the CT findings, PFT results, demographic characteristics, and clinical status were compared. The study group consisted of 20 men (mean age, 58.1 years ± 13.1; range, 15-77 years) and 64 women (mean age, 55.3 years ± 11.5; range, 30-84 years). The most frequent findings were nodules (78.6%) and pleural thickening (48.8%). The most common CT patterns were follicular bronchiolitis (FB) in 28 (33.3%) patients and nodular disease (ND) in 12 (14.3%) others. There was no statistically significant difference between the CT findings and PFT results, and no statistically significant difference was noted in the CT findings between symptomatic and asymptomatic patients. In addition, there were some patients who exhibited no symptoms and/or had abnormal PFT results but had abnormal CT findings. Rheumatoid arthritis is associated with a high frequency of CT findings and CT patterns, with nodules and pleural thickening being the most common CT findings and FB and ND being the most common CT patterns. MDCT identification of patients with RA may be helpful in the evaluation of pulmonary disease, even in patients without symptoms and PFT abnormalities.

Metallic artifacts from internal scaphoid fracture fixation screws: comparison between C-arm flat-panel, cone-beam, and multidetector computed tomography.

PubMed

Finkenstaedt, Tim; Morsbach, Fabian; Calcagni, Maurizio; Vich, Magdalena; Pfirrmann, Christian W A; Alkadhi, Hatem; Runge, Val M; Andreisek, Gustav; Guggenberger, Roman

2014-08-01

The aim of this study was to compare image quality and extent of artifacts from scaphoid fracture fixation screws using different computed tomography (CT) modalities and radiation dose protocols. Imaging of 6 cadaveric wrists with artificial scaphoid fractures and different fixation screws was performed in 2 screw positions (45° and 90° orientation in relation to the x/y-axis) using multidetector CT (MDCT) and 2 flat-panel CT modalities, C-arm flat-panel CT (FPCT) and cone-beam CT (CBCT), the latter 2 with low and standard radiation dose protocols. Mean cartilage attenuation and metal artifact-induced absolute Hounsfield unit changes (= artifact extent) were measured. Two independent radiologists evaluated different image quality criteria using a 5-point Likert-scale. Interreader agreements (Cohen κ) were calculated. Mean absolute Hounsfield unit changes and quality ratings were compared using Friedman and Wilcoxon signed-rank tests. Artifact extent was significantly smaller for MDCT and standard-dose FPCT compared with CBCT low- and standard-dose acquisitions (all P < 0.05). No significant differences in artifact extent among different screw types and scanning positions were noted (P > 0.05). Both MDCT and FPCT standard-dose protocols showed equal ratings for screw bone interface, fracture line, and trabecular bone evaluation (P = 0.06, 0.2, and 0.2, respectively) and performed significantly better than FPCT low- and CBCT low- and standard-dose acquisitions (all P < 0.05). Good interreader agreement was found for image quality comparisons (Cohen κ = 0.76-0.78). Both MDCT and FPCT standard-dose acquisition showed comparatively less metal-induced artifacts and better overall image quality compared with FPCT low-dose and both CBCT acquisitions. Flat-panel CT may provide sufficient image quality to serve as a versatile CT alternative for postoperative imaging of internally fixated wrist fractures.

Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans

PubMed Central

Shokri, Abbas; Bidgoli, Mohsen; Akbarzadeh, Mahdi; Ghazikhanlu-Sani, Karim; Fallahi-Sichani, Hamed

2018-01-01

Purpose This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. Materials and Methods A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. Results In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. Conclusion The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results. PMID:29581947

Blast and ballistic trajectories in combat casualties: a preliminary analysis using a cartesian positioning system with MDCT.

PubMed

Folio, Les R; Fischer, Tatjana; Shogan, Paul; Frew, Michael; Dwyer, Andrew; Provenzale, James M

2011-08-01

The purpose of this study is to determine the agreement with which radiologists identify wound paths in vivo on MDCT and calculate missile trajectories on the basis of Cartesian coordinates using a Cartesian positioning system (CPS). Three radiologists retrospectively identified 25 trajectories on MDCT in 19 casualties who sustained penetrating trauma in Iraq. Trajectories were described qualitatively in terms of directional path descriptors and quantitatively as trajectory vectors. Directional descriptors, trajectory angles, and angles between trajectories were calculated based on Cartesian coordinates of entrance and terminus or exit recorded in x, y image and table space (z) using a Trajectory Calculator created using spreadsheet software. The consistency of qualitative descriptor determinations was assessed in terms of frequency of observer agreement and multirater kappa statistics. Consistency of trajectory vectors was evaluated in terms of distribution of magnitude of the angles between vectors and the differences between their paraaxial and parasagittal angles. In 68% of trajectories, the observers' visual assessment of qualitative descriptors was congruent. Calculated descriptors agreed across observers in 60% of the trajectories. Estimated kappa also showed good agreement (0.65-0.79, p < 0.001); 70% of calculated paraaxial and parasagittal angles were within 20° across observers, and 61.3% of angles between trajectory vectors were within 20° across observers. Results show agreement of visually assessed and calculated qualitative descriptors and trajectory angles among observers. The Trajectory Calculator describes trajectories qualitatively similar to radiologists' visual assessment, showing the potential feasibility of automated trajectory analysis.

Reduction of thoracic aorta motion artifact with high-pitch 128-slice dual-source computed tomographic angiography: a historical control study.

PubMed

Nakagawa, Junichiro; Tasaki, Osamu; Watanabe, Yoshiyuki; Azuma, Takeo; Ohnishi, Mitsuo; Ukai, Isao; Tahara, Kenichi; Ogura, Hiroshi; Kuwagata, Yasuyuki; Hamasaki, Toshimitsu; Shimazu, Takeshi

2013-01-01

Electrocardiogram-gated imaging combined with multi-detector row computed tomography (MDCT) has reduced cardiac motion artifacts, but it was not practical in the emergency setting. The purpose of this study was to evaluate the ability of a high-pitch, 128-slice dual-source CT (DSCT) scanner to reduce motion artifacts in patients admitted to the emergency room. This study comprised 100 patients suspected of having thoracic aorta lesions. We examined 47 patients with the 128-slice DSCT scanner (DSCT group), and 53 patients were examined with a 64-slice MDCT scanner (MDCT group). Six anatomic areas in the thoracic aorta were evaluated. Computed tomography images in the DSCT group were distinct, and significant differences were observed in images of all areas between the 2 groups except for the descending aorta. The high-pitch DSCT scanner can reduce motion artifacts of the thoracic aorta and enable radiological diagnosis even in patients with tachycardia and without breath hold.

Multi-detector CT features of acute intestinal ischemia and their prognostic correlations.

PubMed

Moschetta, Marco; Telegrafo, Michele; Rella, Leonarda; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe

2014-05-28

Acute intestinal ischemia is an abdominal emergency occurring in nearly 1% of patients presenting with acute abdomen. The causes can be occlusive or non occlusive. Early diagnosis is important to improve survival rates. In most cases of late or missed diagnosis, the mortality rate from intestinal infarction is very high, with a reported value ranging from 60% to 90%. Multi-detector computed tomography (MDCT) is a fundamental imaging technique that must be promptly performed in all patients with suspected bowel ischemia. Thanks to the new dedicated reconstruction program, its diagnostic potential is much improved compared to the past and currently it is superior to that of any other noninvasive technique. The increased spatial and temporal resolution, high-quality multi-planar reconstructions, maximum intensity projections, vessel probe, surface-shaded volume rending and tissue transition projections make MDCT the gold standard for the diagnosis of intestinal ischemia, with reported sensitivity, specificity, positive and negative predictive values of 64%-93%, 92%-100%, 90%-100% and 94%-98%, respectively. MDCT contributes to appropriate treatment planning and provides important prognostic information thanks to its ability to define the nature and extent of the disease. The purpose of this review is to examine the diagnostic and prognostic role of MDCT in bowel ischemia with special regard to the state of art new reconstruction software.

Multidetector CT angiography in living donor renal transplantation: accuracy and discrepancies in right venous anatomy.

PubMed

Kulkarni, S; Emre, S; Arvelakis, A; Asch, W; Bia, M; Formica, R; Israel, G

2011-01-01

Multidetector computed tomography (MDCT) angiography is a reliable technique for assessing pre-operative renal anatomy in living kidney donors. The method has largely evolved into protocols that eliminate dedicated venous phase and instead utilize a combined arterial/venous phase to delineate arterial and venous anatomy simultaneously. Despite adoption of this protocol, there has been no study to assess its accuracy. To assess whether or not MDCT angiography compares favorably to intra-operative findings, 102 donors underwent MDCT angiography without a dedicated venous phase with surgical interpretation of renal anatomy. Anatomical variants included multiple arteries (12%), multiple veins (7%), early arterial bifurcation (13%), late venous confluence (5%), circumaortic renal veins (5%), retroaortic vein (1%), and ureteral duplication (2%). The sensitivity and specificity of multiple arterial anomalies were 100% and 97%, respectively. The sensitivity and specificity of multiple venous anomalies were 92% and 98%, respectively. The most common discrepancy was noted exclusively in the interpretation of right venous anatomy as it pertained to the renal vein/vena cava confluence (3%). MDCT angiography using a combined arterial/venous contrast-enhanced phase provides suitable depiction of renal donor anatomy. Careful consideration should be given when planning a right donor nephrectomy whether the radiographic interpretation is suggestive of a late confluence. © 2010 John Wiley & Sons A/S.

Accuracy of Monte Carlo simulations compared to in-vivo MDCT dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bostani, Maryam, E-mail: mbostani@mednet.ucla.edu; McMillan, Kyle; Cagnon, Chris H.

Purpose: The purpose of this study was to assess the accuracy of a Monte Carlo simulation-based method for estimating radiation dose from multidetector computed tomography (MDCT) by comparing simulated doses in ten patients to in-vivo dose measurements. Methods: MD Anderson Cancer Center Institutional Review Board approved the acquisition of in-vivo rectal dose measurements in a pilot study of ten patients undergoing virtual colonoscopy. The dose measurements were obtained by affixing TLD capsules to the inner lumen of rectal catheters. Voxelized patient models were generated from the MDCT images of the ten patients, and the dose to the TLD for allmore » exposures was estimated using Monte Carlo based simulations. The Monte Carlo simulation results were compared to the in-vivo dose measurements to determine accuracy. Results: The calculated mean percent difference between TLD measurements and Monte Carlo simulations was −4.9% with standard deviation of 8.7% and a range of −22.7% to 5.7%. Conclusions: The results of this study demonstrate very good agreement between simulated and measured doses in-vivo. Taken together with previous validation efforts, this work demonstrates that the Monte Carlo simulation methods can provide accurate estimates of radiation dose in patients undergoing CT examinations.« less

Accurate determination of high-risk coronary lesion type by multidetector cardiac computed tomography.

PubMed

Alasnag, Mirvat; Umakanthan, Branavan; Foster, Gary P

2008-07-01

Coronary arteriography (CA) is the standard method to image coronary lesions. Multidetector cardiac computerized tomography (MDCT) provides high-resolution images of coronary arteries, allowing a noninvasive alternative to determine lesion type. To date, no studies have assessed the ability of MDCT to categorize coronary lesion types. The objective of this study was to determine the accuracy of lesion type categorization by MDCT using CA as a reference standard. Patients who underwent both MDCT and CA within 2 months of each other were enrolled. MDCT and CA images were reviewed in a blinded fashion. Lesions were categorized according to the SCAI classification system (Types I-IV). The origin, proximal and middle segments of the major arteries were analyzed. Each segment comprised a data point for comparison. Analysis was performed using the Spearman Correlation Test. Four hundred eleven segments were studied, of which 110 had lesions. The lesion distribution was as follows: 35 left anterior descending (LAD), 29 circumflex (Cx), 31 right coronary artery (RCA), 2 ramus intermedius, 8 diagonal, 4 obtuse marginal and 2 left internal mammary arteries. Correlations between MDCT and CA were significant in all major vessels (LAD, Cx, RCA) (p < 0.001). The overall correlation coefficient was 0.67. Concordance was strong for lesion Types II-IV (97%) and poor for Type I (30%). High-risk coronary lesion types can be accurately categorized by MDCT. This ability may allow MDCT to play an important noninvasive role in the planning of coronary interventions.

Hepatocellular carcinoma in cirrhotic patients at multidetector CT: hepatic venous phase versus delayed phase for the detection of tumour washout

PubMed Central

Furlan, A; Marin, D; Vanzulli, A; Patera, G Palermo; Ronzoni, A; Midiri, M; Bazzocchi, M; Lagalla, R; Brancatelli, G

2011-01-01

Objectives Our aim was to compare retrospectively hepatic venous and delayed phase images for the detection of tumour washout during multiphasic multidetector row CT (MDCT) of the liver in patients with hepatocellular carcinoma (HCC). Methods 30 cirrhotic patients underwent multiphasic MDCT in the 90 days before liver transplantation. MDCT was performed before contrast medium administration and during hepatic arterial hepatic venous and delayed phases, images were obtained at 12, 55 and 120 s after trigger threshold. Two radiologists qualitatively evaluated images for lesion attenuation. Tumour washout was evaluated subjectively and objectively. Tumour-to-liver contrast (TLC) was measured for all pathologically proven HCCs. Results 48 HCCs were detected at MDCT. 46 of the 48 tumours (96%) appeared as either hyper- or isoattenuating during the hepatic arterial phase subjective washout was present in 15 HCCs (33%) during the hepatic venous phase and in 35 (76%) during the delayed phase (p<0.001, McNemar’s test). Objective washout was present in 30 of the 46 HCCs (65%) during the hepatic venous phase and in 42 of the HCCs (91%) during the delayed phase (p=0.001). The delayed phase yielded significantly higher mean TLC absolute values compared with the hepatic venous phase (−16.1±10.8 HU vs −10.5±10.2 HU; p<0.001). Conclusions The delayed phase is superior to the hepatic venous phase for detection of tumour washout of pathologically proven HCC in cirrhotic patients. PMID:21081569

Emergency radiology: straightening of the cervical spine in MDCT after trauma—a sign of injury or normal variant?

PubMed Central

Deak, Zsuszsanna; Krtakovska, Aina; Ruschi, Francesco; Kammer, Nora; Wirth, Stefan; Reiser, Maximilian; Geyer, Lucas

2016-01-01

Objective: To evaluate whether straightening of the cervical spine (C-spine) alignment after trauma can be considered a significant multidetector CT (MDCT) finding. Methods: 160 consecutive patients after C-spine trauma admitted to a Level 1 trauma centre received MDCT according to Canadian Cervical Spine Rule and National Emergency X-Radiography Utilization Study indication rule; subgroups with and without cervical collar immobilization (CCI +/−) were compared with a control group (n = 20) of non-traumatized patients. Two independent readers evaluated retrospectively the alignment, determined the absolute rotational angle of the posterior surface of C2 and C7 (ARA C2–7) and grouped the results for lordosis (<−13°), straight (−13 to +6°) and kyphosis (>+6°). Results: In the two CCI−/CCI+ study groups, the straight or kyphotic alignment significantly (p = 0.001) predominated over lordosis. The number of patients with straight C-spine alignment was higher in the CCI+ group (CCI+ 69% vs CCI− 49%, p = 0.05). A comparison of the CCI+ group vs the CCI− group revealed a slightly smaller number of kyphotic (10% vs 18%, p = 0.34) and lordotic (21% vs 33%, p = 0.33) alignments. Statistically, however, the differences were of no significance. The control group revealed no significant differences. Conclusion: Straightening of the C-spine alone is not a definitive sign of injury but is a biomechanical variation due to CCI and neck positioning during MDCT or active patient control. Advances in knowledge: Straightening of the C-spine alignment in MDCT alone is not a definitive sign of injury. Straightening of the C-spine alignment is related to neck positioning and active patient control. CCI has a straightening effect on the cervical alignment. PMID:26764283

Utility of 16-MDCT angiography for comprehensive preoperative vascular evaluation of laparoscopic renal donors.

PubMed

Raman, Steven S; Pojchamarnwiputh, Suwalee; Muangsomboon, Kobkun; Schulam, Peter G; Gritsch, H Albin; Lu, David S K

2006-06-01

Our objective was to determine the efficacy of 16-MDCT angiography in preoperative evaluation of vascular anatomy of laparoscopic renal donors. Fifty-five consecutive renal donors (25 men and 30 women) underwent 16-MDCT angiography followed by donor nephrectomy. In the arterial and nephrographic phases, images were acquired with 60% overlap and 0.6-mm reconstruction in both phases after 120 mL of iohexol was injected at 4 mL/sec. On a 3D workstation, images were evaluated retrospectively by two abdominal imagers blinded to surgical results with respect to number and branching pattern of renal arteries and major and minor renal veins. These CT angiography results were compared with surgical findings. The surgically confirmed sensitivity of both reviewers (1 and 2) using the MDCT data for detection of renal arteries was 98.5% (65 of 66), and accuracies were 97.0% for reviewer 1 and 95.5% for reviewer 2. Sensitivity and accuracy detection of renal veins was 97% (61 of 63) and 98% (62 of 63) for reviewer 1 and reviewer 2, respectively. Sensitivity and accuracy detection of early arterial bifurcation (< 2 cm from aorta) was 100% (14 of 14), and sensitivity in detection of late venous confluence (< 1.5 cm from aorta) was 100% (8 of 8). All major renal venous variants were identified; reviewer 1 identified 78% (18 of 23) minor venous variants, and reviewer 2 identified 83% (19 of 23) minor venous variants. There were no hemorrhagic complications at surgery. Excellent agreement between reviewers (kappa = 0.92-0.97) was achieved for detection of normal and variant anatomy. 16-MDCT angiography enabled excellent preoperative detection of arterial anatomy and venous laparoscopic donor nephrectomy.

Evaluation of prosthetic valve thrombosis by 64-row multi-detector computed tomography. .

PubMed

Tarzia, Vincenzo; Bortolussi, Giacomo; Rubino, Maurizio; Gallo, Michele; Bottio, Tomaso; Gerosa, Gino

2015-03-01

Multi-detector computed tomography (MDCT), combined with retrospective electrocardiographic gating, permits cardiac imaging with high accuracy. Recent advances in MDCT have seemed to respond adequately to the need for a non-invasive and reliable assessment of the coronary artery lumen. Two patients with prosthetic aortic valves (one bioprosthetic, one mechanical) presented at the authors' institution with dyspnea and syncopal episodes. MDCT was performed to evaluate thrombus characteristics and exclude coronary artery disease (CAD). Based on the MDCT coronary artery assessment, neither patient underwent preoperative invasive coronary angiography, abolishing the risk of any iatrogenic thrombus fragmentation and subsequent embolization. One patient underwent surgical treatment without complications, while medical therapy was successful in the other case. MDCT can be used for the accurate imaging of thrombi on prosthetic aortic valves, and to correctly assess possible CAD.

Visual vs Fully Automatic Histogram-Based Assessment of Idiopathic Pulmonary Fibrosis (IPF) Progression Using Sequential Multidetector Computed Tomography (MDCT)

PubMed Central

Colombi, Davide; Dinkel, Julien; Weinheimer, Oliver; Obermayer, Berenike; Buzan, Teodora; Nabers, Diana; Bauer, Claudia; Oltmanns, Ute; Palmowski, Karin; Herth, Felix; Kauczor, Hans Ulrich; Sverzellati, Nicola

2015-01-01

Objectives To describe changes over time in extent of idiopathic pulmonary fibrosis (IPF) at multidetector computed tomography (MDCT) assessed by semi-quantitative visual scores (VSs) and fully automatic histogram-based quantitative evaluation and to test the relationship between these two methods of quantification. Methods Forty IPF patients (median age: 70 y, interquartile: 62-75 years; M:F, 33:7) that underwent 2 MDCT at different time points with a median interval of 13 months (interquartile: 10-17 months) were retrospectively evaluated. In-house software YACTA quantified automatically lung density histogram (10th-90th percentile in 5th percentile steps). Longitudinal changes in VSs and in the percentiles of attenuation histogram were obtained in 20 untreated patients and 20 patients treated with pirfenidone. Pearson correlation analysis was used to test the relationship between VSs and selected percentiles. Results In follow-up MDCT, visual overall extent of parenchymal abnormalities (OE) increased in median by 5 %/year (interquartile: 0 %/y; +11 %/y). Substantial difference was found between treated and untreated patients in HU changes of the 40th and of the 80th percentiles of density histogram. Correlation analysis between VSs and selected percentiles showed higher correlation between the changes (Δ) in OE and Δ 40th percentile (r=0.69; p<0.001) as compared to Δ 80th percentile (r=0.58; p<0.001); closer correlation was found between Δ ground-glass extent and Δ 40th percentile (r=0.66, p<0.001) as compared to Δ 80th percentile (r=0.47, p=0.002), while the Δ reticulations correlated better with the Δ 80th percentile (r=0.56, p<0.001) in comparison to Δ 40th percentile (r=0.43, p=0.003). Conclusions There is a relevant and fully automatically measurable difference at MDCT in VSs and in histogram analysis at one year follow-up of IPF patients, whether treated or untreated: Δ 40th percentile might reflect the change in overall extent of lung abnormalities, notably of ground-glass pattern; furthermore Δ 80th percentile might reveal the course of reticular opacities. PMID:26110421

Abdominal 64-MDCT for suspected appendicitis: the use of oral and IV contrast material versus IV contrast material only.

PubMed

Anderson, Stephan W; Soto, Jorge A; Lucey, Brian C; Ozonoff, Al; Jordan, Jacqueline D; Ratevosian, Jirair; Ulrich, Andrew S; Rathlev, Niels K; Mitchell, Patricia M; Rebholz, Casey; Feldman, James A; Rhea, James T

2009-11-01

The objective of our study was to compare the diagnostic accuracy of IV contrast-enhanced 64-MDCT with and without the use of oral contrast material in diagnosing appendicitis in patients with abdominal pain. We conducted a randomized trial of a convenience sample of adult patients presenting to an urban academic emergency department with acute nontraumatic abdominal pain and clinical suspicion of appendicitis, diverticulitis, or small-bowel obstruction. Patients were enrolled between 8 am and 11 pm when research assistants were present. Consenting subjects were randomized into one of two groups: Group 1 subjects underwent 64-MDCT performed with oral and IV contrast media and group 2 subjects underwent 64-MDCT performed solely with IV contrast material. Three expert radiologists independently reviewed the CT examinations, evaluating for the presence of appendicitis. Each radiologist interpreted 202 examinations, ensuring that each examination was interpreted by two radiologists. Individual reader performance and a combined interpretation performance of the two readers assigned to each case were calculated. In cases of disagreement, the third reader was asked to deliver a tiebreaker interpretation to be used to calculate the combined reader performance. Final outcome was based on operative, clinical, and follow-up data. We compared radiologic diagnoses with clinical outcomes to calculate the diagnostic accuracy of CT in both groups. Of the 303 patients enrolled, 151 patients (50%) were randomized to group 1 and the remaining 152 (50%) were randomized to group 2. The combined reader performance for the diagnosis of appendicitis in group 1 was a sensitivity of 100% (95% CI, 76.8-100%) and specificity of 97.1% (95% CI, 92.7-99.2%). The performance in group 2 was a sensitivity of 100% (73.5-100%) and specificity of 97.1% (92.9-99.2%). Patients presenting with nontraumatic abdominal pain imaged using 64-MDCT with isotropic reformations had similar characteristics for the diagnosis of appendicitis when IV contrast material alone was used and when oral and IV contrast media were used.

The potential for non-invasive study of mummies: validation of the use of computerized tomography by post factum dissection and histological examination of a 17th century female Korean mummy

PubMed Central

Lim, Do-Seon; Lee, In Sun; Choi, Ki-Ju; Lee, Soong Deok; Oh, Chang Seok; Kim, Yi-Suk; Bok, Gi Dae; Kim, Myeung Ju; Yi, Yang Su; Lee, Eun-Joo; Shin, Dong Hoon

2008-01-01

The socio-cultural antipathies of some descendants with regard to invasive examinations of age-old human remains make permission for dissection of Korean mummies of the Joseon Dynasty (1392–1910) difficult to obtain. Overcoming this obstacle necessitated the use of non-invasive techniques, such as multi-detector computerized tomography (MDCT) and endoscopic examination, enabling determination of the preservation status of internal organs of mummies without significantly damaging the mummies themselves. However, MDCT alone cannot clearly differentiate specific mummified organs. Therefore, in much the same way as diagnostic radiologists make their MDCT readings on living patients more reliable by means of comparison with accumulated post-factum data from autopsies or histological studies, examinations of mummies by invasive techniques should not be decried as mere destruction of age-old human remains. Rather, providing that due permission from descendants and/or other relevant authorities can be obtained, dissection and histological examination should be performed whenever opportunities arise. Therefore, in this study, we compared the radiological data acquired from a 17th century mummy with our dissection results for the same subject. As accumulation of this kind of data could be very crucial for correct interpretation of MDCT findings on Korean mummies, we will perform similar trials on other Korean mummies found in forthcoming days if conditions permit. PMID:19014355

Two examples of indication specific radiation dose calculations in dental CBCT and Multidetector CT scanners.

PubMed

Stratis, Andreas; Zhang, Guozhi; Lopez-Rendon, Xochitl; Politis, Constantinus; Hermans, Robert; Jacobs, Reinhilde; Bogaerts, Ria; Shaheen, Eman; Bosmans, Hilde

2017-09-01

To calculate organ doses and estimate the effective dose for justification purposes in patients undergoing orthognathic treatment planning purposes and temporal bone imaging in dental cone beam CT (CBCT) and Multidetector CT (MDCT) scanners. The radiation dose to the ICRP reference male voxel phantom was calculated for dedicated orthognathic treatment planning acquisitions via Monte Carlo simulations in two dental CBCT scanners, Promax 3D Max (Planmeca, FI) and NewTom VGi evo (QR s.r.l, IT) and in Somatom Definition Flash (Siemens, DE) MDCT scanner. For temporal bone imaging, radiation doses were calculated via MC simulations for a CBCT protocol in NewTom 5G (QR s.r.l, IT) and with the use of a software tool (CT-expo) for Somatom Force (Siemens, DE). All procedures had been optimized at the acceptance tests of the devices. For orthognathic protocols, dental CBCT scanners deliver lower doses compared to MDCT scanners. The estimated effective dose (ED) was 0.32mSv for a normal resolution operation mode in Promax 3D Max, 0.27mSv in VGi-evo and 1.18mSv in the Somatom Definition Flash. For temporal bone protocols, the Somatom Force resulted in an estimated ED of 0.28mSv while for NewTom 5G the ED was 0.31 and 0.22mSv for monolateral and bilateral imaging respectively. Two clinical exams which are carried out with both a CBCT or a MDCT scanner were compared in terms of radiation dose. Dental CBCT scanners deliver lower doses for orthognathic patients whereas for temporal bone procedures the doses were similar. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference.

PubMed

Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Abe, Takayuki; Kuribayashi, Sachio; Ogawa, Kenji

2013-08-01

To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA-950) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P < 0.0001) of tomosynthesis than radiography for the detection of pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA-950. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA-950. • Tomosynthesis showed significantly better diagnostic performance for pulmonary emphysema than radiography. • Interobserver agreement for tomosynthesis was significantly higher than that for radiography. • Sensitivity increased with increasing LAA -950 in both tomosynthesis and radiography. • Tomosynthesis imparts a similar radiation dose to two projection chest radiography. • Radiation dose and cost of tomosynthesis are lower than those of MDCT.

Influence of detector collimation on SNR in four different MDCT scanners using a reconstructed slice thickness of 5 mm.

PubMed

Verdun, F R; Noel, A; Meuli, R; Pachoud, M; Monnin, P; Valley, J-F; Schnyder, P; Denys, A

2004-10-01

The purpose of this paper is to compare the influence of detector collimation on the signal-to-noise ratio (SNR) for a 5.0 mm reconstructed slice thickness for four multi-detector row CT (MDCT) units. SNRs were measured on Catphan test phantom images from four MDCT units: a GE LightSpeed QX/I, a Marconi MX 8000, a Toshiba Aquilion and a Siemens Volume Zoom. Five-millimetre-thick reconstructed slices were obtained from acquisitions performed using detector collimations of 2.0-2.5 mm and 5.0 mm, 120 kV, a 360 degrees tube rotation time of 0.5 s, a wide range of mA and pitch values in the range of 0.75-0.85 and 1.25-1.5. For each set of acquisition parameters, a Wiener spectrum was also calculated. Statistical differences in SNR for the different acquisition parameters were evaluated using a Student's t-test (P<0.05). The influence of detector collimation on the SNR for a 5.0-mm reconstructed slice thickness is different for different MDCT scanners. At pitch values lower than unity, the use of a small detector collimation to produce 5.0-mm thick slices is beneficial for one unit and detrimental for another. At pitch values higher than unity, using a small detector collimation is beneficial for two units. One manufacturer uses different reconstruction filters when switching from a 2.5- to a 5.0-mm detector collimation. For a comparable reconstructed slice thickness, using a smaller detector collimation does not always reduce image noise. Thus, the impact of the detector collimation on image noise should be determined by standard deviation calculations, and also by assessing the power spectra of the noise. Copyright 2004 Springer-Verlag

Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings.

PubMed

Di Grezia, G; Gatta, G; Rella, R; Donatello, D; Falco, G; Grassi, R; Grassi, R

2017-01-01

Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today's experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical intervention or clinical follow-up. The clinical presentation of this illness is frequently nonspecific: abdominal pain, distension, nausea, fever, rectal bleeding, vomiting, constipation, or a palpable mass, depending on the disease. A proper differential diagnosis is essential in the assessment of treatment and in this case MDCT exam plays a central rule. We wish that this article will familiarize the radiologist in the diagnosis of this kind of incidental MDCT findings for better orientation of the therapy.

64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model

PubMed Central

Holalkere, N-S; Matthes, K; Kalva, S P; Brugge, W R; Sahani, D V

2011-01-01

Objective In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml–1) and high-concentration contrast media (HCCM) (370 mg I ml–1) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose. Methods CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml–1), Group B (HCCM; 370 mg I ml–1) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg–1) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test. Results The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose. Conclusion 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced. PMID:21081582

Periportal low attenuation associated with liver metastasis from colorectal cancer: evaluation using multi-detector-row CT with pathological correlation.

PubMed

Takaji, Ryo; Matsumoto, Shunro; Kiyonaga, Maki; Yamada, Yasunari; Mori, Hiromu; Iwashita, Yukio; Ohta, Masayuki; Inomata, Masafumi; Hijiya, Naoki; Moriyama, Masatsugu; Takaki, Hajime; Fukuzawa, Kengo; Yonemasu, Hirotoshi

2017-01-01

Periportal low attenuation (PPLA) associated with metastatic liver cancer is occasionally seen on multi-detector-row CT (MDCT). The purpose of this study was to investigate the MDCT patterns of the PPLA and to correlate it with pathological findings. We retrospectively reviewed the MDCT images of 63 patients with metastatic liver cancers from colorectal adenocarcinoma. On MDCT scans, PPLA associated with liver metastasis was visualized in six patients with colorectal cancer. In these six patients who had undergone surgical resection, the radiologic-pathologic correlation was analyzed. All patients underwent a single contrast-enhanced MDCT within 1 month before surgical resection. The six liver cancers were pathologically proven to be moderately differentiated adenocarcinoma. We assessed the PPLA on MDCT concerning the distribution patterns and contrast enhancement with pathological correlation. In five of the patients, the PPLA extended to the hilar side from metastatic liver cancer. Pathologically, there was no cancer invasion into the intra-hepatic periportal area; however, massive lymphedema and fibrosis occurred in all six cases. PPLA on the hilar and peripheral sides of hepatic metastasis from colorectal cancer may be present suggesting lymphedema and fibrosis of portal tracts not always indicating cancer infiltration.

Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

PubMed Central

Kim, Jong Gyu

2012-01-01

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

3D ECG- and respiratory-gated non-contrast-enhanced (CE) perfusion MRI for postoperative lung function prediction in non-small-cell lung cancer patients: A comparison with thin-section quantitative computed tomography, dynamic CE-perfusion MRI, and perfusion scan.

PubMed

Ohno, Yoshiharu; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Takenaka, Daisuke; Kassai, Yoshimori; Yui, Masao; Sugimura, Kazuro

2015-08-01

To compare predictive capabilities of non-contrast-enhanced (CE)- and dynamic CE-perfusion MRIs, thin-section multidetector computed tomography (CT) (MDCT), and perfusion scan for postoperative lung function in non-small cell lung cancer (NSCLC) patients. Sixty consecutive pathologically diagnosed NSCLC patients were included and prospectively underwent thin-section MDCT, non-CE-, and dynamic CE-perfusion MRIs and perfusion scan, and had their pre- and postoperative forced expiratory volume in one second (FEV1 ) measured. Postoperative percent FEV1 (po%FEV1 ) was then predicted from the fractional lung volume determined on semiquantitatively assessed non-CE- and dynamic CE-perfusion MRIs, from the functional lung volumes determined on quantitative CT, from the number of segments observed on qualitative CT, and from uptakes detected on perfusion scans within total and resected lungs. Predicted po%FEV1 s were then correlated with actual po%FEV1 s, which were %FEV1 s measured postoperatively. The limits of agreement were also determined. All predicted po%FEV1 s showed significant correlation (0.73 ≤ r ≤ 0.93, P < 0.0001) and limits of agreement with actual po%FEV1 (non-CE-perfusion MRI: 0.3 ± 10.0%, dynamic CE-perfusion MRI: 1.0 ± 10.8%, perfusion scan: 2.2 ± 14.1%, quantitative CT: 1.2 ± 9.0%, qualitative CT: 1.5 ± 10.2%). Non-CE-perfusion MRI may be able to predict postoperative lung function more accurately than qualitatively assessed MDCT and perfusion scan. © 2014 Wiley Periodicals, Inc.

Multi-detector CT angiography of the aortic valve—Part 2: disease specific findings

PubMed Central

Ganeshan, Arul

2014-01-01

The aortic valve and adjacent structures should be routinely evaluated on all thoracic cross-sectional imaging studies. Echocardiography and magnetic resonance imaging (MRI) are the main imaging techniques used for assessment of the aortic valve and related pathology but multi-detector computed tomography (MDCT) can offer valuable complimentary information in some clinical scenarios. MDCT is the definite means of assessing aortic valvular calcification, acute aortic syndrome and for non-invasive assessment of the coronary arteries. MDCT also has an emerging role in the planning and follow-up of trans-catheter aortic valve replacement. This article reviews the spectrum of aortic valve disease highlighting the key MDCT imaging features. PMID:25202663

Dose reduction in whole-body computed tomography of multiple injuries (DoReMI): protocol for a prospective cohort study

PubMed Central

2014-01-01

Background Single-pass, contrast-enhanced whole body multidetector computed tomography (MDCT) emerged as the diagnostic standard for evaluating patients with major trauma. Modern iterative image algorithms showed high image quality at a much lower radiation dose in the non-trauma setting. This study aims at investigating whether the radiation dose can safely be reduced in trauma patients without compromising the diagnostic accuracy and image quality. Methods/Design Prospective observational study with two consecutive cohorts of patients. Setting: A high-volume, academic, supra-regional trauma centre in Germany. Study population: Consecutive male and female patients who 1. had been exposed to a high-velocity trauma mechanism, 2. present with clinical evidence or high suspicion of multiple trauma (predicted Injury Severity Score [ISS] ≥16) and 3. are scheduled for primary MDCT based on the decision of the trauma leader on call. Imaging protocols: In a before/after design, a consecutive series of 500 patients will undergo single-pass, whole-body 128-row multi-detector computed tomography (MDCT) with a standard, as low as possible radiation dose. This will be followed by a consecutive series of 500 patients undergoing an approved ultra-low dose MDCT protocol using an image processing algorithm. Data: Routine administrative data and electronic patient records, as well as digital images stored in a picture archiving and communications system will serve as the primary data source. The protocol was approved by the institutional review board. Main outcomes: (1) incidence of delayed diagnoses, (2) diagnostic accuracy, as correlated to the reference standard of a synopsis of all subsequent clinical, imaging, surgical and autopsy findings, (3) patients’ safety, (4) radiation exposure (e.g. effective dose), (5) subjective image quality (assessed independently radiologists and trauma surgeons on a 100-mm visual analogue scale), (6) objective image quality (e.g., contrast-to-noise ratio). Analysis: Multivariate regression will be employed to adjust and correct the findings for time and cohort effects. An exploratory interim analysis halfway after introduction of low-dose MDCT will be conducted to assess whether this protocol is clearly inferior or superior to the current standard. Discussion Although non-experimental, this study will generate first large-scale data on the utility of imaging-enhancing algorithms in whole-body MDCT for major blunt trauma. Trial registration Current Controlled Trials ISRCTN74557102. PMID:24589310

Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings

PubMed Central

Gatta, G.; Rella, R.; Donatello, D.; Falco, G.; Grassi, R.

2017-01-01

Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today's experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical intervention or clinical follow-up. The clinical presentation of this illness is frequently nonspecific: abdominal pain, distension, nausea, fever, rectal bleeding, vomiting, constipation, or a palpable mass, depending on the disease. A proper differential diagnosis is essential in the assessment of treatment and in this case MDCT exam plays a central rule. We wish that this article will familiarize the radiologist in the diagnosis of this kind of incidental MDCT findings for better orientation of the therapy. PMID:28638830

State-of-the-Art Diagnosis and Treatment of Melanoma: Optimal Multidetector Computed Tomographic Practice to Identify Metastatic Disease and Review of Innovative Therapeutic Agents.

PubMed

Jones, Blake C; Lipson, Evan J; Childers, Brandon; Fishman, Elliot K; Johnson, Pamela T

The incidence of melanoma has risen dramatically over the past several decades. Oncologists rely on the ability of radiologists to identify subtle radiographic changes representing metastatic and recurrent melanoma in uncommon locations on multidetector computed tomography (MDCT) as the front-line imaging surveillance tool. To accomplish this goal, MDCT acquisition and display must be optimized and radiologist interpretation and search patterns must be tailored to identify the unique and often subtle metastatic lesions of melanoma. This article describes MDCT acquisition and display techniques that optimize the visibility of melanoma lesions, such as high-contrast display windows and multiplanar reconstructions. In addition, innovative therapies for melanoma, such as immunotherapy and small-molecule therapy, have altered clinical management and outcomes and have also changed the spectrum of therapeutic complications that can be detected on MDCT. Recent advances in melanoma therapy and potential complications that the radiologist can identify on MDCT are reviewed.

Controversies in imaging of hepatocellular carcinoma: multidetector CT (MDCT)

PubMed Central

Silverman, Paul M; Szklaruk, Janio

2005-01-01

Primary hepatocellular carcinoma (HCC) is a significant tumor worldwide and represents the most common primary hepatic neoplasm. Staging criteria are important for appreciation of timely work up of these neoplasms in contradiction with surgical colleagues. This article demonstrates the appearance of HCC on multiphasic, multidetector CT (MDCT) and relates these findings to current staging criteria. The variable appearance on different planes of contrast is critical to appreciate in staging this neoplasm. The hypervascular nature of the primary tumor makes MDCT and three-phase imaging a critical feature in the detection and characterization of this tumor. This is especially critical in the patients who are candidates for surgical resection. Additionally, MDCT has allowed arterial phase imaging to define the vascular supply of the tumor. An accurate representation of the size and number of lesions is critical in not only the initial staging but also the follow-up of hepatocellular carcinoma. The post-treatment features including the appearance post-surgically and after radiofrequency ablation can be well appreciated on MDCT. PMID:16361147

Reduction of effective dose and organ dose to the eye lens in head MDCT using iterative image reconstruction and automatic tube current modulation.

PubMed

Ryska, Pavel; Kvasnicka, Tomas; Jandura, Jiri; Klzo, Ludovit; Grepl, Jakub; Zizka, Jan

2014-06-01

To compare the effective and eye lens radiation dose in helical MDCT brain examinations using automatic tube current modulation in conjunction with either standard filtered back projection (FBP) technique or iterative reconstruction in image space (IRIS). Of 400 adult brain MDCT examinations, 200 were performed using FBP and 200 using IRIS with the following parameters: tube voltage 120 kV, rotation period 1 second, pitch factor 0.55, automatic tube current modulation in both transverse and longitudinal planes with reference mAs 300 (FBP) and 200 (IRIS). Doses were calculated from CT dose index and dose length product values utilising ImPACT software; the organ dose to the lens was derived from the actual tube current-time product value applied to the lens. Image quality was assessed by two independent readers blinded to the type of image reconstruction technique. The average effective scan dose was 1.47±0.26 mSv (FBP) and 0.98±0.15 mSv (IRIS), respectively (33.3% decrease). The average organ dose to the eye lens decreased from 40.0±3.3 mGy (FBP) to 26.6±2.0 mGy (IRIS, 33.5% decrease). No significant change in diagnostic image quality was noted between IRIS and FBP scans (P=0.17). Iterative reconstruction of cerebral MDCT examinations enables reduction of both effective and organ eye lens dose by one third without signficant loss of image quality.

Comparison of hepatic MDCT, MRI, and DSA to explant pathology for the detection and treatment planning of hepatocellular carcinoma.

PubMed

Ladd, Lauren M; Tirkes, Temel; Tann, Mark; Agarwal, David M; Johnson, Matthew S; Tahir, Bilal; Sandrasegaran, Kumaresan

2016-12-01

The diagnosis and treatment plan for hepatocellular carcinoma (HCC) can be made from radiologic imaging. However, lesion detection may vary depending on the imaging modality. This study aims to evaluate the sensitivities of hepatic multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) in the detection of HCC and the consequent management impact on potential liver transplant patients. One hundred and sixteen HCC lesions were analyzed in 41 patients who received an orthotopic liver transplant (OLT). All of the patients underwent pretransplantation hepatic DSA, MDCT, and/or MRI. The imaging results were independently reviewed retrospectively in a blinded fashion by two interventional and two abdominal radiologists. The liver explant pathology was used as the gold standard for assessing each imaging modality. The sensitivity for overall HCC detection was higher for cross-sectional imaging using MRI (51.5%, 95% confidence interval [CI]=36.2-58.4%) and MDCT (49.8%, 95% CI=43.7-55.9%) than for DSA (41.7%, 95% CI=36.2-47.3%) ( P =0.05). The difference in false-positive rate was not statistically significant between MRI (22%), MDCT (29%), and DSA (29%) ( P =0.67). The sensitivity was significantly higher for detecting right lobe lesions than left lobe lesions for all modalities (MRI: 56.1% vs. 43.1%, MDCT: 55.0% vs. 42.0%, and DSA: 46.9% vs. 33.9%; all P <0.01). The sensitivities of the three imaging modalities were also higher for lesions ≥2 cm vs. <2 cm (MRI: 73.4% vs. 32.7%, MDCT: 66.9% vs. 33.8%, and DSA: 62.2% vs. 24.1%; all P <0.01). The interobserver correlation was rated as very good to excellent. The sensitivity for detecting HCC is higher for MRI and MDCT than for DSA, and so cross-sectional imaging modalities should be used to evaluate OLT candidacy.

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose

PubMed Central

Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

2015-01-01

Objectives To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. Methods 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Results Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Conclusion Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels. PMID:26288186

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

PubMed

Wenz, Holger; Maros, Máté E; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

2015-01-01

To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

Scalar localization of the electrode array after cochlear implantation: clinical experience using 64-slice multidetector computed tomography.

PubMed

Lane, John I; Witte, Robert J; Driscoll, Colin L W; Shallop, Jon K; Beatty, Charles W; Primak, Andrew N

2007-08-01

To use the improved resolution available with 64-slice multidetector computed tomography (MDCT) in vivo to localize the cochlear implant electrode array within the basal turn. Sixty-four-slice MDCT examinations of the temporal bones were retrospectively reviewed in 17 patients. Twenty-three implants were evaluated. Tertiary referral facility. All patients with previous cochlear implantation evaluated at our center between January 2004 and March 2006 were offered a computed tomographic examination as part of the study. In addition, preoperative computed tomographic examinations in patients being evaluated for a second bilateral device were included. Sixty-four-slice MDCT examination of the temporal bones. Localization of the electrode array within the basal turn from multiplanar reconstructions of the cochlea. Twenty-three implants were imaged in 17 patients. We were able to localize the electrode array within the scala tympani within the basal turn in 10 implants. In 3 implants, the electrode array was localized to the scala vestibuli. Migration of the electrode array from scala tympani to scala vestibuli was observed in three implants. Of the 7 implants in which localization of the electrode array was indeterminate, all had disease entities that obscured the definition of the normal cochlear anatomy. Sixty-four-slice MDCT with multiplanar reconstructions of the postoperative cochlea after cochlear implantation allows for accurate localization of the electrode array within the basal turn where normal cochlear anatomy is not obscured by the underlying disease process. Correlating the position of the electrode in the basal turn with surgical technique and implant design could be helpful in improving outcomes.

The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and the fetus using Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Gu, J.; Bednarz, B.; Caracappa, P. F.; Xu, X. G.

2009-05-01

The latest multiple-detector technologies have further increased the popularity of x-ray CT as a diagnostic imaging modality. There is a continuing need to assess the potential radiation risk associated with such rapidly evolving multi-detector CT (MDCT) modalities and scanning protocols. This need can be met by the use of CT source models that are integrated with patient computational phantoms for organ dose calculations. Based on this purpose, this work developed and validated an MDCT scanner using the Monte Carlo method, and meanwhile the pregnant patient phantoms were integrated into the MDCT scanner model for assessment of the dose to the fetus as well as doses to the organs or tissues of the pregnant patient phantom. A Monte Carlo code, MCNPX, was used to simulate the x-ray source including the energy spectrum, filter and scan trajectory. Detailed CT scanner components were specified using an iterative trial-and-error procedure for a GE LightSpeed CT scanner. The scanner model was validated by comparing simulated results against measured CTDI values and dose profiles reported in the literature. The source movement along the helical trajectory was simulated using the pitch of 0.9375 and 1.375, respectively. The validated scanner model was then integrated with phantoms of a pregnant patient in three different gestational periods to calculate organ doses. It was found that the dose to the fetus of the 3 month pregnant patient phantom was 0.13 mGy/100 mAs and 0.57 mGy/100 mAs from the chest and kidney scan, respectively. For the chest scan of the 6 month patient phantom and the 9 month patient phantom, the fetal doses were 0.21 mGy/100 mAs and 0.26 mGy/100 mAs, respectively. The paper also discusses how these fetal dose values can be used to evaluate imaging procedures and to assess risk using recommendations of the report from AAPM Task Group 36. This work demonstrates the ability of modeling and validating an MDCT scanner by the Monte Carlo method, as well as assessing fetal and organ doses by combining the MDCT scanner model and the pregnant patient phantom.

Early detection of coronary artery disease by 64-slice multidetector computed tomography in asymptomatic hypertensive high-risk patients.

PubMed

Gaudio, Carlo; Mirabelli, Francesca; Pelliccia, Francesco; Francone, Marco; Tanzilli, Gaetano; Di Michele, Sara; Leonetti, Stefania; De Vincentis, Giuseppe; Carbone, Iacopo; Mangieri, Enrico; Catalano, Carlo; Passariello, Roberto

2009-07-10

The 64-slice multidetector-row computed tomography (MDCT) is an accurate noninvasive technique for assessing the degree of luminal narrowing in coronary arteries of patients with chronic ischemic disease. Aim of this study was to determine the value of MDCT in comparison to invasive coronary angiography (ICA) for detecting the presence and extent of coronary atherosclerotic plaques in a population of asymptomatic, hypertensive patients considered to be at high risk for cardiovascular events. We studied 67 asymptomatic, hypertensive patients at high-risk (Euro Score >5%). All patients had negative or nondiagnostic findings at exercise stress testing and therefore underwent both MDCT and ICA. In the per-patient analysis, MDCT correctly identified 16/17 (94%) patients with significant coronary artery disease involving at least 1 vessel and 48/50 (96%) normal subjects. In the per-segment analysis, MDCT correctly detected 21/22 (95%) coronary segments with a stenosis >or=50% and 856/868 (98%) normal segments, with a high negative predictivity of normal scans (100%). There was a good concordance between MDCT and ICA, with a high Pearson correlation coefficient between the coronary narrowings with the two techniques (r=0.84, p<0.01). Mean coronary calcium score was higher for the 17 patients with significant coronary artery disease on ICA than in the 50 patients without (422+/-223 HU vs 72+/-21 HU p<0.001). The ROC curves identified 160 as the best calcium volumetric score cut-off value able to identify >or=1 significant coronary stenosis with sensitivity 88% and specificity 85%. MDCT is an excellent noninvasive technique for early identification of significant coronary stenoses in high risk asymptomatic hypertensive patients and might provide unique information for the screening of this broad population.

Head multidetector computed tomography: emergency medicine physicians overestimate the pretest probability and legal risk of significant findings.

PubMed

Baskerville, Jerry Ray; Herrick, John

2012-02-01

This study focuses on clinically assigned prospective estimated pretest probability and pretest perception of legal risk as independent variables in the ordering of multidetector computed tomographic (MDCT) head scans. Our primary aim is to measure the association between pretest probability of a significant finding and pretest perception of legal risk. Secondarily, we measure the percentage of MDCT scans that physicians would not order if there was no legal risk. This study is a prospective, cross-sectional, descriptive analysis of patients 18 years and older for whom emergency medicine physicians ordered a head MDCT. We collected a sample of 138 patients subjected to head MDCT scans. The prevalence of a significant finding in our population was 6%, yet the pretest probability expectation of a significant finding was 33%. The legal risk presumed was even more dramatic at 54%. These data support the hypothesis that physicians presume the legal risk to be significantly higher than the risk of a significant finding. A total of 21% or 15% patients (95% confidence interval, ±5.9%) would not have been subjected to MDCT if there was no legal risk. Physicians overestimated the probability that the computed tomographic scan would yield a significant result and indicated an even greater perceived medicolegal risk if the scan was not obtained. Physician test-ordering behavior is complex, and our study queries pertinent aspects of MDCT testing. The magnification of legal risk vs the pretest probability of a significant finding is demonstrated. Physicians significantly overestimated pretest probability of a significant finding on head MDCT scans and presumed legal risk. Copyright © 2012 Elsevier Inc. All rights reserved.

Gd-EOB-DTPA-enhanced MRI is better than MDCT in decision making of curative treatment for hepatocellular carcinoma.

PubMed

Yoo, Sun Hong; Choi, Jong Young; Jang, Jeong Won; Bae, Si Hyun; Yoon, Seung Kew; Kim, Dong Goo; Yoo, Young Kyoung; Rha, Sung Eun; Lee, Young Joon; Jung, Eun Sun

2013-09-01

We assessed the change in the therapeutic decision among curative treatments after adding Gd-EOB-DTPA-enhanced MRI to triple-phase MDCT for patients with early-stage HCC. This study retrospectively investigated two groups: 33 pathologically confirmed HCC patients after liver transplantation in group 1; 34 HCC patients without pathology in group 2. In group 1, we simulated the therapeutic decision-making process by pretransplant MDCT and Gd-EOB-DTPA-enhanced MRI. In group 2, including the 34 early-stage HCC patients consecutively enrolled, we investigated the change of therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT. In the simulation from group 1, after adding Gd-EOB-DTPA-enhanced MRI, 33.3% (11/33 patients) of treatment decisions were changed from the decision based on MDCT alone. Among 22 patients considered eligible for resection and 33 patients for radiofrequency ablation, the therapeutic decision was changed for 10 patients in the surgical group and 4 patients for the RFA group (45.5 and 12.1%). In group 2, the rate of change in the therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT was 41.2% (14/34 patients). In group 1 with explants pathology, the median diameter of HCCs not detected by MDCT but detected by Gd-EOB-DTPA-enhanced MRI was 1.15 cm (0.3-3.0 cm). The median diameter of HCCs seen only in the explanted liver was 1.0 cm (0.3-1.7 cm), and 60.7% of them were well-differentiated HCCs. This study suggests that performing Gd-EOB-DTPA-enhanced MRI before deciding on curative treatment for early-stage HCC may improve the accuracy of treatment decision for early-stage HCC.

Mitral Annular Calcium and Mitral Stenosis Determined by Multidetector Computed Tomography in Patients Referred for Aortic Stenosis.

PubMed

Mejean, Simon; Bouvier, Erik; Bataille, Vincent; Seknadji, Patrick; Fourchy, Dominique; Tabet, Jean-Yves; Lairez, Olivier; Cormier, Bertrand

2016-10-15

Mitral annular calcium (MAC) is a common finding in older patients referred for transcatheter aortic valve implantation (TAVI). Multidetector computed tomography (MDCT) allows fine quantification of the calcific deposits. Our objective was to estimate the prevalence of MAC and associated mitral stenosis (MS) in patients referred for TAVI using MDCT. A cohort of 346 consecutive patients referred for TAVI evaluation was screened by MDCT for MAC: 174 had MAC (50%). Of these patients, 165 patients (95%) had mitral valve area (MVA) assessable by MDCT planimetry (age 83.8 ± 5.9 years). Median mitral calcium volume and MVA were 545 mm 3 (193 to 1,253 mm 3 ) and 234 mm 2 (187 to 297 mm 2 ), respectively. The MS was very severe, severe, and moderate in 2%, 22%, and 10% patients, respectively. By multivariate analysis, MVA was independently correlated to mitral calcium volume, aortic annular area, and some specific patterns of mitral leaflet calcium. Based on these findings, a formula was elaborated to predict the presence of a significant MS. In conclusion, MDCT allows detailed assessment of MAC in TAVI populations, demonstrating a high prevalence. Mitral analysis should become routine during MDCT screening before TAVI as it may alter therapeutic strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection of biliary and vascular anatomy in living liver donors: value of gadobenate dimeglumine enhanced MR and MDCT angiography.

PubMed

Artioli, Diana; Tagliabue, Marianna; Aseni, Paolo; Sironi, Sandro; Vanzulli, Angelo

2010-11-01

To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard. Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference. At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%. MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Evaluation of cardiovascular anomalies in patients with asymptomatic turner syndrome using multidetector computed tomography.

PubMed

Lee, Sun Hee; Jung, Ji Mi; Song, Min Seob; Choi, Seok jin; Chung, Woo Yeong

2013-08-01

Turner syndrome is well known to be associated with significant cardiovascular abnormalities. This paper studied the incidence of cardiovascular abnormalities in asymptomatic adolescent patients with Turner syndrome using multidetector computed tomography (MDCT) instead of echocardiography. Twenty subjects diagnosed with Turner syndrome who had no cardiac symptoms were included. Blood pressure and electrocardiography (ECG) was checked. Cardiovascular abnormalities were checked by MDCT. According to the ECG results, 11 had a prolonged QTc interval, 5 had a posterior fascicular block, 3 had a ventricular conduction disorder. MDCT revealed vascular abnormalities in 13 patients (65%). Three patients had an aberrant right subclavian artery, 2 had dilatation of left subclavian artery, and others had an aortic root dilatation, aortic diverticulum, and abnormal left vertebral artery. As for venous abnormalities, 3 patients had partial anomalous pulmonary venous return and 2 had a persistent left superior vena cava. This study found cardiovascular abnormalities in 65% of asymptomatic Turner syndrome patients using MDCT. Even though, there are no cardiac symptoms in Turner syndrome patients, a complete evaluation of the heart with echocardiography or MDCT at transition period to adults must be performed.

Aortic annulus and ascending aorta: comparison of preoperative and periooperative measurement in patients with aortic stenosis.

PubMed

Smíd, Michal; Ferda, Jirí; Baxa, Jan; Cech, Jakub; Hájek, Tomás; Kreuzberg, Boris; Rokyta, Richard

2010-04-01

Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Polyarteritis nodosa: MDCT as a 'One-Stop Shop' Modality for Whole-Body Arterial Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, W.-L.; Tsai, I-C.; Lee Tain, E-mail: s841082@ym.edu.t

Polyarteritis nodosa is a rare disease, which is characterized by aneurysm formation and occlusion in the arteries of multiple systems. Due to its extensive involvement, whole-body evaluation is necessary for diagnosis and treatment monitoring. We report a case of polyarteritis nodosa using multidetector-row computed tomography (MDCT) as a 'one-stop shop' modality for whole-body arterial evaluation. With precise protocol design, MDCT can be used as a reliable noninvasive modality providing comprehensive whole-body arterial evaluation.

Accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC).

PubMed

Mazzei, Maria Antonietta; Khader, Leila; Cirigliano, Alfredo; Cioffi Squitieri, Nevada; Guerrini, Susanna; Forzoni, Beatrice; Marrelli, Daniele; Roviello, Franco; Mazzei, Francesco Giuseppe; Volterrani, Luca

2013-12-01

To evaluate the accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent a peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) after neoadjuvant chemotherapy to obtain a pre-surgery prognostic evaluation and a prediction of optimal cytoreduction surgery. Pre-HIPEC CT examinations of 43 patients with advanced ovarian cancer after neoadjuvant chemotherapy were analyzed by two radiologists. The PCI was scored according to the Sugarbaker classification, based on lesion size and distribution. The results were compared with macroscopic and histologic data after peritonectomy and HIPEC. To evaluate the accuracy of MDCT to detect and localize peritoneal carcinomatosis, both patient-level and regional-level analyses were conducted. A correlation between PCI CT and histologic values for each patient was searched according to the PCI grading. Considering the patient-level analysis, CT shows a sensitivity, specificity, PPV, NPV, and an accuracy in detecting the peritoneal carcinomatosis of 100 %, 40 %, 93 % 100 %, and 93 %, respectively. Considering the regional level analysis, a sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 72 %, 80 %, 66 %, 84 %, and 77 %, respectively were obtained for the correlation between CT and histology. Our results encourage the use of MDCT as the only technique sufficient to select patients with peritoneal carcinomatosis for cytoreductive surgery and HIPEC on the condition that a CT examination will be performed using a dedicated protocol optimized to detect minimal peritoneal disease and CT images will be analyzed by an experienced reader.

Effect of patient size on radiation dose for abdominal MDCT with automatic tube current modulation: phantom study.

PubMed

Schindera, Sebastian T; Nelson, Rendon C; Toth, Thomas L; Nguyen, Giao T; Toncheva, Greta I; DeLong, David M; Yoshizumi, Terry T

2008-02-01

The purpose of this study was to evaluate in a phantom study the effect of patient size on radiation dose for abdominal MDCT with automatic tube current modulation. One or two 4-cm-thick circumferential layers of fat-equivalent material were added to the abdomen of an anthropomorphic phantom to simulate patients of three sizes: small (cross-sectional dimensions, 18 x 22 cm), average size (26 x 30 cm), and oversize (34 x 38 cm). Imaging was performed with a 64-MDCT scanner with combined z-axis and xy-axis tube current modulation according to two protocols: protocol A had a noise index of 12.5 H, and protocol B, 15.0 H. Radiation doses to three abdominal organs and the skin were assessed. Image noise also was measured. Despite increasing patient size, the image noise measured was similar for protocol A (range, 11.7-12.2 H) and protocol B (range, 13.9-14.8 H) (p > 0.05). With the two protocols, in comparison with the dose of the small patient, the abdominal organ doses of the average-sized patient and the oversized patient increased 161.5-190.6%and 426.9-528.1%, respectively (p < 0.001). The skin dose increased as much as 268.6% for the average-sized patient and 816.3% for the oversized patient compared with the small patient (p < 0.001). Oversized patients undergoing abdominal MDCT with tube current modulation receive significantly higher doses than do small patients. The noise index needs to be adjusted to the body habitus to ensure dose efficiency.

Early post-operative weight loss after laparoscopic sleeve gastrectomy correlates with the volume of the excised stomach and not with that of the sleeve! Preliminary data from a multi-detector computed tomography-based study.

PubMed

Pawanindra, Lal; Vindal, Anubhav; Midha, Manoj; Nagpal, Prashant; Manchanda, Alpana; Chander, Jagdish

2015-10-01

Pre- and post-operative stomach volumes can be important determinants for effectiveness of laparoscopic sleeve gastrectomy (LSG) in causing weight loss. There is little existing data on the volumes of stomach preoperatively and that excised during LSG. This study was designed to evaluate the change in gastric volume after LSG using multi-detector CT and to correlate it with early post-operative weight loss. Twenty consecutive patients with BMI ≥ 40 kg/m(2) and medical comorbidities underwent LSG between October 2011 and October 2013 and were analysed prospectively. The pre-operative stomach volume was measured by MDCT done 1-3 days before the surgery. LSG was performed in the standard manner using a 36F bougie. The volume of excised stomach was measured by distending the specimen with saline. MDCT of the upper abdomen was repeated 3 months postoperatively to calculate the gastric sleeve volume. Weight loss and resolution of comorbidities were documented. The mean pre-operative weight of patients was 123.90 kg, and the mean pre-operative stomach volume on MDCT was 1,067 ml. The stomach volume on pre-operative MDCT correlated with pre-operative weight and BMI. The mean volume of the excised stomach was 859 ml when measured by distension of the specimen and 850 ml on MDCT. After 3 months post surgery, the mean volume of gastric sleeve on MDCT was 217 ml, and the mean weight of the patients was 101.22 kg. The volume of the excised stomach calculated by MDCT correlated with the weight loss achieved 3 months postoperatively. However, no correlation was seen between the gastric sleeve volume 3 months postoperatively and weight loss during this period. MDCT is a good method to measure gastric volume before and after LSG. Early post-operative weight loss (3 months) correlates well with the volume of the excised stomach but not with that of the gastric sleeve.

Calcification Characteristics of Low-Flow Low-Gradient Severe Aortic Stenosis in Patients Undergoing Transcatheter Aortic Valve Replacement

PubMed Central

Stähli, Barbara E.; Nguyen-Kim, Thi Dan Linh; Gebhard, Cathérine; Frauenfelder, Thomas; Tanner, Felix C.; Nietlispach, Fabian; Maisano, Francesco; Falk, Volkmar; Lüscher, Thomas F.; Maier, Willibald; Binder, Ronald K.

2015-01-01

Low-flow low-gradient severe aortic stenosis (LFLGAS) is associated with worse outcomes. Aortic valve calcification patterns of LFLGAS as compared to non-LFLGAS have not yet been thoroughly assessed. 137 patients undergoing transcatheter aortic valve replacement (TAVR) with preprocedural multidetector computed tomography (MDCT) and postprocedural transthoracic echocardiography were enrolled. Calcification characteristics were assessed by MDCT both for the total aortic valve and separately for each leaflet. 34 patients had LFLGAS and 103 non-LFLGAS. Total aortic valve calcification volume (p < 0.001), mass (p < 0.001), and density (p = 0.004) were lower in LFLGAS as compared to non-LFLGAS patients. At 30-day follow-up, mean transaortic pressure gradients and more than mild paravalvular regurgitation did not differ between groups. In conclusion, LFLGAS and non-LFLGAS express different calcification patterns which, however, did not impact on device success after TAVR. PMID:26435875

Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez-Cardona, Daniel; Nagle, Scott K.; Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792

Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiationmore » dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose levels. For FBP, the relative bias and the angular standard deviation of the measured WT increased steeply with decreasing radiation dose. Except for the smallest airway, MBIR enabled significant reduction in both the relative bias and angular standard deviation of the WT, particularly at low radiation dose levels; the SSQ was reduced by 50%–96% by using MBIR. The optimal reconstruction algorithm was found to be MBIR for the seven airways being assessed, and the combined use of MBIR and optimal kV–mAs selection resulted in a radiation dose reduction of 37%–83% compared with a reference scan protocol with a dose level of 1 mGy. Conclusions: The quantification accuracy of airway WT is strongly influenced by radiation dose and reconstruction algorithm. The MBIR algorithm potentially allows the desired WT quantification accuracy to be achieved with reduced radiation dose, which may enable a wider clinical use of MDCT for the assessment of airway WT, particularly for younger patients who may be more sensitive to exposures with ionizing radiation.« less

Robust extraction of the aorta and pulmonary artery from 3D MDCT image data

NASA Astrophysics Data System (ADS)

Taeprasartsit, Pinyo; Higgins, William E.

2010-03-01

Accurate definition of the aorta and pulmonary artery from three-dimensional (3D) multi-detector CT (MDCT) images is important for pulmonary applications. This work presents robust methods for defining the aorta and pulmonary artery in the central chest. The methods work on both contrast enhanced and no-contrast 3D MDCT image data. The automatic methods use a common approach employing model fitting and selection and adaptive refinement. During the occasional event that more precise vascular extraction is desired or the method fails, we also have an alternate semi-automatic fail-safe method. The semi-automatic method extracts the vasculature by extending the medial axes into a user-guided direction. A ground-truth study over a series of 40 human 3D MDCT images demonstrates the efficacy, accuracy, robustness, and efficiency of the methods.

Feasibility of opportunistic osteoporosis screening in routine contrast-enhanced multi detector computed tomography (MDCT) using texture analysis.

PubMed

Mookiah, M R K; Rohrmeier, A; Dieckmeyer, M; Mei, K; Kopp, F K; Noel, P B; Kirschke, J S; Baum, T; Subburaj, K

2018-04-01

This study investigated the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. The results showed an acceptable reproducibility of texture features, and these features could discriminate healthy/osteoporotic fracture cohort with an accuracy of 83%. This aim of this study is to investigate the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. We performed texture analysis at the spine in routine MDCT exams and investigated the effect of intravenous contrast medium (IVCM) (n = 7), slice thickness (n = 7), the long-term reproducibility (n = 9), and the ability to differentiate healthy/osteoporotic fracture cohort (n = 9 age and gender matched pairs). Eight texture features were extracted using gray level co-occurrence matrix (GLCM). The independent sample t test was used to rank the features of healthy/fracture cohort and classification was performed using support vector machine (SVM). The results revealed significant correlations between texture parameters derived from MDCT scans with and without IVCM (r up to 0.91) slice thickness of 1 mm versus 2 and 3 mm (r up to 0.96) and scan-rescan (r up to 0.59). The performance of the SVM classifier was evaluated using 10-fold cross-validation and revealed an average classification accuracy of 83%. Opportunistic osteoporosis screening at the spine using specific texture parameters (energy, entropy, and homogeneity) and SVM can be performed in routine contrast-enhanced MDCT exams.

Surface ECG and Fluoroscopy are Not Predictive of Right Ventricular Septal Lead Position Compared to Cardiac CT.

PubMed

Rowe, Matthew K; Moore, Peter; Pratap, Jit; Coucher, John; Gould, Paul A; Kaye, Gerald C

2017-05-01

Controversy exists regarding the optimal lead position for chronic right ventricular (RV) pacing. Placing a lead at the RV septum relies upon fluoroscopy assisted by a surface 12-lead electrocardiogram (ECG). We compared the postimplant lead position determined by ECG-gated multidetector contrast-enhanced computed tomography (MDCT) with the position derived from the surface 12-lead ECG. Eighteen patients with permanent RV leads were prospectively enrolled. Leads were placed in the RV septum (RVS) in 10 and the RV apex (RVA) in eight using fluoroscopy with anteroposterior and left anterior oblique 30° views. All patients underwent MDCT imaging and paced ECG analysis. ECG criteria were: QRS duration; QRS axis; positive or negative net QRS amplitude in leads I, aVL, V1, and V6; presence of notching in the inferior leads; and transition point in precordial leads at or after V4. Of the 10 leads implanted in the RVS, computed tomography (CT) imaging revealed seven to be at the anterior RV wall, two at the anteroseptal junction, and one in the true septum. For the eight RVA leads, four were anterior, two septal, and two anteroseptal. All leads implanted in the RVS met at least one ECG criteria (median 3, range 1-6). However, no criteria were specific for septal position as judged by MDCT. Mean QRS duration was 160 ± 24 ms in the RVS group compared with 168 ± 14 ms for RVA pacing (P = 0.38). We conclude that the surface ECG is not sufficiently accurate to determine RV septal lead tip position compared to cardiac CT. © 2017 Wiley Periodicals, Inc.

Evaluation of computer-aided diagnosis (CAD) software for the detection of lung nodules on multidetector row computed tomography (MDCT): JAFROC study for the improvement in radiologists' diagnostic accuracy.

PubMed

Hirose, Tomohiro; Nitta, Norihisa; Shiraishi, Junji; Nagatani, Yukihiro; Takahashi, Masashi; Murata, Kiyoshi

2008-12-01

The aim of this study was to evaluate the usefulness of computer-aided diagnosis (CAD) software for the detection of lung nodules on multidetector-row computed tomography (MDCT) in terms of improvement in radiologists' diagnostic accuracy in detecting lung nodules, using jackknife free-response receiver-operating characteristic (JAFROC) analysis. Twenty-one patients (6 without and 15 with lung nodules) were selected randomly from 120 consecutive thoracic computed tomographic examinations. The gold standard for the presence or absence of nodules in the observer study was determined by consensus of two radiologists. Six expert radiologists participated in a free-response receiver operating characteristic study for the detection of lung nodules on MDCT, in which cases were interpreted first without and then with the output of CAD software. Radiologists were asked to indicate the locations of lung nodule candidates on the monitor with their confidence ratings for the presence of lung nodules. The performance of the CAD software indicated that the sensitivity in detecting lung nodules was 71.4%, with 0.95 false-positive results per case. When radiologists used the CAD software, the average sensitivity improved from 39.5% to 81.0%, with an increase in the average number of false-positive results from 0.14 to 0.89 per case. The average figure-of-merit values for the six radiologists were 0.390 without and 0.845 with the output of the CAD software, and there was a statistically significant difference (P < .0001) using the JAFROC analysis. The CAD software for the detection of lung nodules on MDCT has the potential to assist radiologists by increasing their accuracy.

Earthquake-related versus non-earthquake-related injuries in spinal injury patients: differentiation with multidetector computed tomography

PubMed Central

2010-01-01

Introduction In recent years, several massive earthquakes have occurred across the globe. Multidetector computed tomography (MDCT) is reliable in detecting spinal injuries. The purpose of this study was to compare the features of spinal injuries resulting from the Sichuan earthquake with those of non-earthquake-related spinal trauma using MDCT. Methods Features of spinal injuries of 223 Sichuan earthquake-exposed patients and 223 non-earthquake-related spinal injury patients were retrospectively compared using MDCT. The date of non-earthquake-related spinal injury patients was collected from 1 May 2009 to 22 July 2009 to avoid the confounding effects of seasonal activity and clothing. We focused on anatomic sites, injury types and neurologic deficits related to spinal injuries. Major injuries were classified according to the grid 3-3-3 scheme of the Magerl (AO) classification system. Results A total of 185 patients (82.96%) in the earthquake-exposed cohort experienced crush injuries. In the earthquake and control groups, 65 and 92 patients, respectively, had neurologic deficits. The anatomic distribution of these two cohorts was significantly different (P < 0.001). Cervical spinal injuries were more common in the control group (risk ratio (RR) = 2.12, P < 0.001), whereas lumbar spinal injuries were more common in the earthquake-related spinal injuries group (277 of 501 injured vertebrae; 55.29%). The major types of injuries were significantly different between these cohorts (P = 0.002). Magerl AO type A lesions composed most of the lesions seen in both of these cohorts. Type B lesions were more frequently seen in earthquake-related spinal injuries (RR = 1.27), while we observed type C lesions more frequently in subjects with non-earthquake-related spinal injuries (RR = 1.98, P = 0.0029). Conclusions Spinal injuries sustained in the Sichuan earthquake were located mainly in the lumbar spine, with a peak prevalence of type A lesions and a high occurrence of neurologic deficits. The anatomic distribution and type of spinal injuries that varied between earthquake-related and non-earthquake-related spinal injury groups were perhaps due to the different mechanism of injury. PMID:21190568

Temporal resolution improvement using PICCS in MDCT cardiac imaging

PubMed Central

Chen, Guang-Hong; Tang, Jie; Hsieh, Jiang

2009-01-01

The current paradigm for temporal resolution improvement is to add more source-detector units and∕or increase the gantry rotation speed. The purpose of this article is to present an innovative alternative method to potentially improve temporal resolution by approximately a factor of 2 for all MDCT scanners without requiring hardware modification. The central enabling technology is a most recently developed image reconstruction method: Prior image constrained compressed sensing (PICCS). Using the method, cardiac CT images can be accurately reconstructed using the projection data acquired in an angular range of about 120°, which is roughly 50% of the standard short-scan angular range (∼240° for an MDCT scanner). As a result, the temporal resolution of MDCT cardiac imaging can be universally improved by approximately a factor of 2. In order to validate the proposed method, two in vivo animal experiments were conducted using a state-of-the-art 64-slice CT scanner (GE Healthcare, Waukesha, WI) at different gantry rotation times and different heart rates. One animal was scanned at heart rate of 83 beats per minute (bpm) using 400 ms gantry rotation time and the second animal was scanned at 94 bpm using 350 ms gantry rotation time, respectively. Cardiac coronary CT imaging can be successfully performed at high heart rates using a single-source MDCT scanner and projection data from a single heart beat with gantry rotation times of 400 and 350 ms. Using the proposed PICCS method, the temporal resolution of cardiac CT imaging can be effectively improved by approximately a factor of 2 without modifying any scanner hardware. This potentially provides a new method for single-source MDCT scanners to achieve reliable coronary CT imaging for patients at higher heart rates than the current heart rate limit of 70 bpm without using the well-known multisegment FBP reconstruction algorithm. This method also enables dual-source MDCT scanner to achieve higher temporal resolution without further hardware modifications. PMID:19610302

Temporal resolution improvement using PICCS in MDCT cardiac imaging.

PubMed

Chen, Guang-Hong; Tang, Jie; Hsieh, Jiang

2009-06-01

The current paradigm for temporal resolution improvement is to add more source-detector units and/or increase the gantry rotation speed. The purpose of this article is to present an innovative alternative method to potentially improve temporal resolution by approximately a factor of 2 for all MDCT scanners without requiring hardware modification. The central enabling technology is a most recently developed image reconstruction method: Prior image constrained compressed sensing (PICCS). Using the method, cardiac CT images can be accurately reconstructed using the projection data acquired in an angular range of about 120 degrees, which is roughly 50% of the standard short-scan angular range (approximately 240 degrees for an MDCT scanner). As a result, the temporal resolution of MDCT cardiac imaging can be universally improved by approximately a factor of 2. In order to validate the proposed method, two in vivo animal experiments were conducted using a state-of-the-art 64-slice CT scanner (GE Healthcare, Waukesha, WI) at different gantry rotation times and different heart rates. One animal was scanned at heart rate of 83 beats per minute (bpm) using 400 ms gantry rotation time and the second animal was scanned at 94 bpm using 350 ms gantry rotation time, respectively. Cardiac coronary CT imaging can be successfully performed at high heart rates using a single-source MDCT scanner and projection data from a single heart beat with gantry rotation times of 400 and 350 ms. Using the proposed PICCS method, the temporal resolution of cardiac CT imaging can be effectively improved by approximately a factor of 2 without modifying any scanner hardware. This potentially provides a new method for single-source MDCT scanners to achieve reliable coronary CT imaging for patients at higher heart rates than the current heart rate limit of 70 bpm without using the well-known multisegment FBP reconstruction algorithm. This method also enables dual-source MDCT scanner to achieve higher temporal resolution without further hardware modifications.

Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings

PubMed Central

2011-01-01

Background Diagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT) was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography. Results Electrocardiography (ECG)-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol. Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats. Conclusions Contrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional information can be of help with regard to improved diagnoses of thoracic anomalies and the planning of surgical interventions. PMID:21943366

Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings.

PubMed

Catalano, Orlando; de Lutio di Castelguidone, Elisabetta; Sandomenico, Claudia; Petrillo, Mario; Aprea, Pasquale; Granata, Vincenza; D'Errico, Adolfo Gallipoli

2011-03-01

Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD). To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter-related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports. Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis. Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report. CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi.

Multi-Detector Row Computed Tomography Findings of Pelvic Congestion Syndrome Caused by Dilated Ovarian Veins

PubMed Central

Eren, Suat

2010-01-01

Objective: To evaluate the efficacy of multi-detector row CT (MDCT) on pelvic congestion syndrome (PCS), which is often overlooked or poorly visualized with routine imaging examination. Materials and Methods: We evaluated the MDCT features of 40 patients with PCS (mean age, 45 years; range, 29–60 years) using axial, coronal, sagittal, 3D volume-rendered, and Maximum Intensity Projection MIP images. Results: MDCT revealed pelvic varices and ovarian vein dilatations in all patients. Bilateral ovarian vein dilatation was present in 25 patients, and 15 patients had unilateral dilatation. While 12 cases of secondary pelvic varices occurred simultaneously with a retroaortic left renal vein, 10 cases were due solely to a mass obstruction or stenosis of venous structures. Conclusion: MDCT is an effective tool in the evaluation of PCS, and it has more advantages than other imaging modalities. PMID:25610142

Current role of multidetector computed tomography in imaging of wrist injuries.

PubMed

Syed, Mohd Arif; Raj, Vimal; Jeyapalan, Kanagaratnam

2013-01-01

Imaging of the wrist is challenging to both radiologists and orthopedic surgeons. This is primarily because of the complex anatomy/functionality of the wrist and also the fact that many frequent injuries are sustained to the hands. On going developments in multidetector computed tomography (MDCT) technology with its "state of the art" postprocessing capabilities have revolutionized this field. Apart from routine imaging of wrist trauma, it is now possible to assess intrinsic ligaments with MDCT arthrography, thereby avoiding invasive diagnostic arthroscopies. Postoperative wrist imaging can be a diagnostic challenge, and MDCT can be helpful in assessment of these cases because volume acquisition and excellent postprocessing abilities help to evaluate these wrists in any desired plane and thinner slices. This article pictorially reviews the current clinical role of MDCT imaging of wrist in our practice. It also describes arthrography technique and scanning parameters used at our center. Copyright © 2013 Mosby, Inc. All rights reserved.

MDCT for Computerized Volumetry of Pneumothoraces in Pediatric Patients

PubMed Central

Cai, Wenli; Lee, Edward Y.; Vij, Abhinav; Mahmood, Soran A.; Yoshida, Hiroyuki

2010-01-01

OBJECTIVE Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in MDCT images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. MATERIALS AND METHODS Fifty-eight consecutive pediatric patients (mean age 12±6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0 ~ 1.5 pitch, 0.6 ~ 5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 cc were visually identified in the left (n = 30) or/and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, Massachusetts) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. RESULTS The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 cc was 8.2%. For pneumothoraces ≥10 cc, ≥50 cc, and ≥200 cc, the mean differences were 7.7% (n=57), 7.3% (n=33), and 6.4% (n=13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of −5.1% compared to manual volumetry. For all pneumothoraces ≥10 cc, the mean differences for slice thickness ≤1.25 mm, =1.5 mm, and =5.0 mm were 6.1% (n=28), 3.5% (n=10), and 12.2% (n=19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n=42, B70f) and 11.7% (n=15, B31f), respectively. CONCLUSION Our automated CAV scheme provides an accurate measurement of pneumothorax volume in MDCT images of pediatric patients. For accurate volumetric quantification of pneumothorax in children in MDCT images by use of the automated CAV scheme, we recommended reconstruction parameters based on a slice thickness ≤1.5 mm and the reconstruction kernel B70f. PMID:21216160

MDCT for computerized volumetry of pneumothoraces in pediatric patients.

PubMed

Cai, Wenli; Lee, Edward Y; Vij, Abhinav; Mahmood, Soran A; Yoshida, Hiroyuki

2011-03-01

Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f), respectively. Our automated CAV scheme provides an accurate measurement of pneumothorax volume in MDCT images of pediatric patients. For accurate volumetric quantification of pneumothorax in children in MDCT images by use of the automated CAV scheme, we recommended reconstruction parameters based on a slice thickness ≤1.5 mm and the reconstruction kernel B70f. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

In-Vivo Assessment of Femoral Bone Strength Using Finite Element Analysis (FEA) Based on Routine MDCT Imaging: A Preliminary Study on Patients with Vertebral Fractures

PubMed Central

Liebl, Hans; Garcia, Eduardo Grande; Holzner, Fabian; Noel, Peter B.; Burgkart, Rainer; Rummeny, Ernst J.; Baum, Thomas; Bauer, Jan S.

2015-01-01

Purpose To experimentally validate a non-linear finite element analysis (FEA) modeling approach assessing in-vitro fracture risk at the proximal femur and to transfer the method to standard in-vivo multi-detector computed tomography (MDCT) data of the hip aiming to predict additional hip fracture risk in subjects with and without osteoporosis associated vertebral fractures using bone mineral density (BMD) measurements as gold standard. Methods One fresh-frozen human femur specimen was mechanically tested and fractured simulating stance and clinically relevant fall loading configurations to the hip. After experimental in-vitro validation, the FEA simulation protocol was transferred to standard contrast-enhanced in-vivo MDCT images to calculate individual hip fracture risk each for 4 subjects with and without a history of osteoporotic vertebral fractures matched by age and gender. In addition, FEA based risk factor calculations were compared to manual femoral BMD measurements of all subjects. Results In-vitro simulations showed good correlation with the experimentally measured strains both in stance (R2 = 0.963) and fall configuration (R2 = 0.976). The simulated maximum stress overestimated the experimental failure load (4743 N) by 14.7% (5440 N) while the simulated maximum strain overestimated by 4.7% (4968 N). The simulated failed elements coincided precisely with the experimentally determined fracture locations. BMD measurements in subjects with a history of osteoporotic vertebral fractures did not differ significantly from subjects without fragility fractures (femoral head: p = 0.989; femoral neck: p = 0.366), but showed higher FEA based risk factors for additional incident hip fractures (p = 0.028). Conclusion FEA simulations were successfully validated by elastic and destructive in-vitro experiments. In the subsequent in-vivo analyses, MDCT based FEA based risk factor differences for additional hip fractures were not mirrored by according BMD measurements. Our data suggests, that MDCT derived FEA models may assess bone strength more accurately than BMD measurements alone, providing a valuable in-vivo fracture risk assessment tool. PMID:25723187

Validation of multi-detector computed tomography as a non-invasive method for measuring ovarian volume in macaques (Macaca fascicularis).

PubMed

Jones, Jeryl C; Appt, Susan E; Werre, Stephen R; Tan, Joshua C; Kaplan, Jay R

2010-06-01

The purpose of this study was to validate low radiation dose, contrast-enhanced, multi-detector computed tomography (MDCT) as a non-invasive method for measuring ovarian volume in macaques. Computed tomography scans of four known-volume phantoms and nine mature female cynomolgus macaques were acquired using a previously described, low radiation dose scanning protocol, intravenous contrast enhancement, and a 32-slice MDCT scanner. Immediately following MDCT, ovaries were surgically removed and the ovarian weights were measured. The ovarian volumes were determined using water displacement. A veterinary radiologist who was unaware of actual volumes measured ovarian CT volumes three times, using a laptop computer, pen display tablet, hand-traced regions of interest, and free image analysis software. A statistician selected and performed all tests comparing the actual and CT data. Ovaries were successfully located in all MDCT scans. The iliac arteries and veins, uterus, fallopian tubes, cervix, ureters, urinary bladder, rectum, and colon were also consistently visualized. Large antral follicles were detected in six ovaries. Phantom mean CT volume was 0.702+/-SD 0.504 cc and the mean actual volume was 0.743+/-SD 0.526 cc. Ovary mean CT volume was 0.258+/-SD 0.159 cc and mean water displacement volume was 0.257+/-SD 0.145 cc. For phantoms, the mean coefficient of variation for CT volumes was 2.5%. For ovaries, the least squares mean coefficient of variation for CT volumes was 5.4%. The ovarian CT volume was significantly associated with actual ovarian volume (ICC coefficient 0.79, regression coefficient 0.5, P=0.0006) and the actual ovarian weight (ICC coefficient 0.62, regression coefficient 0.6, P=0.015). There was no association between the CT volume accuracy and mean ovarian CT density (degree of intravenous contrast enhancement), and there was no proportional or fixed bias in the CT volume measurements. Findings from this study indicate that MDCT is a valid non-invasive technique for measuring the ovarian volume in macaques.

Diagnostic performance of multidetector computed tomography in distinguishing unilateral from bilateral abnormalities in primary hyperaldosteronism: comparison of multidetector computed tomography with adrenal vein sampling.

PubMed

Raman, Siva P; Lessne, Mark; Kawamoto, Satomi; Chen, Yifei; Salvatori, Roberto; Prescott, Jason D; Fishman, Elliot K

2015-01-01

The management of patients with primary hyperaldosteronism (PH) varies depending on whether the unregulated aldosterone secretion localizes to a single unilateral adrenal gland, traditionally determined using adrenal vein sampling (AVS). This study seeks to determine if the performance of multidetector computed tomography (MDCT) examinations performed using the latest scanner technology can reasonably match the results of AVS, and potentially avoid AVS in some patients. Computed tomographic scans in 56 patients with PH were independently reviewed by 2 radiologists for the presence of adrenal nodules and qualitative adrenal thickening. Results were correlated with AVS results. Of 35 patients with MDCT evidence of unilateral nodules, the imaging findings correctly predicted AVS localization in only 23 (65.7%) cases. When stratified by size, MDCT was accurate in only 71.4% of cases for nodules measuring 10 mm or less, and only 55.0% of cases for nodules measuring 11 to 20 mm. Of the 12 cases where MDCT did not correctly localize, AVS localized to the contralateral adrenal gland in 4 cases, whereas AVS suggested no lateralization in 8 cases. In patients with normal bilateral adrenal glands on MDCT, 2/7 (28.6%) of cases demonstrated unilateral localization on AVS, and in patients with bilateral adrenal nodules, only 3/14 (21.4%) did not demonstrate lateralization on AVS. Multidetector computed tomography, even when performed with the latest generation of MDCT scanners, does not offer sufficient diagnostic accuracy to replace AVS in patients with PH.

The diagnostic test accuracy of magnetic resonance imaging, magnetic resonance arthrography and computer tomography in the detection of chondral lesions of the hip.

PubMed

Smith, Toby O; Simpson, Michael; Ejindu, Vivian; Hing, Caroline B

2013-04-01

The purpose of this study was to assess the diagnostic test accuracy of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and multidetector arrays in CT arthrography (MDCT) for assessing chondral lesions in the hip joint. A review of the published and unpublished literature databases was performed to identify all studies reporting the diagnostic test accuracy (sensitivity/specificity) of MRI, MRA or MDCT for the assessment of adults with chondral (cartilage) lesions of the hip with surgical comparison (arthroscopic or open) as the reference test. All included studies were reviewed using the quality assessment of diagnostic accuracy studies appraisal tool. Pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios were calculated with 95 % confidence intervals using a random-effects meta-analysis for MRI, MRA and MDCT imaging. Eighteen studies satisfied the eligibility criteria. These included 648 hips from 637 patients. MRI indicated a pooled sensitivity of 0.59 (95 % CI: 0.49-0.70) and specificity of 0.94 (95 % CI: 0.90-0.97), and MRA sensitivity and specificity values were 0.62 (95 % CI: 0.57-0.66) and 0.86 (95 % CI: 0.83-0.89), respectively. The diagnostic test accuracy for the detection of hip joint cartilage lesions is currently superior for MRI compared with MRA. There were insufficient data to perform meta-analysis for MDCT or CTA protocols. Based on the current limited diagnostic test accuracy of the use of magnetic resonance or CT, arthroscopy remains the most accurate method of assessing chondral lesions in the hip joint.

Feasibility of MDCT angiography for determination of tumor-feeding vessels in chemoembolization of hepatocellular carcinoma.

PubMed

Kim, Inwha; Kim, Dae Jung; Kim, Kyoung Ah; Yoon, Sang Wook; Lee, Jong Tae

2014-01-01

To investigate the feasibility and accuracy of multidetector computed tomography (MDCT) angiography for assessment of subsegmental tumor-feeding vessels in transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). A total of 23 patients with 36 HCCs who underwent TACE during a 14-month period were enrolled. All patients underwent 3-phase dynamic MDCT within a month before TACE. Arterial phase MDCT images were retrospectively reformatted and analyzed for determination of single subsegmental tumor-feeding vessel using maximum intensity projection (MIP) and volume-rendering technique (VRT). Two radiologists independently assessed and scored the MIP and VRT images using 4-grade visual scores (grade 1, no depiction of tumor-feeding vessel; grade 2, indeterminate tumor-feeding vessel; grade 3, probable tumor-feeding vessel; and grade 4, good depiction of tumor-feeding vessel). The weighted kappa test was used to determine interobserver variability, and Wilcoxon signed rank test was used to differentiate visual scores of each technique. Results of digital subtraction angiography were defined as the criterion standard; therefore, assessment of subsegmental tumor-feeding vessel using MIP or VRT was compared with digital subtraction angiography, and the accuracy of each technique was calculated. Interobserver agreement (weighted kappa, 0.746 on VRT and 0.806 on MIP) was substantial to almost perfect. The visual scores for MIP (mean, 3.64 for reviewer 1 and 3.5 for reviewer 2) were higher than those for VRT (mean, 2.11 for reviewer 1 and 2.22 for reviewer 2; P = 0.000). The accuracy for assessing subsegmental tumor-feeding vessel was 22.2% for VRT and 77.8% for MIP. Multidetector CT angiography using MIP showed good imaging quality and high accuracy for determination of subsegmental tumor-feeding vessels.

Cardiac multidetector computed tomography: basic physics of image acquisition and clinical applications.

PubMed

Bardo, Dianna M E; Brown, Paul

2008-08-01

Cardiac MDCT is here to stay. And, it is more than just imaging coronary arteries. Understanding the differences in and the benefits of one CT scanner from another will help you to optimize the capabilities of the scanner, but requires a basic understanding of the MDCT imaging physics.This review provides key information needed to understand the differences in the types of MDCT scanners, from 64 - 320 detectors, flat panels, single and dual source configurations, step and shoot prospective and retrospective gating, and how each factor influences radiation dose, spatial and temporal resolution, and image noise.

Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging.

PubMed

Fananapazir, Ghaneh; Bashir, Mustafa R; Marin, Daniele; Boll, Daniel T

2015-06-01

To evaluate the performance of a prototype, fully-automated post-processing solution for whole-liver and lobar segmentation based on MDCT datasets. A polymer liver phantom was used to assess accuracy of post-processing applications comparing phantom volumes determined via Archimedes' principle with MDCT segmented datasets. For the IRB-approved, HIPAA-compliant study, 25 patients were enrolled. Volumetry performance compared the manual approach with the automated prototype, assessing intraobserver variability, and interclass correlation for whole-organ and lobar segmentation using ANOVA comparison. Fidelity of segmentation was evaluated qualitatively. Phantom volume was 1581.0 ± 44.7 mL, manually segmented datasets estimated 1628.0 ± 47.8 mL, representing a mean overestimation of 3.0%, automatically segmented datasets estimated 1601.9 ± 0 mL, representing a mean overestimation of 1.3%. Whole-liver and segmental volumetry demonstrated no significant intraobserver variability for neither manual nor automated measurements. For whole-liver volumetry, automated measurement repetitions resulted in identical values; reproducible whole-organ volumetry was also achieved with manual segmentation, p(ANOVA) 0.98. For lobar volumetry, automated segmentation improved reproducibility over manual approach, without significant measurement differences for either methodology, p(ANOVA) 0.95-0.99. Whole-organ and lobar segmentation results from manual and automated segmentation showed no significant differences, p(ANOVA) 0.96-1.00. Assessment of segmentation fidelity found that segments I-IV/VI showed greater segmentation inaccuracies compared to the remaining right hepatic lobe segments. Automated whole-liver segmentation showed non-inferiority of fully-automated whole-liver segmentation compared to manual approaches with improved reproducibility and post-processing duration; automated dual-seed lobar segmentation showed slight tendencies for underestimating the right hepatic lobe volume and greater variability in edge detection for the left hepatic lobe compared to manual segmentation.

Semi-automatic central-chest lymph-node definition from 3D MDCT images

NASA Astrophysics Data System (ADS)

Lu, Kongkuo; Higgins, William E.

2010-03-01

Central-chest lymph nodes play a vital role in lung-cancer staging. The three-dimensional (3D) definition of lymph nodes from multidetector computed-tomography (MDCT) images, however, remains an open problem. This is because of the limitations in the MDCT imaging of soft-tissue structures and the complicated phenomena that influence the appearance of a lymph node in an MDCT image. In the past, we have made significant efforts toward developing (1) live-wire-based segmentation methods for defining 2D and 3D chest structures and (2) a computer-based system for automatic definition and interactive visualization of the Mountain central-chest lymph-node stations. Based on these works, we propose new single-click and single-section live-wire methods for segmenting central-chest lymph nodes. The single-click live wire only requires the user to select an object pixel on one 2D MDCT section and is designed for typical lymph nodes. The single-section live wire requires the user to process one selected 2D section using standard 2D live wire, but it is more robust. We applied these methods to the segmentation of 20 lymph nodes from two human MDCT chest scans (10 per scan) drawn from our ground-truth database. The single-click live wire segmented 75% of the selected nodes successfully and reproducibly, while the success rate for the single-section live wire was 85%. We are able to segment the remaining nodes, using our previously derived (but more interaction intense) 2D live-wire method incorporated in our lymph-node analysis system. Both proposed methods are reliable and applicable to a wide range of pulmonary lymph nodes.

Operational cooling tower model (CTTOOL V1.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleman, S.; LocalDomainServers, L.; Garrett, A.

2015-01-01

Mechanical draft cooling towers (MDCT’s) are widely used to remove waste heat from industrial processes, including suspected proliferators of weapons of mass destruction (WMD). The temperature of the air being exhausted from the MDCT is proportional to the amount of thermal energy being removed from the process cooling water, although ambient weather conditions and cooling water flow rate must be known or estimated to calculate the rate of thermal energy dissipation (Q). It is theoretically possible to derive MDCT air exhaust temperatures from thermal images taken from a remote sensor. A numerical model of a MDCT is required to translatemore » the air exhaust temperature to a Q. This report describes the MDCT model developed by the Problem Centered Integrated Analysis (PCIA) program that was designed to perform those computational tasks. The PCIA program is a collaborative effort between the Savannah River National Laboratory (SRNL), the Northrop-Grumman Corporation (NG) and the Aerospace Corporation (AERO).« less

Multi-detector CT imaging in the postoperative orthopedic patient with metal hardware.

PubMed

Vande Berg, Bruno; Malghem, Jacques; Maldague, Baudouin; Lecouvet, Frederic

2006-12-01

Multi-detector CT imaging (MDCT) becomes routine imaging modality in the assessment of the postoperative orthopedic patients with metallic instrumentation that degrades image quality at MR imaging. This article reviews the physical basis and CT appearance of such metal-related artifacts. It also addresses the clinical value of MDCT in postoperative orthopedic patients with emphasis on fracture healing, spinal fusion or arthrodesis, and joint replacement. MDCT imaging shows limitations in the assessment of the bone marrow cavity and of the soft tissues for which MR imaging remains the imaging modality of choice despite metal-related anatomic distortions and signal alteration.

Value and impact factors of multidetector computed tomography in diagnosis of preoperative lymph node metastasis in gastric cancer: A PRISMA-compliant systematic review and meta-analysis.

PubMed

Luo, Mingxu; Lv, You; Guo, Xiuyu; Song, Hongmei; Su, Guoqiang; Chen, Bo

2017-08-01

Multidetector computed tomography (MDCT) exhibited wide ranges of sensitivities and specificities for lymph node assessment of gastric cancer (GC) in several individual studies. This present meta-analysis was carried out to evaluate the value of MDCT in diagnosis of preoperative lymph node metastasis (LNM) and to explore the impact factors that might explain the heterogeneity of its diagnostic accuracy in GC. A comprehensive search was conducted to collect all the relevant studies about the value of MDCT in assessing LNM of GC within the PubMed, Cochrane library and Embase databases up to Feb 2, 2016. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies. The sensitivity, specificity, and area under ROC curve (AUC) were pooled to estimate the overall accuracy of MDCT. Meta-regression and subgroup analysis were carried out to identify the possible factors influencing the heterogeneity of the accuracy. A total of 27 studies with 6519 subjects were finally included. Overall, the pooled sensitivity, specificity, and AUC were 0.67 (95% CI: 0.56-0.77), 0.86 (95% CI: 0.81-0.90), and 0.86 (95% CI: 0.83-0.89), respectively. Meta-regression revealed that MDCT section thickness, proportion of serosal invasion, and publication year were the main significant impact factors in sensitivity, and MDCT section thickness, multiplanar reformation (MPR), and reference standard were the main significant impact factors in specificity. After the included studies were divided into 2 groups (Group A: studies with proportion of serosa-invasive GC subjects ≥50%; Group B: studies with proportion of serosa-invasive GC subjects <50%), the pooled sensitivity in Group A was significantly higher than in Group B (0.84 [95% CI: 0.75-0.90] vs 0.55 [95% CI: 0.41-0.68], P < .01). For early gastric cancer (EGC), the pooled sensitivity, specificity, and AUC were 0.34 (95% CI: 0.15-0.61), 0.91 (95% CI: 0.84-0.95), and 0.83 (95% CI: 0.80-0.86), respectively. To summarize, MDCT tends to be adequate to assess preoperative LNM in serosa-invasive GC, but insufficient for non-serosa-invasive GC (particularly for EGC) owing to its low sensitivity. Proportion of serosa-invasive GC subjects, MDCT section thickness, MPR, and reference standard are the main factors influencing its diagnostic accuracy.

Ossicles of lumbar articular facets: normal variant or spondylolytic variant?

PubMed

Kumar, Dalavaye S; Fotiadou, Anastasia; Lalam, Radhesh; Ginder, Laurence M; Eisenstein, Stephen M; Tins, Bernard J; Tyrrell, Prudencia N M; Delieu, John M; McCall, Iain W; Rees, Dai A; Cassar-Pullicino, Victor N

2012-12-01

The objective of this study was to establish the prevalence and significance of ossicles of lumbar articular facets (OLAF) in young athletes with backache diagnosed by multi-detector computed tomography (MDCT). The MDCT examinations of the lumbar spine carried out for suspected spondylolysis on 46 consecutive symptomatic young athletes presenting to a sports injury clinic over a 1-year period were retrospectively reviewed. OLAF study included detailed correlation with the structural and morphological stress features of the posterior neural arches. This was then compared with a control group composed of 39 patients. Twenty-three OLAF were identified in 15 patients. Eleven of the 15 patients with ossicles had posterior element stress changes (PEST)/pars defects. In the control group, two OLAF were identified in two patients, one demonstrating PEST changes. The high prevalence of OLAF in young symptomatic athletes compared with the asymptomatic control group is indicative of stress fractures. The non-united articular process fractures should be regarded as part of the spectrum of stress-induced changes in the posterior neural arch in the same way as spondylolysis. MDCT with volumetric acquisition and multi-planar reformation is the most reliable investigation in the diagnosis of OLAF. 1) This CT study supports a traumatic aetiology for lumbar articular facets ossicles. 2) OLAF represent part of a spectrum of stress-induced changes in the posterior neural arch. 3) OLAF are associated with typical spondylolysis. 4) OLAF can be overlooked on reverse gantry angle computed tomography (RG-CT). 5) OLAF may account for some of the discrepancy between radionuclide and RG-CT studies.

A novel multiscale topo-morphometric approach for separating arteries and veins via pulmonary CT imaging

NASA Astrophysics Data System (ADS)

Saha, Punam K.; Gao, Zhiyun; Alford, Sara; Sonka, Milan; Hoffman, Eric

2009-02-01

Distinguishing arterial and venous trees in pulmonary multiple-detector X-ray computed tomography (MDCT) images (contrast-enhanced or unenhanced) is a critical first step in the quantification of vascular geometry for purposes of determining, for instance, pulmonary hypertension, using vascular dimensions as a comparator for assessment of airway size, detection of pulmonary emboli and more. Here, a novel method is reported for separating arteries and veins in MDCT pulmonary images. Arteries and veins are modeled as two iso-intensity objects closely entwined with each other at different locations at various scales. The method starts with two sets of seeds -- one for arteries and another for veins. Initialized with seeds, arteries and veins grow iteratively while maintaining their spatial separation and eventually forming two disjoint objects at convergence. The method combines fuzzy distance transform, a morphologic feature, with a topologic connectivity property to iteratively separate finer and finer details starting at a large scale and progressing towards smaller scales. The method has been validated in mathematically generated tubular objects with different levels of fuzziness, scale and noise. Also, it has been successfully applied to clinical CT pulmonary data. The accuracy of the method has been quantitatively evaluated by comparing its results with manual outlining. For arteries, the method has yielded correctness of 81.7% at the cost of 6.7% false positives and 11.6% false negatives. Our method is very promising for automated separation of arteries and veins in MDCT pulmonary images even when there is no mark of intensity variation at conjoining locations.

Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites.

PubMed

Widmann, Gerlig; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Al-Ekrish, Asma'a A

2017-05-01

Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. • Ultra-low-dose MDCT protocols allowed more than 90 % reductions in dose. • Decreasing the dose generally increased density and noise. • Effect of IRT on density and noise varies with reconstruction kernel. • Accuracy of low-dose protocols for interpretation of bony anatomy not known. • Effect of low doses on accuracy of computer-aided design models unknown.

WE-G-217BCD-04: Diagnostic Image Quality Evaluation of a Dedicated Extremity Cone- Beam CT Scanner: Pre-Clinical Studies and First Clinical Results.

PubMed

Muhit, A; Zbijewski, W; Stayman, J; Thawait, G; Yorkston, J; Foos, D; Packard, N; Yang, D; Senn, R; Carrino, J; Siewerdsen, J

2012-06-01

To assess the diagnostic performance of a prototype cone-beam CT (CBCT) scanner developed for musculoskeletal extremity imaging. Studies involved controlled observer studies conducted subsequent to rigorous technical assessment as well as patient images from the first clinical trial in imaging the hand and knee. Performance assessment included: 1.) rigorous technical assessment; 2.) controlled observer studies using CBCT images of cadaveric specimens; and 3.) first clinical images. Technical assessment included measurement of spatial resolution (MTF), constrast, and noise (SDNR) versus kVp and dose using standard CT phantoms. Diagnostic performance in comparison to multi- detector CT (MDCT) was assessed in controlled observer studies involving 12 cadaveric hands and knees scanned with and without abnormality (fracture). Observer studies involved five radiologists rating pertinent diagnostics tasks in 9-point preference and 10-point diagnostic satisfaction scales. Finally, the first clinical images from an ongoing pilot study were assessed in terms of diagnostic utility in disease assessment and overall workflow in patient setup. Quantitative assessment demonstrated sub-mm spatial resolution (MTF exceeding 10% out to 15-20 cm-1) and SDNR sufficient for relevant soft-tissue visualization tasks at dose <10 mGy. Observer studies confirmed optimal acquisition techniques and demonstrated superior utility of combined soft-tissue visualization and isotropic spatial resolution in diagnostic tasks. Images from the patient trial demonstrate exquisite contrast and detail and the ability to detect tissue impingement in weight-bearing exams. The prototype CBCT scanner provides isotropic spatial resolution superior to standard-protocol MDCT with soft-tissue visibility sufficient for a broad range of diagnostic tasks in musculoskeletal radiology. Dosimetry and workflow were advantageous in comparison to whole-body MDCT. Multi-mode and weight-bearing capabilities add valuable functionality. An ongoing clinical study further assesses diagnostic utility and defines the role of such technology in the diagnostic arsenal. - Research Grant, Carestream Health - Research Grant, National Institutes of Health 2R01-CA-112163. © 2012 American Association of Physicists in Medicine.

Novel imaging strategies for the detection of prosthetic heart valve obstruction and endocarditis.

PubMed

Tanis, W; Budde, R P J; van der Bilt, I A C; Delemarre, B; Hoohenkerk, G; van Rooden, J-K; Scholtens, A M; Habets, J; Chamuleau, S

2016-02-01

Prosthetic heart valve (PHV) dysfunction remains difficult to recognise correctly by two-dimensional (2D) transthoracic and transoesophageal echocardiography (TTE/TEE). ECG-triggered multidetector-row computed tomography (MDCT), 18-fluorine-fluorodesoxyglucose positron emission tomography including low-dose CT (FDG-PET) and three-dimensional transoesophageal echocardiography (3D-TEE) may have additional value. This paper reviews the role of these novel imaging tools in the field of PHV obstruction and endocarditis.For acquired PHV obstruction, MDCT is of additional value in mechanical PHVs to differentiate pannus from thrombus as well as to dynamically study leaflet motion and opening/closing angles. For biological PHV obstruction, additional imaging is not beneficial as it does not change patient management. When performed on top of 2D-TTE/TEE, MDCT has additional value for the detection of both vegetations and pseudoaneurysms/abscesses in PHV endocarditis. FDG-PET has no complementary value for the detection of vegetations; however, it appears more sensitive in the early detection of pseudoaneurysms/abscesses. Furthermore, FDG-PET enables the detection of metastatic and primary extra-cardiac infections. Evidence for the additional value of 3D-TEE is scarce.As clinical implications are major, clinicians should have a low threshold to perform additional MDCT in acquired mechanical PHV obstruction. For suspected PHV endocarditis, both FDG-PET and MDCT have complementary value.

Study of the renal segmental arterial anatomy with contrast-enhanced multi-detector computed tomography.

PubMed

Rocco, Francesco; Cozzi, Luigi Alberto; Cozzi, Gabriele

2015-07-01

To use triphasic multi-detector computed tomography (MDCT) to study the renal segmental arterial anatomy and its relationship with the urinary tract to plan nephron-sparing surgery (NSS). One hundred and fifty nine patients underwent abdominal contrast-enhanced MDCT. We evaluated renal arteries and parenchymal vasculature. In 61 patients, the arteries and the urinary tract were represented simultaneously. 86.60% presented a single renal artery; 13.4%, multiple arteries. All single renal arteries divided into anterior and posterior branch before the hilum. The anterior artery branched into a superior, middle, and inferior branch. In 43.14%, the inferior artery arose before the others; in 45.75%, the superior artery arose before the others; in 9.80%, the branches shared a common trunk. In 26.80%, the posterior artery supplies the entire posterior surface; in 73.20%, it ends along the inferior calyx. In 96.73%, the upper pole was vascularized by the anterior superior branch and the posterior artery: the "tuning fork". MDCT showed four vascular segments in 96.73% and five in 3.27%. MDCT showed two avascular areas: the first along the projection of the inferior calyx on the posterior aspect, the second between the branches of the "tuning fork". The arterial phase provides the arterial tree representation; the delayed phase shows arteries and urinary tract simultaneously. MDCT provides a useful representation of the renal anatomy prior to intervascular-intrarenal NSS.

The development of an automatically produced cholangiography procedure using the reconstruction of portal-phase multidetector-row computed tomography images: preliminary experience.

PubMed

Hirose, Tomoaki; Igami, Tsuyoshi; Koga, Kusuto; Hayashi, Yuichiro; Ebata, Tomoki; Yokoyama, Yukihiro; Sugawara, Gen; Mizuno, Takashi; Yamaguchi, Junpei; Mori, Kensaku; Nagino, Masato

2017-03-01

Fusion angiography using reconstructed multidetector-row computed tomography (MDCT) images, and cholangiography using reconstructed images from MDCT with a cholangiographic agent include an anatomical gap due to the different periods of MDCT scanning. To conquer such gaps, we attempted to develop a cholangiography procedure that automatically reconstructs a cholangiogram from portal-phase MDCT images. The automatically produced cholangiography procedure utilized an original software program that was developed by the Graduate School of Information Science, Nagoya University. This program structured 5 candidate biliary tracts, and automatically selected one as the candidate for cholangiography. The clinical value of the automatically produced cholangiography procedure was estimated based on a comparison with manually produced cholangiography. Automatically produced cholangiograms were reconstructed for 20 patients who underwent MDCT scanning before biliary drainage for distal biliary obstruction. The procedure showed the ability to extract the 5 main biliary branches and the 21 subsegmental biliary branches in 55 and 25 % of the cases, respectively. The extent of aberrant connections and aberrant extractions outside the biliary tract was acceptable. Among all of the cholangiograms, 5 were clinically applied with no correction, 8 were applied with modest improvements, and 3 produced a correct cholangiography before automatic selection. Although our procedure requires further improvement based on the analysis of additional patient data, it may represent an alternative to direct cholangiography in the future.

Hepatic Arterial Configuration in Relation to the Segmental Anatomy of the Liver; Observations on MDCT and DSA Relevant to Radioembolization Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoven, Andor F. van den, E-mail: a.f.vandenhoven@umcutrecht.nl; Leeuwen, Maarten S. van, E-mail: m.s.vanleeuwen@umcutrecht.nl; Lam, Marnix G. E. H., E-mail: m.lam@umcutrecht.nl

PurposeCurrent anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification.MethodsThe hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries weremore » defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA.ResultsThe hepatic arterial configuration and segmental vascularization pattern could be assessed in 110 of 133 patients. In 59 patients (54 %), no aberrant hepatic arteries or early branching was observed. Fourteen patients without aberrant hepatic arteries (13 %) had an early branching pattern. In the 37 patients (34 %) with aberrant hepatic arteries, five also had an early branching pattern. Sixteen different hepatic arterial segmental vascularization patterns were identified and described, differing by the presence of aberrant hepatic arteries, their respective vascular territory, and origin of the artery vascularizing segment four.ConclusionsThe hepatic arterial configuration and segmental vascularization pattern show marked individual variability beyond well-known classifications of anatomical variants. We developed an individualized RE treatment strategy based on an extended anatomical classification.« less

High-intensity focused ultrasound (HIFU) in patients with solid malignancies: evaluation of feasibility, local tumour response and clinical results.

PubMed

Orgera, G; Monfardini, L; Della Vigna, P; Zhang, L; Bonomo, G; Arnone, P; Padrenostro, M; Orsi, F

2011-08-01

The purpose of this study was to evaluate the safety and efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for ablation of solid tumours without damaging the surrounding structures. A specific written informed consent was obtained from every patient before treatment. From September 2008 to April 2009, 22 patients with 29 lesions were treated: nine patients with liver and/or soft-tissue metastases from colorectal carcinoma (CRC), six with pancreatic solid lesions, three with liver and/or bone metastases from breast cancer, one with osteosarcoma, one with muscle metastasis from lung cancer, one with iliac metastasis from multiple myeloma and one with abdominal liposarcoma. The mean diameter of tumours was 4.2 cm. All patients were evaluated 1 day, 1 month and 3 months after HIFU treatment by multidetector computed tomography (MDCT), positron-emission tomography (PET)-CT and clinical evaluation. The treatment time and adverse events were recorded. All patients had one treatment. Average treatment and sonication times were, respectively, 162.7 and 37.4 min. PET-CT or/and MDCT showed complete response in 11/13 liver metastases; all bone, soft-tissue and pancreatic lesions were palliated in symptoms, with complete response to PET-CT, MDCT or magnetic resonance imaging (MRI); the liposarcoma was almost completely ablated at MRI. Local oedema was observed in three patients. No other side effects were observed. All patients were discharged 1-3 days after treatment. According to our preliminary experience in a small number of patients, we conclude that HIFU ablation is a safe and feasible technique for locoregional treatment and is effective in pain control.

Anomalous origin of the right coronary artery evaluated with multidetector computed tomography and its clinical relevance.

PubMed

Hirono, Keiichi; Hata, Yukiko; Miyao, Naruaki; Nakaoka, Hideyuki; Saito, Kazuyoshi; Ibuki, Keijiro; Watanabe, Kazuhiro; Ozawa, Sayaka; Higuma, Tomonori; Yoshimura, Naoki; Nishida, Naoki; Ichida, Fukiko

2016-09-01

Anomalous origin of the right coronary artery (AORCA) is a rare congenital anomaly that may cause myocardial ischemia and sudden death. We reviewed the clinicopathological records of three cases of AORCA, and compared these with two cases of sudden cardiac death with AORCA revealed by autopsy. We report three juvenile cases with an AORCA originating above the commissural junction between the left and right aortic sinuses, with interarterial and intramural compression. They presented with exertional symptoms and were diagnosed with an AORCA by multidetector computed tomography (MDCT), which successfully delineated the spatial resolution of the anomalous origin and course of the right coronary artery (RCA), in the operating room. All three underwent successful surgical unroofing of the RCA. Two cases of sudden cardiac death with AORCA revealed by autopsy showed a slit-like orifice, acute-angled take-off, and long intramural course of the RCA, resembling the RCAs of three juvenile cases. It is crucial to be alert to the presentation of exertional symptoms, as sudden death may be the first manifestation of an anomalous coronary artery, such as those observed in these three cases. MDCT provided an excellent definition and spatial resolution of the unusual origin and intramural course of the RCA, facilitating the correct surgical remedy and resulting in a good outcome for the patients. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models.

PubMed

Baum, Thomas; Grande Garcia, Eduardo; Burgkart, Rainer; Gordijenko, Olga; Liebl, Hans; Jungmann, Pia M; Gruber, Michael; Zahel, Tina; Rummeny, Ernst J; Waldt, Simone; Bauer, Jan S

2015-06-26

Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae. Four thoracic vertebrae were harvested from each of three fresh human cadavers (n=12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months. Changes of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0-5.6% and 1.3-6.1%, respectively, and were not statistically significant (p>0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r=0.89-0.99; p<0.05). The correlation coefficients r were not significantly different for the two preservation methods (p>0.05). Formalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure and FEM-based ACM in human vertebrae and may both be used in corresponding in-vitro experiments in the context of osteoporosis.

Dual-phase CT for the assessment of acute vascular injuries in high-energy blunt trauma: the imaging findings and management implications.

PubMed

Iacobellis, Francesca; Ierardi, Anna M; Mazzei, Maria A; Magenta Biasina, Alberto; Carrafiello, Gianpaolo; Nicola, Refky; Scaglione, Mariano

2016-01-01

Acute vascular injuries are the second most common cause of fatalities in patients with multiple traumatic injuries; thus, prompt identification and management is essential for patient survival. Over the past few years, multidetector CT (MDCT) using dual-phase scanning protocol has become the imaging modality of choice in high-energy deceleration traumas. The objective of this article was to review the role of dual-phase MDCT in the identification and management of acute vascular injuries, particularly in the chest and abdomen following multiple traumatic injuries. In addition, this article will provide examples of MDCT features of acute vascular injuries with correlative surgical and interventional findings.

Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System.

PubMed

Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji; Ban, Nobuhiko; Hasegawa, Takayuki; Katsunuma, Yasushi; Yoshitake, Takayasu; Kai, Michiaki

2015-08-01

A dosimetry system for computed tomography (CT) examinations, named WAZA-ARI, is being developed to accurately assess radiation doses to patients in Japan. For dose calculations in WAZA-ARI, organ doses were numerically analyzed using average adult Japanese male (JM) and female (JF) phantoms with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the photon energy distribution of emitted photons and dose profiles on the table for some multi-detector row CT (MDCT) devices. Numerical analyses using a source model in PHITS could specifically take into account emissions of x rays from the tube to the table with attenuation of photons through a beam-shaping filter for each MDCT device based on the experiment results. The source model was validated by measuring the CT dose index (CTDI). Numerical analyses with PHITS revealed a concordance of organ doses with body sizes of the JM and JF phantoms. The organ doses in the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculations in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model (THRA1 phantom). The results imply that numerical analyses using the Japanese phantoms and specified source models can give reasonable estimates of dose for MDCT devices for typical Japanese adults.

CT in your clinical practice.

PubMed

Kohs, Gregory J; Legunn, Joel

2004-09-01

This report presents the results of a survey of 500 U.S.-based radiologists on critical issues associated with the use of CT. The survey represents a collaboration between the American Roentgen Ray Society (ARRS) and Philips Medical Systems. An outside firm, ICR/International Communications Research, conducted the survey. Survey questions were designed to elicit opinions about the past, present and future of CT, especially MDCT imaging, in various practice environments. Most radiologists (69%) indicated that CT has had a major influence on their specialty, more than any other medical advance, and that they expected this influence to increase. The idea that MDCT radically improves diagnostic quality was not universal, and opinions were mixed about the expansion of CT into new applications such as cardiac imaging. A number of concerns were attributed to the advent of MDCT and expansion in the number of slices-a phenomenon commonly referred to as a "slice war." These concerns revolved around managing the data explosion, excessive patient irradiation, bottlenecks in patient throughput, the ability of CT staffs to keep up with the rapidly evolving technology and the costs of keeping up with these changes. Nevertheless, most radiologists (78%) who were surveyed indicated that they used MDCT and that MDCT has had a positive effect on their practices in the past five years (90%); most (77%) expected that the number of slices would increase by two to 10 times the current level. Fifty-six percent said that they would be adding one to two scanners to their practices in the next five years.

Multidetector computed tomography shows reverse cardiac remodeling after double lung transplantation for pulmonary hypertension.

PubMed

Mandich Crovetto, D; Alonso Charterina, S; Jiménez López-Guarch, C; Pont Vilalta, M; Pérez Núñez, M; de Pablo Gafas, A; Escribano Subías, P

2016-01-01

To use multidetector computed tomography (MDCT) to evaluate the structural changes in the right heart and pulmonary arteries that occur in patients with severe pulmonary hypertension treated by double lung transplantation. This was a retrospective study of 21 consecutive patients diagnosed with severe pulmonary hypertension who underwent double lung transplantation at our center between 2010 and 2014. We analyzed the last MDCT study done before lung transplantation and the first MDCT study done after lung transplantation. We recorded the following variables: diameter of the pulmonary artery trunk, ratio of the diameter of the pulmonary artery trunk to the diameter of the ascending aorta, diameter of the right ventricle, ratio of the diameter of the left ventricle to the diameter of the right ventricle, and eccentricity index. Statistical analysis consisted of the comparison of the means of the variables recorded. In all cases analyzed, the MDCT study done a mean of 24±14 days after double lung transplantation showed a significant reduction in the size of the right heart chambers, with improved indices of ventricular interdependency index, and reduction in the size of the pulmonary artery trunk (p<0.001 for all the variables analyzed). Patients with pulmonary hypertension treated by double lung transplantation present early reverse remodeling of the changes in the structures of the right heart and pulmonary arterial tree. MDCT is useful for detecting these changes. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Effect of an oral anxiolytic medication and heart rate variability on image quality of 64-slice MDCT coronary angiography.

PubMed

Cubuk, R; Tasali, N; Yilmazer, S; Gokalp, P; Celik, L; Dagdeviren, B; Guney, S

2011-02-01

The aim of the study was to investigate the relationship between image quality in 64-slice multidetector computed tomography (MDCT) and patients' preimaging anxiety status and heart rate variability (HRV), and to evaluate the efficacy of an orally administered anxiolytic medication on HRV and image quality. Sixty patients [14 women, 46 men; mean age 52.53 ± 10.55 (SD), range 33-78 years] were studied. Anxiety levels were assessed with the State-Trait Anxiety Inventory 60 min before the procedure. The participating patients were randomly assigned to one of the two study groups: a control group (no medication administered for anxiety reduction) and an anxiolytic medication group, with 30 patients in each group. The presence of motion artefacts and image quality for each coronary artery segment were evaluated using a four-point grading system. To estimate HRV, the duration of each heartbeat during MDCT data acquisition was measured in each patient. A moderate correlation was found between HRV during MDCT scanning and the mean image quality for all coronary segments (r=0.47, p<0.01). There was an association between HRV and state anxiety scores in all cases (r=0.370, p<0.01). HRV in the patients who received alprazolam was statistically significantly lower than in controls (p<0.05). The average image quality in patients who used alprazolam was also statistically significantly higher than in controls (p<0.05). The most important finding in our study is that oral premedication to reduce anxiety is also effective in decreasing HRV and improves image quality. Therefore, we suggest that using alprazolam in addition to a β-blocker may improve image quality in patients undergoing MDCT coronary angiography (MDCT-CA). Anxiolytic usage may improve image quality by lowering the HRV in selected cases where administration of a β-blocker is contraindicated. We also suggest that further studies in larger series are required to validate this finding.

Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study.

PubMed

Tamura, Akio; Kato, Kenichi; Kamata, Masayoshi; Suzuki, Tomohiro; Suzuki, Michiko; Nakayama, Manabu; Tomabechi, Makiko; Nakasato, Tatsuhiko; Ehara, Shigeru

2017-02-01

To compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). In a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than -10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. A total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: -3.17% to 3.28%, non-inferiority P=1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16±0.95kg/cm 2 vs. 4.79±0.63kg/cm 2 , P<0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. In conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300mg/mL at a flow-rate of 3mL/s, and it may contribute to the care of some patients, such as patients who have fragile and small veins. (Trial registration: UMIN000023727). Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Computer-aided detection of artificial pulmonary nodules using an ex vivo lung phantom: influence of exposure parameters and iterative reconstruction.

PubMed

Wielpütz, Mark O; Wroblewski, Jacek; Lederlin, Mathieu; Dinkel, Julien; Eichinger, Monika; Koenigkam-Santos, M; Biederer, Jürgen; Kauczor, Hans-Ulrich; Puderbach, Michael U; Jobst, Bertram J

2015-05-01

To evaluate the influence of exposure parameters and raw-data based iterative reconstruction (IR) on the performance of computer-aided detection (CAD) of pulmonary nodules on chest multidetector computed tomography (MDCT). Seven porcine lung explants were inflated in a dedicated ex vivo phantom shell and prepared with n=162 artificial nodules of a clinically relevant volume and maximum diameter (46-1063 μl, and 6.2-21.5 mm). n=118 nodules were solid and n=44 part-solid. MDCT was performed with different combinations of 120 and 80 kV with 120, 60, 30 and 12 mA*s, and reconstructed with both filtered back projection (FBP) and IR. Subsequently, 16 datasets per lung were subjected to dedicated CAD software. The rate of true positive, false negative and false positive CAD marks was measured for each reconstruction. The rate of true positive findings ranged between 88.9-91.4% for FBP and 88.3-90.1% for IR (n.s.) with most exposure settings, but was significantly lower with the combination of 80 kV and 12 mA*s (80.9% and 81.5%, respectively, p<0.05). False positive findings ranged between 2.3-8.1 annotations per lung. For nodule volumes <200 μl the rate of true positives was significantly lower than for >300 μl (p<0.05). Similarly, it was significantly lower for diameters <12 mm compared to ≥12 mm (p<0.05). The rate of true positives for solid and part-solid nodules was similar. Nodule CAD on chest MDCT is robust over a wide range of exposure settings. Noise reduction by IR is not detrimental for CAD, and may be used to improve image quality in the setting of low-dose MDCT for lung cancer screening. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A method of estimating conceptus doses resulting from multidetector CT examinations during all stages of gestation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damilakis, John; Tzedakis, Antonis; Perisinakis, Kostas

Purpose: Current methods for the estimation of conceptus dose from multidetector CT (MDCT) examinations performed on the mother provide dose data for typical protocols with a fixed scan length. However, modified low-dose imaging protocols are frequently used during pregnancy. The purpose of the current study was to develop a method for the estimation of conceptus dose from any MDCT examination of the trunk performed during all stages of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study to model the Siemens Sensation 16 and Sensation 64 MDCT scanners. Four mathematical phantoms were used, simulatingmore » women at 0, 3, 6, and 9 months of gestation. The contribution to the conceptus dose from single simulated scans was obtained at various positions across the phantoms. To investigate the effect of maternal body size and conceptus depth on conceptus dose, phantoms of different sizes were produced by adding layers of adipose tissue around the trunk of the mathematical phantoms. To verify MCNP results, conceptus dose measurements were carried out by means of three physical anthropomorphic phantoms, simulating pregnancy at 0, 3, and 6 months of gestation and thermoluminescence dosimetry (TLD) crystals. Results: The results consist of Monte Carlo-generated normalized conceptus dose coefficients for single scans across the four mathematical phantoms. These coefficients were defined as the conceptus dose contribution from a single scan divided by the CTDI free-in-air measured with identical scanning parameters. Data have been produced to take into account the effect of maternal body size and conceptus position variations on conceptus dose. Conceptus doses measured with TLD crystals showed a difference of up to 19% compared to those estimated by mathematical simulations. Conclusions: Estimation of conceptus doses from MDCT examinations of the trunk performed on pregnant patients during all stages of gestation can be made using the method developed in the current study.« less

Validity of linear measurements of the jaws using ultralow-dose MDCT and the iterative techniques of ASIR and MBIR.

PubMed

Al-Ekrish, Asma'a A; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Widmann, Gerlig

2016-10-01

To assess the comparability of linear measurements of dental implant sites recorded from multidetector computed tomography (MDCT) images obtained using standard-dose filtered backprojection (FBP) technique with those from various ultralow doses combined with FBP, adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR) techniques. The results of the study may contribute to MDCT dose optimization for dental implant site imaging. MDCT scans of two cadavers were acquired using a standard reference protocol and four ultralow-dose test protocols (TP). The volume CT dose index of the different dose protocols ranged from a maximum of 30.48-36.71 mGy to a minimum of 0.44-0.53 mGy. All scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Linear measurements were recorded from standardized images of the jaws by two examiners. Intra- and inter-examiner reliability of the measurements were analyzed using Cronbach's alpha and inter-item correlation. Agreement between the measurements obtained with the reference-dose/FBP protocol and each of the test protocols was determined with Bland-Altman plots and linear regression. Statistical significance was set at a P-value of 0.05. No systematic variation was found between the linear measurements obtained with the reference protocol and the other imaging protocols. The only exceptions were TP3/ASIR-50 (bone kernel) and TP4/ASIR-100 (bone and standard kernels). The mean measurement differences between these three protocols and the reference protocol were within ±0.1 mm, with the 95 % confidence interval limits being within the range of ±1.15 mm. A nearly 97.5 % reduction in dose did not significantly affect the height and width measurements of edentulous jaws regardless of the reconstruction algorithm used.

Importance of preoperative imaging with 64-row three-dimensional multidetector computed tomography for safer video-assisted thoracic surgery in lung cancer.

PubMed

Akiba, Tadashi; Marushima, Hideki; Harada, Junta; Kobayashi, Susumu; Morikawa, Toshiaki

2009-01-01

Video-assisted thoracic surgery (VATS) has recently been adopted for complicated anatomical lung resections. During these thoracoscopic procedures, surgeons view the operative field on a two-dimensional (2-D) video monitor and cannot palpate the organ directly, thus frequently encountering anatomical difficulties. This study aimed to estimate the usefulness of preoperative three-dimensional (3-D) imaging of thoracic organs. We compared the preoperative 64-row three-dimensional multidetector computed tomography (3DMDCT) findings of lung cancer-affected thoracic organs to the operative findings. In comparison to the operative findings, the branches of pulmonary arteries, veins, and bronchi were well defined in the 3D-MDCT images of 27 patients. 3D-MDCT imaging is useful for preoperatively understanding the individual thoracic anatomy in lung cancer surgery. This modality can therefore contribute to safer anatomical pulmonary operations, especially in VATS.

Thyroid cartilage invasion in laryngeal and hypopharyngeal squamous cell carcinoma treated with total laryngectomy.

PubMed

Koopmann, Mario; Weiss, Daniel; Steiger, Matthias; Elges, Sandra; Rudack, Claudia; Stenner, Markus

2016-11-01

The objective of this study is to analyze the accuracy of computed tomography in detecting malignant thyroid cartilage invasion. In a retrospective chart review, 120 patients with carcinoma of the larynx and hypopharynx underwent computed tomography before total laryngectomy. These data were compared with the histological specimens. Multidetector computed tomography (MDCT) scan had a positive predictive value (PPV) of 76 % and a negative predictive value (NPV) of 69 %. The specificity of MDCT was 89 % and sensitivity was 46 %. Comparison between radiologic suspected cartilage invasion and histologic results showed a significant correlation (p < 0.02). We found no significant impact of cartilage invasion concerning survival rates (5-year overall survival p = 0.683; 5-year disease-free survival p = 0.711). Preoperative CT scan is an important instrument in detecting neoplastic cartilage invasion.

Imaging of Combat-Related Thoracic Trauma - Blunt Trauma and Blast Lung Injury.

PubMed

Lichtenberger, John P; Kim, Andrew M; Fisher, Dane; Tatum, Peter S; Neubauer, Brian; Peterson, P Gabriel; Carter, Brett W

2018-03-01

Combat-related thoracic trauma (CRTT) is a significant contributor to morbidity and mortality of the casualties from Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). Penetrating, blunt, and blast injuries are the most common mechanisms of trauma to the chest. Imaging plays a key role in the battlefield management of CRTT casualties. This work discusses the imaging manifestations of thoracic injuries from blunt trauma and blast injury, emphasizing epidemiology and diagnostic clues seen during OEF and OIF. The assessment of radiologic findings in patients who suffer from combat-related blunt thoracic trauma and blast injury is the basis of this work. The imaging modalities for this work include multi-detector computed tomography (MDCT) and chest radiography. Multiple imaging modalities are available to imagers on or near the battlefront, including radiography, fluoroscopy, and MDCT. MDCT with multi-planar reconstructions is the most sensitive imaging modality available in combat hospitals for the evaluation of CRTT. In modern combat, blunt and blast injuries account for a significant portion of CRTT. Individual body armor converts penetrating trauma to blunt trauma, leading to pulmonary contusion that accounted for 50.2% of thoracic injuries during OIF and OEF. Flail chest, a subset of blunt chest injury, is caused by significant blunt force to the chest and occurs four times as frequently in combat casualties when compared with the civilian population. Imaging features of CRTT have significant diagnostic and prognostic value. Pulmonary contusions on chest radiography appear as patchy consolidations in the acute setting with ill-defined and non-segmental borders. MDCT of the chest is a superior imaging modality in diagnosing and evaluating pulmonary contusion. Contusions on MDCT appear as crescentic ground-glass opacities (opacities through which lung interstitium and vasculature are still visible) and areas of consolidation that often do not respect the anatomic boundaries of the affected lobes. Additionally, small pulmonary contusions may exhibit sub-pleural sparing and may distinguish contusion from pneumonia or other lung pathology. Although pulmonary laceration is typically the result of penetrating trauma, laceration may also be caused by displaced rib fractures or significant shearing forces on the lung without penetrating injury. Because of elastic recoil of the normal pulmonary parenchyma surrounding the injury, pulmonary lacerations may present as late as 48-72 h after injury. Pulmonary lacerations may appear similar to pulmonary contusions on chest radiography initially and will require MDCT for definitive diagnosis. Blast injury is a defining injury of modern combat. Blast lung injury is initially diagnosed with chest radiography, where the pattern of lung opacities has previously been described by clinicians as "batwing" or "butterfly" because of its central appearance in the lung. "Peribronchovascular" may be a more accurate description of primary blast lung based on its appearance on MDCT. This pattern may differentiate primary blast lung injury from other causes of thoracic trauma. CRTT continues to be a significant contributor to the morbidity and mortality of those injured during OEF and OIF. The distinct injury patterns and atypical imaging manifestations of blunt trauma and blast lung injury are important to recognize early because of the acuity of this patient population and the influence of accurate diagnosis on clinical management.

[Comparison of 64 MDCT coronary CTA and coronary angiography in the detection of coronary artery stenosis in low risk patients with stable angina and acute coronary syndrome].

PubMed

Cazalas, G; Sarran, A; Amabile, N; Chaumoitre, K; Marciano-Chagnaud, S; Jacquier, A; Paganelli, F; Panuel, M

2009-09-01

To determine the accuracy of 64 MDCT coronary CTA (CCTA) compared to coronary angiography in low risk patients with stable angina and acute coronary syndrome and determine the number of significant coronary artery stenoses ( 50%) in these patients. Materials and methods. Fifty-five patients underwent CCTA using a 32 MDCT unit with z flying focus allowing the acquisition of 64 slices of 0.6 mm thickness as well as coronary angiography (gold standard). Nine patients were excluded due to prior coronary artery bypass surgery (n=4), insufficient breath hold (n=3), calcium scoring>1000 (n=1) and delay between both examinations over 4 months (n=1). Forty-six patients: 27 males and 19 females were included. CCTA results were compared to coronary angiography per segment and artery with threshold detection of stenoses 50%. The degree of correlation between both examinations was performed using a regression analysis with a Pearson correlation coefficient<0.05 considered significant. The overall accuracy of CCTA was 90%; limitations related to the presence of calcifications, motion artifacts or insufficient vessel opacification. The correlation for all analyzed segments was 96.4%. Thirty-eight of 50 significant stenoses seen on coronary angiography were correctly detected on CCTA. Sensitivity, specificity, PPVC and NPV for detection of stenoses 50% were 76%, 98.3%, 80.3% and 97.7% respectively. Evaluation per segment had a NPV of 96.8% (interventricular and diagonal segments) to 100% (main trunk). Our results for specificity and NPV are similar to reports from the literature. This suggests that CCTA in this clinical setting may replace coronary angiography.

A Comparison of the Use of Contrast Media with Different Iodine Concentrations for Multidetector CT of the Kidney

PubMed Central

Jung, Seung Chai; Cho, Jeong Yeon

2011-01-01

Objective To determine the optimal iodine concentration of contrast media for kidney multidetector computed tomography (MDCT) by comparing the degree of renal parenchymal enhancement and the severity of the renal streak artifact with contrast media of different iodine concentrations. Materials and Methods A 16-row MDCT was performed in 15 sedated rabbits by injection of 2 mL contrast media/kg body weight at a rate of 0.3 mL/sec. Monomeric nonionic contrast media of 250, 300, and 370 mg iodine/mL were injected at 1-week intervals. Mean attenuation values were measured in each renal structure with attenuation differences among the structures. The artifact was evaluated by CT window width/level and three grading methods. The values were compared with iodine concentrations. Results The 370 mg iodine/mL concentration showed significantly higher cortical enhancement than 250 mg iodine/mL in all phases (p < 0.05). There was however no significant difference in the degree of enhancement between the 300 mg iodine/mL and 370 mg iodine/mL concentrations in all phases. There is a significant difference in attenuation for the cortex-outer medulla between 250 mg iodine/mL and 300 mg iodine/mL (p < 0.05). The artifact was more severe with a medium of 370 mg iodine/mL than with 250 mg iodine/mL by all grading methods (p < 0.05). Conclusion The 300 mg iodine/mL is considered to be the most appropriate iodine concentration in an aspect of the enhancement and artifact on a kidney MDCT scan. PMID:22043154

Assessment of temporal resolution of multi-detector row computed tomography in helical acquisition mode using the impulse method.

PubMed

Ichikawa, Katsuhiro; Hara, Takanori; Urikura, Atsushi; Takata, Tadanori; Ohashi, Kazuya

2015-06-01

The purpose of this study was to propose a method for assessing the temporal resolution (TR) of multi-detector row computed tomography (CT) (MDCT) in the helical acquisition mode using temporal impulse signals generated by a metal ball passing through the acquisition plane. An 11-mm diameter metal ball was shot along the central axis at approximately 5 m/s during a helical acquisition, and the temporal sensitivity profile (TSP) was measured from the streak image intensities in the reconstructed helical CT images. To assess the validity, we compared the measured and theoretical TSPs for the 4-channel modes of two MDCT systems. A 64-channel MDCT system was used to compare TSPs and image quality of a motion phantom for the pitch factors P of 0.6, 0.8, 1.0 and 1.2 with a rotation time R of 0.5 s, and for two R/P combinations of 0.5/1.2 and 0.33/0.8. Moreover, the temporal transfer functions (TFs) were calculated from the obtained TSPs. The measured and theoretical TSPs showed perfect agreement. The TSP narrowed with an increase in the pitch factor. The image sharpness of the 0.33/0.8 combination was inferior to that of the 0.5/1.2 combination, despite their almost identical full width at tenth maximum values. The temporal TFs quantitatively confirmed these differences. The TSP results demonstrated that the TR in the helical acquisition mode significantly depended on the pitch factor as well as the rotation time, and the pitch factor and reconstruction algorithm affected the TSP shape. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

64-MDCT angiography of blunt vascular injuries of the neck.

PubMed

Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

2011-03-01

CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

MDCT Venography Evaluation of a Rare Collateral Vein Draining from the Left Subclavian Vein to the Great Cardiac Vein

PubMed Central

Abchee, Antoine; Saade, Charbel; Al-Mohiy, Hussain; El-Merhi, Fadi

2014-01-01

Congenital vascular anomalies of the venous drainage in the chest affect both cardiac and non-cardiac structures. Collateral venous drainage from the left subclavian vein to the great cardiac vein is a rare venous drainage pattern. These anomalies present a diagnostic challenge. Multi-detector computed tomography (MDCT) is useful in the diagnosis and treatment planning of these clinically complex disorders. We present a case report of an 18-year-old Caucasian male who came to our institute for evaluation of venous drainage patterns to the heart. We describe the contrast technique of bilateral dual injection MDCT venography and the imaging features of the venous drainage patterns to the heart. PMID:25379351

MDCT Venography Evaluation of a Rare Collateral Vein Draining from the Left Subclavian Vein to the Great Cardiac Vein.

PubMed

Abchee, Antoine; Saade, Charbel; Al-Mohiy, Hussain; El-Merhi, Fadi

2014-01-01

Congenital vascular anomalies of the venous drainage in the chest affect both cardiac and non-cardiac structures. Collateral venous drainage from the left subclavian vein to the great cardiac vein is a rare venous drainage pattern. These anomalies present a diagnostic challenge. Multi-detector computed tomography (MDCT) is useful in the diagnosis and treatment planning of these clinically complex disorders. We present a case report of an 18-year-old Caucasian male who came to our institute for evaluation of venous drainage patterns to the heart. We describe the contrast technique of bilateral dual injection MDCT venography and the imaging features of the venous drainage patterns to the heart.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

PubMed

Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

2013-02-01

To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0.007). Significantly increased pancreatic lesion contrast was noted at lower viewing energies using spectral MDCT. Individual patient CNR-optimized energy level images have the potential to improve lesion conspicuity. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

MDCT findings of renal cell carcinoma associated with Xp11.2 translocation and TFE3 gene fusion and papillary renal cell carcinoma.

PubMed

Woo, Sungmin; Kim, Sang Youn; Lee, Myoung Seok; Moon, Kyung Chul; Kim, See Hyung; Cho, Jeong Yeon; Kim, Seung Hyup

2015-03-01

OBJECTIVE. The purpose of this study was to compare the MDCT features of renal cell carcinoma (RCC) associated with Xp11.2 translocation and TFE3 gene fusion (Xp11 RCC) and papillary RCC. MATERIALS AND METHODS. The study included 19 and 39 patients with histologically proven Xp11 RCC and papillary RCC, respectively, who underwent multiphase renal MDCT before nephrectomy. CT findings were compared between Xp11 RCC and papillary RCC using the Student t test and chi-square test. Subgroup analyses of small (< 4 cm) renal masses for these features were performed. RESULTS. Patients with Xp11 RCC were younger (p < 0.001), and it was more prevalent in women (p = 0.007). Tumor size was greater in Xp11 RCC (p = 0.004) and more common in cystic change (p < 0.001). Calcification and unenhanced high-attenuating areas were more frequent in Xp11 RCC (p = 0.001 and 0.026, respectively). Xp11 RCCs were more prevalent in lymph node and distant metastasis (p < 0.001 and p = 0.031, respectively). Xp11 RCC and papillary RCC showed no significant difference in epicenter, margin, and venous and collecting duct invasion (p = 0.403-1.000). Although Xp11 RCC and papillary RCC had lower attenuation than the renal cortex on corticomedullary and early excretory phases (p < 0.001), only Xp11 RCCs were hyperattenuating to the cortex on the unenhanced phase (p < 0.001). Xp11 RCCs had significantly higher attenuation compared with papillary RCCs on all phases (p ≤ 0.02). Regarding small masses, cystic change, calcification, and lymph node metastasis were still more frequent in Xp11 RCCs (p ≤ 0.016). CONCLUSION. Greater size, more cystic change, calcification, high-attenuating areas on unenhanced imaging, and lymph node and distant metastasis were helpful for differentiating Xp11 RCC from papillary RCC.

Optimization of 64-MDCT urography: effect of dual-phase imaging with furosemide on collecting system opacification and radiation dose.

PubMed

Portnoy, Orith; Guranda, Larisa; Apter, Sara; Eiss, David; Amitai, Marianne Michal; Konen, Eli

2011-11-01

The purpose of this study was to compare opacification of the urinary collecting system and radiation dose associated with three-phase 64-MDCT urographic protocols and those associated with a split-bolus dual-phase protocol including furosemide. Images from 150 CT urographic examinations performed with three scanning protocols were retrospectively evaluated. Group A consisted of 50 sequentially registered patients who underwent a three-phase protocol with saline infusion. Group B consisted of 50 sequentially registered patients who underwent a reduced-radiation three-phase protocol with saline. Group C consisted of 50 sequentially registered patients who underwent a dual-phase split-bolus protocol that included a low-dose furosemide injection. Opacification of the urinary collecting system was evaluated with segmental binary scoring. Contrast artifacts were evaluated, and radiation doses were recorded. Results were compared by analysis of variance. A significant reduction in mean effective radiation dose was found between groups A and B (p < 0.001) and between groups B and C (p < 0.001), resulting in 65% reduction between groups A and C (p < 0.001). This reduction did not significantly affect opacification score in any of the 12 urinary segments (p = 0.079). In addition, dense contrast artifacts overlying the renal parenchyma observed with the three-phase protocols (groups A and B) were avoided with the dual-phase protocol (group C) (p < 0.001). A dual-phase protocol with furosemide injection is the preferable technique for CT urography. In comparison with commonly used three-phase protocols, the dual-phase protocol significantly reduces radiation exposure dose without reduction in image quality.

MDCT-Guided Transthoracic Needle Aspiration Biopsy of the Lung Using the Transscapular Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara; Ferro, Carlo

2011-02-15

The purpose of this study is to report our preliminary experience using MDCT-guided percutaneous transthoracic needle aspiration biopsy using the transscapular approach in the upper posterolateral lung nodules, an area that it is difficult or hazardous to reach with the conventional approach. Five patients underwent CT-guided percutaneous transthoracic needle aspiration biopsy of the lung via the transscapular approach. A coaxial needle technique was used in all patients. Biopsy was successful in all patients. No major complications were encountered. One patient developed a minimal pneumothorax next to the lesion immediately after biopsy, which resolved spontaneously. MDCT-guided percutaneous transthoracic needle aspiration biopsymore » of the lung via the transscapular approach is an effective and safe procedure that reduces the risk of pneumothorax in selected patients.« less

The New Approach to Sport Medicine: 3-D Reconstruction

ERIC Educational Resources Information Center

Ince, Alparslan

2015-01-01

The aim of this study is to present a new approach to sport medicine. Comparative analysis of the Vertebrae Lumbales was done in sedentary group and Muay Thai athletes. It was done by acquiring three dimensional (3-D) data and models through photogrammetric methods from the Multi-detector Computerized Tomography (MDCT) images of the Vertebrae…

MDCT quantification is the dominant parameter in decision–making regarding chest tube drainage for stable patients with traumatic pneumothorax

PubMed Central

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2013-01-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. PMID:22560899

Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis.

PubMed

Luo, Mingxu; Song, Hongmei; Liu, Gang; Lin, Yikai; Luo, Lintao; Zhou, Xin; Chen, Bo

2017-10-13

The diagnostic values of diffusion weighted imaging (DWI) and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) for N-staging of gastric cancer (GC) were identified and compared. After a systematic search to identify relevant articles, meta-analysis was used to summarize the sensitivities, specificities, and areas under curves (AUCs) for DWI and PET/CT. To better understand the diagnostic utility of DWI and PET/CT for N-staging, the performance of multi-detector computed tomography (MDCT) was used as a reference. Fifteen studies were analyzed. The pooled sensitivity, specificity, and AUC with 95% confidence intervals of DWI were 0.79 (0.73-0.85), 0.69 (0.61-0.77), and 0.81 (0.77-0.84), respectively. For PET/CT, the corresponding values were 0.52 (0.39-0.64), 0.88 (0.61-0.97), and 0.66 (0.62-0.70), respectively. Comparison of the two techniques revealed DWI had higher sensitivity and AUC, but no difference in specificity. DWI exhibited higher sensitivity but lower specificity than MDCT, and 18 F-FDG PET/CT had lower sensitivity and equivalent specificity. Overall, DWI performed better than 18 F-FDG PET/CT for preoperative N-staging in GC. When the efficacy of MDCT was taken as a reference, DWI represented a complementary imaging technique, while 18 F-FDG PET/CT had limited utility for preoperative N-staging.

The effects of emphysema on airway disease: correlations between multi-detector CT and pulmonary function tests in smokers.

PubMed

Yahaba, Misuzu; Kawata, Naoko; Iesato, Ken; Matsuura, Yukiko; Sugiura, Toshihiko; Kasai, Hajime; Sakurai, Yoriko; Terada, Jiro; Sakao, Seiichiro; Tada, Yuji; Tanabe, Nobuhiro; Tatsumi, Koichiro

2014-06-01

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and small airway narrowing. Quantitative evaluation of airway dimensions by multi-detector computed tomography (MDCT) has revealed a correlation between airway dimension and airflow limitation. However, the effect of emphysema on this correlation is unclear. The goal of this study was to determine whether emphysematous changes alter the relationships between airflow limitation and airway dimensions as measured by inspiratory and expiratory MDCT. Ninety-one subjects underwent inspiratory and expiratory MDCT. Images were evaluated for mean airway luminal area (Ai), wall area percentage (WA%) from the third to the fifth generation of three bronchi (B1, B5, B8) in the right lung, and low attenuation volume percent (LAV%). Correlations between each airway index and airflow limitation were determined for each patient and compared between patients with and without evidence of emphysema. In patients without emphysema, Ai and WA% from both the inspiratory and expiratory scans were significantly correlated with FEV1. No correlation was detected in patients with emphysema. In addition, emphysematous COPD patients with GOLD stage 1 or 2 disease had significantly lower changes in B8 Ai than non-emphysematous patients. A significant correlation exists between airway parameters and FEV1 in patients without emphysema. Emphysema may influence airway dimensions even in patients with mild to moderate COPD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

[Study of anatomy of the lateral attachment of the renal fascia in adult with multidetector computed tomography].

PubMed

Qi, Rui; Zhou, Xianping; Yu, Jianqun; Chen, Weixia; Li, Zhenlin; Zhang, Chunle

2012-08-01

The present paper is aimed to observe the lateral attachment of the renal fascia (RF) in vivo with multidetector computed tomography (MDCT) scanning, and to discuss its diagnostic value. 121 healthy adults were adopted into this experiment. All images were obtained with MDCT and double phase enhancement scanning. Then we observed the lateral attachment of RF. In addition, we mad a fresh body specimen as anatomical basis. The study found that above the renal hilar plane (RHP), the anterior renal fascia laterally fused with the peritoneum of the liver on the right and the peritoneum of the spleen on the left,and the posterior renal fascia fused with the subdiaphragmatic fascia. The lateral attachment of the RF at the RHP and the lower renal pole(LRP)is divided into three types. The RF in Type I is about 47.9% (58/121) at the left RHP, while about 33.9% (41/121) at the right RHP. At the LRP of the kidney is about 55.3% (67/121) on the left, and about 42.1% (51/121) on the right. The RF in Type I is about 38.8% (47/121) on the left side at the RHP, about 26.4% (32/121) on the right side. At the LRP, left side about 27.3% (33/121), right side about 13.3%(16/121). The RF in Type III at the RHP is 13.3% (16/121) on the left side, and on the right side is about 39.7% (48/121). At the LRP, it is about 17.4% (21/121) on the left side, and about 44.6% (54/121) on the right side. MDCT can display the lateral attachment of the RF better as well as the outside connection of the retroperitoneal space.

Computed Tomography Helps to Plan Minimally Invasive Aortic Valve Replacement Operations.

PubMed

Stoliński, Jarosław; Plicner, Dariusz; Grudzień, Grzegorz; Kruszec, Paweł; Fijorek, Kamil; Musiał, Robert; Andres, Janusz

2016-05-01

This study evaluated the role of multidetector computed tomography (MDCT) in preparation for minimally invasive aortic valve replacement (MIAVR). An analysis of 187 patients scheduled for MIAVR between June 2009 and December 2014 was conducted. In the study group (n = 86), MDCT of the thorax, aorta, and femoral arteries was performed before the operation. In the control group (n = 101), patients qualified for MIAVR without receiving preoperative MDCT. The surgical strategy was changed preoperatively in 12.8% of patients from the study group and in 2.0% of patients from the control group (p = 0.010) and intraoperatively in 9.9% of patients from the control group and in none from the study group (p = 0.002). No conversion to median sternotomy was necessary in the study group; among the controls, there were 4.0% conversions. On the basis of the MDCT measurements, optimal access to the aortic valve was achieved when the angle between the aortic valve plane and the line to the second intercostal space was 91.9 ± 10.0 degrees and to the third intercostal space was 94.0 ± 1.4 degrees, with the distance to the valve being 94.8 ± 13.8 mm and 84.5 ± 9.9 mm for the second and third intercostal spaces, respectively. The right atrium covering the site of the aortotomy was present in 42.9% of cases when MIAVR had been performed through the third intercostal space and in 1.3% when through the second intercostal space (p = 0.001). Preoperative MDCT of the thorax, aorta, and femoral arteries makes it possible to plan MIAVR operations. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Dose versus diagnosis: iatrogenic radiation exposure by multidetector computerised tomography in an academic emergency department with measurement of clinically actionable results and emergently treatable findings.

PubMed

Baskerville, J R; Chang, J H; Viator, M; Rutledge, W; Miryala, R; Duval, K E; Nishino, T K

2009-01-01

To determine the iatrogenic absorbed dosage of radiation of the patient in milligray (mGy) computerised tomography dose index volume (CTDIvol) when tested with multidetector computerised tomography (MDCT) in the emergency department (ED) setting and calculate the absorbed dosage of radiation per clinically actionable result and emergently treatable finding (ETF). The University of Texas Medical Branch (UTMB) ED located in Galveston, Texas, USA, is a level 1 trauma and tertiary referral centre treating 70,000 patients per annum. A retrospective cross-sectional data analysis of 770 emergency patients investigated by MDCT in July 2007. The presence of actionable results and ETF were determined by chart review. A total of 5320 emergency patients was treated in the UTMB ED in July 2007. This included 4508 medical and 812 trauma patients. A total of 1094 MDCT studies was performed, of which complete data were available on 1046. A total of 770 patients was investigated by MDCT, representing 14.47% of all emergency patients. This included 33.99% of trauma patients and 10.96% of medical patients. Actionable results were found in 341 studies and ETF in 105 studies. The mean radiation was 163.27 and 530.23 mGy CTDIvol for actionable results and ETF, respectively, for all studies. The mean radiation was 53.27 and 106.36 mGy CTDIvol for medical and trauma patients, respectively. The absorbed dosage of radiation of patients investigated by MDCT is clinically significant. The actionable results and ETF in our study demonstrate considerable opportunity for improvement in the utilisation of this technology by physicians.

Integration of 3D imaging data in the assessment of aortic stenosis: impact on classification of disease severity.

PubMed

O'Brien, Bridget; Schoenhagen, Paul; Kapadia, Samir R; Svensson, Lars G; Rodriguez, Leonardo; Griffin, Brian P; Tuzcu, E Murat; Desai, Milind Y

2011-09-01

In patients with aortic stenosis (AS), precise assessment of severity is critical for treatment decisions. Estimation of aortic valve area (AVA) with transthoracic echocardiographic (TTE)-continuity equation (CE) assumes a circular left ventricular outflow tract (LVOT). We evaluated incremental utility of 3D multidetector computed tomography (MDCT) over TTE assessment of AS severity. We included 51 patients (age, 81±8 years; 61% men; mean gradient, 42 ± 12 mm Hg) with calcific AS who underwent evaluation for treatment options. TTE parameters included systolic LVOT diameter (D) and continuous and pulsed wave (CW and PW) velocity-time integrals (VTI) through the LVOT and mean transaortic gradient. MDCT parameters included systolic LVOT area, ratio of maximal to minimal LVOT diameter (eccentricity index), and aortic planimetry (AVA(p)). TTE-CE AVA [(D(2)×0.786×VTIpw)/VTIcw] and dimensionless index (DI) [VTIpw/VTIcw] were calculated. Corrected AVA was calculated by substituting MDCT LVOT area into CE. The majority (96%) of patients had eccentric LVOT. LVOT area, measured on MDCT, was higher than on TTE (3.84 ± 0.8 cm(2) versus 3.03 ± 0.5 cm(2), P<0.01). TTE-AVA was smaller than AVA(p) and corrected AVA (0.67 ± 0.1cm(2), 0.82 ± 0.3 cm(2), and 0.86 ± 0.3 cm(2), P<0.01). Using TTE measurements alone, 73% of patients had congruence for severe AS (DI ≤0.25 and CE AVA <0.8 cm(2)), which increased to 92% using corrected CE. In patients with suspected severe AS, incorporation of MDCT-LVOT area into CE improves congruence for AS severity.

Prognostic value of right ventricular dilatation in patients with low-risk pulmonary embolism.

PubMed

Côté, Benoit; Jiménez, David; Planquette, Benjamin; Roche, Anne; Marey, Jonathan; Pastré, Jean; Meyer, Guy; Sanchez, Olivier

2017-12-01

The prognosis of multidetector computed tomography (MDCT) assessed right ventricular dilatation (RVD) is unclear in patients with pulmonary embolism (PE) and a simplified Pulmonary Embolism Severity Index (sPESI) of 0. We investigated in these patients whether MDCT-assessed RVD, defined by a right to left ventricular ratio (RV/LV) ≥0.9 or ≥1.0, is associated with worse outcomes.We combined data from three prospective cohorts of patients with PE. The main study outcome was the composite of 30-day all-cause mortality, haemodynamic collapse or recurrent PE in patients with sPESI of 0.Among 779 patients with a sPESI 0, 420 (54%) and 299 (38%) had a RV/LV ≥0.9 and ≥1.0 respectively. No difference in primary outcome was observed, 0.95% (95% CI 0.31-2.59) versus 0.56% (95% CI 0.10-2.22; p=0.692) and 1.34% (95% CI 0.43-3.62) versus 0.42% (95% CI 0.07-1.67; p=0.211) with RV/LV ≥0.9 and ≥1.0 respectively. Increasing the RV/LV threshold to ≥1.1, the outcome occurred more often in patients with RVD (2.12%, 95% CI 0.68-5.68 versus 0.34%, 95% CI 0.06-1.36; p=0.033).MDCT RV/LV ratio of ≥0.9 and ≥1.0 in sPESI 0 patients is frequent but not associated with a worse prognosis but higher cut-off values might be associated with worse outcome in these patients. Copyright ©ERS 2017.

Effects of sparse sampling in combination with iterative reconstruction on quantitative bone microstructure assessment

NASA Astrophysics Data System (ADS)

Mei, Kai; Kopp, Felix K.; Fehringer, Andreas; Pfeiffer, Franz; Rummeny, Ernst J.; Kirschke, Jan S.; Noël, Peter B.; Baum, Thomas

2017-03-01

The trabecular bone microstructure is a key to the early diagnosis and advanced therapy monitoring of osteoporosis. Regularly measuring bone microstructure with conventional multi-detector computer tomography (MDCT) would expose patients with a relatively high radiation dose. One possible solution to reduce exposure to patients is sampling fewer projection angles. This approach can be supported by advanced reconstruction algorithms, with their ability to achieve better image quality under reduced projection angles or high levels of noise. In this work, we investigated the performance of iterative reconstruction from sparse sampled projection data on trabecular bone microstructure in in-vivo MDCT scans of human spines. The computed MDCT images were evaluated by calculating bone microstructure parameters. We demonstrated that bone microstructure parameters were still computationally distinguishable when half or less of the radiation dose was employed.

CT angiography of the renal arteries and veins: normal anatomy and variants.

PubMed

Hazırolan, Tuncay; Öz, Meryem; Türkbey, Barış; Karaosmanoğlu, Ali Devrim; Oğuz, Berna Sayan; Canyiğit, Murat

2011-03-01

Conventional angiography has long been regarded as gold standard imaging modality for evaluation of the renal vasculature. Introduction of multidetector computed tomography (MDCT) angiography had a groundbreaking impact on evaluation of the renal vessels and is gradually replacing conventional angiography as standard imaging. Herein, we review and illustrate the normal and variant anatomy of renal vessels with special emphasis on imaging protocols and reconstruction techniques in MDCT.

Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

PubMed Central

Tsili, Athina C; Argyropoulou, Maria I

2015-01-01

Renal cell carcinoma (RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography (CT) is considered the examination of choice for the detection and staging of RCC. Multidetector CT (MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and three-dimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment. PMID:26120380

Multidetector row computed tomography evaluation of the micropig kidney as a potential renal donor.

PubMed

Yoon, Woong; Lee, Min Young; Ryu, Jung Min; Moon, Yong Ju; Lee, Sang Hun; Park, Jae Hong; Yun, Seung Pil; Jang, Min Woo; Park, Sung Su; Han, Ho Jae

2010-03-01

Multidetector row computed tomography (MDCT) provides anatomical information about the kidney and other internal organs. Presently, the suitability of 64-channel MDCT to assess the kidney of healthy micropigs was evaluated. Morphological evaluations of the kidney and the major renal vessels of six healthy micropigs were carried out using MDCT, recording kidney volume and the diameter and length of renal arteries and veins. The mean diameters and lengths of the renal artery were 0.44 +/- 0.05 and 4.51 +/- 0.55 cm on the right side and 0.46 +/- 0.06 and 3.36 +/- 0.27 cm on the left side, respectively. The mean diameters and lengths of the renal vein were 1.44 +/- 0.52 and 4.22 +/- 1.29 cm on the right side and 1.38 +/- 0.17 and 5.15 +/- 0.87 cm on the left side, respectively. The mean volume of the right kidney was 79.3 +/- 14.5 mL and of the left kidney was 78.0 +/- 13.9 mL. The data presented in this study suggest that the MDCT offers a noninvasive, rapid, and accurate method for the evaluation of the renal anatomy in living kidney donors. It also provides sufficient information about extra-renal anatomy important for donor surgery and determination of organ suitability.

Association between diabetes and different components of coronary atherosclerotic plaque burden as measured by coronary multidetector computed tomography.

PubMed

Yun, Chun-Ho; Schlett, Christopher L; Rogers, Ian S; Truong, Quynh A; Toepker, Michael; Donnelly, Patrick; Brady, Thomas J; Hoffmann, Udo; Bamberg, Fabian

2009-08-01

The aim of the study was to assess differences in the presence, extent, and composition of coronary atherosclerotic plaque burden as detected by coronary multidetector computed tomography (MDCT) between patients with and without diabetes mellitus. We compared coronary atherosclerotic plaques (any plaque, calcified [CAP], non-calcified [NCAP, and mixed plaque [MCAP

Cardiac veins: collateral venous drainage pathways in chronic hemodialysis patients.

PubMed

Ozmen, Evrim; Algin, Oktay

2016-07-12

Venous anomalies are diagnostic and therapeutic challenges. Subclavian or superior vena cava stenosis can be developed and venous return can be achieved via cardiac veins and coronary sinus in patients with central venous catheter for long-term hemodialysis. These types of abnormalities are not extremely rare especially in patients with a history of central venous catheter placement. Detection of these anomalies and subclavian vein stenosis before the surgical creation of hemodialysis fistulae or tunneled central venous catheter placement may prevent unnecessary interventions in those patients. Multidetector computed tomography (MDCT) technique can give further information when compared with fluoroscopy or digital subtraction angiography in the management of these patients. This case report describes interesting aspects of central vein complications in hemodialysis patients. As a conclusion, there are limited data about thoracic venous return, and further prospective studies with large patient number are required. MDCT with 3D reconstruction is particularly useful for the accurate evaluation of venous patency, variations, and collateral circulation. Also it is an excellent tool for choosing and planning treatment.

SU-E-I-42: Measurement of X-Ray Beam Width and Geometric Efficiency in MDCT Using Radiochromic Films.

PubMed

Liillau, T; Liebmann, M; von Boetticher, H; Poppe, B

2012-06-01

The purpose of this work was to measure the x-ray beam width and geometric efficiency (GE) of a multi detector computed tomography scanner (MDCT) for different beam collimations using radiochromic films. In MDCT, the primary beam width extends the nominal beam collimation to irradiate the active detector elements uniformly (called 'over-beaming') which contributes to increased radiation dose to the patient compared to single detector CT. Therefore, the precise determination of the primary beam width and GE is of value for any CT dose calculation using Monte Carlo or analytical methods. Single axial dose profiles free in air were measured for 6 different beam collimations nT for a Siemens SOMATOM Sensation 64 Scanner with Gafchromic XR-QA2 films. The films were calibrated relative to the measured charge of a PTW semiflex ionization chamber (type: 31010) for a single rotation in the CT scanner at the largest available beam collimation of 28.8 mm. The beam energy for all measurements in this work was set to 120 kVp. For every measured dose profile and beam collimation the GEin-air and the full-width-at-half- maximum value (FWHM) as a value for the x-ray beam width was determined. Over-beaming factors FWHM / nT were calculated accordingly. For MDCT beam collimations from 7.2 (12×0.6 mm) to 28.8 (24×1.2 mm) the geometric efficiency was between 58 and 85 %. The over- beaming factor ranged from 1.43 to 1.11. For beam collimations of 1×5 mm and 1×10 mm the GE was 77 % and 84 % respectively. The over-beaming factors were close to 1, as expected. This work has shown that radiochromic films can be used for accurate x-ray beam width and geometric efficiency measurements due to their high spatial resolution. The measured free-in-air geometric efficiency and the over-beaming factor depend strongly on beam collimation. © 2012 American Association of Physicists in Medicine.

Value of 3D printing for the comprehension of surgical anatomy.

PubMed

Marconi, Stefania; Pugliese, Luigi; Botti, Marta; Peri, Andrea; Cavazzi, Emma; Latteri, Saverio; Auricchio, Ferdinando; Pietrabissa, Andrea

2017-10-01

In a preliminary experience, we claimed the potential value of 3D printing technology for pre-operative counseling and surgical planning. However, no objective analysis has ever assessed its additional benefit in transferring anatomical information from radiology to final users. We decided to validate the pre-operative use of 3D-printed anatomical models in patients with solid organs' diseases as a new tool to deliver morphological information. Fifteen patients scheduled for laparoscopic splenectomy, nephrectomy, or pancreatectomy were selected and, for each, a full-size 3D virtual anatomical object was reconstructed from a contrast-enhanced MDCT (Multiple Detector Computed Tomography) and then prototyped using a 3D printer. After having carefully evaluated-in a random sequence-conventional contrast MDCT scans, virtual 3D reconstructions on a flat monitor, and 3D-printed models of the same anatomy for each selected case, thirty subjects with different expertise in radiological imaging (10 medical students, 10 surgeons and 10 radiologists) were administered a multiple-item questionnaire. Crucial issues for the anatomical understanding and the pre-operative planning of the scheduled procedure were addressed. The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical anatomy. As expected, less experienced medical students perceived the highest benefit (53.9% ± 4.14 of correct answers with 3D-printed models, compared to 53.4 % ± 4.6 with virtual models and 45.5% ± 4.6 with MDCT), followed by surgeons and radiologists. The average time spent by participants in 3D model assessing was shorter (60.67 ± 25.5 s) than the one of the corresponding virtual 3D reconstruction (70.8 ± 28.18 s) or conventional MDCT scan (127.04 ± 35.91 s). 3D-printed models help to transfer complex anatomical information to clinicians, resulting useful in the pre-operative planning, for intra-operative navigation and for surgical training purposes.

Diagnosis of blunt traumatic aortic injury 2007: still a nemesis.

PubMed

Mirvis, Stuart E; Shanmuganathan, K

2007-10-01

In recent years, the use of multidetector computed tomography (MDCT) for the diagnosis of acute thoracic injury in blunt trauma has expanded. MDCT has shown high accuracy for the diagnosis or exclusion of injury to the aorta and its primary branches, decreasing the need for thoracic angiography and allowing earlier treatment of this often rapidly fatal lesion. With increasing use of MDCT, more subtle injuries and variants of vascular anatomy are being recognized that create pitfalls in the diagnosis. Of perhaps more concern is the recognition that aortic injury can occur with little or no associated mediastinal hematoma, the principle chest radiographic finding indicating a need for further imaging. The importance of recognizing unusual sites of aortic injury, congenital variants of mediastinal anatomy, the precise extent of injury, and the anatomic pathology present as key factors in deciding among treatment options is emphasized.

Image quality improvement in MDCT cardiac imaging via SMART-RECON method

NASA Astrophysics Data System (ADS)

Li, Yinsheng; Cao, Ximiao; Xing, Zhanfeng; Sun, Xuguang; Hsieh, Jiang; Chen, Guang-Hong

2017-03-01

Coronary CT angiography (CCTA) is a challenging imaging task currently limited by the achievable temporal resolution of modern Multi-Detector CT (MDCT) scanners. In this paper, the recently proposed SMARTRECON method has been applied in MDCT-based CCTA imaging to improve the image quality without any prior knowledge of cardiac motion. After the prospective ECG-gated data acquisition from a short-scan angular span, the acquired data were sorted into several sub-sectors of view angles; each corresponds to a 1/4th of the short-scan angular range. Information of the cardiac motion was thus encoded into the data in each view angle sub-sector. The SMART-RECON algorithm was then applied to jointly reconstruct several image volumes, each of which is temporally consistent with the data acquired in the corresponding view angle sub-sector. Extensive numerical simulations were performed to validate the proposed technique and investigate the performance dependence.

Influence of Contrast Media on Bone Mineral Density (BMD) Measurements from Routine Contrast-Enhanced MDCT Datasets using a Phantom-less BMD Measurement Tool.

PubMed

Toelly, Andrea; Bardach, Constanze; Weber, Michael; Gong, Rui; Lai, Yanbo; Wang, Pei; Guo, Yulin; Kirschke, Jan; Baum, Thomas; Gruber, Michael

2017-06-01

Aim  To evaluate the differences in phantom-less bone mineral density (BMD) measurements in contrast-enhanced routine MDCT scans at different contrast phases, and to develop an algorithm for calculating a reliable BMD value. Materials and Methods  112 postmenopausal women from the age of 40 to 77 years (mean age: 57.31 years; SD 9.61) who underwent a clinically indicated MDCT scan, consisting of an unenhanced, an arterial, and a venous phase, were included. A retrospective analysis of the BMD values of the Th12 to L4 vertebrae in each phase was performed using a commercially available phantom-less measurement tool. Results  The mean BMD value in the unenhanced MDCT scans was 79.76 mg/cm³ (SD 31.20), in the arterial phase it was 85.09 mg/cm³ (SD 31.61), and in the venous phase it was 86.18 mg/cm³ (SD 31.30). A significant difference (p < 0.001) was found between BMD values on unenhanced and contrast-enhanced MDCT scans. There was no significant difference between BMD values in the arterial and venous phases (p = 0.228). The following conversion formulas were calculated using linear regression: unenhanced BMD = -2.287 + 0.964 * [arterial BMD value] and -4.517 + 0.978 * [venous BMD value]. The intrarater agreement of BMD measurements was calculated with an intraclass correlation (ICC) of 0.984 and the interobserver reliability was calculated with an ICC of 0.991. Conclusion  Phantom-less BMD measurements in contrast-enhanced MDCT scans result in increased mean BMD values, but, with the formulas applied in our study, a reliable BMD value can be calculated. However, the mean BMD values did not differ significantly between the arterial and venous phases. Key points   · BMD can be assessed on routine CT scans using a phantom-less tool.. · i. v. contrast agent significantly elevates BMD values measured on routine CT scans.. · BMD values measured in the arterial and venous phase did not differ significantly.. · Conversion formulas were defined for the calculation of a reliable BMD.. · The phantom-less tool showed good reliability and is a promising method.. Citation Format · Toelly A, Bardach C, Weber M et al. Influence of Contrast Media on Bone Mineral Density (BMD) Measurements from Routine Contrast-Enhanced MDCT Datasets using a Phantom-less BMD Measurement Tool. Fortschr Röntgenstr 2017; 189: 537 - 543. © Georg Thieme Verlag KG Stuttgart · New York.

MDCT quantification is the dominant parameter in decision-making regarding chest tube drainage for stable patients with traumatic pneumothorax.

PubMed

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2012-07-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis

PubMed Central

Luo, Mingxu; Song, Hongmei; Liu, Gang; Lin, Yikai; Luo, Lintao; Zhou, Xin; Chen, Bo

2017-01-01

The diagnostic values of diffusion weighted imaging (DWI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for N-staging of gastric cancer (GC) were identified and compared. After a systematic search to identify relevant articles, meta-analysis was used to summarize the sensitivities, specificities, and areas under curves (AUCs) for DWI and PET/CT. To better understand the diagnostic utility of DWI and PET/CT for N-staging, the performance of multi-detector computed tomography (MDCT) was used as a reference. Fifteen studies were analyzed. The pooled sensitivity, specificity, and AUC with 95% confidence intervals of DWI were 0.79 (0.73–0.85), 0.69 (0.61–0.77), and 0.81 (0.77–0.84), respectively. For PET/CT, the corresponding values were 0.52 (0.39–0.64), 0.88 (0.61–0.97), and 0.66 (0.62–0.70), respectively. Comparison of the two techniques revealed DWI had higher sensitivity and AUC, but no difference in specificity. DWI exhibited higher sensitivity but lower specificity than MDCT, and 18F-FDG PET/CT had lower sensitivity and equivalent specificity. Overall, DWI performed better than 18F-FDG PET/CT for preoperative N-staging in GC. When the efficacy of MDCT was taken as a reference, DWI represented a complementary imaging technique, while 18F-FDG PET/CT had limited utility for preoperative N-staging. PMID:29137440

Heterogeneity of pulmonary perfusion as a mechanistic image-based phenotype in emphysema susceptible smokers.

PubMed

Alford, Sara K; van Beek, Edwin J R; McLennan, Geoffrey; Hoffman, Eric A

2010-04-20

Recent evidence suggests that endothelial dysfunction and pathology of pulmonary vascular responses may serve as a precursor to smoking-associated emphysema. Although it is known that emphysematous destruction leads to vasculature changes, less is known about early regional vascular dysfunction which may contribute to and precede emphysematous changes. We sought to test the hypothesis, via multidetector row CT (MDCT) perfusion imaging, that smokers showing early signs of emphysema susceptibility have a greater heterogeneity in regional perfusion parameters than emphysema-free smokers and persons who had never smoked (NS). Assuming that all smokers have a consistent inflammatory response, increased perfusion heterogeneity in emphysema-susceptible smokers would be consistent with the notion that these subjects may have the inability to block hypoxic vasoconstriction in patchy, small regions of inflammation. Dynamic ECG-gated MDCT perfusion scans with a central bolus injection of contrast were acquired in 17 NS, 12 smokers with normal CT imaging studies (SNI), and 12 smokers with subtle CT findings of centrilobular emphysema (SCE). All subjects had normal spirometry. Quantitative image analysis determined regional perfusion parameters, pulmonary blood flow (PBF), and mean transit time (MTT). Mean and coefficient of variation were calculated, and statistical differences were assessed with one-way ANOVA. MDCT-based MTT and PBF measurements demonstrate globally increased heterogeneity in SCE subjects compared with NS and SNI subjects but demonstrate similarity between NS and SNI subjects. These findings demonstrate a functional lung-imaging measure that provides a more mechanistically oriented phenotype that differentiates smokers with and without evidence of emphysema susceptibility.

Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

PubMed Central

Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro

2016-01-01

AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant (P = 0.02). CONCLUSION: New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications. PMID:27239115

Subclinical coronary artery disease in Asian rheumatoid arthritis patients who were in remission: a pilot study.

PubMed

Ma, N Hanim; Teh, C L; Rapaee, A; Lau, K B; Fong, Alan Y Y; Hi, Sithy; Chang, B C; Yew, K L; Liew, H B; Ang, C K; Ong, T K; Chua, S K; Chin, Rowland W M; Sim, K H

2010-08-01

Rheumatoid arthritis (RA) patients who have active disease with longer disease duration have been reported to have increased risk of cardiovascular events compared to the normal population. The primary aim of our study is to ascertain the prevalence of significant asymptomatic coronary artery disease (CAD) in Asian RA patients who are in remission using multi-detector computed tomography (MDCT). The secondary aims of our study are the usage of pulse wave velocity and the biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-senstivity C-reactive protein (hs-CRP) to detect subclinical atherosclerosis in RA patients. We performed a comparative cross-sectional study of 47 RA patients who were in remission with a control group of non-RA patients with a history of atypical chest pain in Sarawak General Hospital from November 2008 to February 2009. All patients underwent 64-slice MDCT, assessment of arterial stiffness using the SphygmoCor test and blood analysis for NT-proBNP and hsCRP. There were 94 patients in our study with a mean age of 50 +/- 8.8 years. The RA and control patients in each group were matched in terms of traditional CV risk factors. Our RA patients had a median disease duration of 3 years (IQR 5.5). MDCT showed evidence of CAD in nine (19.1%) RA patients and three (6.4%) control patients (P = 0.06). There was no significant association between pulse wave velocity (PWV) and presence of CAD in our RA group. There was no significant correlation between PWV with levels of proBNP or hsCRP in our RA patients. In our current pilot study with the limitation of small sample size, RA was not associated with an increased risk of CAD in our RA patients who were in remission. Larger studies of CAD in Asian RA patients are needed to confirm our current finding.

Pulmonary Emphysema in Cystic Fibrosis Detected by Densitometry on Chest Multidetector Computed Tomography

PubMed Central

Wielpütz, Mark O.; Weinheimer, Oliver; Eichinger, Monika; Wiebel, Matthias; Biederer, Jürgen; Kauczor, Hans-Ulrich; Heußel, Claus P.

2013-01-01

Background Histopathological studies on lung specimens from patients with cystic fibrosis (CF) and recent results from a mouse model indicate that emphysema may contribute to CF lung disease. However, little is known about the relevance of emphysema in patients with CF. In the present study, we used computationally generated density masks based on multidetector computed tomography (MDCT) of the chest for non-invasive characterization and quantification of emphysema in CF. Methods Volumetric MDCT scans were acquired in parallel to pulmonary function testing in 41 patients with CF (median age 20.1 years; range 7-66 years) and 21 non-CF controls (median age 30.4 years; range 4-68 years), and subjected to dedicated software. The lung was segmented, low attenuation volumes below a threshold of -950 Hounsfield units were assigned to emphysema volume (EV), and the emphysema index was computed (EI). Results were correlated with forced expiratory volume in 1 s percent predicted (FEV1%), residual volume (RV), and RV/total lung capacity (RV/TLC). Results We show that EV was increased in CF (457±530 ml) compared to non-CF controls (78±90 ml) (P<0.01). EI was also increased in CF (7.7±7.5%) compared to the control group (1.2±1.4%) (P<0.05). EI correlated inversely with FEV1% (rs=-0.66), and directly with RV (rs=0.69) and RV/TLC (rs=0.47) in patients with CF (P<0.007), but not in non-CF controls. Emphysema in CF was detected from early adolescence (~13 years) and increased with age (rs=0.67, P<0.001). Conclusions Our results indicate that early onset emphysema detected by densitometry on chest MDCT is a characteristic pathology that contributes to airflow limitation and may serve as a novel endpoint for monitoring lung disease in CF. PMID:23991177

Comparison of 0.625-mm source computed tomographic images versus 5-mm thick reconstructed images in the evaluation for renal calculi in at-risk patients.

PubMed

Berkenblit, Robert; Hoenig, David; Lerer, Daniel; Moses, Melanie; Minsky, Lloyd

2013-02-01

CT has become a well-established modality in the evaluation of urinary calculi. The advent of multidetector CT (MDCT) scanners and submillimeter thick slice acquisitions has yielded CT images with even greater resolution. MDCT scanners allow for source data slice acquisition with submillimeter slice thickness. These source images can then be reconstructed to thicker slices for more convenient interpretation of the CT scan. Previous authors have looked at the effect of slice thickness on detection of urinary calculi. We investigated whether the thin slice source images yielded detection of additional stones and the potential significance of detecting these additional stones. Ninety-five consecutive patients who were referred to our outpatient imaging center for CT, with a clinical history placing them at risk for urinary calculi, were included in the study. In 49 (52%) of the 95 patients, more calculi were visualized using the 0.625-mm thick images than with the 5-mm thick images. In 34 (69%) of these 49 patients, the additional findings were thought to be "clinically significant," while in the remaining 15 (31%) patients, the additional findings were not thought to be clinically significant. In 46 (48%) of the 95 patients, there were no additional urinary calculi identified on the 0.625-mm thick images compared with that observed on 5-mm thick images. The results from this study encourage reviewing the thin slice source images of MDCTs in patients at risk for urinary calculi, because important clinical decisions may hinge on the additional findings made on these images.

Update on the imaging diagnosis of otosclerosis.

PubMed

Gredilla Molinero, J; Mancheño Losa, M; Santamaría Guinea, N; Arévalo Galeano, N; Grande Bárez, M

2016-01-01

Otosclerosis is a primary osteodystrophy of the temporal bone that causes progressive conductive hearing loss. The diagnosis is generally clinical, but multidetector CT (MDCT), the imaging technique of choice, is sometimes necessary. The objective of this article is to systematically review the usefulness of imaging techniques for the diagnosis and postsurgical assessment of otosclerosis, fundamentally the role of MDCT, to decrease the surgical risk. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Preoperative localization of Adamkiewicz arteries and their origins by using MDCT angiography.

PubMed

Sukeeyamanon, Wiwithawan; Siriapisith, Thanongchai; Wasinrat, Jitladda

2010-12-01

To evaluate the ability of thoraco-abdominal MDCT angiography to visualize Adamkiewicz arteries for preoperative planning in patients diagnosed with aortic disease. The present study retrospectively reviewed clinical data from 73 patients who underwent a thoraco-abdominal 64-slice MDCT angiography. The Adamkiewicz artery was evaluated on multiplanar reformation images in each case. The visualization of the Adamkiewicz artery, level of origin, side of origin and continuation from an intercostal artery was investigated. The Adamkiewicz arteries were visualized in 52 of the 73 patients (71.2%), and the total number of the delineated Adamkiewicz arteries was 64. Two Adamkiewicz arteries were found in nine patients (17.3%). Four Adamkiewicz arteries were found in one patient (1.9%). Most of the delineated arteries arose from the T9-L2 levels (89.1%). A left side of origin was found in 41 of 64 arteries (64.1%), and a right side of origin was found in 23 of 64 arteries (35.9%). Only 12 of 64 delineated arteries (18.8%) showed continuity from their origins to the anterior radiculomedullary artery. The preoperative detection rate of the Adamkiewicz artery with the routine technique of 64-slice MDCT angiography was 71.2%. The preoperative location of the Adamkiewicz artery may help to reduce the risk of perioperative ischemic changes in the spinal cord.

MDCT evaluation of acute aortic syndrome (AAS)

PubMed Central

Rossi, Giovanni; Lassandro, Francesco; Rea, Gaetano; Marino, Maurizio; Muto, Maurizio; Molino, Antonio; Scaglione, Mariano

2016-01-01

Non-traumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. There is a common pathway for the various manifestations of AAS that eventually leads to a breakdown of the aortic intima and media. Improvements in biology and health policy and diffusion of technology into the community resulted in an associated decrease in mortality and morbidity related to aortic therapeutic interventions. Hybrid procedures, branched and fenestrated endografts, and percutaneous aortic valves have emerged as potent and viable alternatives to traditional surgeries. In this context, current state-of-the art multidetector CT (MDCT) is actually the gold standard in the emergency setting because of its intrinsic diagnostic value. Management of acute aortic disease has changed with the increasing realization that endovascular therapies may offer distinct advantages in these situations. This article provides a summary of AAS, focusing especially on the MDCT technique, typical and atypical findings and common pitfalls of AAS, as well as recent concepts regarding the subtypes of AAS, consisting of aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and unstable aortic aneurysm or contained aortic rupture. MDCT findings will be related to pathophysiology, timing and management options to achieve a definite and timely diagnostic and therapeutic definition. In the present article, we review the aetiology, pathophysiology, clinical presentation, outcomes and therapeutic approaches to acute aortic syndromes. PMID:27033344

Cardiac Multi-detector CT Segmentation Based on Multiscale Directional Edge Detector and 3D Level Set.

PubMed

Antunes, Sofia; Esposito, Antonio; Palmisano, Anna; Colantoni, Caterina; Cerutti, Sergio; Rizzo, Giovanna

2016-05-01

Extraction of the cardiac surfaces of interest from multi-detector computed tomographic (MDCT) data is a pre-requisite step for cardiac analysis, as well as for image guidance procedures. Most of the existing methods need manual corrections, which is time-consuming. We present a fully automatic segmentation technique for the extraction of the right ventricle, left ventricular endocardium and epicardium from MDCT images. The method consists in a 3D level set surface evolution approach coupled to a new stopping function based on a multiscale directional second derivative Gaussian filter, which is able to stop propagation precisely on the real boundary of the structures of interest. We validated the segmentation method on 18 MDCT volumes from healthy and pathologic subjects using manual segmentation performed by a team of expert radiologists as gold standard. Segmentation errors were assessed for each structure resulting in a surface-to-surface mean error below 0.5 mm and a percentage of surface distance with errors less than 1 mm above 80%. Moreover, in comparison to other segmentation approaches, already proposed in previous work, our method presented an improved accuracy (with surface distance errors less than 1 mm increased of 8-20% for all structures). The obtained results suggest that our approach is accurate and effective for the segmentation of ventricular cavities and myocardium from MDCT images.

MDCT distinguishing features of focal aortic projections (FAP) in acute clinical settings.

PubMed

Valente, Tullio; Rossi, Giovanni; Lassandro, Francesco; Rea, Gaetano; Marino, Maurizio; Urciuolo, Salvatore; Tortora, Giovanni; Muto, Maurizio

2015-01-01

Focal aortic projections (FAP) are protrusion images of the contrast medium (focal contour irregularity, breaks in the intimal contour, outward lumen bulging or localized blood-filled outpouching) projecting beyond the aortic lumen in the aortic wall and are commonly seen on multidetector computed tomography (MDCT) scans of the chest and abdomen. FAP include several common and uncommon etiologies, which can be demonstrated both in the native aorta, mainly in acute aortic syndromes, and in the post-surgical aorta or after endovascular therapy. They are also found in some types of post-traumatic injuries and in impending rupture of the aneurysms. The expanding, routine use of millimetric or submillimetric collimation of current state-of-the-art MDCT scanners (16 rows and higher) all the time allows the identification and characterization of these small ulcer-like lesions or irregularities in the entire aorta, as either an incidental or expected finding, and provides detailed three-dimensional pictures of these pathologic findings. In this pictorial review, we illustrate the possible significance of FAP and the discriminating MDCT features that help to distinguish among different types of aortic protrusions and their possible evolution. Awareness of some related and distinctive radiologic features in FAP may improve our understanding of aortic diseases, provide further insight into the pathophysiology and natural history, and guide the appropriate management of these lesions.

Evaluation of the anterior ethmoidal artery by 3D dual volume rotational digital subtraction angiography and native multidetector CT with multiplanar reformations. Initial findings.

PubMed

Pandolfo, Ignazio; Vinci, Sergio; Salamone, Ignazio; Granata, Francesca; Mazziotti, Silvio

2007-06-01

Our purpose is to codify the anterior ethmoidal artery (AEA) course and its relationship with adjacent structures. Twenty patients with cerebrovascular disease underwent selective internal carotid dual volume angiography. Fusion of the vascular and bony images was obtained successively on a second console. MDCT of the cranium was performed in all patients. To identify the AEA course, multiplanar CT reformations were obtained. In all cases the entry-point of AEA and its course were identified by means of dual volume angiography. The information was confirmed by MDCT. In a second phase, we studied another 78 patients affected by inflammatory disease and polyposis only by means of MDCT, in order to confirm the previous data obtained by comparison between angiography and MDCT. In this second phase, 110/156 vessels were indirectly detected by means of visualization of the ethmoidal entry point. In the remaining cases, AEA was directly shown due to integrity of the thin ethmoidal bone lamellae or bony canal. Dual volume angiography is essential to identify the course of the AEA (standard of reference for the interpretation of CT). In patients with benign rhinosinusal pathology, where invasivity techniques are not justified, MPR reconstructions were of pivotal importance in the evaluation of the course of the artery with particular reference to its relationship with the frontal recess.

Single-phase Whole-body 64-MDCT Split-bolus Protocol for Pediatric Oncology: Diagnostic Efficacy and Dose Radiation.

PubMed

Scialpi, Michele; Schiavone, Raffaele; D'Andrea, Alfredo; Palumbo, Isabella; Magli, Michelle; Gravante, Sabrina; Falcone, Giuseppe; De Filippi, Claudio; Manganaro, Lucia; Palumbo, Barbara

2015-05-01

To evaluate the image quality and the diagnostic efficacy by single-phase whole-body 64-slice multidetector CT (MDCT) for pediatric oncology. Chest-abdomen-pelvis CT examinations with single-phase split-bolus technique were evaluated for T: detection and delineation of primary tumor (assessment of the extent of the lesion to neighboring tissues), N: regional lymph nodes and M: distant metastasis. Quality scores (5-point scale) were assessed by two radiologists on parenchymal and vascular enhancement. Accurate TNM staging in term of detection and delineation of primary tumor, regional lymph nodes and distant metastasis was obtained in all cases. On the image quality and severity artifact, the Kappa value for the interobserver agreement measure obtained from the analysis was 0.754, (p<0.001), characterizing a very good agreement between observers. Single-pass total body CT split-bolus technique reached the highest overall image quality and an accurate TNM staging in pediatric patients with cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Accuracy of computer-aided design models of the jaws produced using ultra-low MDCT doses and ASIR and MBIR.

PubMed

Al-Ekrish, Asma'a A; Alfadda, Sara A; Ameen, Wadea; Hörmann, Romed; Puelacher, Wolfgang; Widmann, Gerlig

2018-06-16

To compare the surface of computer-aided design (CAD) models of the maxilla produced using ultra-low MDCT doses combined with filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) reconstruction techniques with that produced from a standard dose/FBP protocol. A cadaveric completely edentulous maxilla was imaged using a standard dose protocol (CTDIvol: 29.4 mGy) and FBP, in addition to 5 low dose test protocols (LD1-5) (CTDIvol: 4.19, 2.64, 0.99, 0.53, and 0.29 mGy) reconstructed with FBP, ASIR 50, ASIR 100, and MBIR. A CAD model from each test protocol was superimposed onto the reference model using the 'Best Fit Alignment' function. Differences between the test and reference models were analyzed as maximum and mean deviations, and root-mean-square of the deviations, and color-coded models were obtained which demonstrated the location, magnitude and direction of the deviations. Based upon the magnitude, size, and distribution of areas of deviations, CAD models from the following protocols were comparable to the reference model: FBP/LD1; ASIR 50/LD1 and LD2; ASIR 100/LD1, LD2, and LD3; MBIR/LD1. The following protocols demonstrated deviations mostly between 1-2 mm or under 1 mm but over large areas, and so their effect on surgical guide accuracy is questionable: FBP/LD2; MBIR/LD2, LD3, LD4, and LD5. The following protocols demonstrated large deviations over large areas and therefore were not comparable to the reference model: FBP/LD3, LD4, and LD5; ASIR 50/LD3, LD4, and LD5; ASIR 100/LD4, and LD5. When MDCT is used for CAD models of the jaws, dose reductions of 86% may be possible with FBP, 91% with ASIR 50, and 97% with ASIR 100. Analysis of the stability and accuracy of CAD/CAM surgical guides as directly related to the jaws is needed to confirm the results.

P2Y2 receptor activation inhibits the expression of the sodium-chloride cotransporter NCC in distal convoluted tubule cells.

PubMed

Gailly, P; Szutkowska, M; Olinger, E; Debaix, H; Seghers, F; Janas, S; Vallon, V; Devuyst, O

2014-11-01

Luminal nucleotide stimulation is known to reduce Na(+) transport in the distal nephron. Previous studies suggest that this mechanism may involve the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which plays an essential role in NaCl reabsorption in the cells lining the distal convoluted tubule (DCT). Here we show that stimulation of mouse DCT (mDCT) cells with ATP or UTP promoted Ca(2+) transients and decreased the expression of NCC at both mRNA and protein levels. Specific siRNA-mediated silencing of P2Y2 receptors almost completely abolished ATP/UTP-induced Ca(2+) transients and significantly reduced ATP/UTP-induced decrease of NCC expression. To test whether local variations in the intracellular Ca(2+) concentration ([Ca(2+)]i) may control NCC transcription, we overexpressed the Ca(2+)-binding protein parvalbumin selectively in the cytosol or in the nucleus of mDCT cells. The decrease in NCC mRNA upon nucleotide stimulation was abolished in cells overexpressing cytosolic PV but not in cells overexpressing either a nuclear-targeted PV or a mutated PV unable to bind Ca(2+). Using a firefly luciferase reporter gene strategy, we observed that the activity of NCC promoter region from -1 to -2,200 bp was not regulated by changes in [Ca(2+)]i. In contrast, high cytosolic calcium level induced instability of NCC mRNA. We conclude that in mDCT cells: (1) P2Y2 receptor is essential for the intracellular Ca(2+) signaling induced by ATP/UTP stimulation; (2) P2Y2-mediated increase of cytoplasmic Ca(2+) concentration down-regulates the expression of NCC; (3) the decrease of NCC expression occurs, at least in part, via destabilization of its mRNA.

Computed tomographic angiography in stroke imaging: fundamental principles, pathologic findings, and common pitfalls.

PubMed

Gupta, Rajiv; Jones, Stephen E; Mooyaart, Eline A Q; Pomerantz, Stuart R

2006-06-01

The development of multidetector row computed tomography (MDCT) now permits visualization of the entire vascular tree that is relevant for the management of stroke within 15 seconds. Advances in MDCT have brought computed tomography angiography (CTA) to the frontline in evaluation of stroke. CTA is a rapid and noninvasive modality for evaluating the neurovasculature. This article describes the role of CTA in the management of stroke. Fundamentals of contrast delivery, common pathologic findings, artifacts, and pitfalls in CTA interpretation are discussed.

MDCT imaging of the stomach: advances and applications

PubMed Central

Prakash, Anjali; Pradhan, Gaurav; Vidholia, Aditi; Nagpal, Nishant; Saboo, Sachin S; Kuehn, David M; Khandelwal, Ashish

2017-01-01

The stomach may be involved by a myriad of pathologies ranging from benign aetiologies like inflammation to malignant aetiologies like carcinoma or lymphoma. Multidetector CT (MDCT) of the stomach is the first-line imaging for patients with suspected gastric pathologies. Conventionally, CT imaging had the advantage of simultaneous detection of the mural and extramural disease extent, but advances in MDCT have allowed mucosal assessment by virtual endoscopy (VE). Also, better three-dimensional (3D) post-processing techniques have enabled more robust and accurate pre-operative planning in patients undergoing gastrectomy and even predict the response to surgery for patients undergoing laparoscopic sleeve gastrectomy for weight loss. The ability of CT to obtain stomach volume (for bariatric surgery patients) and 3D VE images depends on various patient and protocol factors that are important for a radiologist to understand. We review the appropriate CT imaging protocol in the patients with suspected gastric pathologies and highlight the imaging pearls of various gastric pathologies on CT and VE. PMID:27785936

MDCT imaging of the stomach: advances and applications.

PubMed

Nagpal, Prashant; Prakash, Anjali; Pradhan, Gaurav; Vidholia, Aditi; Nagpal, Nishant; Saboo, Sachin S; Kuehn, David M; Khandelwal, Ashish

2017-01-01

The stomach may be involved by a myriad of pathologies ranging from benign aetiologies like inflammation to malignant aetiologies like carcinoma or lymphoma. Multidetector CT (MDCT) of the stomach is the first-line imaging for patients with suspected gastric pathologies. Conventionally, CT imaging had the advantage of simultaneous detection of the mural and extramural disease extent, but advances in MDCT have allowed mucosal assessment by virtual endoscopy (VE). Also, better three-dimensional (3D) post-processing techniques have enabled more robust and accurate pre-operative planning in patients undergoing gastrectomy and even predict the response to surgery for patients undergoing laparoscopic sleeve gastrectomy for weight loss. The ability of CT to obtain stomach volume (for bariatric surgery patients) and 3D VE images depends on various patient and protocol factors that are important for a radiologist to understand. We review the appropriate CT imaging protocol in the patients with suspected gastric pathologies and highlight the imaging pearls of various gastric pathologies on CT and VE.

Acute Perforated Diverticulitis: Assessment With Multidetector Computed Tomography.

PubMed

Sessa, Barbara; Galluzzo, Michele; Ianniello, Stefania; Pinto, Antonio; Trinci, Margherita; Miele, Vittorio

2016-02-01

Colonic diverticulitis is a common condition in the western population. Complicated diverticulitis is defined as the presence of extraluminal air or abscess, peritonitis, colon occlusion, or fistulas. Multidetector row computed tomography (MDCT) is the modality of choice for the diagnosis and the staging of diverticulitis and its complications, which enables performing an accurate differential diagnosis and addressing the patients to a correct management. MDCT is accurate in diagnosing the site of perforation in approximately 85% of cases, by the detection of direct signs (focal bowel wall discontinuity, extraluminal gas, and extraluminal enteric contrast) and indirect signs, which are represented by segmental bowel wall thickening, abnormal bowel wall enhancement, perivisceral fat stranding of fluid, and abscess. MDCT is accurate in the differentiation from complicated colon diverticulitis and colon cancer, often with a similar imaging. The computed tomography-guided classification is recommended to discriminate patients with mild diverticulitis, generally treated with antibiotics, from those with severe diverticulitis with a large abscess, which may be drained with a percutaneous approach. Copyright © 2016 Elsevier Inc. All rights reserved.

Longitudinal changes in airway remodeling and air trapping in severe asthma

PubMed Central

Witt, Chad A.; Sheshadri, Ajay; Carlstrom, Luke; Tarsi, Jaime; Kozlowski, James; Wilson, Brad; Gierada, David; Hoffman, Eric; Fain, Sean; Cook-Granroth, Janice; Sajol, Geneline; Sierra, Oscar; Giri, Tusar; O'Neil, Michael; Zheng, Jie; Schechtman, Kenneth B.; Bacharier, Leonard B.; Jarjour, Nizar; Busse, William; Castro, Mario

2014-01-01

Rationale and Objectives Previous cross-sectional studies have demonstrated that airway wall thickness and air trapping are greater in subjects with severe asthma than in those with mild-to-moderate asthma. However, a better understanding of how airway remodeling and lung density change over time is needed. This study aims to evaluate predictors of airway wall remodeling and change in lung function and lung density over time in severe asthma. Materials and Methods Phenotypic characterization and quantitative multidetector computed tomography (MDCT) of the chest was performed at baseline and ∼2.6 years later in 38 participants with asthma (severe n=24, mild-moderate n=14) and 9 normal controls from the Severe Asthma Research Program. Results Subjects with severe asthma had a significant decline in post-bronchodilator FEV1% predicted over time (p = <0.001). Airway wall thickness measured by MDCT was increased at multiple airway generations in severe asthma compared to mild-to-moderate asthma (wall area percent (WA%): p <0.05) and normals (p <0.05) at baseline and year 2. Over time, there was an increase in WA% and wall thickness (WT%) in all subjects (p = 0.030 and 0.009 respectively) with no change in emphysema-like lung or air trapping. Baseline pre-bronchodilator FEV1% inversely correlated with WA% and WT% (both p = <0.05). In a multivariable regression model, baseline WA%, race and healthcare utilization were predictors of subsequent airway remodeling. Conclusions Severe asthma subjects have a greater decline in lung function over time than normal subjects or those with mild-to-moderate asthma. MDCT provides a noninvasive measure of airway wall thickness that may predict subsequent airway remodeling. PMID:25018070

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

PubMed

Dantas, Roberto Nery; Assuncao, Antonildes Nascimento; Marques, Ismar Aguiar; Fahel, Mateus Guimaraes; Nomura, Cesar Higa; Avila, Luiz Francisco Rodrigues; Giorgi, Maria Clementina Pinto; Soares, Jose; Meneghetti, Jose Claudio; Parga, Jose Rodrigues

2018-06-01

Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography ( 82 RbPET) MPI. Thus, this study aimed to evaluate agreement between 82 RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82 RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). There was a significant agreement between dipyridamole stress 320-CT MPI and 82 RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Effects of computing parameters and measurement locations on the estimation of 3D NPS in non-stationary MDCT images.

PubMed

Miéville, Frédéric A; Bolard, Gregory; Bulling, Shelley; Gudinchet, François; Bochud, François O; Verdun, François R

2013-11-01

The goal of this study was to investigate the impact of computing parameters and the location of volumes of interest (VOI) on the calculation of 3D noise power spectrum (NPS) in order to determine an optimal set of computing parameters and propose a robust method for evaluating the noise properties of imaging systems. Noise stationarity in noise volumes acquired with a water phantom on a 128-MDCT and a 320-MDCT scanner were analyzed in the spatial domain in order to define locally stationary VOIs. The influence of the computing parameters in the 3D NPS measurement: the sampling distances bx,y,z and the VOI lengths Lx,y,z, the number of VOIs NVOI and the structured noise were investigated to minimize measurement errors. The effect of the VOI locations on the NPS was also investigated. Results showed that the noise (standard deviation) varies more in the r-direction (phantom radius) than z-direction plane. A 25 × 25 × 40 mm(3) VOI associated with DFOV = 200 mm (Lx,y,z = 64, bx,y = 0.391 mm with 512 × 512 matrix) and a first-order detrending method to reduce structured noise led to an accurate NPS estimation. NPS estimated from off centered small VOIs had a directional dependency contrary to NPS obtained from large VOIs located in the center of the volume or from small VOIs located on a concentric circle. This showed that the VOI size and location play a major role in the determination of NPS when images are not stationary. This study emphasizes the need for consistent measurement methods to assess and compare image quality in CT. Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Influence of aortic valve leaflet calcification on dynamic aortic valve motion assessed by cardiac computed tomography.

PubMed

Minami, Keisuke; Yoneyama, Kihei; Izumo, Masaki; Suzuki, Kengo; Ogawa, Yasuyoshi; Chikaraishi, Kousuke; Ogawa, Yukihisa; Kobayashi, Yasuyuki; Furukawa, Toshiyuki; Tanabe, Yasuhiro; Akashi, Yoshihiro J

Computed tomography is the best noninvasive imaging modality for evaluating valve leaflet calcification. To evaluate the association of aortic valve leaflet calcification with instantaneous valve opening and closing using dynamic multidetector computed tomography (MDCT). We retrospectively evaluated 58 consecutive patients who underwent dynamic MDCT imaging. Aortic valve calcification (AVC) was quantified using the Agatston method. The aortic valve area (AVA) tracking curves were derived by planimetry during the cardiac cycle using all 20 phases (5% reconstruction). da/dt in cm 2 /s was calculated as the rate of change of AVA during opening (positive) or closing (negative). Patients were divided into 3 three groups according to Agatston score quartile: no AVC (Q2, Score 0, n = 18), mild AVC (Q3, Score 1-2254, n = 24), and severe AVC (Q4 Score >2254, n = 14). In multivariable linear regression, compared to the non AVC group, the mild and severe AVC groups had lower maximum AVA (by -1.71 cm 2 and -2.25 cm 2 , respectively), lower peak positive da/dt (by -21.88 cm 2 /s and -26.65 cm 2 /s, respectively), and higher peak negative da/dt (by 13.78 cm 2 /s and 18.11 cm 2 /s, respectively) (p < 0.05 for all comparisons). AVA and its opening and closing were influenced by leaflet calcification. The present study demonstrates the ability of dynamic MDCT imaging to assess quantitative aortic valve motion in a clinical setting. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Increasing bone sclerosis during bortezomib therapy in multiple myeloma patients: results of a reduced-dose whole-body MDCT study.

PubMed

Schulze, Maximilian; Weisel, Katja; Grandjean, Caroline; Oehrlein, Katharina; Zago, Manola; Spira, Daniel; Horger, Marius

2014-01-01

The objective of our study was to assess the frequency, location, extent, and patterns of bone sclerosis occurring in patients with multiple myeloma (MM) during bortezomib-based therapy. From June 2003 through December 2011, 593 whole-body reduced-dose MDCT studies were performed of 79 consecutive patients receiving bortezomib. The median surveillance time was 21 months (range, 3-67 months). Baseline studies were compared with follow-up studies during therapy (follow-up 1), at the end of therapy (follow-up 2), and 12 months after cessation of bortezomib therapy (follow-up 3). We recorded any sclerotic change occurring inside or along the margins of the osteolytic lesions, in the cancellous bone, or inside preexistent medullary or extramedullary lesions. The time point of occurrence of bone sclerosis was correlated with the best hematologic response category. Fourteen (17.7%) patients developed focal (n = 11) or diffuse (n = 3) bone sclerosis. The time window from bortezomib initiation to radiographic detection of bone sclerosis was 8 months (SD, 7 months). Sclerosis occurred at multiple sites (n = 7) or at an isolated site (n = 7). On subsequent whole-body reduced-dose MDCT studies, sclerosis further increased in seven (50%) patients. Hematologic best response during bortezomib treatment was complete response (n = 1), very good partial response (n = 2), partial response (n = 8), and stable disease (n = 3). Radiologic response at the time of sclerosis detection was partial response (n = 8), stable disease (n = 2), and progressive disease (n = 4). Bone remineralization may occur during bortezomib-based therapy for MM in a substantial proportion of patients. The extent, location, and patterns of sclerosis differ among patients and are unpredictable. Sclerosis was documented even in patients showing suboptimal hematologic response.

Is multidetector CT-based bone mineral density and quantitative bone microstructure assessment at the spine still feasible using ultra-low tube current and sparse sampling?

PubMed

Mei, Kai; Kopp, Felix K; Bippus, Rolf; Köhler, Thomas; Schwaiger, Benedikt J; Gersing, Alexandra S; Fehringer, Andreas; Sauter, Andreas; Münzel, Daniela; Pfeiffer, Franz; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B; Baum, Thomas

2017-12-01

Osteoporosis diagnosis using multidetector CT (MDCT) is limited to relatively high radiation exposure. We investigated the effect of simulated ultra-low-dose protocols on in-vivo bone mineral density (BMD) and quantitative trabecular bone assessment. Institutional review board approval was obtained. Twelve subjects with osteoporotic vertebral fractures and 12 age- and gender-matched controls undergoing routine thoracic and abdominal MDCT were included (average effective dose: 10 mSv). Ultra-low radiation examinations were achieved by simulating lower tube currents and sparse samplings at 50%, 25% and 10% of the original dose. BMD and trabecular bone parameters were extracted in T10-L5. Except for BMD measurements in sparse sampling data, absolute values of all parameters derived from ultra-low-dose data were significantly different from those derived from original dose images (p<0.05). BMD, apparent bone fraction and trabecular thickness were still consistently lower in subjects with than in those without fractures (p<0.05). In ultra-low-dose scans, BMD and microstructure parameters were able to differentiate subjects with and without vertebral fractures, suggesting osteoporosis diagnosis is feasible. However, absolute values differed from original values. BMD from sparse sampling appeared to be more robust. This dose-dependency of parameters should be considered for future clinical use. • BMD and quantitative bone parameters are assessable in ultra-low-dose in vivo MDCT scans. • Bone mineral density does not change significantly when sparse sampling is applied. • Quantitative trabecular bone microstructure measurements are sensitive to dose reduction. • Osteoporosis subjects could be differentiated even at 10% of original dose. • Radiation exposure should be considered when comparing quantitative bone parameters.

Novel prediction model of renal function after nephrectomy from automated renal volumetry with preoperative multidetector computed tomography (MDCT).

PubMed

Isotani, Shuji; Shimoyama, Hirofumi; Yokota, Isao; Noma, Yasuhiro; Kitamura, Kousuke; China, Toshiyuki; Saito, Keisuke; Hisasue, Shin-ichi; Ide, Hisamitsu; Muto, Satoru; Yamaguchi, Raizo; Ukimura, Osamu; Gill, Inderbir S; Horie, Shigeo

2015-10-01

The predictive model of postoperative renal function may impact on planning nephrectomy. To develop the novel predictive model using combination of clinical indices with computer volumetry to measure the preserved renal cortex volume (RCV) using multidetector computed tomography (MDCT), and to prospectively validate performance of the model. Total 60 patients undergoing radical nephrectomy from 2011 to 2013 participated, including a development cohort of 39 patients and an external validation cohort of 21 patients. RCV was calculated by voxel count using software (Vincent, FUJIFILM). Renal function before and after radical nephrectomy was assessed via the estimated glomerular filtration rate (eGFR). Factors affecting postoperative eGFR were examined by regression analysis to develop the novel model for predicting postoperative eGFR with a backward elimination method. The predictive model was externally validated and the performance of the model was compared with that of the previously reported models. The postoperative eGFR value was associated with age, preoperative eGFR, preserved renal parenchymal volume (RPV), preserved RCV, % of RPV alteration, and % of RCV alteration (p < 0.01). The significant correlated variables for %eGFR alteration were %RCV preservation (r = 0.58, p < 0.01) and %RPV preservation (r = 0.54, p < 0.01). We developed our regression model as follows: postoperative eGFR = 57.87 - 0.55(age) - 15.01(body surface area) + 0.30(preoperative eGFR) + 52.92(%RCV preservation). Strong correlation was seen between postoperative eGFR and the calculated estimation model (r = 0.83; p < 0.001). The external validation cohort (n = 21) showed our model outperformed previously reported models. Combining MDCT renal volumetry and clinical indices might yield an important tool for predicting postoperative renal function.

Imaging of non-neoplastic duodenal diseases. A pictorial review with emphasis on MDCT.

PubMed

Juanpere, Sergi; Valls, Laia; Serra, Isabel; Osorio, Margarita; Gelabert, Arantxa; Maroto, Albert; Pedraza, Salvador

2018-04-01

A wide spectrum of abnormalities can affect the duodenum, ranging from congenital anomalies to traumatic and inflammatory entities. The location of the duodenum and its close relationship with other organs make it easy to miss or misinterpret duodenal abnormalities on cross-sectional imaging. Endoscopy has largely supplanted fluoroscopy for the assessment of the duodenal lumen. Cross-sectional imaging modalities, especially multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), enable comprehensive assessment of the duodenum and surrounding viscera. Although overlapping imaging findings can make it difficult to differentiate between some lesions, characteristic features may suggest a specific diagnosis in some cases. Familiarity with pathologic conditions that can affect the duodenum and with the optimal MDCT and MRI techniques for studying them can help ensure diagnostic accuracy in duodenal diseases. The goal of this pictorial review is to illustrate the most common non-malignant duodenal processes. Special emphasis is placed on MDCT features and their endoscopic correlation as well as on avoiding the most common pitfalls in the evaluation of the duodenum. • Cross-sectional imaging modalities enable comprehensive assessment of duodenum diseases. • Causes of duodenal obstruction include intraluminal masses, inflammation and hematomas. • Distinguishing between tumour and groove pancreatitis can be challenging by cross-sectional imaging. • Infectious diseases of the duodenum are difficult to diagnose, as the findings are not specific. • The most common cause of nonvariceal upper gastrointestinal bleeding is peptic ulcer disease.

Association of Apolipoprotein B/Apolipoprotein A1 Ratio and Coronary Artery Stenosis and Plaques Detected by Multi-Detector Computed Tomography in Healthy Population

PubMed Central

Jung, Chang Hee; Hwang, Jenie Yoonoo; Shin, Mi Seon; Yu, Ji Hee; Kim, Eun Hee; Bae, Sung Jin; Yang, Dong Hyun; Kang, Joon-Won; Park, Joong-Yeol; Kim, Hong-Kyu

2013-01-01

Despite the noninvasiveness and accuracy of multidetector computed tomography (MDCT), its use as a routine screening tool for occult coronary atherosclerosis is unclear. We investigated whether the ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1), an indicator of the balance between atherogenic and atheroprotective cholesterol transport could predict occult coronary atherosclerosis detected by MDCT. We collected the data of 1,401 subjects (877 men and 524 women) who participated in a routine health screening examination of Asan Medical Center. Significant coronary artery stenosis defined as > 50% stenosis was detected in 114 subjects (8.1%). An increase in apoB/A1 quartiles was associated with increased percentages of subjects with significant coronary stenosis and noncalcified plaques (NCAP). After adjustment for confounding variables, each 0.1 increase in serum apoB/A1 was significantly associated with increased odds ratios (ORs) for coronary stenosis and NCAP of 1.23 and 1.18, respectively. The optimal apoB/A1 ratio cut off value for MDCT detection of significant coronary stenosis was 0.58, which had a sensitivity of 70.2% and a specificity of 48.2% (area under the curve, 0.61; 95% CI, 0.58-0.63, P < 0.001). Our results indicate that apoB/A1 ratio is a good indicator of occult coronary atherosclerosis detected by coronary MDCT. PMID:23678262

Association of apolipoprotein b/apolipoprotein A1 ratio and coronary artery stenosis and plaques detected by multi-detector computed tomography in healthy population.

PubMed

Jung, Chang Hee; Hwang, Jenie Yoonoo; Shin, Mi Seon; Yu, Ji Hee; Kim, Eun Hee; Bae, Sung Jin; Yang, Dong Hyun; Kang, Joon-Won; Park, Joong-Yeol; Kim, Hong-Kyu; Lee, Woo Je

2013-05-01

Despite the noninvasiveness and accuracy of multidetector computed tomography (MDCT), its use as a routine screening tool for occult coronary atherosclerosis is unclear. We investigated whether the ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1), an indicator of the balance between atherogenic and atheroprotective cholesterol transport could predict occult coronary atherosclerosis detected by MDCT. We collected the data of 1,401 subjects (877 men and 524 women) who participated in a routine health screening examination of Asan Medical Center. Significant coronary artery stenosis defined as > 50% stenosis was detected in 114 subjects (8.1%). An increase in apoB/A1 quartiles was associated with increased percentages of subjects with significant coronary stenosis and noncalcified plaques (NCAP). After adjustment for confounding variables, each 0.1 increase in serum apoB/A1 was significantly associated with increased odds ratios (ORs) for coronary stenosis and NCAP of 1.23 and 1.18, respectively. The optimal apoB/A1 ratio cut off value for MDCT detection of significant coronary stenosis was 0.58, which had a sensitivity of 70.2% and a specificity of 48.2% (area under the curve, 0.61; 95% CI, 0.58-0.63, P < 0.001). Our results indicate that apoB/A1 ratio is a good indicator of occult coronary atherosclerosis detected by coronary MDCT.

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

PubMed

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors.

Emerging role of multi-detector computed tomography in the diagnosis of hematuria following percutaneous nephrolithotomy: A case scenario.

PubMed

Sivanandam, S E; Mathew, Georgie; Bhat, Sanjay H

2009-07-01

Persistent hematuria is one of the most dreaded complications following percutanous nephrolithotomy (PCNL). Although invasive, a catheter-based angiogram is usually used to localize the bleeding vessel and subsequently embolize it. Advances in imaging technology have now made it possible to use a non invasive multi-detector computed tomography (MDCT) angiogram with 3-D reconstruction to establish the diagnosis. We report a case of post-PCNL hemorrhage due to a pseudo aneurysm that was missed by a conventional angiogram and subsequently detected on MDCT angiogram.

Experimental Model of Tuberculosis in the Domestic Goat after Endobronchial Infection with Mycobacterium caprae ▿

PubMed Central

Pérez de Val, Bernat; López-Soria, Sergio; Nofrarías, Miquel; Martín, Maite; Vordermeier, H. Martin; Villarreal-Ramos, Bernardo; Romera, Nadine; Escobar, Manel; Solanes, David; Cardona, Pere-Joan; Domingo, Mariano

2011-01-01

Caprine tuberculosis (TB) has increased in recent years, highlighting the need to address the problem the infection poses in goats. Moreover, goats may represent a cheaper alternative for testing of prototype vaccines in large ruminants and humans. With this aim, a Mycobacterium caprae infection model has been developed in goats. Eleven 6-month-old goats were infected by the endobronchial route with 1.5 × 103 CFU, and two other goats were kept as noninfected controls. The animals were monitored for clinical and immunological parameters throughout the experiment. After 14 weeks, the goats were euthanized, and detailed postmortem analysis of lung lesions was performed by multidetector computed tomography (MDCT) and direct observation. The respiratory lymph nodes were also evaluated and cultured for bacteriological analysis. All infected animals were positive in a single intradermal comparative cervical tuberculin (SICCT) test at 12 weeks postinfection (p.i.). Gamma interferon (IFN-γ) antigen-specific responses were detected from 4 weeks p.i. until the end of the experiment. The humoral response to MPB83 was especially strong at 14 weeks p.i. (13 days after SICCT boost). All infected animals presented severe TB lesions in the lungs and associated lymph nodes. M. caprae was recovered from pulmonary lymph nodes in all inoculated goats. MDCT allowed a precise quantitative measure of TB lesions. Lesions in goats induced by M. caprae appeared to be more severe than those induced in cattle by M. bovis over a similar period of time. The present work proposes a reliable new experimental animal model for a better understanding of caprine tuberculosis and future development of vaccine trials in this and other species. PMID:21880849

Evaluation of chest tomosynthesis for the detection of pulmonary nodules: effect of clinical experience and comparison with chest radiography

NASA Astrophysics Data System (ADS)

Zachrisson, Sara; Vikgren, Jenny; Svalkvist, Angelica; Johnsson, Åse A.; Boijsen, Marianne; Flinck, Agneta; Månsson, Lars Gunnar; Kheddache, Susanne; Båth, Magnus

2009-02-01

Chest tomosynthesis refers to the technique of collecting low-dose projections of the chest at different angles and using these projections to reconstruct section images of the chest. In this study, a comparison of chest tomosynthesis and chest radiography in the detection of pulmonary nodules was performed and the effect of clinical experience of chest tomosynthesis was evaluated. Three senior thoracic radiologists, with more than ten years of experience of chest radiology and 6 months of clinical experience of chest tomosynthesis, acted as observers in a jackknife free-response receiver operating characteristics (JAFROC-1) study, performed on 42 patients with and 47 patients without pulmonary nodules examined with both chest tomosynthesis and chest radiography. MDCT was used as reference and the total number of nodules found using MDCT was 131. To investigate the effect of additional clinical experience of chest tomosynthesis, a second reading session of the tomosynthesis images was performed one year after the initial one. The JAFROC-1 figure of merit (FOM) was used as the principal measure of detectability. In comparison with chest radiography, chest tomosynthesis performed significantly better with regard to detectability. The observer-averaged JAFROC-1 FOM was 0.61 for tomosynthesis and 0.40 for radiography, giving a statistically significant difference between the techniques of 0.21 (p<0.0001). The observer-averaged JAFROC-1 FOM of the second reading of the tomosynthesis cases was not significantly higher than that of the first reading, indicating no improvement in detectability due to additional clinical experience of tomosynthesis.

Adrenal and nephrogenic hypertension: an image quality study of low tube voltage, low-concentration contrast media combined with adaptive statistical iterative reconstruction.

PubMed

Li, Zhen; Li, Qiong; Shen, Yaqi; Li, Anqin; Li, Haojie; Liang, Lili; Hu, Yao; Hu, Xuemei; Hu, Daoyu

2016-09-01

The aim of this study was to investigate the effect of using low tube voltage, low-concentration contrast media and adaptive statistical iterative reconstruction (ASIR) for reducing the radiation and iodine contrast doses in adrenal and nephrogenic hypertension patients. A total of 148 hypertension patients who were suspected for adrenal lesions or renal artery stenoses were assigned to two groups and. Group A (n=74) underwent a low tube voltage, low molecular weight dextran enhanced multi-detector row spiral CT (MDCT) (80 kVp, 270 mg I/mL contrast agent), and the raw data were reconstructed with standard filtered back projection (FBP) and ASIR at four different levels of blending (20%, 40%, 60% and 80%, respectively). The control group (Group B, n=74) underwent conventional MDCT (120 kVp, 370 mg I/mL contrast agent), and the data were reconstructed with FBP. The CT values, standard deviation (SD), signal-noise-ratio (SNR) and contrast-noise-ratio (CNR) were measured in the renal vessels, normal adrenal tissue, adrenal neoplasms and subcutaneous fat. The volume CT dose index (CTDIvol ) and dose length product (DLP) were recorded, and an effective dose (ED) was obtained. Two-tailed independent t-tests, paired Chi-square tests and Kappa consistency tests were used for statistical analysis of the data. The CTDIvol , DLP and total iodine dose in group A were decreased by 47.8%, 49.0% and 26.07%, respectively, compared to group B (P<.001). In the qualitative quality analysis, the radiologists rated the 60% ASIR the highest. The mean value of noise (SD) was significantly lower in the 40%, 60% and 80% ASIR-A groups compared with FBP-B for all comparisons. Compared to FBP-B, CNR was significantly higher, with 40%, 60% and 80% ASIR in renal artery stems (P<.05). Compared with FBP-B, a significant increase in the SNR of 40%, 60%, or 80% ASIR was observed in all cases (P<.05). Compared with conventional protocols, the use of low tube voltage, low-concentration contrast media and 60% ASIR provides similar enhancement and image quality with a reduced radiation dose and contrast iodine dose. © 2016 John Wiley & Sons Ltd.

[Study of radiation dose to the eye lens by multi-detector row computed tomography of the temporal bone].

PubMed

Hirakuri, Ayaka; Numasawa, Kanako; Takeishi, Hideki; Satomura, Minato; Takeda, Hiromitsu; Harada, Kuniaki; Asanuma, Osamu; Sakata, Motomichi

2012-01-01

The exposure of the eye lens caused by multi-detector row computed tomography (MDCT) of the temporal bone is a serious problem. Our aim was to evaluate the radiation dose to the eye lens by different scan baselines (orbitomeatal line; OML, acanthiomeatal line; AML) and examine the difference of the depiction of the temporal bone structures. Measurement of the exposure to the eye lens was performed by means of MDCT of the temporal bone with a radio-photoluminescence glass dosimeter using a rand phantom. Moreover, we studied only one volunteer (58-year-old male) who had no symptom and was not suspected of having any ear abnormalities with a two scan baseline. Visualization of the major anatomical structures of the temporal bone (the tympanic portion of the facial nerve canal, the body of the incus, stapes superstructures, vestibule etc.) was performed on the volunteer. The average absorbed dose was 6.42 mGy by the OML and 1.59 mGy by the AML, respectively. With regard to visualization of the temporal bone structures, all structures were of equal quality with the two scan baseline. With the AML line, the radiation dose to the eye lens was reduced to 75%. Therefore, the authors recommended an AML for use for MDCT of the temporal bone. In clinical practice, the optimization of scanning factor (kVp, mAs etc.) and the use of the radio-protection should be implemented for radiation dose reduction of the eye lens by MDCT of the temporal bone.

Assessment of aortic valve calcium load by multidetector computed tomography. Anatomical validation, impact of scanner settings and incremental diagnostic value.

PubMed

Boulif, Jamila; Gerber, Bernhard; Slimani, Alisson; Lazam, Siham; de Meester, Christophe; Piérard, Sophie; Pasquet, Agnès; Pouleur, Anne-Catherine; Vancraeynest, David; El Khoury, Gébrine; de Kerchove, Laurent; Noirhomme, Philippe; Vanoverschelde, Jean-Louis

To validate aortic valve calcium (AVC) load measurements by multidetector row computed tomography (MDCT), to evaluate the impact of tube potential and slice thickness on AVC scores, to examine the accuracy of AVC load in distinguishing severe from nonsevere aortic stenosis (AS) and to investigate its effectiveness as an alternative diagnosis method when echocardiography remains inconclusive. We prospectively studied 266 consecutive patients with moderate to severe AS who underwent MDCT to measure AVC load and a comprehensive echocardiographic examination to assess AS severity. AVC load was validated against valve weight in 57 patients undergoing aortic valve replacement. The dependence of AVC scores on tube potential and slice thickness was also tested, as well as the relationship between AVC load and echocardiographic criteria of AS severity. MDCT Agatston score correlated well with valve weight (r = 0.82, p < 0.001) and hemodynamic indices of AS severity (all p < 0.001). Ex-vivo Agatston scores decreased significantly with increasing tube potential and slice thickness (repeated measures ANOVA p < 0.001). Multivariate analysis identified mean gradient, the indexed effective orifice area, male gender and left ventricular outflow tract cross-sectional area as independent correlates of the in-vivo AVC load. MDCT-derived AVC load correlated well with valve weight and hemodynamic indices of AS severity. It also depends on tube potential and slice thickness, thus suggesting that these parameters should be standardized to optimize reproducibility and accuracy. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

A comparison of virtual bronchoscopy versus flexible bronchoscopy in the diagnosis of tracheobronchomalacia in children.

PubMed

Su, Siew Choo; Masters, Ian Brent; Buntain, Helen; Frawley, Kieran; Sarikwal, Anubhav; Watson, Debbie; Ware, Frances; Wuth, Jan; Chang, Anne Bernadette

2017-04-01

Flexible bronchoscopy (FB) is the current gold standard for diagnosing tracheobronchomalacia. However, it is not always feasible and virtual bronchoscopy (VB), acquired from chest multi-detector CT (MDCT) scan is an alternative diagnostic tool. We determined the sensitivity, specificity, and positive and negative predictive values of VB compared to FB in diagnosing tracheobronchomalacia. Children aged <18-years scheduled for FB and MDCT were recruited. FB and MDCT were undertaken within 30-min to 7-days of each other. Tracheobronchomalacia (mild, moderate, severe, very severe) diagnosed on FB were independently scored by two pediatric pulmonologists; VB was independently scored by two pairs (each pair = pediatric pulmonologist and radiologist), in a blinded manner. In 53 children (median age = 2.5 years, range 0.8-14.3) evaluated for airway abnormalities, tracheomalacia was detected in 37 (70%) children at FB. Of these, VB detected tracheomalacia in 20 children, with a sensitivity of 54.1% (95%CI 37.1-70.2), specificity = 87.5% (95%CI 60.4-97.8), and positive predictive value = 90.9% (95%CI 69.4-98.4). The agreement between pediatric pulmonologists for diagnosing tracheomalacia by FB was excellent, weighted κ = 0.8 (95%CI 0.64-0.97); but only fair between the pairs of pediatric pulmonologists/radiologists for VB, weighted κ = 0.47 (95%CI 0.23-0.71). There were 42 cases of bronchomalacia detected on FB. VB had a sensitivity = 45.2% (95%CI 30.2-61.2), specificity = 95.5% (95%CI 94.2-96.5), and positive predictive value = 23.2 (95%CI 14.9-34.0) compared to FB in detecting bronchomalacia. VB cannot replace FB as the gold standard for detecting tracheobronchomalacia in children. However, VB could be considered as an alternative diagnostic modality in children with symptoms suggestive of tracheobronchomalacia where FB is unavailable. Pediatr Pulmonol. 2017;52:480-486. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Monte Carlo simulations in multi-detector CT (MDCT) for two PET/CT scanner models using MASH and FASH adult phantoms

NASA Astrophysics Data System (ADS)

Belinato, W.; Santos, W. S.; Paschoal, C. M. M.; Souza, D. N.

2015-06-01

The combination of positron emission tomography (PET) and computed tomography (CT) has been extensively used in oncology for diagnosis and staging of tumors, radiotherapy planning and follow-up of patients with cancer, as well as in cardiology and neurology. This study determines by the Monte Carlo method the internal organ dose deposition for computational phantoms created by multidetector CT (MDCT) beams of two PET/CT devices operating with different parameters. The different MDCT beam parameters were largely related to the total filtration that provides a beam energetic change inside the gantry. This parameter was determined experimentally with the Accu-Gold Radcal measurement system. The experimental values of the total filtration were included in the simulations of two MCNPX code scenarios. The absorbed organ doses obtained in MASH and FASH phantoms indicate that bowtie filter geometry and the energy of the X-ray beam have significant influence on the results, although this influence can be compensated by adjusting other variables such as the tube current-time product (mAs) and pitch during PET/CT procedures.

Radiation dose of digital tomosynthesis for sinonasal examination: comparison with multi-detector CT.

PubMed

Machida, Haruhiko; Yuhara, Toshiyuki; Tamura, Mieko; Numano, Tomokazu; Abe, Shinji; Sabol, John M; Suzuki, Shigeru; Ueno, Eiko

2012-06-01

Using an anthropomorphic phantom, we have investigated the feasibility of digital tomosynthesis (DT) of flat-panel detector (FPD) radiography to reduce radiation dose for sinonasal examination compared to multi-detector computed tomography (MDCT). A female Rando phantom was scanned covering frontal to maxillary sinus using the clinically routine protocol by both 64-detector CT (120 kV, 200 mAs, and 1.375-pitch) and DT radiography (80 kV, 1.0 mAs per projection, 60 projections, 40° sweep, and posterior-anterior projections). Glass dosimeters were used to measure the radiation dose to internal organs including the thyroid gland, brain, submandibular gland, and the surface dose at various sites including the eyes during those scans. We compared the radiation dose to those anatomies between both modalities. In DT radiography, the doses of the thyroid gland, brain, submandibular gland, skin, and eyes were 230 ± 90 μGy, 1770 ± 560 μGy, 1400 ± 80 μGy, 1160 ± 2100 μGy, and 112 ± 6 μGy, respectively. These doses were reduced to approximately 1/5, 1/8, 1/12, 1/17, and 1/290 of the respective MDCT dose. For sinonasal examinations, DT radiography enables dramatic reduction in radiation exposure and dose to the head and neck region, particularly to the lens of the eye. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Efficient FFT Algorithm for Psychoacoustic Model of the MPEG-4 AAC

NASA Astrophysics Data System (ADS)

Lee, Jae-Seong; Lee, Chang-Joon; Park, Young-Cheol; Youn, Dae-Hee

This paper proposes an efficient FFT algorithm for the Psycho-Acoustic Model (PAM) of MPEG-4 AAC. The proposed algorithm synthesizes FFT coefficients using MDCT and MDST coefficients through circular convolution. The complexity of the MDCT and MDST coefficients is approximately half of the original FFT. We also design a new PAM based on the proposed FFT algorithm, which has 15% lower computational complexity than the original PAM without degradation of sound quality. Subjective as well as objective test results are presented to confirm the efficiency of the proposed FFT computation algorithm and the PAM.

Imaging of pannus formation in patients with mechanical heart valves.

PubMed

Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-11-26

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.

Imaging of pannus formation in patients with mechanical heart valves

PubMed Central

Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-01-01

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients. PMID:26635931

Anatomical variation of celiac axis, superior mesenteric artery, and hepatic artery: Evaluation with multidetector computed tomography angiography.

PubMed

Farghadani, Maryam; Momeni, Mohammad; Hekmatnia, Ali; Momeni, Fateme; Baradaran Mahdavi, Mohammad Mehdi

2016-01-01

The celiac axis, superior mesenteric artery (SMA), and hepatic artery are the most important branches of abdominal aorta due to their vascularization field. The aim of our study was to evaluate the prevalence of different anatomical variation of celiac axis, SMA, hepatic artery, and its branches with multidetector computed tomography (MDCT) angiography of upper abdomen arteries. MDCT of 607 kidney donor and traumatic patients that referred to MDCT unit at Al Zahra Hospital in Isfahan from 2012 to 2015 were retrospectively evaluated. We excluded patients with history of abdominal vascular surgery and hepatic or pancreatic surgery. Computed tomography images of the patient were obtained with 64-row MDCT scanner and anatomical variations were analyzed. Three hundred and eighty-eight (63.9%) of the 607 patients had classic arterial anatomy and 219 (36.1%) patients had variant types. The most common type of variation was the origin of the right hepatic artery (RHA) from SMA (9.6%), and the next common variation was the origin of the left hepatic artery (LHA) from the left gastric artery (6.9%). Variations in the origin of the common hepatic artery (CHA) were seen in 16 (2.6%) patients. Buhler arc was identified in two patients. The RHA originated from the celiac axis in 11 (1.8%) patients and from the aorta in 8 (1.3%) patients. Trifurcation of CHA into gastroduodenal artery, RHA, and LHA was detected in 11 (1.8%) patients. The results of the present study showed that anatomical variation occurs in a high percentage of patients. Detection of these variations can guide surgical and radiological interventional planning.

Imaging before cryoablation of atrial fibrillation: is phrenic nerve palsy predictable?

PubMed

Canpolat, Uğur; Aytemir, Kudret; Hızal, Mustafa; Hazırolan, Tuncay; Yorgun, Hikmet; Sahiner, Levent; Kaya, Ergun Barış; Oto, Ali

2014-04-01

Multidetector computerized tomography (MDCT) with improved temporal and spatial resolution is one of the most commonly used non-invasive tests for evaluation of pulmonary veins (PVs) and adjacent structures before cryoablation of atrial fibrillation (AF). Identification of spatial neighbouring of phrenic nerves is important to decrease likelihood of phrenic nerve palsy (PNP). The purpose of our study is to clarify the course of right phrenic nerve, its relations to PVs using 64-slice MDCT, and effect on occurrence of PNP. A total of 162 patients underwent MDCT with 3D reconstruction of left atrium prior to cryoablation for AF. The location of the right pericardiophrenic artery (RPA) was identified on axial images and artery distance to the right upper PV (RUPV) ostium was measured in 3D image. Right pericardiophrenic artery was detectable in 145 of 162 (89.5%) patients (52.4% male, age 54.5 ± 10.1 years, and 80.7% paroxysmal AF). Acute procedural success rate was 96.2%. Mean procedural and fluoroscopy times were 74.4 ± 6.2 and 15.7 ± 4.3 min. Transient right PNP was developed in four (2.75%) patients. RUPV ostium to RPA distance was lower in patients with PNP (P = 0.033). In multivariate regression analysis, only RUPV ostium to RPA distance (odds ratio: 2.95; 95% confidence interval: 1.76-4.66, P = 0.001) was the independent predictor of PNP occurrence during cryoablation. Our results revealed that pre-ablation cardiac imaging with 64-slice MDCT adequately detected RPA bordering the phrenic nerve, which was an important determinant of PNP development during cryoballoon-based AF ablation.

Emergency CT for assessment and management of blunt traumatic splenic injuries at a Level 1 Trauma Center: 13-year study.

PubMed

Margari, Sergio; Garozzo Velloni, Fernanda; Tonolini, Massimo; Colombo, Ettore; Artioli, Diana; Allievi, Niccolò Ettore; Sammartano, Fabrizio; Chiara, Osvaldo; Vanzulli, Angelo

2018-05-12

To determine the relationship between multidetector computed tomography (MDCT) findings, management strategies, and ultimate clinical outcomes in patients with splenic injuries secondary to blunt trauma. This Institutional Review Board-approved study collected 351 consecutive patients admitted at the Emergency Department (ED) of a Level I Trauma Center with blunt splenic trauma between October 2002 and November 2015. Their MDCT studies were retrospectively and independently reviewed by two radiologists to grade splenic injuries according to the American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) and to detect intraparenchymal (type A) or extraparenchymal (type B) active bleeding and/or contained vascular injuries (CVI). Clinical data, information on management, and outcome were retrieved from the hospital database. Statistical analysis relied on Student's t, chi-squared, and Cohen's kappa tests. Emergency multiphase MDCT was obtained in 263 hemodynamically stable patients. Interobserver agreement for both AAST grading of injuries and vascular lesions was excellent (k = 0.77). Operative management (OM) was performed in 160 patients (45.58% of the whole cohort), and high-grade (IV and V) OIS injuries and type B bleeding were statistically significant (p < 0.05) predictors of OM. Nonoperative management (NOM) failed in 23 patients out of 191 (12.04%). In 75% of them, NOM failure occurred within 30 h from the trauma event, without significant increase of mortality. Both intraparenchymal and extraparenchymal active bleeding were predictive of NOM failure (p < 0.05). Providing detection and characterization of parenchymal and vascular traumatic lesions, MDCT plays a crucial role for safe and appropriate guidance of ED management of splenic traumas and contributes to the shift toward NOM in hemodynamically stable patients.

Multiscale topo-morphologic opening of arteries and veins: a validation study on phantoms and CT imaging of pulmonary vessel casting of pigs

NASA Astrophysics Data System (ADS)

Gao, Zhiyun; Holtze, Colin; Sonka, Milan; Hoffman, Eric; Saha, Punam K.

2010-03-01

Distinguishing pulmonary arterial and venous (A/V) trees via in vivo imaging is a critical first step in the quantification of vascular geometry for purposes of determining, for instance, pulmonary hypertension, detection of pulmonary emboli and more. A multi-scale topo-morphologic opening algorithm has recently been introduced by us separating A/V trees in pulmonary multiple-detector X-ray computed tomography (MDCT) images without contrast. The method starts with two sets of seeds - one for each of A/V trees and combines fuzzy distance transform, fuzzy connectivity, and morphologic reconstruction leading to multi-scale opening of two mutually fused structures while preserving their continuity. The method locally determines the optimum morphological scale separating the two structures. Here, a validation study is reported examining accuracy of the method using mathematically generated phantoms with different levels of fuzziness, overlap, scale, resolution, noise, and geometric coupling and MDCT images of pulmonary vessel casting of pigs. After exsanguinating the animal, a vessel cast was generated using rapid-hardening methyl methacrylate compound with additional contrast by 10cc of Ethiodol in the arterial side which was scanned in a MDCT scanner at 0.5mm slice thickness and 0.47mm in plane resolution. True segmentations of A/V trees were computed from these images by thresholding. Subsequently, effects of distinguishing A/V contrasts were eliminated and resulting images were used for A/V separation by our method. Experimental results show that 92% - 98% accuracy is achieved using only one seed for each object in phantoms while 94.4% accuracy is achieved in MDCT cast images using ten seeds for each of A/V trees.

Construction of a multimodal CT-video chest model

NASA Astrophysics Data System (ADS)

Byrnes, Patrick D.; Higgins, William E.

2014-03-01

Bronchoscopy enables a number of minimally invasive chest procedures for diseases such as lung cancer and asthma. For example, using the bronchoscope's continuous video stream as a guide, a physician can navigate through the lung airways to examine general airway health, collect tissue samples, or administer a disease treatment. In addition, physicians can now use new image-guided intervention (IGI) systems, which draw upon both three-dimensional (3D) multi-detector computed tomography (MDCT) chest scans and bronchoscopic video, to assist with bronchoscope navigation. Unfortunately, little use is made of the acquired video stream, a potentially invaluable source of information. In addition, little effort has been made to link the bronchoscopic video stream to the detailed anatomical information given by a patient's 3D MDCT chest scan. We propose a method for constructing a multimodal CT-video model of the chest. After automatically computing a patient's 3D MDCT-based airway-tree model, the method next parses the available video data to generate a positional linkage between a sparse set of key video frames and airway path locations. Next, a fusion/mapping of the video's color mucosal information and MDCT-based endoluminal surfaces is performed. This results in the final multimodal CT-video chest model. The data structure constituting the model provides a history of those airway locations visited during bronchoscopy. It also provides for quick visual access to relevant sections of the airway wall by condensing large portions of endoscopic video into representative frames containing important structural and textural information. When examined with a set of interactive visualization tools, the resulting fused data structure provides a rich multimodal data source. We demonstrate the potential of the multimodal model with both phantom and human data.

Characterization of constitutive and acid-induced outwardly rectifying chloride currents in immortalized mouse distal tubular cells.

PubMed

Valinsky, William C; Touyz, Rhian M; Shrier, Alvin

2017-08-01

Thiazides block Na + reabsorption while enhancing Ca 2+ reabsorption in the kidney. As previously demonstrated in immortalized mouse distal convoluted tubule (MDCT) cells, chlorothiazide application induced a robust plasma membrane hyperpolarization, which increased Ca 2+ uptake. This essential thiazide-induced hyperpolarization was prevented by the Cl - channel inhibitor 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), implicating NPPB-sensitive Cl - channels, however the nature of these Cl - channels has been rarely described in the literature. Here we show that MDCT cells express a dominant, outwardly rectifying Cl - current at extracellular pH7.4. This constitutive Cl - current was more permeable to larger anions (Eisenman sequence I; I - >Br - ≥Cl - ) and was substantially inhibited by >100mM [Ca 2+ ] o , which distinguished it from ClC-K2/barttin. Moreover, the constitutive Cl - current was blocked by NPPB, along with other Cl - channel inhibitors (4,4'-diisothiocyanatostilbene-2,2'-disulfonate, DIDS; flufenamic acid, FFA). Subjecting the MDCT cells to an acidic extracellular solution (pH<5.5) induced a substantially larger outwardly rectifying NPPB-sensitive Cl - current. This acid-induced Cl - current was also anion permeable (I - >Br - >Cl - ), but was distinguished from the constitutive Cl - current by its rectification characteristics, ion sensitivities, and response to FFA. In addition, we have identified similar outwardly rectifying and acid-sensitive currents in immortalized cells from the inner medullary collecting duct (mIMCD-3 cells). Expression of an acid-induced Cl - current would be particularly relevant in the acidic IMCD (pH<5.5). To our knowledge, the properties of these Cl - currents are unique and provide the mechanisms to account for the Cl - efflux previously speculated to be present in MDCT cells. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Hi-Res scan mode in clinical MDCT systems: Experimental assessment of spatial resolution performance

PubMed Central

Cruz-Bastida, Juan P.; Gomez-Cardona, Daniel; Li, Ke; Sun, Heyi; Hsieh, Jiang; Szczykutowicz, Timothy P.; Chen, Guang-Hong

2016-01-01

Purpose: The introduction of a High-Resolution (Hi-Res) scan mode and another associated option that combines Hi-Res mode with the so-called High Definition (HD) reconstruction kernels (referred to as a Hi-Res/HD mode in this paper) in some multi-detector CT (MDCT) systems offers new opportunities to increase spatial resolution for some clinical applications that demand high spatial resolution. The purpose of this work was to quantify the in-plane spatial resolution along both the radial direction and tangential direction for the Hi-Res and Hi-Res/HD scan modes at different off-center positions. Methods: A technique was introduced and validated to address the signal saturation problem encountered in the attempt to quantify spatial resolution for the Hi-Res and Hi-Res/HD scan modes. Using the proposed method, the modulation transfer functions (MTFs) of a 64-slice MDCT system (Discovery CT750 HD, GE Healthcare) equipped with both Hi-Res and Hi-Res/HD modes were measured using a metal bead at nine different off-centered positions (0–16 cm with a step size of 2 cm); at each position, both conventional scans and Hi-Res scans were performed. For each type of scan and position, 80 repeated acquisitions were performed to reduce noise induced uncertainties in the MTF measurements. A total of 15 reconstruction kernels, including eight conventional kernels and seven HD kernels, were used to reconstruct CT images of the bead. An ex vivo animal study consisting of a bone fracture model was performed to corroborate the MTF results, as the detection of this high-contrast and high frequency task is predominantly determined by spatial resolution. Images of this animal model generated by different scan modes and reconstruction kernels were qualitatively compared with the MTF results. Results: At the centered position, the use of Hi-Res mode resulted in a slight improvement in the MTF; each HD kernel generated higher spatial resolution than its counterpart conventional kernel. However, the MTF along the tangential direction of the scan field of view (SFOV) was significantly degraded at off-centered positions, yet the combined Hi-Res/HD mode reduced this azimuthal MTF degradation. Images of the animal bone fracture model confirmed the improved spatial resolution at the off-centered positions through the use of the Hi-Res mode and HD kernels. Conclusions: The Hi-Res/HD scan improve spatial resolution of MDCT systems at both centered and off-centered positions. PMID:27147351

Hi-Res scan mode in clinical MDCT systems: Experimental assessment of spatial resolution performance.

PubMed

Cruz-Bastida, Juan P; Gomez-Cardona, Daniel; Li, Ke; Sun, Heyi; Hsieh, Jiang; Szczykutowicz, Timothy P; Chen, Guang-Hong

2016-05-01

The introduction of a High-Resolution (Hi-Res) scan mode and another associated option that combines Hi-Res mode with the so-called High Definition (HD) reconstruction kernels (referred to as a Hi-Res/HD mode in this paper) in some multi-detector CT (MDCT) systems offers new opportunities to increase spatial resolution for some clinical applications that demand high spatial resolution. The purpose of this work was to quantify the in-plane spatial resolution along both the radial direction and tangential direction for the Hi-Res and Hi-Res/HD scan modes at different off-center positions. A technique was introduced and validated to address the signal saturation problem encountered in the attempt to quantify spatial resolution for the Hi-Res and Hi-Res/HD scan modes. Using the proposed method, the modulation transfer functions (MTFs) of a 64-slice MDCT system (Discovery CT750 HD, GE Healthcare) equipped with both Hi-Res and Hi-Res/HD modes were measured using a metal bead at nine different off-centered positions (0-16 cm with a step size of 2 cm); at each position, both conventional scans and Hi-Res scans were performed. For each type of scan and position, 80 repeated acquisitions were performed to reduce noise induced uncertainties in the MTF measurements. A total of 15 reconstruction kernels, including eight conventional kernels and seven HD kernels, were used to reconstruct CT images of the bead. An ex vivo animal study consisting of a bone fracture model was performed to corroborate the MTF results, as the detection of this high-contrast and high frequency task is predominantly determined by spatial resolution. Images of this animal model generated by different scan modes and reconstruction kernels were qualitatively compared with the MTF results. At the centered position, the use of Hi-Res mode resulted in a slight improvement in the MTF; each HD kernel generated higher spatial resolution than its counterpart conventional kernel. However, the MTF along the tangential direction of the scan field of view (SFOV) was significantly degraded at off-centered positions, yet the combined Hi-Res/HD mode reduced this azimuthal MTF degradation. Images of the animal bone fracture model confirmed the improved spatial resolution at the off-centered positions through the use of the Hi-Res mode and HD kernels. The Hi-Res/HD scan improve spatial resolution of MDCT systems at both centered and off-centered positions.

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors

PubMed Central

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

Purpose To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Methods Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Results Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm—56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm—68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). Conclusion MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors. PMID:26332466

PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer.

PubMed

Ghaneh, Paula; Hanson, Robert; Titman, Andrew; Lancaster, Gill; Plumpton, Catrin; Lloyd-Williams, Huw; Yeo, Seow Tien; Edwards, Rhiannon Tudor; Johnson, Colin; Abu Hilal, Mohammed; Higginson, Antony P; Armstrong, Tom; Smith, Andrew; Scarsbrook, Andrew; McKay, Colin; Carter, Ross; Sutcliffe, Robert P; Bramhall, Simon; Kocher, Hemant M; Cunningham, David; Pereira, Stephen P; Davidson, Brian; Chang, David; Khan, Saboor; Zealley, Ian; Sarker, Debashis; Al Sarireh, Bilal; Charnley, Richard; Lobo, Dileep; Nicolson, Marianne; Halloran, Christopher; Raraty, Michael; Sutton, Robert; Vinjamuri, Sobhan; Evans, Jonathan; Campbell, Fiona; Deeks, Jon; Sanghera, Bal; Wong, Wai-Lup; Neoptolemos, John P

2018-02-01

Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer. To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer. A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy. Patients with suspected pancreatic malignancy. All patients to undergo PET/CT following standard diagnostic work-up. The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours. Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUV max. ) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity ( p  = 0.01) and specificity ( p  = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios ( p  < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients ( p  = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval -0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable. PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer. Current Controlled Trials ISRCTN73852054 and UKCRN 8166. The National Institute for Health Research Health Technology Assessment programme.

Automated Quantification of Pneumothorax in CT

PubMed Central

Do, Synho; Salvaggio, Kristen; Gupta, Supriya; Kalra, Mannudeep; Ali, Nabeel U.; Pien, Homer

2012-01-01

An automated, computer-aided diagnosis (CAD) algorithm for the quantification of pneumothoraces from Multidetector Computed Tomography (MDCT) images has been developed. Algorithm performance was evaluated through comparison to manual segmentation by expert radiologists. A combination of two-dimensional and three-dimensional processing techniques was incorporated to reduce required processing time by two-thirds (as compared to similar techniques). Volumetric measurements on relative pneumothorax size were obtained and the overall performance of the automated method shows an average error of just below 1%. PMID:23082091

Pacemaker-induced Metallic Artifacts in Coronary Computed Tomography Angiography: Clinical Feasibility of Single Energy Metal Artifact Reduction Technique.

PubMed

Takayanagi, Tomoya; Arai, Takehiro; Amanuma, Makoto; Sano, Tomonari; Ichiba, Masato; Ishizaka, Kazumasa; Sekine, Takako; Matsutani, Hideyuki; Morita, Hitomi; Takase, Shinichi

2017-01-01

Coronary computed tomography angiography (CCTA) in patients with pacemaker suffers from metallic lead-induced artifacts, which often interfere with accurate assessment of coronary luminal stenosis. The purpose of this study was to assess a frequency of the lead-induced artifacts and artifact-suppression effect by the single energy metal artifact reduction (SEMAR) technique. Forty-one patients with a dual-chamber pacemaker were evaluated using a 320 multi-detector row CT (MDCT). Among them, 22 patients with motion-free full data reconstruction images were the final candidates. Images with and without the SMEAR technique were subjectively compared, and the degree of metallic artifacts was compared. On images without SEMAR, severe metallic artifacts were often observed in the right coronary artery (#1, #2, #3) and distal anterior descending branch (#8). These artifacts were effectively suppressed by SEMAR, and the luminal accessibility was significantly improved in #3 and #8. While pacemaker leads often cause metallic-induced artifacts, SEMAR technique reduced the artifacts and significantly improved the accessibility of coronary lumen in #3 and #8.

Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

PubMed Central

Matos, António P.; Mascarenhas, Vasco; Herédia, Vasco

2014-01-01

Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. PMID:25295188

Multidetector computer tomography: evaluation of blunt chest trauma in adults.

PubMed

Palas, João; Matos, António P; Mascarenhas, Vasco; Herédia, Vasco; Ramalho, Miguel

2014-01-01

Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall.

Validation of the Australian diagnostic reference levels for paediatric multi detector computed tomography: a comparison of RANZCR QUDI data and subsequent NDRLS data from 2012 to 2015.

PubMed

Anna, Hayton; Wallace, Anthony; Thomas, Peter

2017-03-01

The national diagnostic reference level service (NDRLS), was launched in 2011, however no paediatric data were submitted during the first calendar year of operation. As such, Australian national diagnostic reference levels (DRLs), for paediatric multi detector computed tomography (MDCT), were established using data obtained from a Royal Australian and New Zealand College of Radiologists (RANZCR), Quality Use of Diagnostic Imaging (QUDI), study. Paediatric data were submitted to the NDRLS in 2012 through 2015. An analysis has been made of the NDRLS paediatric data using the same method as was used to analyse the QUDI data to establish the Australian national paediatric DRLs for MDCT. An analysis of the paediatric NDRLS data has also been made using the method used to calculate the Australian national adult DRLs for MDCT. A comparison between the QUDI data and subsequent NDRLS data shows the NDRLS data to be lower on average for the Head and AbdoPelvis protocol and similar for the chest protocol. Using an average of NDRLS data submitted between 2012 and 2015 implications for updated paediatric DRLS are considered.

Extraction and visualization of the central chest lymph-node stations

NASA Astrophysics Data System (ADS)

Lu, Kongkuo; Merritt, Scott A.; Higgins, William E.

2008-03-01

Lung cancer remains the leading cause of cancer death in the United States and is expected to account for nearly 30% of all cancer deaths in 2007. Central to the lung-cancer diagnosis and staging process is the assessment of the central chest lymph nodes. This assessment typically requires two major stages: (1) location of the lymph nodes in a three-dimensional (3D) high-resolution volumetric multi-detector computed-tomography (MDCT) image of the chest; (2) subsequent nodal sampling using transbronchial needle aspiration (TBNA). We describe a computer-based system for automatically locating the central chest lymph-node stations in a 3D MDCT image. Automated analysis methods are first run that extract the airway tree, airway-tree centerlines, aorta, pulmonary artery, lungs, key skeletal structures, and major-airway labels. This information provides geometrical and anatomical cues for localizing the major nodal stations. Our system demarcates these stations, conforming to criteria outlined for the Mountain and Wang standard classification systems. Visualization tools within the system then enable the user to interact with these stations to locate visible lymph nodes. Results derived from a set of human 3D MDCT chest images illustrate the usage and efficacy of the system.

[Vascular anatomy of donor and recipient in living kidney transplantation].

PubMed

Zhang, Jiqing; Zhang, Xiaodong

2009-09-01

To review the vascular anatomy of the donor and the recipient for the living kidney transplantation. The recent literature about the vessels of donor and recipient in clinical applications was extensively reviewed. The pertinent vascular anatomy of the donor and recipient was essential for the screening of the proper candidates, surgical planning and long-term outcome. Early branching and accessory renal artery of the donor were particularly important to deciding the side of nephrectomy, surgical technique and anastomosing pattern, and their injuries were the most frequent factor of the conversion from laparoscopic to open surgery. With increase of laparoscopic nephrectomy in donors, accurate venous anatomy was paid more and more attention to because venous bleeding could also lead to conversion to open nephrectomy. Multidetector CT (MDCT) could supplant the conventional excretory urography and renal catheter angiography and could accurately depict the donors' vessels, vascular variations. In addition, MDCT can excellently evaluate the status of donor kidney, collecting system and other pertinent anatomy details. Accurate master of related vascular anatomy can facilitate operation plan and success of operation and can contribute to the rapid development of living donor kidney transplantation. MDCT has become the choice of preoperative one-stop image assessment for living renal donors.

Improved motion compensation in 3D-CT using respiratory-correlated segment reconstruction: diagnostic and radiotherapy applications.

PubMed

Mori, S; Endo, M; Kohno, R; Minohara, S

2006-09-01

Conventional respiratory-gated CT and four-dimensional CT (4DCT) are disadvantaged by their low temporal resolution, which results in the inclusion of anatomic motion-induced artefacts. These represent a significant source of error both in radiotherapy treatment planning for the thorax and upper abdomen and in diagnostic procedures. In particular, temporal resolution and image quality are vitally important to accurate diagnosis and the minimization of planning target volume margin due to respiratory motion. To improve both temporal resolution and signal-to-noise ratio (SNR), we developed a respiratory-correlated segment reconstruction method (RS) and adapted it to the Feldkamp-Davis-Kress algorithm (FDK) with a 256 multidetector row CT (256MDCT). The 256MDCT scans approximately 100 mm in the craniocaudal direction with a 0.5 mm slice thickness in one rotation. Data acquisition for the RS-FDK relies on the assistance of a respiratory sensing system operating in cine scan mode (continuous axial scan with the table stationary). We evaluated the RS-FDK for volume accuracy and image noise in a phantom study with the 256MDCT and compared results with those for a full scan (FS-FDK), which is usually employed in conventional 4DCT and in half scan (HS-FDK). Results showed that the RS-FDK gave a more accurate volume than the others and had the same SNR as the FS-FDK. In a subsequent animal study, we demonstrated a practical sorting process for projection data which was unaffected by variations in respiratory period, and found that the RS-FDK gave the clearest visualization among the three algorithms of the margins of the liver and pulmonary vessels. In summary, the RS-FDK algorithm provides multi-phase images with higher temporal resolution and better SNR. This method should prove useful when combined with new radiotherapeutic and diagnostic techniques.

[Detection of intraorbital foreign material using MDCT].

PubMed

Hoffstetter, P; Friedrich, C; Framme, C; Hoffstetter, M; Zorger, N; Stierstorfer, K; Ross, C; Uller, W; Müller-Wille, R; Rennert, J; Jung, E M; Schreyer, A G

2011-06-01

To judge the possibilities of detection of orbital foreign bodies in multidetector CT (MDCT) with a focus on glass slivers. Experimental systematic measuring of Hounsfield Units (HU) of 20 different materials, containing 16 different types of glass with 4 different types of ophthalmic lenses among them. The measurements were performed using a standardized protocol with an orbita phantom being scanned with 16-slice MDCT. Using the resulting density values, the smallest detectable volume was calculated. Using this data we produced slivers of 5 different glass types in the sub-millimeter range and calculated their volume. Those micro-slivers underwent another CT scan using the same protocol as mentioned above to experimentally discern and confirm the detection limit for micro-slivers made of different materials. Glass has comparatively high density values of at least 2000 HU. The density of glasses with strong refraction is significantly higher and reaches up to 12 400 HU. We calculated a minimum detectable volume of 0.07 mm (3) for glass with a density of 2000 HU. Only glass slivers with a density higher than 8300 HU were experimentally detectable in the sub-millimeter range up to a volume as small as 0.01 mm (3). Less dense glass slivers could not be seen, even though their volume was above the theoretically calculated threshold for detection. Due to its high density of at least 2000 HU, glass is usually easily recognizable as an orbital foreign body. The detection threshold depends on the object's density and size and can be as low as 0.01 mm (3) in the case of glass with strong refraction and thus high density. The detection of glass as an orbital foreign body seems to be secure for slivers with a volume of at least 0.2 mm (3) for all types of glass. © Georg Thieme Verlag KG Stuttgart · New York.

Dose reduction for abdominal and pelvic MDCT after change to graduated weight-based protocol for selecting quality reference tube current, peak kilovoltage, and slice collimation.

PubMed

Herts, Brian R; Baker, Mark E; Obuchowski, Nancy; Primak, Andrew; Schneider, Erika; Rhana, Harpreet; Dong, Frank

2013-06-01

The purpose of this article is to determine the decrease in volume CT dose index (CTDI(vol)) and dose-length product (DLP) achieved by switching from fixed quality reference tube current protocols with automatic tube current modulation to protocols adjusting the quality reference tube current, slice collimation, and peak kilovoltage according to patient weight. All adult patients who underwent CT examinations of the abdomen or abdomen and pelvis during 2010 using weight-based protocols who also underwent a CT examination in 2008 or 2009 using fixed quality reference tube current protocols were identified from the radiology information system. Protocol pages were electronically retrieved, and the CT model, examination date, scan protocol, CTDI(vol), and DLP were extracted from the DICOM header or by optical character recognition. There were 15,779 scans with dose records for 2700 patients. Changes in CTDI(vol) and DLP were compared only between examinations of the same patient and same CT system model for examinations performed in 2008 or 2009 and those performed in 2010. The final analysis consisted of 1117 comparisons in 1057 patients, and 1209 comparisons in 988 patients for CTDI(vol) and DLP, respectively. The change to a weight-based protocol resulted in a statistically significant reduction in CTDI(vol) and DLP on three MDCT system models (p < 0.001). The largest average CTDI(vol) decrease was 13.9%, and the largest average DLP decrease was 16.1% on a 64-MDCT system. Both the CTDI(vol) and DLP decreased the most for patients who weighed less than 250 lb (112.5 kg). Adjusting the CT protocol by selecting parameters according to patient weight is a viable method for reducing CT radiation dose. The largest reductions occurred in the patients weighing less than 250 lb.

Electromagnetic navigation versus fluoroscopy in aortic endovascular procedures: a phantom study.

PubMed

Tystad Lund, Kjetil; Tangen, Geir Arne; Manstad-Hulaas, Frode

2017-01-01

To explore the possible benefits of electromagnetic (EM) navigation versus conventional fluoroscopy during abdominal aortic endovascular procedures. The study was performed on a phantom representing the abdominal aorta. Intraoperative cone beam computed tomography (CBCT) of the phantom was acquired and merged with a preoperative multidetector CT (MDCT). The CBCT was performed with a reference plate fixed to the phantom that, after merging the CBCT with the MDCT, facilitated registration of the MDCT volume with the EM space. An EM field generator was stationed near the phantom. Navigation software was used to display EM-tracked instruments within the 3D image volume. Fluoroscopy was performed using a C-arm system. Five operators performed a series of renal artery cannulations using modified instruments, alternatingly using fluoroscopy or EM navigation as the sole guidance method. Cannulation durations and associated radiation dosages were noted along with the number of cannulations complicated by loss of guidewire insertion. A total of 120 cannulations were performed. The median cannulation durations were 41.5 and 34.5 s for the fluoroscopy- and EM-guided cannulations, respectively. No significant difference in cannulation duration was found between the two modalities (p = 0.736). Only EM navigation showed a significant reduction in cannulation duration in the latter half of its cannulation series compared with the first half (p = 0.004). The median dose area product for fluoroscopy was 0.0836 [Formula: see text]. EM-guided cannulations required a one-time CBCT dosage of 3.0278 [Formula: see text]. Three EM-guided and zero fluoroscopy-guided cannulations experienced loss of guidewire insertion. Our findings indicate that EM navigation is not inferior to fluoroscopy in terms of the ability to guide endovascular interventions. Its utilization may be of particular interest in complex interventions where adequate visualization or minimal use of contrast agents is critical. In vivo studies featuring an optimized implementation of EM navigation should be conducted.

Peripheral Quantitative CT (pQCT) Using a Dedicated Extremity Cone-Beam CT Scanner

PubMed Central

Muhit, A. A.; Arora, S.; Ogawa, M.; Ding, Y.; Zbijewski, W.; Stayman, J. W.; Thawait, G.; Packard, N.; Senn, R.; Yang, D.; Yorkston, J.; Bingham, C.O.; Means, K.; Carrino, J. A.; Siewerdsen, J. H.

2014-01-01

Purpose We describe the initial assessment of the peripheral quantitative CT (pQCT) imaging capabilities of a cone-beam CT (CBCT) scanner dedicated to musculoskeletal extremity imaging. The aim is to accurately measure and quantify bone and joint morphology using information automatically acquired with each CBCT scan, thereby reducing the need for a separate pQCT exam. Methods A prototype CBCT scanner providing isotropic, sub-millimeter spatial resolution and soft-tissue contrast resolution comparable or superior to standard multi-detector CT (MDCT) has been developed for extremity imaging, including the capability for weight-bearing exams and multi-mode (radiography, fluoroscopy, and volumetric) imaging. Assessment of pQCT performance included measurement of bone mineral density (BMD), morphometric parameters of subchondral bone architecture, and joint space analysis. Measurements employed phantoms, cadavers, and patients from an ongoing pilot study imaged with the CBCT prototype (at various acquisition, calibration, and reconstruction techniques) in comparison to MDCT (using pQCT protocols for analysis of BMD) and micro-CT (for analysis of subchondral morphometry). Results The CBCT extremity scanner yielded BMD measurement within ±2–3% error in both phantom studies and cadaver extremity specimens. Subchondral bone architecture (bone volume fraction, trabecular thickness, degree of anisotropy, and structure model index) exhibited good correlation with gold standard micro-CT (error ~5%), surpassing the conventional limitations of spatial resolution in clinical MDCT scanners. Joint space analysis demonstrated the potential for sensitive 3D joint space mapping beyond that of qualitative radiographic scores in application to non-weight-bearing versus weight-bearing lower extremities and assessment of phalangeal joint space integrity in the upper extremities. Conclusion The CBCT extremity scanner demonstrated promising initial results in accurate pQCT analysis from images acquired with each CBCT scan. Future studies will include improved x-ray scatter correction and image reconstruction techniques to further improve accuracy and to correlate pQCT metrics with known pathology. PMID:25076823

Accuracy and reproducibility of novel echocardiographic three-dimensional automated software for the assessment of the aortic root in candidates for thanscatheter aortic valve replacement.

PubMed

García-Martín, Ana; Lázaro-Rivera, Carla; Fernández-Golfín, Covadonga; Salido-Tahoces, Luisa; Moya-Mur, Jose-Luis; Jiménez-Nacher, Jose-Julio; Casas-Rojo, Eduardo; Aquila, Iolanda; González-Gómez, Ariana; Hernández-Antolín, Rosana; Zamorano, José Luis

2016-07-01

A specialized three-dimensional transoesophageal echocardiography (3D-TOE) reconstruction tool has recently been introduced; the system automatically configures a geometric model of the aortic root from the images obtained by 3D-TOE and performs quantitative analysis of these structures. The aim of this study was to compare the measurements of the aortic annulus (AA) obtained by the new model to that obtained by 3D-TOE and multidetector computed tomography (MDCT) in candidates to transcatheter aortic valve implantation (TAVI) and to assess the reproducibility of this new method. We included 31 patients who underwent TAVI. The AA diameters and area were evaluated by the manual 3D-TOE method and by the automatic software. We showed an excellent correlation between the measurements obtained by both methods: intra-class correlation coefficient (ICC): 0.731 (0.508-0.862), r: 0.742 for AA diameter and ICC: 0.723 (0.662-0.923), r: 0.723 for the AA area, with no significant differences regardless of the method used. The interobserver variability was superior for the automatic measurements than for the manual ones. In a subgroup of 10 patients, we also found an excellent correlation between the automatic measurements and those obtained by MDCT, ICC: 0.941 (0.761-0.985), r: 0.901 for AA diameter and ICC: 0.853 (0.409-0.964), r: 0.744 for the AA area. The new automatic 3D-TOE software allows modelling and quantifying the aortic root from 3D-TOE data with high reproducibility. There is good correlation between the automated measurements and other 3D validated techniques. Our results support its use in clinical practice as an alternative to MDCT previous to TAVI. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Effect of mixing scanner types and reconstruction kernels on the characterization of lung parenchymal pathologies: emphysema, interstitial pulmonary fibrosis and normal non-smokers

NASA Astrophysics Data System (ADS)

Xu, Ye; van Beek, Edwin J.; McLennan, Geoffrey; Guo, Junfeng; Sonka, Milan; Hoffman, Eric

2006-03-01

In this study we utilize our texture characterization software (3-D AMFM) to characterize interstitial lung diseases (including emphysema) based on MDCT generated volumetric data using 3-dimensional texture features. We have sought to test whether the scanner and reconstruction filter (kernel) type affect the classification of lung diseases using the 3-D AMFM. We collected MDCT images in three subject groups: emphysema (n=9), interstitial pulmonary fibrosis (IPF) (n=10), and normal non-smokers (n=9). In each group, images were scanned either on a Siemens Sensation 16 or 64-slice scanner, (B50f or B30 recon. kernel) or a Philips 4-slice scanner (B recon. kernel). A total of 1516 volumes of interest (VOIs; 21x21 pixels in plane) were marked by two chest imaging experts using the Iowa Pulmonary Analysis Software Suite (PASS). We calculated 24 volumetric features. Bayesian methods were used for classification. Images from different scanners/kernels were combined in all possible combinations to test how robust the tissue classification was relative to the differences in image characteristics. We used 10-fold cross validation for testing the result. Sensitivity, specificity and accuracy were calculated. One-way Analysis of Variances (ANOVA) was used to compare the classification result between the various combinations of scanner and reconstruction kernel types. This study yielded a sensitivity of 94%, 91%, 97%, and 93% for emphysema, ground-glass, honeycombing, and normal non-smoker patterns respectively using a mixture of all three subject groups. The specificity for these characterizations was 97%, 99%, 99%, and 98%, respectively. The F test result of ANOVA shows there is no significant difference (p <0.05) between different combinations of data with respect to scanner and convolution kernel type. Since different MDCT and reconstruction kernel types did not show significant differences in regards to the classification result, this study suggests that the 3-D AMFM can be generally introduced.

Comparison of sensitivity and reading time for the use of computer aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader

NASA Astrophysics Data System (ADS)

Beyer, F.; Zierott, L.; Fallenberg, E. M.; Juergens, K.; Stoeckel, J.; Heindel, W.; Wormanns, D.

2006-03-01

Purpose: To compare sensitivity and reading time when using CAD as second reader resp. concurrent reader. Materials and Methods: Fifty chest MDCT scans due to clinical indication were analysed independently by four radiologists two times: First with CAD as concurrent reader (display of CAD results simultaneously to the primary reading by the radiologist); then after a median of 14 weeks with CAD as second reader (CAD results were shown after completion of a reading session without CAD). A prototype version of Siemens LungCAD (Siemens,Malvern,USA) was used. Sensitivities and reading times for detecting nodules >=4mm of concurrent reading, reading without CAD and second reading were recorded. In a consensus conference false positive findings were eliminated. Student's T-Test was used to compare sensitivities and reading times. Results: 108 true positive nodules were found. Mean sensitivity was .68 for reading without CAD, .68 for concurrent reading and .75 for second reading. Differences of sensitivities were significant between concurrent and second reading (p<.001) resp. reading without CAD and second reading (p=.001). Mean reading time for concurrent reading was significant shorter (274s) compared to reading without CAD (294s;p=.04) and second reading (337sp<.001). New work to be presented: To our knowledge this is the first study that compares sensitivities and reading times between use of CAD as concurrent resp. second reader. Conclusion: CAD can either be used to speed up reading of chest CT cases for pulmonary nodules without loss of sensitivity as concurrent reader -OR (and not AND) to increase sensitivity and reading time as second reader.

Postmortem dynamic cerebral angiography for detecting aneurysm and bleeding sites in cases of subarachnoid hemorrhage.

PubMed

Inokuchi, Go; Yajima, Daisuke; Hayakawa, Mutsumi; Motomura, Ayumi; Chiba, Fumiko; Torimitsu, Suguru; Makino, Yohsuke; Iwase, Hirotaro

2014-12-01

One of the advantages of postmortem imaging is its ability to obtain diagnostic findings in a non-destructive manner when autopsy is either difficult or may destroy forensic evidence. In recent years, efforts have been made to incorporate computed tomography (CT) based postmortem angiography into forensic pathology; however, it is not currently clear how well the modality can determine sites of bleeding in cases of subarachnoid hemorrhage. Therefore, in this study, we investigated the utility of postmortem cerebral angiography using multi-detector row CT (MDCT) by injecting a contrast medium through a catheter inserted into the internal carotid and vertebral arteries of 10 subarachnoid hemorrhage cases. While postmortem MDCT angiography (PMCTA) was capable of detecting aneurysms in a non-destructive manner, it was sometimes difficult to identify the aneurysm and bleeding sites because of a large amount of contrast medium leaking into the extravascular space. To overcome this problem, we developed the novel contrast imaging method "dynamic cerebral angiography," which involves scanning the same area multiple times while injecting contrast medium to enable real-time observation of the contrasted vasculature. Using multiphase contrast images acquired by this method, we successfully captured the moment when contrast medium leaked from the hemorrhage site. This method will be useful for identifying exact bleeding sites on PMCTA.

Right heart on multidetector CT

PubMed Central

Gopalan, D

2011-01-01

Right ventricular function plays an integral role in the pathogenesis and outcome of many cardiovascular diseases. Imaging the right ventricle has long been a challenge because of its complex geometry. In recent years there has been a tremendous expansion in multidetector row CT (MDCT) and its cardiac applications. By judicious modification of contrast medium protocol, it is possible to achieve good opacification of the right-sided cardiac chambers, thereby paving the way for exploring the overshadowed right heart. This article will describe the key features of right heart anatomy, review MDCT acquisition techniques, elaborate the various morphological and functional information that can be obtained, and illustrate some important clinical conditions associated with an abnormal right heart. PMID:22723537

Congenital Anomaly of Single Dominant Right Coronary Artery with Hypoplastic Left Coronary Artery.

PubMed

Chuang, Cheng-Yen; Chen, Yen-Chou; Cheng, Ho-Shun; Hsieh, Ming-Hsiung

2015-11-01

With the popularization of new imaging technology, more people are deciding to undergo non-invasive studies such as multidetector computerized tomography (MDCT) before receiving coronary angiography. For this reason, coronary anomalies of coronary artery are being encountered more frequently. We here report a 68-year-old male presenting with typical angina. The MDCT images suggested chronic total occlusion of the left anterior descending (LAD) artery with collateral circulation from the right coronary artery (RCA). The patient's coronary angiography showed a congenital coronary anomaly with a single dominant RCA supplying the entire coronary circulation of the heart with both LAD and left circumflex artery hypoplasia. Angiography; Anomaly; Computerized tomography; Coronary artery.

Errors in imaging of traumatic injuries.

PubMed

Scaglione, Mariano; Iaselli, Francesco; Sica, Giacomo; Feragalli, Beatrice; Nicola, Refky

2015-10-01

The advent of multi-detector computed tomography (MDCT) has drastically improved the outcomes of patients with multiple traumatic injuries. However, there are still diagnostic challenges to be considered. A missed or the delay of a diagnosis in trauma patients can sometimes be related to perception or other non-visual cues, while other errors are due to poor technique or poor image quality. In order to avoid any serious complications, it is important for the practicing radiologist to be cognizant of some of the most common types of errors. The objective of this article is to review the various types of errors in the evaluation of patients with multiple trauma injuries or polytrauma with MDCT.

Multislice CT perfusion imaging of the lung in detection of pulmonary embolism

NASA Astrophysics Data System (ADS)

Hong, Helen; Lee, Jeongjin

2006-03-01

We propose a new subtraction technique for accurately imaging lung perfusion and efficiently detecting pulmonary embolism in chest MDCT angiography. Our method is composed of five stages. First, optimal segmentation technique is performed for extracting same volume of the lungs, major airway and vascular structures from pre- and post-contrast images with different lung density. Second, initial registration based on apex, hilar point and center of inertia (COI) of each unilateral lung is proposed to correct the gross translational mismatch. Third, initial alignment is refined by iterative surface registration. For fast and robust convergence of the distance measure to the optimal value, a 3D distance map is generated by the narrow-band distance propagation. Fourth, 3D nonlinear filter is applied to the lung parenchyma to compensate for residual spiral artifacts and artifacts caused by heart motion. Fifth, enhanced vessels are visualized by subtracting registered pre-contrast images from post-contrast images. To facilitate visualization of parenchyma enhancement, color-coded mapping and image fusion is used. Our method has been successfully applied to ten patients of pre- and post-contrast images in chest MDCT angiography. Experimental results show that the performance of our method is very promising compared with conventional methods with the aspects of its visual inspection, accuracy and processing time.

Differentiation of thrombus from pannus as the cause of acquired mechanical prosthetic heart valve obstruction by non-invasive imaging: a review of the literature.

PubMed

Tanis, Wilco; Habets, Jesse; van den Brink, Renee B A; Symersky, Petr; Budde, Ricardo P J; Chamuleau, Steven A J

2014-02-01

For acquired mechanical prosthetic heart valve (PHV) obstruction and suspicion on thrombosis, recently updated European Society of Cardiology guidelines advocate the confirmation of thrombus by transthoracic echocardiography, transesophageal echocardiography (TEE), and fluoroscopy. However, no evidence-based diagnostic algorithm is available for correct thrombus detection, although this is clinically important as fibrinolysis is contraindicated in non-thrombotic obstruction (isolated pannus). Here, we performed a review of the literature in order to propose a diagnostic algorithm. We performed a systematic search in Pubmed and Embase. Included publications were assessed on methodological quality based on the validated Quality Assessment of Diagnostic Accuracy Studies (QUADAS) II checklist. Studies were scarce (n = 15) and the majority were of moderate methodological quality. In total, 238 mechanical PHV's with acquired obstruction and a reliable reference standard were included for the evaluation of the role of fluoroscopy, echocardiography, or multidetector-row computed tomography (MDCT). In acquired PHV obstruction caused by thrombosis, mass detection by TEE and leaflet restriction detected by fluoroscopy were observed in the majority of cases (96 and 100%, respectively). In contrast, in acquired PHV obstruction free of thrombosis (pannus), leaflet restriction detected by fluoroscopy was absent in some cases (17%) and mass detection by TEE was absent in the majority of cases (66%). In case of mass detection by TEE, predictors for obstructive thrombus masses (compared with pannus masses) were leaflet restriction, soft echo density, and increased mass length. In situations of inconclusive echocardiography, MDCT may correctly detect pannus/thrombus based on the morphological aspects and localization. In acquired mechanical PHV obstruction without leaflet restriction and absent mass on TEE, obstructive PHV thrombosis cannot be confirmed and consequently, fibrinolysis is not advised. Based on the literature search and our opinion, a diagnostic algorithm is provided to correctly identify non-thrombotic PHV obstruction, which is highly relevant in daily clinical practice.

Primary intestinal lymphangiectasia: Multiple detector computed tomography findings after direct lymphangiography.

PubMed

Sun, Xiaoli; Shen, Wenbin; Chen, Xiaobai; Wen, Tingguo; Duan, Yongli; Wang, Rengui

2017-10-01

To analyse the findings of multiple detector computed tomography (MDCT) after direct lymphangiography in primary intestinal lymphangiectasia (PIL). Fifty-five patients with PIL were retrospectively reviewed. All patients underwent MDCT after direct lymphangiography. The pathologies of 16 patients were confirmed by surgery and the remaining 39 patients were confirmed by gastroendoscopy and/or capsule endoscopy. After direct lymphangiography, MDCT found intra- and extraintestinal as well as lymphatic vessel abnormalities. Among the intra- and extraintestinal disorders, 49 patients had varying degrees of intestinal dilatation, 46 had small bowel wall thickening, 9 had pleural and pericardial effusions, 21 had ascites, 41 had mesenteric oedema, 20 had mesenteric nodules and 9 had abdominal lymphatic cysts. Features of lymphatic vessel abnormalities included intestinal trunk reflux (43.6%, n = 24), lumbar trunk reflux (89.1%, n = 49), pleural and pulmonary lymph reflux (14.5%, n = 8), pericardial and mediastinal lymph reflux (16.4%, n = 9), mediastinal and pulmonary lymph reflux (18.2%, n = 10), and thoracic duct outlet obstruction (90.9%, n = 50). Multiple detector computed tomography after direct lymphangiography provides a safe and accurate examination method and is an excellent tool for the diagnosis of PIL. © 2017 The Royal Australian and New Zealand College of Radiologists.

Contour variations of the body and tail of the pancreas: evaluation with MDCT.

PubMed

Omeri, Ahmad Khalid; Matsumoto, Shunro; Kiyonaga, Maki; Takaji, Ryo; Yamada, Yasunari; Kosen, Kazuhisa; Mori, Hiromu; Miyake, Hidetoshi

2017-06-01

To analyze morphology/contour variations of the pancreatic body and tail in subjects free of pancreatic disease. We retrospectively reviewed triple-phase, contrast-enhanced multi-detector row computed tomography (3P-CE-MDCT) examinations of 449 patients who had no clinical or CT evidence of pancreatic diseases. These patients were evaluated for morphologic/contour variations of the pancreatic body and tail, which were classified into two types. In Type I, a portion of normal pancreatic parenchyma protrudes >1 cm in maximum diameter from the body or tail (Ia-anteriorly; Ib-posteriorly). Type II was defined as a morphologic anomaly of the pancreatic tail (IIa-globular; IIb-lobulated; IIc-tapered; IId-bifid). Thirty-eight (8.5%) out of 449 patients had body or tail variations. Of those, 23 patients showed Type I variant: Ia in 21 and Ib in two. Type II variant was identified in 15 patients: IIa in eight, IIb in two, IIc in two and IId in three. Protrusion of the anterior surface of the normal pancreas, especially in the tail, was the most frequently occurring variant. Recognizing the types and subtypes of morphology/contour variations of the pancreatic body and tail could help prevent misinterpretation of normal variants as pancreatic tumors on unenhanced MDCT.

Current topics in surgery for isolated total anomalous pulmonary venous connection.

PubMed

Yoshimura, Naoki; Fukahara, Kazuaki; Yamashita, Akio; Doki, Yoshinori; Takeuchi, Katsunori; Higuma, Tomonori; Senda, Kazutaka; Toge, Masayoshi; Matsuo, Tatsuro; Nagura, Saori; Aoki, Masaya; Sakata, Kimimasa; Obi, Hayato

2014-12-01

Surgical correction of total anomalous pulmonary venous connection (TAPVC) remains a challenge, with reported early mortality rates of up to 20%. In this review article, we describe several topics, including surgery for neonates, diagnoses with multidetector computed tomography (MDCT), and primary sutureless repair. Several studies have reported mortality rates of around 10%, and demonstrated unchanged hospital mortality in neonates, despite improvement of the overall mortality of cohorts including older patients. Previous reports identified a low body weight at the time of the operation, preoperative pulmonary venous obstruction (PVO), and a prolonged cardiopulmonary bypass time as risk factors for hospital mortality. With the development of new technologies, MDCT has become a good diagnostic modality for use in the pre- and post-operative evaluation. MDCT delineates the drainage site of the vertical vein and the atypical vessel into the systemic vein, and it can also evaluate the existence of obstruction in the vertical vein. Following favorable experiences with post-repair PVO, the indications for sutureless repair as a primary operation have been expanded for infants, including those at risk of developing PVO after the repair of TAPVC. Primary sutureless repair has proven especially useful for difficult patient groups, such as those with congenital PVO, infracardiac TAPVC with small pulmonary veins, or mixed-type TAPVC.

A new registration method with voxel-matching technique for temporal subtraction images

NASA Astrophysics Data System (ADS)

Itai, Yoshinori; Kim, Hyoungseop; Ishikawa, Seiji; Katsuragawa, Shigehiko; Doi, Kunio

2008-03-01

A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes on medical images by removing most of normal structures. One of the important problems in temporal subtraction is that subtraction images commonly include artifacts created by slight differences in the size, shape, and/or location of anatomical structures. In this paper, we developed a new registration method with voxel-matching technique for substantially removing the subtraction artifacts on the temporal subtraction image obtained from multiple-detector computed tomography (MDCT). With this technique, the voxel value in a warped (or non-warped) previous image is replaced by a voxel value within a kernel, such as a small cube centered at a given location, which would be closest (identical or nearly equal) to the voxel value in the corresponding location in the current image. Our new method was examined on 16 clinical cases with MDCT images. Preliminary results indicated that interval changes on the subtraction images were enhanced considerably, with a substantial reduction of misregistration artifacts. The temporal subtraction images obtained by use of the voxel-matching technique would be very useful for radiologists in the detection of interval changes on MDCT images.

MDCT findings in sports and recreational accidents.

PubMed

Bensch, Frank V; Koivikko, Mika P; Koskinen, Seppo K

2011-12-01

Sports and recreational accidents involving critical areas of the body occur commonly in the general population. Reports on their demographics and recommendations for screening procedures are, however, few. To assess injuries of the craniofacial area, spine, and torso resulting from sports and recreational accidents with multidetector computed tomography (MDCT) as primary imaging method in a Level I trauma center. All emergency room CT requests over a time span of 105 months were reviewed retrospectively for trauma mechanism and injury. Patients were identified using an electronic picture archiving and communications system (PACS), and MDCT studies interpreted by two radiologists independently. Of a total of 5898 patients, 492 patients (301 boys/men, 191 girls/women, age range 2-76 years, mean 33.5 years, median 29.5 years) with sports or recreational accidents emerged. A total of 102 traumatic findings were diagnosed, thereof 72 (71%) serious. The three most commonly encountered serious injuries were intracranial injury, fractures of facial bones, and vertebral injuries. The three most common injury mechanisms were bicycling, horseback riding, and team ball sports. Patients from recreational activities were on average significantly younger (29.2 years) than those from sports accidents (36.9 years; P < 0.001). Only age groups <21 years and 41-50 years differed in injury severity from the other age groups (P = 0.004 and P = 0.063, respectively). Of all trauma mechanisms, only bicycling had a significantly increased risk of injury (P < 0.001). Injuries in sports and recreational accidents presented with an overall incidence of 21%, of which 71% are serious. The most common mechanisms of injury were bicycling, horseback riding, and team ball sports. The largest incidence of serious injury involved bicycling. Because of the high probability of a serious injury and the high energies that are often involved in these accidents, we recommend ruling out of internal injury by MDCT as the primary imaging modality.

Carcinoid tumor of the small intestine: MDCT findings with pathologic correlation.

PubMed

Coulier, B; Pringot, J; Gielen, I; Maldague, P; Broze, B; Ramboux, A; Clausse, M

2007-01-01

MDCT currently frequently represents the first choice modality for imaging in acute or subacute abdominal conditions implicating the small bowel. As a consequence, the MDCT features of intestinal carcinoid tumors and of their peculiar metastatic spread have to be known by abdominal radiologists. These features are described and illustrated in the retrospective review of seven proven cases of small intestine carcinoids diagnosed and treated in our institution. The findings are described and correlated with gross anatomy specimens. The primary tumour clearly appeared as a contrast-enhancing intraluminal lesion in all cases except in one case in which the primary lesion remained unlocalized and in another in which the primary tumour finally appeared infracted at gross anatomy. The maximal tumoral enhancement was obtained in 3 patients imaged during the acute arterial phase. The diameter of the primary tumour ranged from 1 to 3 cm and all masses were ileal comprising one lesion in the proximal ileum, two in the medium ileum and three in the distal ileum. 6/7 patients had multiple prominent mesenteric nodal metastases, all also appearing as hypervascularised enhancing masses. In 4/7 patients the nodal metastases represented the major finding being much prominent and larger than the primary tumour. Signs of retractile mesenteritis with soft tissue stranding, retraction and stellate pattern of the mesentery were found around the mesenteric metastases in 5/7 patients and direct incarceration of vessels were found in 3 cases. The analysis of the arterial phase of MDCT study appears primordial to detect the sometimes very small but intensively enhancing primary tumor and to delineate encasement or direct obstruction of mesenteric vessels frequently caused by enhancing nodal metastases which volume often exceeds that of the primary tumor. Secondary retractile mesenteritis, deformation or ischemia of bowel loops, and hypervascular hepatic metastases are typical associated findings.

Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

PubMed

Trattner, Sigal; Chelliah, Anjali; Prinsen, Peter; Ruzal-Shapiro, Carrie B; Xu, Yanping; Jambawalikar, Sachin; Amurao, Maxwell; Einstein, Andrew J

2017-03-01

The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy -1 · cm -1 , for the 1-year-old phantom, and 0.049 mSv · mGy -1 · cm -1 , for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

Balancing Radiation and Contrast Media Dose in Single-Pass Abdominal Multidetector CT: Prospective Evaluation of Image Quality.

PubMed

Camera, Luigi; Romano, Federica; Liccardo, Immacolata; Liuzzi, Raffaele; Imbriaco, Massimo; Mainenti, Pier Paolo; Pizzuti, Laura Micol; Segreto, Sabrina; Maurea, Simone; Brunetti, Arturo

2015-11-01

As both contrast and radiation dose affect the quality of CT images, a constant image quality in abdominal contrast-enhanced multidetector computed tomography (CE-MDCT) could be obtained balancing radiation and contrast media dose according to the age of the patients. Seventy-two (38 Men; 34 women; aged 20-83 years) patients underwent a single-pass abdominal CE-MDCT. Patients were divided into three different age groups: A (20-44 years); B (45-65 years); and C (>65 years). For each group, a different noise index (NI) and contrast media dose (370 mgI/mL) was selected as follows: A (NI, 15; 2.5 mL/kg), B (NI, 12.5; 2 mL/kg), and C (NI, 10; 1.5 mL/kg). Radiation exposure was reported as dose-length product (DLP) in mGy × cm. For quantitative analysis, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated for both the liver (L) and the abdominal aorta (A). Statistical analysis was performed with a one-way analysis of variance. Standard imaging criteria were used for qualitative analysis. Although peak hepatic enhancement was 152 ± 16, 128 ± 12, and 101 ± 14 Hounsfield units (P < .001) for groups A, B, and C, respectively, no significant differences were observed in the corresponding SNRL with 9.2 ± 1.4, 9.1 ± 1.2, and 9.2 ± 3. Radiation (mGy × cm) and contrast media dose (mL) administered were 476 ± 147 and 155 ± 27 for group A, 926 ± 291 and 130 ± 16 for group B, and 1981 ± 451 and 106 ± 15 for group C, respectively (P < .001). None of the studies was graded as poor or inadequate by both readers, and the prevalence-adjusted bias-adjusted kappa ranged between 0.48 and 0.93 for all but one criteria. A constant image quality in CE-MDCT can be obtained balancing radiation and contrast media dose administered to patients of different age. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

[Differential diagnosis of the MDCT features between lung adenocarcinoma preinvasive lesions and minimally invasive adenocarcinoma appearing as ground-glass nodules].

PubMed

Liu, Jia; Li, Wenwu; Huang, Yong; Mu, Dianbin; Yu, Haiying; Li, Shanshan

2015-08-01

The aim of this study was to retrospectively investigate the multi-detector computed tomography (MDCT) features of preinvasive lesions and minimally invasive adenocarcinoma (MIA) appearing as ground-glass nodules (GGNs), and to analyze their significance in differential diagnosis. The pathological data and MDCT images of 111 GGNs in 93 patients were reviewed and analyzed retrospectively, to identify the differentiating CT features between preinvasive lesions and MIA and to evaluate their differentiating accuracy. In the 93 patients included in the study, there were 27 cases with preinvasive lesions (38 GGNs) and 66 cases with MIA (73 GGNs). No statistically significant difference was observed in terms of the gender, age and number of lesions between the two groups. There were significant differences (P<0.05) in the size of lesion, size of solid portion, content of solid portion, and morphological characteristics of the lesion edge between preinvasive lesions and MIA. ROC curve analysis showed that the optimal cut-off value of lesion size for differentiating preinvasive lesions from MIA was 13.0 mm (sensitivity, 83.0%; specificity, 80.0%), and that of solid portion size was 2.0 mm (sensitivity, 90.0%; specificity, 97.0%) and that of solid proportion was 12.0% (sensitivity, 88.0%; specificity, 97.0%). The analysis of CT morphological features showed that there were significant differences in the terms of lesion nature (pGGO, mGGO), presence or absence of lobulated sign and spiculated sign (P<0.05) between preinvasive lesions and MIA, but there were no significant differences in terms of the lesion edge, the presence or absence of vacuole sign, bubble lucency and pleural retraction (P>0.05). Preinvasive lesions can be accurately distinguished from MIA by the size of lesion, size of solid portion,solid proportion and morphological characteristics of the lesion edge. The size of lesion, size of solid portion, content of solid proportion and morphological characteristics of the lesion edge are of significance in the differential diagnosis of preinvasive lesions and minimally invasive adenocarcinoma of the lung.

T2* measurements of 3-T MRI with ultrashort TEs: capabilities of pulmonary function assessment and clinical stage classification in smokers.

PubMed

Ohno, Yoshiharu; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Keiko; Takahashi, Masaya; Van Cauteren, Marc; Sugimura, Kazuro

2011-08-01

The purpose of this study was to determine the usefulness of MRI with ultrashort TEs on a 3-T system and of thin-section MDCT for pulmonary function assessment and clinical stage classification of chronic obstructive pulmonary disease (COPD) in smokers. Forty smokers (24 men and 16 women; mean age ± SD, 68.0 ± 9.3 years) underwent MRI with ultrashort TEs and thin-section MDCT. Pulmonary function testing was also performed to determine the following: the ratio of forced expiratory volume in 1 second to forced vital capacity (percentage predicted) (FEV(1/)FVC%), percentage predicted forced expiratory volume in 1 second (%FEV(1)), and percentage predicted diffusing capacity of lung for carbon monoxide corrected for alveolar volume (%DLCO/V(A)). All subjects were classified into one of four groups as follows: smokers without COPD, with mild COPD, with moderate COPD, and with severe or very severe COPD. T2(*) maps were expressed using proprietary software. Regional T2(*) values were determined by region of interest measurements and were averaged to determine a mean T2(*) value for each subject. CT-based functional lung volume and the ratio of the wall area to the total airway area were also determined. All indexes were statistically correlated with pulmonary function parameters. Then, all indexes were compared among all groups by means of Tukey's honest significance test. All indexes had significant correlation with FEV(1)/FVC%, %FEV(1), and % DLCO/V(A) (p < 0.05). All indexes except WA% of smokers without COPD and smokers with mild COPD differed significantly from those of smokers with moderate COPD and smokers with severe or very severe COPD (p < 0.05). Moreover, the mean T2(*) value of the moderate COPD group was significantly different from that of the severe or very severe COPD group (p < 0.05). MRI with ultrashort TEs is potentially as useful as quantitatively assessed MDCT for pulmonary function loss assessment and clinical stage classification of COPD in smokers.

Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema.

PubMed

Lan, Hai; Nishitani, Hiromu; Nishihara, Sadamitsu; Ueno, Junji; Takao, Shoichiro; Iwamoto, Seiji; Kawanaka, Takashi; Mahmut, Mawlan; Qingge, Si

2011-08-01

The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data. Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods. The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods. There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.

Paramuscular perforators in DIEAP flap for breast reconstruction.

PubMed

Pons, Gemma; Masia, Jaume; Sanchez-Porro, Lídia; Larrañaga, Jose; Clavero, Juan Angel

2014-12-01

One of the main steps in perforator flap surgery is to identify the dominant perforator. Using multidetector row computed tomography (MDCT) for the preoperative planning of deep inferior epigastric artery perforator (DIEAP) flap surgery, we identified a perforator with a large caliber, an excellent location in the middle abdominal region, and a totally extramuscular trajectory in a significant number of patients. We describe the frequency of this perforator and determine its characteristics. We conducted a retrospective study of 482 patients who underwent 526 DIEAP flaps for breast reconstruction from October 2003 to October 2011. Mean age at surgery was 51.3 years old. A preoperative MDCT of abdominal vascularization was performed in all patients. MDCT identified a dominant perforator with a paramuscular course in 12.4% of abdominal walls. In all cases, it was located in the midline and emerged directly from the deep inferior epigastric system. Its mean caliber was 1.9 mm. The flap was harvested based on this perforator in all these patients, and mean harvest time was 51 minutes. The characteristics of this perforator made dissection easier and reduced morbidity at the donor site. There were no flap losses and the only complications were minor. We located a paramuscular perforator in 12.4% of patients undergoing breast reconstruction with abdominal perforator flaps. Its morphological features and extramuscular course make it the perforator of choice in DIEAP flap surgery.

Prevalence of Temporal Bone Fractures in Patients with Mandibular Fractures Using Multidetector-Row CT.

PubMed

Ogura, I; Kaneda, T; Sasaki, Y; Buch, K; Sakai, O

2015-06-01

Temporal bone fracture after mandibular trauma is thought to be rare, and its prevalence has not been reported in the literature. The purpose of this study was to investigate the prevalence of temporal bone fractures in patients with mandibular fractures and the relationship between temporal bone fractures and the mandibular fracture location using multidetector-row computed tomography (MDCT). A prospective study was performed in 201 patients with mandibular fractures who underwent 64-MDCT scans. The mandibular fracture locations were classified as median, paramedian, angle, and condylar types. Statistical analysis for the relationship between prevalence of temporal bone fractures and mandibular fracture locations was performed using χ(2) test with Fisher's exact test. A P-value < 0.05 was considered statistically significant. The percentage of cases with temporal bone fracture was 3.0 % of all patients with mandibular fractures and 19.0 % of those with multiple mandibular fractures of paramedian and condylar type. There was a significant relationship between the incidence of temporal bone fracture and the paramedian- and condylar-type mandibular fracture (P = 0.001). Multiple mandibular fractures of paramedian and condylar type may be a stronger indicator for temporal bone fractures. This study suggests that patients with mandibular fracture, especially the paramedian and condylar type, should be examined for coexisting temporal bone fracture using MDCT.

Dose reduction in paediatric MDCT: general principles.

PubMed

Paterson, A; Frush, D P

2007-06-01

The number of multi-detector array computed tomography (MDCT) examinations performed per annum continues to increase in both the adult and paediatric populations. Estimates from 2003 suggested that CT contributed 17% of a radiology department's workload, yet was responsible for up to 75% of the collective population dose from medical radiation. The effective doses for some CT examinations today overlap with those argued to have an increased risk of cancer. This is especially pertinent for paediatric CT, as children are more radiosensitive than adults (and girls more radiosensitive than boys). In addition, children have a longer life ahead of them, in which radiation induced cancers may become manifest. Radiologists must be aware of these facts and practise the ALARA (as low as is reasonably achievable) principle, when it comes to deciding CT protocols and parameters.

Trabecular bone class mapping across resolutions: translating methods from HR-pQCT to clinical CT

NASA Astrophysics Data System (ADS)

Valentinitsch, Alexander; Fischer, Lukas; Patsch, Janina M.; Bauer, Jan; Kainberger, Franz; Langs, Georg; DiFranco, Matthew

2015-03-01

Quantitative assessment of 3D bone microarchitecture in high-resolution peripheral quantitative computed tomography (HR-pQCT) has shown promise in fracture risk assessment and biomechanics, but is limited to the distal radius and tibia. Trabecular microarchitecture classes (TMACs), based on voxel-wise clustering texture and structure tensor features in HRpQCT, is extended in this paper to quantify trabecular bone classes in clinical multi-detector CT (MDCT) images. Our comparison of TMACs in 12 cadaver radii imaged using both HRpQCT and MDCT yields a mean Dice score of up to 0.717+/-0.40 and visually concordant bone quality maps. Further work to develop clinically viable bone quantitative imaging using HR-pQCT validation could have a significant impact on overall bone health assessment.

One-stop shop for 3-dimensional anatomy of hepatic vasculature and bile duct with special reference to biliary image reconstruction.

PubMed

Enkhbold, Ch; Shimada, M; Utsunomiya, T; Ishibashi, H; Yamada, S; Kanamoto, M; Arakawa, Y; Ikemoto, Z; Morine, E; Imura, S

2013-01-01

Three-dimensional CT has become an essential tool for successful hepatic surgery. Up to now, efforts have been made to simultaneously visualize hepatic vasculature and bile ducts. Herein, we introduce a new one-stop shop approach to hepatic 3D-anatomy, using a standard enhanced MDCT alone. A 3D-reconstruction of hepatic vasculature was made using data from contrast enhanced MDCT and SYNAPSE VINCENT software. We identified bile ducts from axial 2D image, and then reconstructed the 3D image. Both hepatic vasculature and bile duct images were integrated into a single image and it was compared with the 3D image, utilized with MRCP or DIC-CT. The first branches of both the right and left hepatic ducts were hand-traced and visualized for all 100 cases. The second branches of these ducts were visualized in 69 cases, and only the right second branch was recognized in 52 cases. Anomalous variations of bile ducts, such as posterior branch joining into common hepatic duct, were recognized in 12 cases. These biliary tract variations were all confirmed by MRCP or DIC-CT. Our new one-stop shop approach using the 3D imaging technique might contribute to successful hepatectomy as well as reduce medical costs and radiation exposure by omission of MRCP and DIC-CT.

Effects of dose reduction on bone strength prediction using finite element analysis

NASA Astrophysics Data System (ADS)

Anitha, D.; Subburaj, Karupppasamy; Mei, Kai; Kopp, Felix K.; Foehr, Peter; Noel, Peter B.; Kirschke, Jan S.; Baum, Thomas

2016-12-01

This study aimed to evaluate the effect of dose reduction, by means of tube exposure reduction, on bone strength prediction from finite-element (FE) analysis. Fresh thoracic mid-vertebrae specimens (n = 11) were imaged, using multi-detector computed tomography (MDCT), at different intensities of X-ray tube exposures (80, 150, 220 and 500 mAs). Bone mineral density (BMD) was estimated from the mid-slice of each specimen from MDCT images. Differences in image quality and geometry of each specimen were measured. FE analysis was performed on all specimens to predict fracture load. Paired t-tests were used to compare the results obtained, using the highest CT dose (500 mAs) as reference. Dose reduction had no significant impact on FE-predicted fracture loads, with significant correlations obtained with reference to 500 mAs, for 80 mAs (R2  = 0.997, p < 0.001), 150 mAs (R2 = 0.998, p < 0.001) and 220 mAs (R2 = 0.987, p < 0.001). There were no significant differences in volume quantification between the different doses examined. CT imaging radiation dose could be reduced substantially to 64% with no impact on strength estimates obtained from FE analysis. Reduced CT dose will enable early diagnosis and advanced monitoring of osteoporosis and associated fracture risk.

Computational fluid dynamics simulation of airflow in the trachea and main bronchi for the subjects with left pulmonary artery sling

PubMed Central

2014-01-01

Background Left pulmonary artery sling (LPAS) is a rare but severe congenital anomaly, in which the stenoses are formed in the trachea and/or main bronchi. Multi-detector computed tomography (MDCT) provides useful anatomical images, but does not offer functional information. The objective of the present study is to quantitatively analyze the airflow in the trachea and main bronchi of LPAS subjects through computational fluid dynamics (CFD) simulation. Methods Five subjects (four LPAS patients, one normal control) aging 6-19 months are analyzed. The geometric model of the trachea and the two main bronchi is extracted from the MDCT images. The inlet velocity is determined based on the body weight and the inlet area. Both the geometric model and personalized inflow conditions are imported into CFD software, ANSYS. The pressure drop, mass flow ratio through two bronchi, wall pressure, flow velocity and wall shear stress (WSS) are obtained, and compared to the normal control. Results Due to the tracheal and/or bronchial stenosis, the pressure drop for the LPAS patients ranges 78.9 - 914.5 Pa, much higher than for the normal control (0.7 Pa). The mass flow ratio through the two bronchi does not correlate with the sectional area ratio if the anomalous left pulmonary artery compresses the trachea or bronchi. It is suggested that the C-shaped trachea plays an important role on facilitating the air flow into the left bronchus with the inertia force. For LPAS subjects, the distributions of velocities, wall pressure and WSS are less regular than for the normal control. At the stenotic site, high velocity, low wall pressure and high WSS are observed. Conclusions Using geometric models extracted from CT images and the patient-specified inlet boundary conditions, CFD simulation can provide vital quantitative flow information for LPAS. Due to the stenosis, high pressure drops, inconsistent distributions of velocities, wall pressure and WSS are observed. The C-shaped trachea may facilitate a larger flow of air into the left bronchus under the inertial force, and decrease the ventilation of the right lung. Quantitative and personalized information may help understand the mechanism of LPAS and the correlations between stenosis and dyspnea, and facilitate the structural and functional assessment of LPAS. PMID:24957947

Computed tomography measurement of the left atrial appendage for optimal sizing of the Watchman device.

PubMed

Xu, Bo; Betancor, Jorge; Sato, Kimi; Harb, Serge; Abdur Rehman, Karim; Patel, Kunal; Kumar, Arnav; Cremer, Paul C; Jaber, Wael; Rodriguez, L Leonardo; Schoenhagen, Paul; Wazni, Oussama

Percutaneous left atrial appendage (LAA) occlusion is an emerging treatment option for patients with non-valvular atrial fibrillation who cannot tolerate oral anticoagulation. The Watchman device (Boston Scientific Corporation, Natick, MA, USA) is deployed at the ostium of the LAA, and an appropriately sized device is critical for successful occlusion. However, standardized imaging protocols for device sizing have not been established. We investigated the clinical utility of a standardized imaging protocol, with pre-procedural multi-detector cardiac computed tomography (MDCT), and intra-procedural transesophageal echocardiography (TEE), for Watchman device sizing. Patients who underwent Watchman device implantation between 2010 and 2016 at our center, and who had pre-procedural MDCT and intra-procedural TEE were included. MDCT measurements (CTmax, CTmin, CTmean), and TEE measurement (TEEmax) of the LAA ostium were determined for each case, and correlated with the final size of the Watchman device implanted. Demographic data and clinical outcomes were collected. The study included 80 patients (mean age: 75 ± 9.6 years; male: 68%; mean CHA2DS2-VASc score: 4.5 ± 1.4). CTmax of the LAA ostium correlated strongly with the final deployed Watchman device size (Spearman's rho: 0.81, p < 0.001), while TEEmax of the LAA ostium showed only moderate correlation with the final deployed Watchman device size (Spearman's rho: 0.61, p < 0.001). Implantation success rate was 100%. At a mean duration of follow-up of 197 days, there were no device-related complications (device embolization, cardiac perforation and pericardial tamponade). At follow-up, the vast majority of patients (76 patients; 95%) had either no or trivial (≤3 mm) residual peri-device leak on TEE. A standardized imaging protocol for assessment of Watchman device implantation incorporating pre-procedural MDCT and intra-procedural TEE, was associated with excellent procedural outcomes at a mean duration of follow-up of 197 days. Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Genome-wide analysis of murine renal distal convoluted tubular cells for the target genes of mineralocorticoid receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueda, Kohei; Fujiki, Katsunori; Shirahige, Katsuhiko

Highlights: • We define a target gene of MR as that with MR-binding to the adjacent region of DNA. • We use ChIP-seq analysis in combination with microarray. • We, for the first time, explore the genome-wide binding profile of MR. • We reveal 5 genes as the direct target genes of MR in the renal epithelial cell-line. - Abstract: Background and objective: Mineralocorticoid receptor (MR) is a member of nuclear receptor family proteins and contributes to fluid homeostasis in the kidney. Although aldosterone-MR pathway induces several gene expressions in the kidney, it is often unclear whether the gene expressionsmore » are accompanied by direct regulations of MR through its binding to the regulatory region of each gene. The purpose of this study is to identify the direct target genes of MR in a murine distal convoluted tubular epithelial cell-line (mDCT). Methods: We analyzed the DNA samples of mDCT cells overexpressing 3xFLAG-hMR after treatment with 10{sup −7} M aldosterone for 1 h by chromatin immunoprecipitation with deep-sequence (ChIP-seq) and mRNA of the cell-line with treatment of 10{sup −7} M aldosterone for 3 h by microarray. Results: 3xFLAG-hMR overexpressed in mDCT cells accumulated in the nucleus in response to 10{sup −9} M aldosterone. Twenty-five genes were indicated as the candidate target genes of MR by ChIP-seq and microarray analyses. Five genes, Sgk1, Fkbp5, Rasl12, Tns1 and Tsc22d3 (Gilz), were validated as the direct target genes of MR by quantitative RT-qPCR and ChIP-qPCR. MR binding regions adjacent to Ctgf and Serpine1 were also validated. Conclusions: We, for the first time, captured the genome-wide distribution of MR in mDCT cells and, furthermore, identified five MR target genes in the cell-line. These results will contribute to further studies on the mechanisms of kidney diseases.« less

Impact of bowtie filter and object position on the two-dimensional noise power spectrum of a clinical MDCT system.

PubMed

Gomez-Cardona, Daniel; Cruz-Bastida, Juan Pablo; Li, Ke; Budde, Adam; Hsieh, Jiang; Chen, Guang-Hong

2016-08-01

Noise characteristics of clinical multidetector CT (MDCT) systems can be quantified by the noise power spectrum (NPS). Although the NPS of CT has been extensively studied in the past few decades, the joint impact of the bowtie filter and object position on the NPS has not been systematically investigated. This work studies the interplay of these two factors on the two dimensional (2D) local NPS of a clinical CT system that uses the filtered backprojection algorithm for image reconstruction. A generalized NPS model was developed to account for the impact of the bowtie filter and image object location in the scan field-of-view (SFOV). For a given bowtie filter, image object, and its location in the SFOV, the shape and rotational symmetries of the 2D local NPS were directly computed from the NPS model without going through the image reconstruction process. The obtained NPS was then compared with the measured NPSs from the reconstructed noise-only CT images in both numerical phantom simulation studies and experimental phantom studies using a clinical MDCT scanner. The shape and the associated symmetry of the 2D NPS were classified by borrowing the well-known atomic spectral symbols s, p, and d, which correspond to circular, dumbbell, and cloverleaf symmetries, respectively, of the wave function of electrons in an atom. Finally, simulated bar patterns were embedded into experimentally acquired noise backgrounds to demonstrate the impact of different NPS symmetries on the visual perception of the object. (1) For a central region in a centered cylindrical object, an s-wave symmetry was always present in the NPS, no matter whether the bowtie filter was present or not. In contrast, for a peripheral region in a centered object, the symmetry of its NPS was highly dependent on the bowtie filter, and both p-wave symmetry and d-wave symmetry were observed in the NPS. (2) For a centered region-ofinterest (ROI) in an off-centered object, the symmetry of its NPS was found to be different from that of a peripheral ROI in the centered object, even when the physical positions of the two ROIs relative to the isocenter were the same. (3) The potential clinical impact of the highly anisotropic NPS, caused by the interplay of the bowtie filter and position of the image object, was highlighted in images of specific bar patterns oriented at different angles. The visual perception of the bar patterns was found to be strongly dependent on their orientation. The NPS of CT depends strongly on the bowtie filter and object position. Even if the location of the ROI with respect to the isocenter is fixed, there can be different symmetries in the NPS, which depend on the object position and the size of the bowtie filter. For an isolated off-centered object, the NPS of its CT images cannot be represented by the NPS measured from a centered object.

First-line sonographic diagnosis of pneumothorax in major trauma: accuracy of e-FAST and comparison with multidetector computed tomography.

PubMed

Ianniello, Stefania; Di Giacomo, Vincenza; Sessa, Barbara; Miele, Vittorio

2014-09-01

Combined clinical examination and supine chest radiography have shown low accuracy in the assessment of pneumothorax in unstable patients with major chest trauma during the primary survey in the emergency room. The aim of our study was to evaluate the diagnostic accuracy of extended-focused assessment with sonography in trauma (e-FAST), in the diagnosis of pneumothorax, compared with the results of multidetector computed tomography (MDCT) and of invasive interventions (thoracostomy tube placement). This was a retrospective case series involving 368 consecutive unstable adult patients (273 men and 95 women; average age, 25 years; range, 16-68 years) admitted to our hospital's emergency department between January 2011 and December 2012 for major trauma (Injury Severity Score ≥ 15). We evaluated the accuracy of thoracic ultrasound in the detection of pneumothorax compared with the results of MDCT and invasive interventions (thoracostomy tube placement). Institutional review board approval was obtained prior to commencement of this study. Among the 736 lung fields included in the study, 87 pneumothoraces were detected with thoracic CT scans (23.6%). e-FAST detected 67/87 and missed 20 pneumothoraces (17 mild, 3 moderate). The diagnostic performance of ultrasound was: sensitivity 77% (74% in 2011 and 80% in 2012), specificity 99.8%, positive predictive value 98.5%, negative predictive value 97%, accuracy 97.2% (67 true positive; 668 true negative; 1 false positive; 20 false negative); 17 missed mild pneumothoraces were not immediately life-threatening (thickness less than 5 mm). Thoracic ultrasound (e-FAST) is a rapid and accurate first-line, bedside diagnostic modality for the diagnosis of pneumothorax in unstable patients with major chest trauma during the primary survey in the emergency room.

Syringeless power injector versus dual-syringe power injector: economic evaluation of user performance, the impact on contrast enhanced computed tomography (CECT) workflow exams, and hospital costs.

PubMed

Colombo, Giorgio L; Andreis, Ivo A Bergamo; Di Matteo, Sergio; Bruno, Giacomo M; Mondellini, Claudio

2013-01-01

The utilization of diagnostic imaging has substantially increased over the past decade in Europe and North America and continues to grow worldwide. The purpose of this study was to develop an economic evaluation of a syringeless power injector (PI) versus a dual-syringe PI for contrast enhanced computed tomography (CECT) in a hospital setting. Patients (n=2379) were enrolled at the Legnano Hospital between November 2012 and January 2013. They had been referred to the hospital for a CECT analysis and were randomized into two groups. The first group was examined with a 256-MDCT (MultiDetector Computed Tomography) scanner using a syringeless power injector, while the other group was examined with a 64-MDCT scanner using a dual-syringe. Data on the operators' time required in the patient analysis steps as well as on the quantity of consumable materials used were collected. The radiologic technologists' satisfaction with the use of the PIs was rated on a 10-point scale. A budget impact analysis and sensitivity analysis were performed under the base-case scenario. A total of 1,040 patients were examined using the syringeless system, and 1,339 with the dual-syringe system; the CECT examination quality was comparable for both PI systems. Equipment preparation time and releasing time per examination for syringeless PIs versus dual-syringe PIs were 100±30 versus 180±30 seconds and 90±30 and 140±20 seconds, respectively. On average, 10±3 mL of contrast media (CM) wastage per examination was observed with the dual-syringe PI and 0±1 mL with the syringeless PI. Technologists had higher satisfaction with the syringeless PI than with the dual-syringe system (8.8 versus 8.0). The syringeless PI allows a saving of about €6.18 per patient, both due to the lower cost of the devices and to the better performance of the syringeless system. The univariate sensitivity analysis carried out on the base-case results within the standard deviation range confirmed the saving generated by using the syringeless device, with saving values between €5.40 and €6.20 per patient. The syringeless PI was found to be more user-friendly and efficient, minimizing contrast wastage and providing similar contrast enhancement quality compared to the dual-syringe injector, with comparable CECT examination quality.

Cardiac Computed Tomography (Multidetector CT, or MDCT)

MedlinePlus

... other tests, such as chest X-rays , electrocardiograms (ECG) , echocardiograms (echocardiography) , or stress tests , don’t give ... be attached to your chest to monitor your ECG. The ECG is also needed to help the ...

An automatic bone segmentation method based on anatomical structure for the knee joint in MDCT image.

PubMed

Uozumi, Y; Nagamune, K

2013-01-01

The purpose of this study is to propose an automatic segmentation about each bone (the femur, the tibia, the patellar, and fibular) of the knee in MDCT image. The proposed method was applied for six patients (Age 33 ± 13, four males/tew females). The proposed method segmented the knee joint into each bone by using anatomical structure for the knee joint. The experiments calculate matching rate of the manual and the proposed method for evaluating it. As a result, The matching rate of the femur, the tibia, the patellar, and fibula were 95.84 ± 0.57%, 94.12 ± 1.01%, 94.49 ± 0.83%, 86.37 ± 4.28%, respectively. This study concluded that the proposed method is enough to segment the knee bones.

That liver lesion on MDCT in the oncology patient: is it important?

PubMed Central

Thakrar, Kiran H.; Wenzke, Daniel R.; Newmark, Geraldine M.; Mehta, Uday K.; Berlin, Jonathan W.

2012-01-01

Abstract Multidetector-row computed tomography (MDCT) has become the primary imaging test for the staging and follow-up of most malignancies that originate outside of the central nervous system. Technical advances in this imaging technique have led to significant improvement in the detection of metastatic disease to the liver. An unintended by-product of this improving diagnostic acumen is the discovery of incidental hepatic lesions in oncology patients that in the past remained undetected. These ubiquitous, incidentally identified hepatic lesions have created a management dilemma for both clinicians and radiologists: are these lesions benign or do they represent metastases? Naturally, the answer to this question has profound prognostic and therapeutic implications. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidental lesions detected in patients with extrahepatic malignancies are presented. PMID:23023318

Dressing up Nanoparticles: A Membrane Wrap to Induce Formation of the Virological Synapse

PubMed Central

Yu, Xinwei; Xu, Fangda; Ramirez, Nora-Guadalupe P.; Kijewski, Suzanne D. G.; Akiyama, Hisashi; Gummuluru, Suryaram; Reinhard, Björn M.

2015-01-01

Next generation nanoparticle-based drug delivery systems require the ability to target specific organelles or subcellular regions in selected target cells. Human immunodeficiency virus type I (HIV-1) particles are evolutionarily optimized nanocarriers that have evolved to avoid intracellular degradation and achieve enrichment at the synapse between mature dendritic cells (mDCs) and T cells by subverting cellular trafficking mechanisms. This study demonstrates that integration of the glycosphingolipid, GM3, in a membrane around a solid nanoparticle (NP) core is sufficient to recapitulate key aspects of the virus particle trafficking in mDCs. GM3 presenting artificial virus NPs (GM3-AVNs) accumulate in CD169+, CD81+, non-lysosomal compartments in an actin-dependent process that mimics the sequestration of HIV-1. Live-cell optical tracking studies reveal a preferential recruitment and arrest of surface scanning CD4+ T cells in direct vicinity to the AVN-enriched compartments. The formed mDC-T cell conjugates exhibit strong morphological similarities between the GM3-AVN-containing mDC-T cell synapse and the HIV-1 virological synapse, indicating that GM3-CD169 interactions alone are sufficient for establishing the mDC-T cell virological synapse. These results emphasize the potential of the GM3-AVN approach for providing therapeutic access to a key step of the host immune response – formation of the synaptic junction between an antigen-presenting cell (mDC) and T cells – for modulating and controlling immune responses. PMID:25853367

The utility of postmortem computed tomography selective coronary angiography in parallel with autopsy.

PubMed

Inokuchi, Go; Yajima, Daisuke; Hayakawa, Mutsumi; Motomura, Ayumi; Chiba, Fumiko; Torimitsu, Suguru; Makino, Yohsuke; Iwase, Hirotaro

2013-12-01

Historically, coronary angiography of the isolated heart has played an important role in the detection of stenotic or occlusive lesions that are difficult to identify by autopsy alone. Meanwhile, although the application of multidetector computed tomography (MDCT) to forensic fields has accelerated recently, isolated single organ angiography with MDCT is rarely performed. In this article, we present an evaluation of postmortem selective coronary CT angiography of the isolated heart with MDCT and discuss its utility for autopsy. First, in a preliminary experiment using pig coronary artery, we examined the behavior of water soluble contrast material on postmortem computed tomography angiography (PMCTA) and found that better angiographic images were acquired when the viscosity of the contrast material was increased and CT was performed under conditions of sustained perfusion. Based on these results, we devised a selective coronary angiography procedure using a pressurized bag for drip infusion that can be performed easily, quickly, and at low cost. The angiographic images obtained provided useful supportive evidence of autopsy findings suggestive of ischemic heart disease. With active discussions underway in forensic fields on the proper use of postmortem computed tomography, PMCTA has also naturally attracted attention as it compensates for some of the shortcomings of CT alone. Although PMCTA typically involves whole-body angiography, if we view PMCTA as one of the many useful and supplementary tools available for autopsy, then isolated heart angiography continues to have utility in autopsy today.

The reverse Segond fracture: not associated with knee dislocation and rarely with posterior cruciate ligament tear.

PubMed

Peltola, Erno K; Lindahl, Jan; Koskinen, Seppo K

2014-06-01

The aims of this study were to assess the incidence of reverse Segond fracture, to examine the associated ligamentous injuries, and to examine how often reverse Segond fracture coexists with a knee dislocation. At a level 1 trauma center, an 11-year period of emergency department multidetector-row computed tomography (MDCT) examinations for knee trauma was evaluated for reverse Segond and Segond fractures. Surgical findings served as the reference standard for intra-articular injuries. The hospital discharge register was searched for the diagnosis of knee dislocation from August 2000 through the end of August 2011. A total of 1,553 knee MDCT examinations were evaluated. Ten patients with a reverse Segond fracture were found, comprising 0.64 % of emergency room acute knee trauma MDCT examinations. Seven patients who had a reverse Segond fracture were operated: Three had an avulsion fracture of the anterior cruciate ligament, one had an avulsion fracture of posterior cruciate ligament, two had a lateral meniscal tear, and two had a medial collateral ligament tear. The ratio of reverse Segond fractures to Segond fractures was 1:4. None of the 71 knee dislocation patients had a reverse Segond fracture. Reverse Segond fracture is a rare finding even in a level 1 trauma center. Cruciate ligament injuries appear to be associated with avulsion fracture, but every patient does not have PCL injury, as previously reported. Our results do not support the association of knee dislocation with reverse Segond fracture.

Craniofacial and dental malformations in Costello syndrome: A detailed evaluation using multi-detector row computed tomography.

PubMed

Takahashi, Masashi; Ohashi, Hirofumi

2013-06-01

Costello syndrome is a rare multiple congenital anomaly syndrome caused by heterozygous germline HRAS mutations, which is characterized by intellectual disability, growth retardation, distinctive facies, loose skin, cardiomyopathy and a preposition to malignancies. Although teeth abnormalities have been encountered in nearly two-thirds of the patients in literature, the evaluation tended to be limited to the extent which can be obtained from physical examination. We investigated detailed craniofacial, oral and dental findings in four patients with Costello syndrome. In this study, images reconstructed by multi-detector row computed tomography (MDCT) were used as substitutes for dental cast study and panoramic and lateral cephalometric radiograph studies to evaluate dental arches, tooth size, relationships between craniofacial and dental structures, and hypodontia. All four patients showed true/relative macrocephaly with facial bone hypoplasia and gingival hypertrophy. Occlusal attrition, malocclusion, small dental arches, microdontia, and convex face were noted in three patients. In addition, one patient showed dental caries, conic tooth and gingivitis, and another patient showed hypodontia. Our study suggests that craniofacial and dental abnormalities are common in Costello syndrome patients and comprehensive dental care should be provided from early infancy. To our knowledge, this is the first study of thorough craniofacial and dental evaluation by using MDCT in Costello syndrome. MDCT is a useful tool for precise evaluation of craniofacial and oral manifestations in patients with congenital anomaly/intellectual disability syndromes. © 2012 The Authors. Congenital Anomalies © 2012 Japanese Teratology Society.

Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma.

PubMed

Geyer, L L; Körner, M; Hempel, R; Deak, Z; Mueck, F G; Linsenmaier, U; Reiser, M F; Wirth, S

2013-07-01

To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose-length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann-Whitney U and Wilcoxon's test were used. In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p < 0.001) and scan length (p = 0.01). There was no significant difference in the subjective image quality (p > 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Radiofrequency ablation of liver metastases-software-assisted evaluation of the ablation zone in MDCT: tumor-free follow-up versus local recurrent disease.

PubMed

Keil, Sebastian; Bruners, Philipp; Schiffl, Katharina; Sedlmair, Martin; Mühlenbruch, Georg; Günther, Rolf W; Das, Marco; Mahnken, Andreas H

2010-04-01

The purpose of this study was to investigate differences in change of size and CT value between local recurrences and tumor-free areas after CT-guided radiofrequency ablation (RFA) of hepatic metastases during follow-up by means of dedicated software for automatic evaluation of hepatic lesions. Thirty-two patients with 54 liver metastases from breast or colorectal cancer underwent triphasic contrast-enhanced multidetector-row computed tomography (MDCT) to evaluate hepatic metastatic spread and localization before CT-guided RFA and for follow-up after intervention. Sixteen of these patients (65.1 + or - 10.3 years) with 30 metastases stayed tumor-free (group 1), while the other group (n = 16 with 24 metastases; 62.0 + or - 13.8 years) suffered from local recurrent disease (group 2). Applying an automated software tool (SyngoCT Oncology; Siemens Healthcare, Forchheim, Germany), size parameters (volume, RECIST, WHO) and attenuation were measured within the lesions before, 1 day after, and 28 days after RFA treatment. The natural logarithm (ln) of the quotient of the volume 1 day versus 28 days after RFA treament was computed: lnQ1//28/0(volume). Analogously, ln ratios of RECIST, WHO, and attenuation were computed and statistically evaluated by repeated-measures ANOVA. One lesion in group 2 was excluded from further evaluation due to automated missegmentation. Statistically significant differences between the two groups were observed with respect to initial volume, RECIST, and WHO (p < 0.05). Furthermore, ln ratios corresponding to volume, RECIST, and WHO differed significantly between the two groups. Attenuation evaluations showed no significant differences, but there was a trend toward attenuation assessment for the parameter lnQ28/0(attenuation) (p = 0.0527), showing higher values for group 1 (-0.4 + or - 0.3) compared to group 2 (-0.2 + or - 0.2). In conclusion, hepatic metastases and their zone of coagulation necrosis after RFA differed significantly between tumor-free and local-recurrent ablation zones with respect to the corresponding size parameters. A new parameter (lnQ1//28/0(volume/RECIST/WHO/attenuation)) was introduced, which appears to be of prognostic value at early follow-up CT.

Defining the optimal cut-off values for liver enzymes in diagnosing blunt liver injury.

PubMed

Koyama, Tomohide; Hamada, Hirohisa; Nishida, Masamichi; Naess, Paal A; Gaarder, Christine; Sakamoto, Tetsuya

2016-01-25

Patients with blunt trauma to the liver have elevated levels of liver enzymes within a short time post injury, potentially useful in screening patients for computed tomography (CT). This study was performed to define the optimal cut-off values for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in patients with blunt liver injury diagnosed with contrast enhanced multi detector-row CT (CE-MDCT). All patients admitted from May 2006 to July 2013 to Teikyo University Hospital Trauma and Critical Care Center, and who underwent abdominal CE-MDCT within 3 h after blunt trauma, were retrospectively enrolled. Using receiver operating characteristic (ROC) curve analysis, the optimal cut-off values for AST and ALT were defined, and sensitivity and specificity were calculated. Of a total of 676 blunt trauma patients 64 patients were diagnosed with liver injury (Group LI+) and 612 patients without liver injury (Group LI-). Group LI+ and LI- were comparable for age, Revised Trauma Score, and Probability of survival. The groups differed in Injury Severity Score [median 21 (interquartile range 9-33) vs. 17 (9-26) (p < 0.01)]. Group LI+ had higher AST than LI- [276 (48-503) vs. 44 (16-73); p < 0.001] and higher ALT [240 (92-388) vs. 32 (16-49); p < 0.001]. Using ROC curve analysis, the optimal cut-off values for AST and ALT were set at 109 U/l and 97 U/l, respectively. Based on these values, AST ≥ 109 U/l had a sensitivity of 81%, a specificity of 82%, a positive predictive value of 32%, and a negative predictive value of 98%. The corresponding values for ALT ≥ 97 U/l were 78, 88, 41 and 98%, respectively, and for the combination of AST ≥ 109 U/l and/or ALT ≥ 97 U/l were 84, 81, 32, 98%, respectively. We have identified AST ≥ 109 U/l and ALT ≥ 97 U/l as optimal cut-off values in predicting the presence of liver injury, potentially useful as a screening tool for CT scan in patients otherwise eligible for observation only or as a transfer criterion to a facility with CT scan capability.

[Application possibilities and initial experience with digital volume tomography in hand and wrist imaging].

PubMed

Goerke, Sebastian M; Neubauer, J; Zajonc, H; Thiele, J R; Kotter, E; Langer, M; Stark, G B; Lampert, F M

2015-02-01

During the last decade, DVT (digital volume tomography) imaging has become a widely used standard technique in head and neck imaging. Lower radiation exposure compared to conventional computed tomography (MDCT) has been described. Recently, DVT has been developed as an extremity scanner and as such represents a new imaging technique for hand surgery. We here describe the first 24 months experience with this new imaging modality in hand and wrist imaging by presenting representative cases and by describing the technical background. Furthermore, the method's advantages and disadvantages are discussed with reference to the given literature. © Georg Thieme Verlag KG Stuttgart · New York.

The feasibility of a scanner-independent technique to estimate organ dose from MDCT scans: Using CTDI{sub vol} to account for differences between scanners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Adam C.; Zankl, Maria; DeMarco, John J.

2010-04-15

Purpose: Monte Carlo radiation transport techniques have made it possible to accurately estimate the radiation dose to radiosensitive organs in patient models from scans performed with modern multidetector row computed tomography (MDCT) scanners. However, there is considerable variation in organ doses across scanners, even when similar acquisition conditions are used. The purpose of this study was to investigate the feasibility of a technique to estimate organ doses that would be scanner independent. This was accomplished by assessing the ability of CTDI{sub vol} measurements to account for differences in MDCT scanners that lead to organ dose differences. Methods: Monte Carlo simulationsmore » of 64-slice MDCT scanners from each of the four major manufacturers were performed. An adult female patient model from the GSF family of voxelized phantoms was used in which all ICRP Publication 103 radiosensitive organs were identified. A 120 kVp, full-body helical scan with a pitch of 1 was simulated for each scanner using similar scan protocols across scanners. From each simulated scan, the radiation dose to each organ was obtained on a per mA s basis (mGy/mA s). In addition, CTDI{sub vol} values were obtained from each scanner for the selected scan parameters. Then, to demonstrate the feasibility of generating organ dose estimates from scanner-independent coefficients, the simulated organ dose values resulting from each scanner were normalized by the CTDI{sub vol} value for those acquisition conditions. Results: CTDI{sub vol} values across scanners showed considerable variation as the coefficient of variation (CoV) across scanners was 34.1%. The simulated patient scans also demonstrated considerable differences in organ dose values, which varied by up to a factor of approximately 2 between some of the scanners. The CoV across scanners for the simulated organ doses ranged from 26.7% (for the adrenals) to 37.7% (for the thyroid), with a mean CoV of 31.5% across all organs. However, when organ doses are normalized by CTDI{sub vol} values, the differences across scanners become very small. For the CTDI{sub vol}, normalized dose values the CoVs across scanners for different organs ranged from a minimum of 2.4% (for skin tissue) to a maximum of 8.5% (for the adrenals) with a mean of 5.2%. Conclusions: This work has revealed that there is considerable variation among modern MDCT scanners in both CTDI{sub vol} and organ dose values. Because these variations are similar, CTDI{sub vol} can be used as a normalization factor with excellent results. This demonstrates the feasibility of establishing scanner-independent organ dose estimates by using CTDI{sub vol} to account for the differences between scanners.« less

Gender differences of airway dimensions in anatomically matched sites on CT in smokers.

PubMed

Kim, Yu-Il; Schroeder, Joyce; Lynch, David; Newell, John; Make, Barry; Friedlander, Adam; Estépar, Raúl San José; Hanania, Nicola A; Washko, George; Murphy, James R; Wilson, Carla; Hokanson, John E; Zach, Jordan; Butterfield, Kiel; Bowler, Russell P; Copdgene Investigators

2011-08-01

There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers. We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions. Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm(2) for segmental bronchial lumen area, 10.4 vs 12.5 mm(2) for subsegmental bronchi, 6.5 vs 7.7 mm(2) for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness. Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation.

Evaluation and Influence of Brachiocephalic Branch Re-entry in Patients With Type A Acute Aortic Dissection.

PubMed

Yasuda, Shota; Imoto, Kiyotaka; Uchida, Keiji; Karube, Norihisa; Minami, Tomoyuki; Goda, Motohiko; Suzuki, Shinichi; Masuda, Munetaka

2016-12-22

Stanford type A acute aortic dissection (A-AAD) extends to the brachiocephalic branches in some patients. After ascending aortic replacement, a remaining re-entry tear in the distal brachiocephalic branches may act as an entry and result in a patent false lumen in the aortic arch. However, the effect of brachiocephalic branch re-entry concomitant with A-AAD remains unknown.Methods and Results:Eighty-five patients with A-AAD who underwent ascending aortic replacement in which both preoperative and postoperative multiple-detector computed tomography (MDCT) scans could be evaluated were retrospectively studied. The presence of a patent false lumen in at least one of the brachiocephalic branches on preoperative MDCT was defined as brachiocephalic branch re-entry, and 41 patients (48%) had this. Postoperatively, 47 of 85 (55%) patients had a patent false lumen in the aortic arch. False lumen remained patent after operation in 34 out of the 41 (83%) patients with brachiocephalic branch re-entry, as compared to that in 13 of the 44 (30%) patients without such re-entry (P<0.001). Brachiocephalic branch re-entry was a significant risk factor for a late increase in the aortic arch diameter greater than 10 mm (P=0.047). Brachiocephalic branch re-entry in patients with A-AAD is related to a patent false lumen in the aortic arch early after ascending aortic replacement and is a risk factor for late aortic arch enlargement.

Sensitivity and specificity of 3-D texture analysis of lung parenchyma is better than 2-D for discrimination of lung pathology in stage 0 COPD

NASA Astrophysics Data System (ADS)

Xu, Ye; Sonka, Milan; McLennan, Geoffrey; Guo, Junfeng; Hoffman, Eric

2005-04-01

Lung parenchyma evaluation via multidetector-row CT (MDCT), has significantly altered clinical practice in the early detection of lung disease. Our goal is to enhance our texture-based tissue classification ability to differentiate early pathologic processes by extending our 2-D Adaptive Multiple Feature Method (AMFM) to 3-D AMFM. We performed MDCT on 34 human volunteers in five categories: emphysema in severe Chronic Obstructive Pulmonary Disease (COPD) as EC, emphysema in mild COPD (MC), normal appearing lung in COPD (NC), non-smokers with normal lung function (NN), smokers with normal function (NS). We volumetrically excluded the airway and vessel regions, calculated 24 volumetric texture features for each Volume of Interest (VOI); and used Bayesian rules for discrimination. Leave-one-out and half-half methods were used for testing. Sensitivity, specificity and accuracy were calculated. The accuracy of the leave-one-out method for the four-class classification in the form of 3-D/2-D is: EC: 84.9%/70.7%, MC: 89.8%/82.7%; NC: 87.5.0%/49.6%; NN: 100.0%/60.0%. The accuracy of the leave-one-out method for the two-class classification in the form of 3-D/2-D is: NN: 99.3%/71.6%; NS: 99.7%/74.5%. We conclude that 3-D AMFM analysis of the lung parenchyma improves discrimination compared to 2-D analysis of the same images.

Small bowel volvulus with jejunal diverticulum: Primary or secondary?

PubMed

Shen, Xiao-Fei; Guan, Wen-Xian; Cao, Ke; Wang, Hao; Du, Jun-Feng

2015-09-28

Small bowel volvulus, which is torsion of the small bowel and its mesentery, is a medical emergency, and is categorized as primary or secondary type. Primary type often occurs without any apparent intrinsic anatomical anomalies, while the secondary type is common clinically and could be caused by numerous factors including postoperative adhesions, intestinal diverticulum, and/or tumors. Here, we report a rare case of a 60-year-old man diagnosed with small bowel volvulus using multidetector computed tomography (MDCT) angiography. Further discovery by laparotomy showed one jejunal diverticulum, longer corresponding mesentery with a narrower insertion, and a lack of mesenteric fat. This case report includes several etiological factors of small bowel volvulus, and we discuss the possible cause of small bowel volvulus in this patient. We also highlight the importance of MDCT angiography in the diagnosis of volvulus and share our experience in treating this disease.

Small bowel volvulus with jejunal diverticulum: Primary or secondary?

PubMed Central

Shen, Xiao-Fei; Guan, Wen-Xian; Cao, Ke; Wang, Hao; Du, Jun-Feng

2015-01-01

Small bowel volvulus, which is torsion of the small bowel and its mesentery, is a medical emergency, and is categorized as primary or secondary type. Primary type often occurs without any apparent intrinsic anatomical anomalies, while the secondary type is common clinically and could be caused by numerous factors including postoperative adhesions, intestinal diverticulum, and/or tumors. Here, we report a rare case of a 60-year-old man diagnosed with small bowel volvulus using multidetector computed tomography (MDCT) angiography. Further discovery by laparotomy showed one jejunal diverticulum, longer corresponding mesentery with a narrower insertion, and a lack of mesenteric fat. This case report includes several etiological factors of small bowel volvulus, and we discuss the possible cause of small bowel volvulus in this patient. We also highlight the importance of MDCT angiography in the diagnosis of volvulus and share our experience in treating this disease. PMID:26420976

CT, MRI and PET imaging in peritoneal malignancy

PubMed Central

Sahdev, Anju; Reznek, Rodney H.

2011-01-01

Abstract Imaging plays a vital role in the evaluation of patients with suspected or proven peritoneal malignancy. Nevertheless, despite significant advances in imaging technology and protocols, assessment of peritoneal pathology remains challenging. The combination of complex peritoneal anatomy, an extensive surface area that may host tumour deposits and the considerable overlap of imaging appearances of various peritoneal diseases often makes interpretation difficult. Contrast-enhanced multidetector computed tomography (MDCT) remains the most versatile tool in the imaging of peritoneal malignancy. However, conventional and emerging magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT techniques offer significant advantages over MDCT in detection and surveillance. This article reviews established and new techniques in CT, MRI and PET imaging in both primary and secondary peritoneal malignancies and provides an overview of peritoneal anatomy, function and modes of disease dissemination with illustration of common sites and imaging features of peritoneal malignancy. PMID:21865109

Posterior semicircular canal dehiscence: value of VEMP and multidetector CT.

PubMed

Vanspauwen, R; Salembier, L; Van den Hauwe, L; Parizel, P; Wuyts, F L; Van de Heyning, P H

2006-01-01

To illustrate that posterior semicircular canal dehiscence can present similarly to superior semicircular canal dehiscence. The symptomatology initially presented as probable Menière's disease evolving into a mixed conductive hearing loss with a Carhart notch-type perceptive component suggestive of otosclerosis-type stapes fixation. A small hole stapedotomy resulted in a dead ear and a horizontal semicircular canal hypofunction. Recurrent incapacitating vertigo attacks developed. Vestibular evoked myogenic potential (VEMP) testing demonstrated intact vestibulocollic reflexes. Additional evaluation with high resolution multidetector computed tomography (MDCT) of the temporal bone showed a dehiscence of the left posterior semicircular canal. Besides superior semicircular canal dehiscence, posterior semicircular canal dehiscence has to be included in the differential diagnosis of atypical Menière's disease and/or low tone conductive hearing loss. The value of performing MDCT before otosclerosis-type surgery is stressed. VEMP might contribute to establishing the differential diagnosis.

An anomalous origin of the gastrosplenic trunk and common hepatic artery arising independently from the abdominal aorta: a case report using MDCT angiography.

PubMed

Iacob, Nicoleta; Pusztai, Agneta Maria; Miclăuş, Graţian Dragoslav; Pop, Elena; Matusz, Petru

2018-01-01

The authors describe a case of a 61-year-old female patient, which presented on multidetector computed tomographic (MDCT) angiography a gastrosplenic trunk (GST) and common hepatic artery (CHA) arose independently from abdominal aorta (AA). The GST arose from the anterior wall of the AA, at the level of upper edge of the L1 vertebral body. The left gastric artery (LGA) arose from the superior wall of the GST. The splenic artery (SA) continuous the path of GST. The CHA arose from the anterior wall of the AA, at the level of upper one third of the L1 vertebral body, at 15.3 mm above the origin of superior mesenteric artery (SMA). The incidence and developmental and clinical significance of this vascular variation is discussed with a detailed review of the literature.

Survival in Nonocclusive Mesenteric Ischemia

PubMed Central

Mitsuyoshi, Akira; Obama, Kazutaka; Shinkura, Nobuhiko; Ito, Takashi; Zaima, Masazumi

2007-01-01

Objectives: The aim of the study was to establish a procedure for early diagnosis and treatment of nonocclusive mesenteric ischemia (NOMI). Background: NOMI has a high mortality rate, and early diagnosis and treatment are important for improving survival in patients with this condition. Methods: The subjects were 22 patients treated at our hospital over 13 years. Diagnostic criteria for NOMI were established based on the first 13 cases. In the 9 more recent cases, we performed abdominal contrast multidetector row computed tomography (MDCT) upon suspicion of NOMI based on these criteria. Imaging allowed definite diagnosis of NOMI, and continuous intravenous high-dose PGE1 administration was initiated immediately after diagnosis (dose, 0.01–0.03 μg/kg per min; mean administration period, 4.8 days). Results: Nine of the first 13 patients died of multiple organ failure associated with multiple intestinal necrosis. These cases suggested that NOMI may develop when 3 of the following 4 criteria are met after cardiovascular surgery or maintenance dialysis in elderly patients: symptoms of the ileus develop slowly from abdominal symptoms, such as an unpleasant abdominal feeling or pain; a requirement for catecholamine treatment; an episode of hypotension; and slow elevation of the serum transaminase level. In the 9 recent cases, definite diagnosis was made from spasm of the principal arteries in arterial volume rendering and curved planar reformation MDCT images. Early treatment with PGE1 prevented acute-stage NOMI in 8 of the 9 cases. Conclusions: Early diagnosis of NOMI is possible using the above criteria and MDCT, and initiation of PGE1 treatment may increase survival in patients with NOMI. PMID:17667501

Pulmonary vein anatomy predicts freedom from atrial fibrillation using remote magnetic navigation for circumferential pulmonary vein ablation.

PubMed

Sohns, Christian; Sohns, Jan M; Bergau, Leonard; Sossalla, Samuel; Vollmann, Dirk; Lüthje, Lars; Staab, Wieland; Dorenkamp, Marc; Harrison, James L; O'Neill, Mark D; Lotz, Joachim; Zabel, Markus

2013-08-01

Multidetector computed tomography (MDCT) is frequently used to guide circumferential pulmonary vein ablation (PVA) for treatment of atrial fibrillation (AF) as it offers accurate visualization of the left atrial (LA) and pulmonary vein (PV) anatomy. This study aimed to identify if PV anatomy is associated with outcomes following PVA using remote magnetic navigation (RMN). We analysed data from 138 consecutive patients and 146 ablation procedures referred for PVA due to drug-refractory symptomatic AF (age 63 ± 11 years; 57% men; 69% paroxysmal AF). The RMN using the stereotaxis system and open-irrigated 3.5 mm ablation catheters was used in all procedures. Prior to PVA, all patients underwent electrocardiogram-gated 64-MDCT for assessment of LA dimensions, PV anatomy, and electro-anatomical image integration during the procedure. Regular PV anatomy was found in 68%, a common left PV ostium was detected in 26%, and variant anatomy of the right PVs was detected in 6%. After a mean follow-up of 337 ± 102 days, 63% of the patients maintained sinus rhythm after the initial ablation, and 83% when including repeat PVA. Although acutely successful PV isolation did not differ between anatomical subgroups (regular 3.5 ± 0.8 vs. variant 3.2 ± 1.3; P = 0.31), AF recurrence was significantly higher in patients with non-regular PV anatomy (P = 0.04, hazard ratio 1.72). Pulmonary vein anatomy did not influence complication rates. Pulmonary vein anatomy assessed by MDCT is a good predictor of AF recurrence after PVA using RMN.

Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

PubMed

Gupta, Pushpender; Barnwell, Jonathan C; Lenchik, Leon; Wuertzer, Scott D; Miller, Anna N

2016-06-01

The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8 years (range 18.8 to 87.7). Five fractures (24 %) were U-shaped, six (29 %) H-shaped, four (19 %) Y-shaped, and six (29 %) burst. Nine patients (43 %) had central canal narrowing, and 19 (90 %) had neural foramina narrowing. Eleven patients (52 %) had kyphotic angulation between major fracture fragments, and seven patients (33 %) had either anterior (24 %) or posterior (10 %) displacement of the proximal fracture fragment. Fourteen patients (67 %) had associated pelvic fractures, and 20 (95 %) had associated non-pelvic fractures. Two patients (10 %) had associated urethral injuries, and one (5 %) had an associated colon injury. Seven patients (33 %) had associated nerve injuries. Six patients (29 %) had surgical fixation while 15 (71 %) were managed non-operatively. On trauma MDCT examinations, patients with SPD have characteristic fracture patterns. It is important to differentiate SPD from other pelvic ring injuries due to high rate of associated injuries. Although all SPD injuries are unstable and need fixation, the decision for operative management in an individual patient depends on the systemic injury pattern, specific fracture pattern, and the ability to attain stable screw fixation.

Organ dose measurements from multiple-detector computed tomography using a commercial dosimetry system and tomographic, physical phantoms

NASA Astrophysics Data System (ADS)

Lavoie, Lindsey K.

The technology of computed tomography (CT) imaging has soared over the last decade with the use of multi-detector CT (MDCT) scanners that are capable of performing studies in a matter of seconds. While the diagnostic information obtained from MDCT imaging is extremely valuable, it is important to ensure that the radiation doses resulting from these studies are at acceptably safe levels. This research project focused on the measurement of organ doses resulting from modern MDCT scanners. A commercially-available dosimetry system was used to measure organ doses. Small dosimeters made of optically-stimulated luminescent (OSL) material were analyzed with a portable OSL reader. Detailed verification of this system was performed. Characteristics studied include energy, scatter, and angular responses; dose linearity, ability to erase the exposed dose and ability to reuse dosimeters multiple times. The results of this verification process were positive. While small correction factors needed to be applied to the dose reported by the OSL reader, these factors were small and expected. Physical, tomographic pediatric and adult phantoms were used to measure organ doses. These phantoms were developed from CT images and are composed of tissue-equivalent materials. Because the adult phantom is comprised of numerous segments, dosimeters were placed in the phantom at several organ locations, and doses to select organs were measured using three clinical protocols: pediatric craniosynostosis, adult brain perfusion and adult cardiac CT angiography (CTA). A wide-beam, 320-slice, volumetric CT scanner and a 64-slice, MDCT scanner were used for organ dose measurements. Doses ranged from 1 to 26 mGy for the pediatric protocol, 1 to 1241 mGy for the brain perfusion protocol, and 2-100 mGy for the cardiac protocol. In most cases, the doses measured on the 64-slice scanner were higher than those on the 320-slice scanner. A methodology to measure organ doses with OSL dosimeters received from CT imaging has been presented. These measurements are especially important in keeping with the ALARA (as low as reasonably achievable) principle. While diagnostic information from CT imaging is valuable and necessary, the dose to patients is always a consideration. This methodology aids in this important task. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

Impact of Aortic Valve Calcification, as Measured by MDCT, on Survival in Patients With Aortic Stenosis

PubMed Central

Clavel, Marie-Annick; Pibarot, Philippe; Messika-Zeitoun, David; Capoulade, Romain; Malouf, Joseph; Aggarval, Shivani; Araoz, Phillip A.; Michelena, Hector I.; Cueff, Caroline; Larose, Eric; Miller, Jordan D.; Vahanian, Alec; Enriquez-Sarano, Maurice

2014-01-01

BACKGROUND Aortic valve calcification (AVC) load measures lesion severity in aortic stenosis (AS) and is useful for diagnostic purposes. Whether AVC predicts survival after diagnosis, independent of clinical and Doppler echocardiographic AS characteristics, has not been studied. OBJECTIVES This study evaluated the impact of AVC load, absolute and relative to aortic annulus size (AVCdensity), on overall mortality in patients with AS under conservative treatment and without regard to treatment. METHODS In 3 academic centers, we enrolled 794 patients (mean age, 73 ± 12 years; 274 women) diagnosed with AS by Doppler echocardiography who underwent multidetector computed tomography (MDCT) within the same episode of care. Absolute AVC load and AVCdensity (ratio of absolute AVC to cross-sectional area of aortic annulus) were measured, and severe AVC was separately defined in men and women. RESULTS During follow-up, there were 440 aortic valve implantations (AVIs) and 194 deaths (115 under medical treatment). Univariate analysis showed strong association of absolute AVC and AVCdensity with survival (both, p < 0.0001) with a spline curve analysis pattern of threshold and plateau of risk. After adjustment for age, sex, coronary artery disease, diabetes, symptoms, AS severity on hemodynamic assessment, and LV ejection fraction, severe absolute AVC (adjusted hazard ratio [HR]: 1.75; 95% confidence interval [CI]: 1.04 to 2.92; p = 0.03) or severe AVCdensity (adjusted HR: 2.44; 95% CI: 1.37 to 4.37; p = 0.002) independently predicted mortality under medical treatment, with additive model predictive value (all, p ≤ 0.04) and a net reclassification index of 12.5% (p = 0.04). Severe absolute AVC (adjusted HR: 1.71; 95% CI: 1.12 to 2.62; p = 0.01) and severe AVCdensity (adjusted HR: 2.22; 95% CI: 1.40 to 3.52; p = 0.001) also independently predicted overall mortality, even with adjustment for time-dependent AVI. CONCLUSIONS This large-scale, multicenter outcomes study of quantitative Doppler echocardiographic and MDCT assessment of AS shows that measuring AVC load provides incremental prognostic value for survival beyond clinical and Doppler echocardiographic assessment. Severe AVC independently predicts excess mortality after AS diagnosis, which is greatly alleviated by AVI. Thus, measurement of AVC by MDCT should be considered for not only diagnostic but also risk-stratification purposes in patients with AS. PMID:25236511

Perfusion MDCT enables early detection of therapeutic response to antiangiogenic therapy.

PubMed

Sabir, Adeel; Schor-Bardach, Rachel; Wilcox, Carol J; Rahmanuddin, Syed; Atkins, Michael B; Kruskal, Jonathan B; Signoretti, Sabina; Raptopoulos, Vassilios D; Goldberg, S Nahum

2008-07-01

The objective of our study was to determine whether perfusion CT can be used to detect early changes in therapeutic response to antiangiogenic therapy in an animal tumor model. Twenty-five rats implanted with R3230 mammary adenocarcinoma (diameter, 1.2-2.0 cm) randomly received 7.5 or 30 mg/kg of an antiangiogenic agent, sorafenib, by daily gavage for 4 (n = 4), 9 (n = 9), or 14 (n = 5) days. Seven untreated animals served as a control group. Perfusion MDCT was performed at days 0, 4, 9, and 14 with 0.4 mL of ioversol (350 mg/mL) and included four 5-mm slices covering the entire tumor volume. Changes in tumor growth were determined by volumetric analysis of CT data. Serial changes in tumor volume and blood flow were assessed and correlated with pathology findings. All control tumors grew larger (from 2.0 +/- 0.7 cm(3) at day 0 to 5.9 +/- 1.0 cm(3) at day 14), whereas all treated tumors shrank (from 2.5 +/- 1.1 to 2.1 +/- 1.0 cm(3)), with a statistically significant rate of growth or shrinkage in both groups (p < 0.05). Although perfusion in the control tumors changed little from day 0 to day 14 (day 0, 18.1 +/- 9.2 mL/min/100 g; day 4, 15.8 +/- 5.6; day 9, 21.7 +/- 12.2; day 14, 27.7 +/- 34), in the sorafenib group, the mean blood flow was significantly lower at day 4 (5.2 +/- 3.2 mL/min/100 g, 77% decrease), day 9 (6.4 +/- 4.0 mL/min/100 g, 66% decrease), and day 14 (6.3 +/- 5.2 mL/min/100 g, 83% decrease) compared with day 0 (23.8 +/- 11.6 mL/min/100 g) (p < 0.05). Poor correlation was seen between changes in blood flow and tumor volume for days 0-9 (r(2) = 0.34), 4-9 (r(2) = 0.0004), and 9-14 (r(2) = 0.16). However, when comparing day 4 images with days 9 and 14 images, seven of 14 (50%) sorafenib-treated tumors had focal areas of new perfusion that correlated with areas of histopathologic viability despite the fact that these tumors were shrinking in size from day 4 onward (day 4, 2.18 +/- 0.8 cm(3); day 9, 1.98 +/- 0.8 cm(3)). Perfusion MDCT can detect focal blood flow changes even when the tumor is shrinking, possibly indicating early reversal of tumor responsiveness to antiangiogenic therapy. Given that changes in tumor volume after antiangiogenic therapy do not necessarily correlate with true treatment response, physiologic imaging of tumor perfusion may be necessary.

Detecting Regional Myocardial Abnormalities in Patients With Wolff-Parkinson-White Syndrome With the Use of ECG-Gated Cardiac MDCT.

PubMed

Lee, Hye-Jeong; Uhm, Jae-Sun; Joung, Boyoung; Hong, Yoo Jin; Hur, Jin; Choi, Byoung Wook; Kim, Young Jin

2016-04-01

Myocardial dyskinesia caused by the accessory pathway and related reversible heart failure have been well documented in echocardiographic studies of pediatric patients with Wolff-Parkinson-White (WPW) syndrome. However, the long-term effects of dyskinesia on the myocardium of adult patients have not been studied in depth. The goal of the present study was to evaluate regional myocardial abnormalities on cardiac CT examinations of adult patients with WPW syndrome. Of 74 patients with WPW syndrome who underwent cardiac CT from January 2006 through December 2013, 58 patients (mean [± SD] age, 52.2 ± 12.7 years), 36 (62.1%) of whom were men, were included in the study after the presence of combined cardiac disease was excluded. Two observers blindly evaluated myocardial thickness and attenuation on cardiac CT scans. On the basis of CT findings, patients were classified as having either normal or abnormal findings. We compared the two groups for other clinical findings, including observations from ECG, echocardiography, and electrophysiologic study. Of the 58 patients studied, 16 patients (27.6%) were found to have myocardial abnormalities (i.e., abnormal wall thinning with or without low attenuation). All abnormal findings corresponded with the location of the accessory pathway. Patients with abnormal findings had statistically significantly decreased left ventricular function, compared with patients with normal findings (p < 0.001). The frequency of regional wall motion abnormality was statistically significantly higher in patients with abnormal findings (p = 0.043). However, echocardiography documented structurally normal hearts in all patients. A relatively high frequency (27.6%) of regional myocardial abnormalities was observed on the cardiac CT examinations of adult patients with WPW syndrome. These abnormal findings might reflect the long-term effects of dyskinesia, suggesting irreversible myocardial injury that ultimately causes left ventricular dysfunction.

Impact of bowtie filter and object position on the two-dimensional noise power spectrum of a clinical MDCT system

PubMed Central

Gomez-Cardona, Daniel; Cruz-Bastida, Juan Pablo; Li, Ke; Budde, Adam; Hsieh, Jiang; Chen, Guang-Hong

2016-01-01

Purpose: Noise characteristics of clinical multidetector CT (MDCT) systems can be quantified by the noise power spectrum (NPS). Although the NPS of CT has been extensively studied in the past few decades, the joint impact of the bowtie filter and object position on the NPS has not been systematically investigated. This work studies the interplay of these two factors on the two dimensional (2D) local NPS of a clinical CT system that uses the filtered backprojection algorithm for image reconstruction. Methods: A generalized NPS model was developed to account for the impact of the bowtie filter and image object location in the scan field-of-view (SFOV). For a given bowtie filter, image object, and its location in the SFOV, the shape and rotational symmetries of the 2D local NPS were directly computed from the NPS model without going through the image reconstruction process. The obtained NPS was then compared with the measured NPSs from the reconstructed noise-only CT images in both numerical phantom simulation studies and experimental phantom studies using a clinical MDCT scanner. The shape and the associated symmetry of the 2D NPS were classified by borrowing the well-known atomic spectral symbols s, p, and d, which correspond to circular, dumbbell, and cloverleaf symmetries, respectively, of the wave function of electrons in an atom. Finally, simulated bar patterns were embedded into experimentally acquired noise backgrounds to demonstrate the impact of different NPS symmetries on the visual perception of the object. Results: (1) For a central region in a centered cylindrical object, an s-wave symmetry was always present in the NPS, no matter whether the bowtie filter was present or not. In contrast, for a peripheral region in a centered object, the symmetry of its NPS was highly dependent on the bowtie filter, and both p-wave symmetry and d-wave symmetry were observed in the NPS. (2) For a centered region-ofinterest (ROI) in an off-centered object, the symmetry of its NPS was found to be different from that of a peripheral ROI in the centered object, even when the physical positions of the two ROIs relative to the isocenter were the same. (3) The potential clinical impact of the highly anisotropic NPS, caused by the interplay of the bowtie filter and position of the image object, was highlighted in images of specific bar patterns oriented at different angles. The visual perception of the bar patterns was found to be strongly dependent on their orientation. Conclusions: The NPS of CT depends strongly on the bowtie filter and object position. Even if the location of the ROI with respect to the isocenter is fixed, there can be different symmetries in the NPS, which depend on the object position and the size of the bowtie filter. For an isolated off-centered object, the NPS of its CT images cannot be represented by the NPS measured from a centered object. PMID:27487866

Impact of bowtie filter and object position on the two-dimensional noise power spectrum of a clinical MDCT system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez-Cardona, Daniel; Cruz-Bastida, Juan Pablo

2016-08-15

Purpose: Noise characteristics of clinical multidetector CT (MDCT) systems can be quantified by the noise power spectrum (NPS). Although the NPS of CT has been extensively studied in the past few decades, the joint impact of the bowtie filter and object position on the NPS has not been systematically investigated. This work studies the interplay of these two factors on the two dimensional (2D) local NPS of a clinical CT system that uses the filtered backprojection algorithm for image reconstruction. Methods: A generalized NPS model was developed to account for the impact of the bowtie filter and image object locationmore » in the scan field-of-view (SFOV). For a given bowtie filter, image object, and its location in the SFOV, the shape and rotational symmetries of the 2D local NPS were directly computed from the NPS model without going through the image reconstruction process. The obtained NPS was then compared with the measured NPSs from the reconstructed noise-only CT images in both numerical phantom simulation studies and experimental phantom studies using a clinical MDCT scanner. The shape and the associated symmetry of the 2D NPS were classified by borrowing the well-known atomic spectral symbols s, p, and d, which correspond to circular, dumbbell, and cloverleaf symmetries, respectively, of the wave function of electrons in an atom. Finally, simulated bar patterns were embedded into experimentally acquired noise backgrounds to demonstrate the impact of different NPS symmetries on the visual perception of the object. Results: (1) For a central region in a centered cylindrical object, an s-wave symmetry was always present in the NPS, no matter whether the bowtie filter was present or not. In contrast, for a peripheral region in a centered object, the symmetry of its NPS was highly dependent on the bowtie filter, and both p-wave symmetry and d-wave symmetry were observed in the NPS. (2) For a centered region-ofinterest (ROI) in an off-centered object, the symmetry of its NPS was found to be different from that of a peripheral ROI in the centered object, even when the physical positions of the two ROIs relative to the isocenter were the same. (3) The potential clinical impact of the highly anisotropic NPS, caused by the interplay of the bowtie filter and position of the image object, was highlighted in images of specific bar patterns oriented at different angles. The visual perception of the bar patterns was found to be strongly dependent on their orientation. Conclusions: The NPS of CT depends strongly on the bowtie filter and object position. Even if the location of the ROI with respect to the isocenter is fixed, there can be different symmetries in the NPS, which depend on the object position and the size of the bowtie filter. For an isolated off-centered object, the NPS of its CT images cannot be represented by the NPS measured from a centered object.« less

Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

PubMed

Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

2009-03-01

The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

Quantification of normative ranges and baseline predictors of aortoventricular interface dimensions using multi-detector computed tomographic imaging in patients without aortic valve disease.

PubMed

Gooley, Robert P; Cameron, James D; Soon, Jennifer; Loi, Duncan; Chitale, Gauri; Syeda, Rifath; Meredith, Ian T

2015-09-01

Multidetector computed tomographic (MDCT) assessment of the aortoventricular interface has gained increased importance with the advent of minimally invasive treatment modalities for aortic and mitral valve disease. This has included a standardised technique of identifying a plane through the nadir of each coronary cusp, the basal plane, and taking further measurements in relation to this plane. Despite this there is no published data defining normal ranges for these aortoventricular metrics in a healthy cohort. This study seeks to quantify normative ranges for MDCT derived aortoventricular dimensions and evaluate baseline demographic and anthropomorphic associates of these measurements in a normal cohort. 250 consecutive patients undergoing MDCT coronary angiography were included. Aortoventricular dimensions at multiple levels of the aortoventricular interface were assessed and normative ranges quantified. Multivariate linear regression was performed to identify baseline predictors of each metric. The mean age was 59±12 years. The basal plane was eccentric (EI=0.22±0.06) while the left ventricular outflow tract was more eccentric (EI=0.32±0.06), with no correlation to gender, age or hypertension. Male gender, height and body mass index were consistent independent predictors of larger aortoventricular dimensions at all anatomical levels, while age was predictive of supra-annular measurements. Male gender, height and BMI are independent predictors of all aortoventricular dimensions while age predicts only supra-annular dimensions. Use of defined metrics such as the basal plane and formation of normative ranges for these metrics allows reference for clinical reporting and for future research studies by using a standardised measurement technique. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Diagnostic and prognostic role of computed tomography in extracorporeal shock wave lithotripsy complications

PubMed Central

Telegrafo, Michele; Carluccio, Davide Antonio; Rella, Leonarda; Ianora, Amato Antonio Stabile; Angelelli, Giuseppe; Moschetta, Marco

2016-01-01

Purpose: To evaluate the role of multidetector computed tomography (MDCT) in recognizing the complications of extracorporeal shock wave lithotripsy (ESWL) and providing a prognostic grading system for the therapeutic approach. Materials and Methods: A total of 43 patients who underwent ESWL because of urinary stone disease were assessed by 320-row MDCT examination before and after ESWL. Pre-ESWL CT unenhanced scans were performed for diagnosing stone disease. Post-ESWL CT scans were acquired before and after intravenous injection of contrast medium searching for peri-renal fluid collection or hyper-density, pyelic or ureteral wall thickening, blood clots in the urinary tract, peri- or intra-renal hematoma or abscess, active bleeding. A severity grading system of ESWL complications was established. Results: Patients were affected by renal (n = 36) or ureteral (n = 7) lithiasis. Post-ESWL CT examination detected small fluid collections and hyper-density of peri-renal fat tissue in 35/43 patients (81%), pyelic or ureteral wall thickening in 2/43 (4%), blood clots in the urinary tract in 9/43 (21%), renal abscesses or hematomas with a diameter of <2 cm in 10/43 (23%), large retroperitoneal collections in 3/43 (7%), active bleeding from renal vessels in 1/43 (2%). Mild complications were found in 30 cases; moderate in 9; severe in 4. The therapeutic choice was represented by clinical follow-up (n = 20), clinical and CT follow-up (n = 10), ureteral stenting (n = 9), drainage of large retroperitoneal collections (n = 3), and arterial embolization (n = 1). Conclusion: MDCT plays a crucial role in the diagnosis of urolithiasis and follow-up of patients treated with ESWL recognizing its complications and providing therapeutic and prognostic indications. PMID:27141186

Diagnostic and prognostic role of computed tomography in extracorporeal shock wave lithotripsy complications.

PubMed

Telegrafo, Michele; Carluccio, Davide Antonio; Rella, Leonarda; Ianora, Amato Antonio Stabile; Angelelli, Giuseppe; Moschetta, Marco

2016-01-01

To evaluate the role of multidetector computed tomography (MDCT) in recognizing the complications of extracorporeal shock wave lithotripsy (ESWL) and providing a prognostic grading system for the therapeutic approach. A total of 43 patients who underwent ESWL because of urinary stone disease were assessed by 320-row MDCT examination before and after ESWL. Pre-ESWL CT unenhanced scans were performed for diagnosing stone disease. Post-ESWL CT scans were acquired before and after intravenous injection of contrast medium searching for peri-renal fluid collection or hyper-density, pyelic or ureteral wall thickening, blood clots in the urinary tract, peri- or intra-renal hematoma or abscess, active bleeding. A severity grading system of ESWL complications was established. Patients were affected by renal (n = 36) or ureteral (n = 7) lithiasis. Post-ESWL CT examination detected small fluid collections and hyper-density of peri-renal fat tissue in 35/43 patients (81%), pyelic or ureteral wall thickening in 2/43 (4%), blood clots in the urinary tract in 9/43 (21%), renal abscesses or hematomas with a diameter of <2 cm in 10/43 (23%), large retroperitoneal collections in 3/43 (7%), active bleeding from renal vessels in 1/43 (2%). Mild complications were found in 30 cases; moderate in 9; severe in 4. The therapeutic choice was represented by clinical follow-up (n = 20), clinical and CT follow-up (n = 10), ureteral stenting (n = 9), drainage of large retroperitoneal collections (n = 3), and arterial embolization (n = 1). MDCT plays a crucial role in the diagnosis of urolithiasis and follow-up of patients treated with ESWL recognizing its complications and providing therapeutic and prognostic indications.

Perfusion CT of the Brain and Liver and of Lung Tumors: Use of Monte Carlo Simulation for Patient Dose Estimation for Examinations With a Cone-Beam 320-MDCT Scanner.

PubMed

Cros, Maria; Geleijns, Jacob; Joemai, Raoul M S; Salvadó, Marçal

2016-01-01

The purpose of this study was to estimate the patient dose from perfusion CT examinations of the brain, lung tumors, and the liver on a cone-beam 320-MDCT scanner using a Monte Carlo simulation and the recommendations of the International Commission on Radiological Protection (ICRP). A Monte Carlo simulation based on the Electron Gamma Shower Version 4 package code was used to calculate organ doses and the effective dose in the reference computational phantoms for an adult man and adult woman as published by the ICRP. Three perfusion CT acquisition protocols--brain, lung tumor, and liver perfusion--were evaluated. Additionally, dose assessments were performed for the skin and for the eye lens. Conversion factors were obtained to estimate effective doses and organ doses from the volume CT dose index and dose-length product. The sex-averaged effective doses were approximately 4 mSv for perfusion CT of the brain and were between 23 and 26 mSv for the perfusion CT body protocols. The eye lens dose from the brain perfusion CT examination was approximately 153 mGy. The sex-averaged peak entrance skin dose (ESD) was 255 mGy for the brain perfusion CT studies, 157 mGy for the lung tumor perfusion CT studies, and 172 mGy for the liver perfusion CT studies. The perfusion CT protocols for imaging the brain, lung tumors, and the liver performed on a 320-MDCT scanner yielded patient doses that are safely below the threshold doses for deterministic effects. The eye lens dose, peak ESD, and effective doses can be estimated for other clinical perfusion CT examinations from the conversion factors that were derived in this study.

Gender Differences of Airway Dimensions in Anatomically Matched Sites on CT in Smokers

PubMed Central

Kim, Yu-Il; Schroeder, Joyce; Lynch, David; Newell, John; Make, Barry; Friedlander, Adam; Estépar, Raúl San José; Hanania, Nicola A.; Washko, George; Murphy, James R.; Wilson, Carla; Hokanson, John E.; Zach, Jordan; Butterfield, Kiel; Bowler, Russell P.

2013-01-01

Rationale and Objectives There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers. Materials and Methods We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions. Results Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm2 for segmental bronchial lumen area, 10.4 vs 12.5 mm2 for subsegmental bronchi, 6.5 vs 7.7 mm2 for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness. Conclusion Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation. PMID:21756032

Investigation of the relative effects of vascular branching structure and gravity on pulmonary arterial blood flow heterogeneity via an image-based computational model.

PubMed

Burrowes, Kelly S; Hunter, Peter J; Tawhai, Merryn H

2005-11-01

A computational model of blood flow through the human pulmonary arterial tree has been developed to investigate the relative influence of branching structure and gravity on blood flow distribution in the human lung. Geometric models of the largest arterial vessels and lobar boundaries were first derived using multidetector row x-ray computed tomography (MDCT) scans. Further accompanying arterial vessels were generated from the MDCT vessel endpoints into the lobar volumes using a volume-filling branching algorithm. Equations governing the conservation of mass and momentum were solved within the geometric model to calculate pressure, velocity, and vessel radius. Blood flow results in the anatomically based model, with and without gravity, and in a symmetric geometric model were compared to investigate their relative contributions to blood flow heterogeneity. Results showed a persistent blood flow gradient and flow heterogeneity in the absence of gravitational forces in the anatomically based model. Comparison with flow results in the symmetric model revealed that the asymmetric vascular branching structure was largely responsible for producing this heterogeneity. Analysis of average results in varying slice thicknesses illustrated a clear flow gradient because of gravity in "lower resolution" data (thicker slices), but on examination of higher resolution data, a trend was less obvious. Results suggest that although gravity does influence flow distribution, the influence of the tree branching structure is also a dominant factor. These results are consistent with high-resolution experimental studies that have demonstrated gravity to be only a minor determinant of blood flow distribution.

Pulmonary MR imaging with ultra-short TEs: utility for disease severity assessment of connective tissue disease patients.

PubMed

Ohno, Yoshiharu; Nishio, Mizuho; Koyama, Hisanobu; Takenaka, Daisuke; Takahashi, Masaya; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Obara, Makoto; van Cauteren, Marc; Sugimura, Kazuro

2013-08-01

To evaluate the utility of pulmonary magnetic resonance (MR) imaging with ultra-short echo times (UTEs) at a 3.0 T MR system for pulmonary functional loss and disease severity assessments of connective tissue disease (CTD) patients with interstitial lung disease (ILD). This prospective study was approved by the institutional review board, and written informed consent was obtained from 18 CTD patients (eight men and ten women) and eight normal subjects with suspected chest disease (three men and five women). All subjects underwent thin-section MDCT, pulmonary MR imaging with UTEs, pulmonary function test and serum KL-6. Regional T2 maps were generated from each MR data set, and mean T2 values were determined from ROI measurements. From each thin-section MDCT data set, CT-based disease severity was evaluated with a visual scoring system. Mean T2 values for normal and CTD subjects were statistically compared by using Student's t-test. To assess capability for pulmonary functional loss and disease severity assessments, mean T2 values were statistically correlated with pulmonary functional parameters, serum KL-6 and CT-based disease severity. Mean T2 values for normal and CTD subjects were significantly different (p=0.0019) and showed significant correlations with %VC, %DLCO, serum KL-6 and CT-based disease severity of CTD patients (p<0.05). Pulmonary MR imaging with UTEs is useful for pulmonary functional loss and disease severity assessments of CTD patients with ILD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Generation of intra-oral-like images from cone beam computed tomography volumes for dental forensic image comparison.

PubMed

Trochesset, Denise A; Serchuk, Richard B; Colosi, Dan C

2014-03-01

Identification of unknown individuals using dental comparison is well established in the forensic setting. The identification technique can be time and resource consuming if many individuals need to be identified at once. Medical CT (MDCT) for dental profiling has had limited success, mostly due to artifact from metal-containing dental restorations and implants. The authors describe a CBCT reformatting technique that creates images, which closely approximate conventional dental images. Using a i-CAT Platinum CBCT unit and standard issue i-CAT Vision software, a protocol is developed to reproducibly and reliably reformat CBCT volumes. The reformatted images are presented with conventional digital images from the same anatomic area for comparison. The authors conclude that images derived from CBCT volumes following this protocol are similar enough to conventional dental radiographs to allow for dental forensic comparison/identification and that CBCT offers a superior option over MDCT for this purpose. © 2013 American Academy of Forensic Sciences.

Whole-brain perfusion CT using a toggling table technique to predict final infarct volume in acute ischemic stroke.

PubMed

Schrader, I; Wilk, D; Jansen, O; Riedel, C

2013-09-01

To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the "toggling table" technique within the first three hours after symptom onset. In patients with successful thrombolytic therapy (n = 48) and in those without effective thrombolytic therapy (n = 41), the infarct volume and the volume of the penumbra on PCT were compared to the infarct size on follow-up images (CT or MRI) performed within 8 days. The feasibility of complete infarct volume prediction by 8 cm cranio-caudal coverage was evaluated. The correlation between the volume of hypoperfusion on PCT defined by cerebral blood volume reduction and final infarct volume was strongest in patients with successful thrombolytic therapy with underestimation of the definite infarct volume by 8.5 ml on average. The CBV map had the greatest prognostic value. In patients without successful thrombolytic therapy, the final infarct volume was overestimated by 12.1 ml compared to the MTT map on PCT. All infarcts were detected completely. There were no false-positive or false-negative results. Using PCT and the "toggling table" technique in acute stroke patients is helpful for the rapid and accurate quantification of the minimal final infarct and is therefore a prognostic parameter which has to be evaluated in further studies to assess its impact on therapeutic decision. ▶ Using PCT and the “toggling table technique” allows accurate quantification of the infarct core and penumbra. ▶ It is possible to record dynamic perfusion parameters quickly and easily of almost the entire supratentorial brain volume on a 64-slice MDCT unit. ▶ The technique allows identification of those patients who could profit from thrombolytic therapy outside the established time intervals. © Georg Thieme Verlag KG Stuttgart · New York.

SU-F-I-05: Dose Symmetry for CTDI Equivalent Measurements with Limited Angle CBCT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, V; McKenney, S; Sunde, P

Purpose: CTDI measurements, useful for characterizing the x-ray output for multi-detector CT (MDCT), require a 360° rotation of the gantry; this presents a problem for cone beam CT (CBCT) due to its limited angular rotation. The purpose of this work is to demonstrate a methodology for overcoming this limited angular rotation so that CTDI measurements can also be made on CBCT systems making it possible to compare the radiation output from both types of system with a common metric. Methods: The symmetry of the CTDI phantom allows a 360° CTDI measurement to be replaced with two 180° measurements. A pencilmore » chamber with a real-time digitizer was placed at the center of the head phantom (16 cm, PMMA) and the resulting exposure measurement from a 180° acquisition was doubled. A pair of edge measurements, each obtained with the gantry passing through the same 180 arc, was obtained with the pencil chamber at opposite edges of the diameter of the phantom and then summed. The method was demonstrated on a clinical CT scanner (Philips, Brilliance6) and then implemented on an interventional system (Siemens, Axiom Artis). Results: The equivalent CTDI measurement agreed with the conventional CTDI measurement within 8%. The discrepancy in the two measurements is largely attributed to uncertainties in cropping the waveform to a 180°acquisition. (Note: Because of the reduced fan angle in the CBCT, CTDI is not directly comparable to MDCT values when a 32 cm phantom is used.) Conclusion: The symmetry-based CTDI measurement is an equivalent measurement to the conventional CTDI measurement when the fan angle is large enough to encompass the phantom diameter. This allows a familiar metric of radiation output to be employed on systems with a limited angular rotation.« less

Tube focal spot size and power capability impact image quality in the evaluation of intracoronary stents

NASA Astrophysics Data System (ADS)

Cesmeli, Erdogan; Berry, Joel L.; Carr, J. J.

2005-04-01

Proliferation of coronary stent deployment for treatment of coronary heart disease (CHD) creates a need for imaging-based follow-up examinations to assess patency. Technological improvements in multi-detector computer tomography (MDCT) make it a potential non-invasive alternative to coronary catheterization for evaluation of stent patency; however, image quality with MDCT varies based on the size and composition of the stent. We studied the role of tube focal spot size and power in the optimization of image quality in a stationary phantom. A standard uniform physical phantom with a tubular insert was used where coronary stents (4 mm in diameter) were deployed in a tube filled with contrast to simulate a typical imaging condition observed in clinical practice. We utilized different commercially available stents and scanned them with different tube voltage and current settings (LightSpeed Pro16, GE Healthcare Technologies, Waukesha, WI, USA). The scanner used different focal spot size depending on the power load and thus allowed us to assess the combined effect of the focal spot size and the power. A radiologist evaluated the resulting images in terms of image quality and artifacts. For all stents, we found that the small focal spot size yielded better image quality and reduced artifacts. In general, higher power capability for the given focal spot size improved the signal-to-noise ratio in the images allowing improved assessment. Our preliminary study in a non-moving phantom suggests that a CT scanner that can deliver the same power on a small focal spot size is better suited to have an optimized scan protocol for reliable stent assessment.

Comparison of tomographic and colonoscopic diagnoses in the presence of colonic wall thickening

PubMed Central

İnce, Ali Tüzün; Baysal, Birol; Kayar, Yusuf; Arabacı, Elif; Bilgin, Mehmet; Hamdard, Jamshid; Yay, Adnan; Şentürk, Hakan

2014-01-01

Introduction and objective: Colonic wall thickening is a common condition in a number of benignant and malignant diseases. This study investigated the accuracy of radiological diagnoses in patients diagnosed with colonic wall thickening using multislice CT (MDCT). Materials and Method: Files of patients with colonic wall thickening diagnosed with 64-slice MDCT were reviewed retrospectively. The colonoscopy results of these patients were grouped under neoplastic process (cancer and adenomatous polyp), inflammatory bowel disease (IBD), diverticulitis and other etiology (nonspecific events, ischemic colitis, solitary rectal ulcer, external compression, secondary to volvulus and radiotherapy), and the results were statistically evaluated. p values < 0.05 were considered statistically significant. Results: The study was performed on 505 files (290 males [57.4%], 215 females [42.6%], mean age: 49.15 ± 18.4 years). CT and colonoscopic diagnoses were reviewed and the following CT to colonoscopy ratios was observed: neoplastic process: 44.4% vs. 40.2%; IBD: 42.4% vs. 42.4%; diverticulitis: 4% vs. 4.2%; other etiology: 9.3% vs. 3.2%. Colonoscopy failed to identify pathology in 9.9% of the patients. The sensitivity, specificity, PPV, NPV and accuracy of CT were 95.6%, 90.4%, 87.1%, 96.8% and 92.4%, respectively, in detecting neoplastic processes; 97.2%, 97.9%, 97.2%, 97.9% and 97.6%, respectively, in detecting IBD; 90.5%, 99.8%, 95%, 99.6% and 99.4%, respectively, in detecting diverticulitis, and 50%, 96,7%, 62.5%, 94.6% and 92%, respectively, in detecting other etiology. Conclusion: While, accuracy of 64 slice-CT in diagnosing colonic wall thickenings secondary especially to neoplastic processes, IBD and diverticulitis was significantly higher, but differential diagnosis is challenging in pathologies due to other etiologies. PMID:25550962

Maintenance of Ideal Cardiovascular Health and Coronary Artery Calcium Progression in Low-Risk Men and Women in the Framingham Heart Study.

PubMed

Hwang, Shih-Jen; Onuma, Oyere; Massaro, Joseph M; Zhang, Xiaoling; Fu, Yi-Ping; Hoffmann, Udo; Fox, Caroline S; O'Donnell, Christopher J

2018-01-01

Ideal cardiovascular health (CVH) is associated with a lower risk of cardiovascular disease and freedom from coronary artery calcium (CAC). Prospective data on the association between maintenance of optimal CVH and the progression of subclinical coronary atherosclerosis are limited. We assessed the influence of unfavorable versus favorable CVH on the incidence of CAC progression. The study population consisted of 1119 FHS (Framingham Heart Study) participants who attended the serial FHS MDCT I and MDCT II study (Multi-Detector Computed Tomography) and had a zero Agatston CAC score at baseline. CVH status was defined using 6 CVH metrics from the American Heart Association definition. CAC progression was defined by an increase in Agatston CAC score to ≥3.4. Generalized estimating equations were applied to identify significant associations of CAC progression with both the baseline measurement of CVH and the longitudinal maintenance of CVH. After follow-up (mean, 6.1 years), we observed CAC progression in 191 participants (17.1%). Participants with unfavorable CVH at baseline had a greater risk of CAC progression (odds ratio, 2.43; 95% confidence interval, 1.40-4.23; P =0.0017). In addition, each unit decrease in ideal CVH metric was associated with an increase in CAC progression (odds ratio, 1.15; 95% confidence interval, 0.99-1.34; P =0.067), after adjustment for baseline ideal CVH metrics. Significant associations between an unfavorable CVH profile and CAC progression support public health measures that seek to prevent cardiovascular disease by promoting favorable CVH profiles in persons free of clinical and subclinical cardiovascular disease. © 2018 American Heart Association, Inc.

Volume-rendered hemorrhage-responsible arteriogram created by 64 multidetector-row CT during aortography: utility for catheterization in transcatheter arterial embolization for acute arterial bleeding.

PubMed

Minamiguchi, Hiroki; Kawai, Nobuyuki; Sato, Morio; Ikoma, Akira; Sanda, Hiroki; Nakata, Kouhei; Tanaka, Fumihiro; Nakai, Motoki; Sonomura, Tetsuo; Murotani, Kazuhiro; Hosokawa, Seiki; Nishioku, Tadayoshi

2014-01-01

Aortography for detecting hemorrhage is limited when determining the catheter treatment strategy because the artery responsible for hemorrhage commonly overlaps organs and non-responsible arteries. Selective catheterization of untargeted arteries would result in repeated arteriography, large volumes of contrast medium, and extended time. A volume-rendered hemorrhage-responsible arteriogram created with 64 multidetector-row CT (64MDCT) during aortography (MDCTAo) can be used both for hemorrhage mapping and catheter navigation. The MDCTAo depicted hemorrhage in 61 of 71 cases of suspected acute arterial bleeding treated at our institute in the last 3 years. Complete hemostasis by embolization was achieved in all cases. The hemorrhage-responsible arteriogram was used for navigation during catheterization, thus assisting successful embolization. Hemorrhage was not visualized in the remaining 10 patients, of whom 6 had a pseudoaneurysm in a visceral artery; 1 with urinary bladder bleeding and 1 with chest wall hemorrhage had gaze tamponade; and 1 with urinary bladder hemorrhage and 1 with uterine hemorrhage had spastic arteries. Six patients with pseudoaneurysm underwent preventive embolization and the other 4 patients were managed by watchful observation. MDCTAo has the advantage of depicting the arteries responsible for hemoptysis, whether from the bronchial arteries or other systemic arteries, in a single scan. MDCTAo is particularly useful for identifying the source of acute arterial bleeding in the pancreatic arcade area, which is supplied by both the celiac and superior mesenteric arteries. In a case of pelvic hemorrhage, MDCTAo identified the responsible artery from among numerous overlapping visceral arteries that branched from the internal iliac arteries. In conclusion, a hemorrhage-responsible arteriogram created by 64MDCT immediately before catheterization is useful for deciding the catheter treatment strategy for acute arterial bleeding.

Toward assessing the diagnostic influence of dose reduction in pediatric CT: a study based on simulated lung nodules

NASA Astrophysics Data System (ADS)

Li, Xiang; Samei, Ehsan; DeLong, David M.; Jones, Robert P.; Colsher, James G.; Frush, Donald P.

2008-03-01

The purpose of this study is to evaluate the effect of reduced tube current, as a surrogate for radiation dose, on lung nodule detection in pediatric chest multi-detector CT (MDCT). Normal chest MDCT images of 13 patients aged 1 to 7 years old were used as templates for this study. The original tube currents were between 70 mA and 180 mA. Using proprietary noise addition software, noise was added to the images to create 13 cases at the lowest common mA (i.e. 70 mA), 13 cases at 35 mA (50% reduction), and 13 cases at 17.5 mA (75% reduction). Three copies of each case were made for a total of 117 series for simulated nodule insertion. A technique for three-dimensional simulation of small lung nodules was developed, validated through an observer study, and used to add nodules to the series. Care was taken to ensure that each of three lung zones (upper, middle, lower) contained 0 or 1 nodule. The series were randomized and the presence of a nodule in each lung zone was rated independently and blindly by three pediatric radiologists on a continuous scale between 0 (definitely absent) and 100 (definitely present). Receiver operating characteristic analysis of the data showed no general significant difference in diagnostic accuracy between the reduced mA values and 70 mA, suggesting a potential for dose reduction with preserved diagnostic quality. To our knowledge, this study is the first controlled, systematic, and task-specific assessment of the influence of dose reduction in pediatric chest CT.

Impact of aortic valve calcification, as measured by MDCT, on survival in patients with aortic stenosis: results of an international registry study.

PubMed

Clavel, Marie-Annick; Pibarot, Philippe; Messika-Zeitoun, David; Capoulade, Romain; Malouf, Joseph; Aggarval, Shivani; Araoz, Phillip A; Michelena, Hector I; Cueff, Caroline; Larose, Eric; Miller, Jordan D; Vahanian, Alec; Enriquez-Sarano, Maurice

2014-09-23

Aortic valve calcification (AVC) load measures lesion severity in aortic stenosis (AS) and is useful for diagnostic purposes. Whether AVC predicts survival after diagnosis, independent of clinical and Doppler echocardiographic AS characteristics, has not been studied. This study evaluated the impact of AVC load, absolute and relative to aortic annulus size (AVCdensity), on overall mortality in patients with AS under conservative treatment and without regard to treatment. In 3 academic centers, we enrolled 794 patients (mean age, 73 ± 12 years; 274 women) diagnosed with AS by Doppler echocardiography who underwent multidetector computed tomography (MDCT) within the same episode of care. Absolute AVC load and AVCdensity (ratio of absolute AVC to cross-sectional area of aortic annulus) were measured, and severe AVC was separately defined in men and women. During follow-up, there were 440 aortic valve implantations (AVIs) and 194 deaths (115 under medical treatment). Univariate analysis showed strong association of absolute AVC and AVCdensity with survival (both, p < 0.0001) with a spline curve analysis pattern of threshold and plateau of risk. After adjustment for age, sex, coronary artery disease, diabetes, symptoms, AS severity on hemodynamic assessment, and LV ejection fraction, severe absolute AVC (adjusted hazard ratio [HR]: 1.75; 95% confidence interval [CI]: 1.04 to 2.92; p = 0.03) or severe AVCdensity (adjusted HR: 2.44; 95% CI: 1.37 to 4.37; p = 0.002) independently predicted mortality under medical treatment, with additive model predictive value (all, p ≤ 0.04) and a net reclassification index of 12.5% (p = 0.04). Severe absolute AVC (adjusted HR: 1.71; 95% CI: 1.12 to 2.62; p = 0.01) and severe AVCdensity (adjusted HR: 2.22; 95% CI: 1.40 to 3.52; p = 0.001) also independently predicted overall mortality, even with adjustment for time-dependent AVI. This large-scale, multicenter outcomes study of quantitative Doppler echocardiographic and MDCT assessment of AS shows that measuring AVC load provides incremental prognostic value for survival beyond clinical and Doppler echocardiographic assessment. Severe AVC independently predicts excess mortality after AS diagnosis, which is greatly alleviated by AVI. Thus, measurement of AVC by MDCT should be considered for not only diagnostic but also risk-stratification purposes in patients with AS. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Breathlessness and Restrictive Lung Disease: An Important Diabetes-Related Feature in Patients with Type 2 Diabetes.

PubMed

Kopf, Stefan; Groener, Jan B; Kender, Zoltan; Fleming, Thomas; Brune, Maik; Riedinger, Christin; Volk, Nadine; Herpel, Esther; Pesta, Dominik; Szendrödi, Julia; Wielpütz, Mark O; Kauczor, Hans-Ulrich; Katus, Hugo A; Kreuter, Michael; Nawroth, Peter P

2018-06-06

Diabetes mellitus is a significant comorbidity of interstitial lung disease (ILD). The aim of this study was to investigate the incidence of restrictive lung disease (RLD) and ILD in patients with prediabetes and type 2 diabetes (T2D). Forty-eight nondiabetics, 68 patients with prediabetes, 29 newly diagnosed T2D, and 110 patients with long-term T2D were examined for metabolic control, diabetes-related complications, breathlessness, and lung function. Five participants with T2D, breathlessness, and RLD underwent multidetector computed tomography (MDCT) and a Six-Minute Walk Test (6MWT). Lung tissue from 4 patients without diabetes and from 3 patients with T2D was histologically examined for presence of pulmonary fibrosis. Breathlessness in combination with RLD was significantly increased in patients with prediabetes and T2D (p < 0.01). RLD was found in 9% of patients with prediabetes, in 20% of patients with newly diagnosed T2D, and in 27% of patients with long-term T2D. Thus, patients with long-term T2D had an increased risk of RLD (OR 5.82 [95% CI 1.71-20.5], p < 0.01). RLD was significantly associated with glucose metabolism and albuminuria (p < 0.01); furthermore, presence of nephropathy increased the risk of RLD (OR 8.57 [95% CI 3.4-21.9], p < 0.01) compared to nondiabetics. MDCT revealed ILD in 4 patients, the 6MWT correlated with the extent of ILD, and histological analysis showed fibrosing ILD in patients with T2D. This study demonstrates increased breathlessness and a high prevalence of RLD in patients with T2D, indicating an association between diabetes and fibrosing ILD. © 2018 S. Karger AG, Basel.

Multidetector CT radiation dose optimisation in adults: short- and long-term effects of a clinical audit.

PubMed

Tack, Denis; Jahnen, Andreas; Kohler, Sarah; Harpes, Nico; De Maertelaer, Viviane; Back, Carlo; Gevenois, Pierre Alain

2014-01-01

To report short- and long-term effects of an audit process intended to optimise the radiation dose from multidetector row computed tomography (MDCT). A survey of radiation dose from all eight MDCT departments in the state of Luxembourg performed in 2007 served as baseline, and involved the most frequently imaged regions (head, sinus, cervical spine, thorax, abdomen, and lumbar spine). CT dose index volume (CTDIvol), dose-length product per acquisition (DLP/acq), and DLP per examination (DLP/exa) were recorded, and their mean, median, 25th and 75th percentiles compared. In 2008, an audit conducted in each department helped to optimise doses. In 2009 and 2010, two further surveys evaluated the audit's impact on the dose delivered. Between 2007 and 2009, DLP/exa significantly decreased by 32-69 % for all regions (P < 0.001) except the lumbar spine (5 %, P = 0.455). Between 2009 and 2010, DLP/exa significantly decreased by 13-18 % for sinus, cervical and lumbar spine (P ranging from 0.016 to less than 0.001). Between 2007 and 2010, DLP/exa significantly decreased for all regions (18-75 %, P < 0.001). Collective dose decreased by 30 % and the 75th percentile (diagnostic reference level, DRL) by 20-78 %. The audit process resulted in long-lasting dose reduction, with DRLs reduced by 20-78 %, mean DLP/examination by 18-75 %, and collective dose by 30 %. • External support through clinical audit may optimise default parameters of routine CT. • Reduction of 75th percentiles used as reference diagnostic levels is 18-75 %. • The effect of this audit is sustainable over time. • Dose savings through optimisation can be added to those achievable through CT.

Quantitative Analysis of First-Pass Contrast-Enhanced Myocardial Perfusion Multidetector CT Using a Patlak Plot Method and Extraction Fraction Correction During Adenosine Stress

NASA Astrophysics Data System (ADS)

Ichihara, Takashi; George, Richard T.; Silva, Caterina; Lima, Joao A. C.; Lardo, Albert C.

2011-02-01

The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement that can be used to derive accurate myocardial perfusion measurements from dynamic multidetector computed tomography (MDCT) images by using a compartment model for calculating the first-order transfer constant (K1) with correction for the capillary transit extraction fraction (E). Six canine models of left anterior descending (LAD) artery stenosis were prepared and underwent first-pass contrast-enhanced MDCT perfusion imaging during adenosine infusion (0.14-0.21 mg/kg/min). K1 , which is the first-order transfer constant from left ventricular (LV) blood to myocardium, was measured using the Patlak plot method applied to time-attenuation curve data of the LV blood pool and myocardium. The results were compared against microsphere MBF measurements, and the extraction fraction of contrast agent was calculated. K1 is related to the regional MBF as K1=EF, E=(1-exp(-PS/F)), where PS is the permeability-surface area product and F is myocardial flow. Based on the above relationship, a look-up table from K1 to MBF can be generated and Patlak plot-derived K1 values can be converted to the calculated MBF. The calculated MBF and microsphere MBF showed a strong linear association. The extraction fraction in dogs as a function of flow (F) was E=(1-exp(-(0.2532F+0.7871)/F)) . Regional MBF can be measured accurately using the Patlak plot method based on a compartment model and look-up table with extraction fraction correction from K1 to MBF.

Systolic hypertension and progression of aortic valve calcification in patients with aortic stenosis: results from the PROGRESSA study

PubMed Central

Tastet, Lionel; Capoulade, Romain; Clavel, Marie-Annick; Larose, Éric; Shen, Mylène; Dahou, Abdellaziz; Arsenault, Marie; Mathieu, Patrick; Bédard, Élisabeth; Dumesnil, Jean G.; Tremblay, Alexe; Bossé, Yohan; Després, Jean-Pierre; Pibarot, Philippe

2017-01-01

Aims Hypertension is highly prevalent in patients with aortic stenosis (AS) and is associated with worse outcomes. The current prospective study assessed the impact of systolic hypertension (SHPT) on the progression of aortic valve calcification (AVC) measured by multidetector computed tomography (MDCT) in patients with AS. Methods and results The present analysis includes the first series of 101 patients with AS prospectively recruited in the PROGRESSA study. Patients underwent comprehensive Doppler echocardiography and MDCT exams at baseline and after 2-year follow-up. AVC and coronary artery calcification (CAC) were measured using the Agatston method. Patients with SHPT at baseline (i.e. systolic blood pressure ≥140 mmHg; n = 37, 37%) had faster 2-year AVC progression compared with those without SHPT (i.e. systolic blood pressure <140 mmHg) (AVC median [25th percentile–75th percentile]: +370 [126–824] vs. +157 [58–303] AU; P = 0.007, respectively). Similar results were obtained with the analysis of AVC progression divided by the cross-sectional area of the aortic annulus (AVCdensity: +96 [34–218] vs. +45 [14–82] AU/cm2, P = 0.01, respectively). In multivariable analysis, SHPT remained significantly associated with faster progression of AVC or AVCdensity (all P = 0.001). There was no significant difference between groups with respect to progression of CAC (+39 [3–199] vs. +41 [0–156] AU, P = 0.88). Conclusion This prospective study shows for the first time that SHPT is associated with faster AVC progression but not with CAC progression in AS patients. These findings provide further support for the elaboration of randomized clinical trials to assess the efficacy of antihypertensive medication to slow the stenosis progression in patients with AS. PMID:26896413

Influence of pulmonary emphysema on COPD assessment test-oriented categorization in GOLD document.

PubMed

Suzuki, Toshio; Tada, Yuji; Kawata, Naoko; Ikari, Jun; Kasahara, Yasunori; Sakurai, Yoriko; Iesato, Ken; Nishimura, Rintaro; West, James; Tatsumi, Koichiro

2015-01-01

The COPD assessment test (CAT) score is a key component of the multifactorial assessment of COPD in the Global initiative for chronic Obstructive Lung Disease (GOLD) guidelines of 2014. Nevertheless, little is known regarding the differences among COPD categories in terms of clinical parameters such as pulmonary function or radiological findings. Thus, our aims in this study were to evaluate the associations between CAT scores and pulmonary clinical parameters, and to investigate factors that could discriminate between a "less symptomatic group" (categories A and C) and a "more symptomatic group" (categories B and D) among stable COPD patients. We enrolled 200 outpatients at Chiba University Hospital. Study subjects were assessed by CAT, pulmonary function testing, and multidetector computed tomography (MDCT). We assessed possible correlations between these indices. CAT scores were negatively correlated with percentage of the forced expiratory volume in 1 second predicted value (FEV1 %predicted) and percentage of the diffusing capacity for carbon monoxide per liter of lung volume predicted value (DLCO/VA [%predicted]) results and positively correlated with low attenuation volume percentage (LAV%) and residual volume to total lung capacity ratios (RV/TLC). In the "more symptomatic group" (category B or D), the mean DLCO/VA (%predicted) was significantly lower and the mean LAV% and RV/TLC was significantly higher than those in the "less symptomatic group" (category A or C), respectively. Interestingly, those in category B had higher mean LAV% compared to those in category C. CAT scores were significantly correlated with pulmonary function parameters and emphysematous changes on MDCT. The new GOLD classification system would be a step toward a phenotypic approach, especially taking into account the degree of emphysema and hyperinflation.

A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

PubMed Central

Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

2012-01-01

A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C1 continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung. PMID:23794749

Severity of nonalcoholic fatty liver disease is associated with subclinical cerebro-cardiovascular atherosclerosis risk in Korean men.

PubMed

Lee, Jung Eun; Lee, Yong Jae; Chung, Soo Yoon; Cho, Hee Woo; Park, Byoung Jin; Jung, Dong Hyuk

2018-01-01

No studies have reported the relationship between nonalcoholic fatty liver disease (NAFLD) and concurrent cerebral artery and coronary artery atherosclerosis simultaneously. We aimed at determining whether NAFLD, as assessed by ultrasound, is associated with subclinical cerebro-cardio vascular atherosclerosis (CCVA) by multidetector-row computed tomography (MDCT), and high resolution-magnetic resonance angiography (HR-MRA). This cross-sectional study included men in the general Korean population aged 20-70 years. A total of 1,652 men participated in the study (normal, n = 835; mild-to-moderate NAFLD, n = 512; severe NAFLD, n = 305). The risk of subclinical CCVA was positively associated with age (odds ratio [OR] 1.068; 1.054-1.081, p < 0.001), body mass index (OR 1.120; 1.08 0-1.162, p < 0.001), hepatic enzyme levels (OR 1.012; 1.001-1.023, p = 0.027; OR 1.006; 1.001-1.012, p = 0.036), fasting glucose (OR 1.021; 1.015-1.027, p < 0.001), triglycerides (OR 1.002; 1.000-1.003, p = 0.016), hypertension (OR 2.836; 2.268-3.546, p < 0.001), and diabetes (OR 2.911; 2.137-3.964, p < 0.001). Also, high-density lipoprotein cholesterol was inversely associated with subclinical CCVA (OR 0.974; 0.965-0.982, p < 0.001). Compared with normal controls, the OR for subclinical CCVA after full adjustment was 1.46 in the mild-to-moderate NAFLD group (95% confidence interval [CI]: 1.10 to 1.93) and 2.04 in the severe NAFLD group (95% CI: 1.44 to 2.89). Our data show that NAFLD is common among Korean men, and NAFLD severity on ultrasonography is associated with subclinical CCVA, as assessed by MDCT, and HR-MRA.

Comparison of image quality and radiation dose between fixed tube current and combined automatic tube current modulation in craniocervical CT angiography.

PubMed

Lee, E J; Lee, S K; Agid, R; Howard, P; Bae, J M; terBrugge, K

2009-10-01

The combined automatic tube current modulation (ATCM) technique adapts and modulates the x-ray tube current in the x-y-z axis according to the patient's individual anatomy. We compared image quality and radiation dose of the combined ATCM technique with those of a fixed tube current (FTC) technique in craniocervical CT angiography performed with a 64-section multidetector row CT (MDCT) system. A retrospective review of craniocervical CT angiograms (CTAs) by using combined ATCM (n = 25) and FTC techniques (n = 25) was performed. Other CTA parameters, such as kilovolt (peak), matrix size, FOV, section thickness, pitch, contrast agent, and contrast injection techniques, were held constant. We recorded objective image noise in the muscles at 2 anatomic levels: radiation exposure doses (CT dose index volume and dose-length product); and subjective image quality parameters, such as vascular delineation of various arterial vessels, visibility of small arterial detail, image artifacts, and certainty of diagnosis. The Mann-Whitney U test was used for statistical analysis. No significant difference was detected in subjective image quality parameters between the FTC and combined ATCM techniques. Most subjects in both study groups (49/50, 98%) had acceptable subjective artifacts. The objective image noise values at shoulder level did not show a significant difference, but the noise value at the upper neck was higher with the combined ATCM (P < .05) technique. Significant reduction in radiation dose (18% reduction) was noted with the combined ATCM technique (P < .05). The combined ATCM technique for craniocervical CTA performed at 64-section MDCT substantially reduced radiation exposure dose but maintained diagnostic image quality.

Detection and classification of interstitial lung diseases and emphysema using a joint morphological-fuzzy approach

NASA Astrophysics Data System (ADS)

Chang Chien, Kuang-Che; Fetita, Catalin; Brillet, Pierre-Yves; Prêteux, Françoise; Chang, Ruey-Feng

2009-02-01

Multi-detector computed tomography (MDCT) has high accuracy and specificity on volumetrically capturing serial images of the lung. It increases the capability of computerized classification for lung tissue in medical research. This paper proposes a three-dimensional (3D) automated approach based on mathematical morphology and fuzzy logic for quantifying and classifying interstitial lung diseases (ILDs) and emphysema. The proposed methodology is composed of several stages: (1) an image multi-resolution decomposition scheme based on a 3D morphological filter is used to detect and analyze the different density patterns of the lung texture. Then, (2) for each pattern in the multi-resolution decomposition, six features are computed, for which fuzzy membership functions define a probability of association with a pathology class. Finally, (3) for each pathology class, the probabilities are combined up according to the weight assigned to each membership function and two threshold values are used to decide the final class of the pattern. The proposed approach was tested on 10 MDCT cases and the classification accuracy was: emphysema: 95%, fibrosis/honeycombing: 84% and ground glass: 97%.

Radiation exposure in X-ray-based imaging techniques used in osteoporosis

PubMed Central

Adams, Judith E.; Guglielmi, Giuseppe; Link, Thomas M.

2010-01-01

Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks. PMID:20559834

Comparison of biophysical factors influencing on emphysema quantification with low-dose CT

NASA Astrophysics Data System (ADS)

Heo, Chang Yong; Kim, Jong Hyo

2014-03-01

Emphysema Index(EI) measurements in MDCT is known to be influenced by various biophysical factors such as total lung volume, and body size. We investigated the association of the four biophysical factors with emphysema index in low-dose MDCT. In particular, we attempted to identify a potentially stronger biophysical factor than total lung volume. A total of 400 low-dose MDCT volumes taken at 120kVp, 40mAs, 1mm thickness, and B30f reconstruction kernel were used. The lungs, airways, and pulmonary vessels were automatically segmented, and two Emphysema Indices, relative area below -950HU(RA950) and 15th percentile(Perc15), were extracted from the segmented lungs. The biophysical factors such as total lung volume(TLV), mode of lung attenuation(ModLA), effective body diameter(EBD), and the water equivalent body diameter(WBD) were estimated from the segmented lung and body area. The association of biophysical factors with emphysema indices were evaluated by correlation coefficients. The mean emphysema indices were 8.3±5.5(%) in RA950, and -930±18(HU) in Perc15. The estimates of biophysical factors were 4.7±1.0(L) in TLV, -901±21(HU) in ModLA, 26.9±2.2(cm) in EBD, and 25.9±2.6(cm) in WBD. The correlation coefficients of biophysical factors with RA950 were 0.73 in TLV, 0.94 in ModLA, 0.31 in EBD, and 0.18 WBD, the ones with Perc15 were 0.74 in TLV, 0.98 in ModLA, 0.29 in EBD, and 0.15 WBD. Study results revealed that two biophysical factors, TLV and ModLA, mostly affects the emphysema indices. In particular, the ModLA exhibited strongest correlation of 0.98 with Perc15, which indicating the ModLA is the most significant confounding biophysical factor in emphysema indices measurement.

Combined presence of aortic valve calcification and mitral annular calcification as a marker of the extent and vulnerable characteristics of coronary artery plaque assessed by 64-multidetector computed tomography.

PubMed

Utsunomiya, Hiroto; Yamamoto, Hideya; Kunita, Eiji; Kitagawa, Toshiro; Ohashi, Norihiko; Oka, Toshiharu; Yamazato, Ryo; Horiguchi, Jun; Kihara, Yasuki

2010-11-01

We examined the association of aortic valve calcification (AVC) and mitral annular calcification (MAC) to coronary atherosclerosis using 64-multidetector computed tomography (MDCT). Valvular calcification is considered a manifestation of atherosclerosis. The impact of multiple heart valve calcium deposits on the distribution and characteristics of coronary plaque is unknown. We evaluated 322 patients referred for 64-MDCT, and assessed valvular calcification and the extent of calcified (CAP), mixed (MCAP), and noncalcified coronary atherosclerotic plaque (NCAP) in accordance with the 17-coronary segments model. We assessed the vulnerable characteristics of coronary plaque with positive remodeling, low-density plaque (CT density ≤38 Hounsfield units), and the presence of adjacent spotty calcification. In 49 patients with both AVC and MAC, the segment numbers of CAP and MCAP were larger than in those with a lack of valvular calcification and an isolated AVC (p<0.001 for both). Multivariate analyses revealed that a combined presence of AVC and MAC was independently associated with the presence (odds ratio [OR] 9.36, 95% confidence interval [95%CI] 1.55-56.53, p=0.015) and extent (β-estimate 1.86, p<0.001) of overall coronary plaque. When stratified by plaque composition, it was associated with the extent of CAP (β-estimate 1.77, p<0.001) and MCAP (β-estimate 1.04, p<0.001), but not with NCAP. Moreover, it was also related to the presence of coronary plaque with all three vulnerable characteristics (OR 4.87, 95%CI 1.85-12.83, p=0.001). The combined presence of AVC and MAC is highly associated with the presence, extent, and vulnerable characteristics of coronary plaque identified by 64-MDCT. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Abdominal CT with model-based iterative reconstruction (MBIR): initial results of a prospective trial comparing ultralow-dose with standard-dose imaging.

PubMed

Pickhardt, Perry J; Lubner, Meghan G; Kim, David H; Tang, Jie; Ruma, Julie A; del Rio, Alejandro Muñoz; Chen, Guang-Hong

2012-12-01

The purpose of this study was to report preliminary results of an ongoing prospective trial of ultralow-dose abdominal MDCT. Imaging with standard-dose contrast-enhanced (n = 21) and unenhanced (n = 24) clinical abdominal MDCT protocols was immediately followed by ultralow-dose imaging of a matched series of 45 consecutively registered adults (mean age, 57.9 years; mean body mass index, 28.5). The ultralow-dose images were reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR). Standard-dose series were reconstructed with FBP (reference standard). Image noise was measured at multiple predefined sites. Two blinded abdominal radiologists interpreted randomly presented ultralow-dose images for multilevel subjective image quality (5-point scale) and depiction of organ-based focal lesions. Mean dose reduction relative to the standard series was 74% (median, 78%; range, 57-88%; mean effective dose, 1.90 mSv). Mean multiorgan image noise for low-dose MBIR was 14.7 ± 2.6 HU, significantly lower than standard-dose FBP (28.9 ± 9.9 HU), low-dose FBP (59.2 ± 23.3 HU), and ASIR (45.6 ± 14.1 HU) (p < 0.001). The mean subjective image quality score for low-dose MBIR (3.0 ± 0.5) was significantly higher than for low-dose FBP (1.6 ± 0.7) and ASIR (1.8 ± 0.7) (p < 0.001). Readers identified 213 focal noncalcific lesions with standard-dose FBP. Pooled lesion detection was higher for low-dose MBIR (79.3% [169/213]) compared with low-dose FBP (66.2% [141/213]) and ASIR (62.0% [132/213]) (p < 0.05). MBIR shows great potential for substantially reducing radiation doses at routine abdominal CT. Both FBP and ASIR are limited in this regard owing to reduced image quality and diagnostic capability. Further investigation is needed to determine the optimal dose level for MBIR that maintains adequate diagnostic performance. In general, objective and subjective image quality measurements do not necessarily correlate with diagnostic performance at ultralow-dose CT.

Ten-Year Follow-Up of Endovascular Aneurysm Treatment with Talent Stent-Grafts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pitton, Michael B., E-mail: pitton@radiologie.klinik.uni-mainz.de; Scheschkowski, Tobias; Ring, Markus

2009-09-15

The purpose of this study was to evaluate the clinical results, complications, and secondary interventions during long-term follow-up after endovascular aneurysm repair (EVAR) and to investigate the impact of endoleak sizes on aneurysm shrinkage. From 1997 to March 2007, 127 patients (12 female, 115 male; age, 73.0 {+-} 7.2 years) with abdominal aortic aneurysms were treated with Talent stent-grafts. Follow-up included clinical visits, contrast-enhanced MDCT, and radiographs at 3, 6, and 12 months and then annually. Results were analyzed with respect to clinical outcome, secondary interventions, endoleak rate and management, and change in aneurysm size. There was no need formore » primary conversion surgery. Thirty-day mortality was 1.6% (two myocardial infarctions). Procedure-related morbidity was 2.4% (paraplegia, partial infarction of one kidney, and inguinal bleeding requiring surgery). Mean follow-up was 47.7 {+-} 34.2 months (range, 0-123 months). Thirty-nine patients died during follow-up; three of the deaths were related to aneurysm (aneurysm rupture due to endoleak, n = 1; secondary surgical reintervention n = 2). During follow-up, a total of 29 secondary procedures were performed in 19 patients, including 14 percutaneous procedures (10 patients) and 15 surgical procedures (12 patients), including 4 cases with late conversion to open aortic repair (stent-graft infection, n = 1; migration, endoleak, or endotension, n = 3). Overall mean survival was 84.5 {+-} 4.7 months. Mean survival and freedom from any event was 66.7 {+-} 4.5 months. MRI depicted significantly more endoleaks compared to MDCT (23.5% vs. 14.3%; P < 0.01). Patients in whom all aneurysm side branches were occluded prior to stent-grafting showed a significantly reduced incidence of large endoleaks. Endoleaks >10% of the aneurysm area were associated with reduced aneurysm shrinkage compared to no endoleaks or <10% endoleaks ({Delta} at 3 years, -1.8% vs. -12.0%; P < 0.05). In conclusion, endovascular aneurysm treatment with Talent stent-grafts demonstrated encouraging long-term results with moderate secondary intervention rates. Primary occlusion of all aortic side branches reduced the incidence of large endoleaks. Large endoleaks significantly impaired aneurysm shrinkage, whereas small endoleaks did not.« less

MDCT detection of anomalous origins of the left main coronary artery: report of 2 cases.

PubMed

Matsumoto, Naoya; Sato, Yuichi; Kunimasa, Taeko; Yoda, Shunichi; Yokoyama, Shinichiro; Takayama, Tadateru; Komatsu, Sei; Achenbach, Stephan; Saito, Satoshi; Hirayama, Atsushi

2008-11-28

The left main coronary artery (LMCA) arising either from the right sinus of Valsalva, separately from the right coronary artery (RCA), or from the RCA as a single coronary artery is an extremely rare coronary artery anomaly. We report 2 cases of anomalous origins of the LMCA detected by multidetector-row computed tomography.

Bailout intravenous esmolol for heart rate control in cardiac computed tomography angiography.

PubMed

Aguiar Rosa, Sílvia; Ramos, Ruben; Marques, Hugo; Santos, Rosana; Leal, Cecília; Casado, Helena; Saraiva, Márcia; Figueiredo, Luísa; Cruz Ferreira, Rui

2016-12-01

To evaluate the efficacy and safety of a heart rate (HR) reduction protocol using intravenous esmolol as bailout for failed oral metoprolol regimens in patients undergoing coronary computed tomography angiography (CCTA) with 64-slice multidetector computed tomography (64-MDCT). Patients who underwent cardiac 64-MDCT in a single institution between 2011 and 2014 were analyzed. Those with HR above 60 beats per minute (bpm) on presentation received oral metoprolol (50-200 mg) at least one hour before CCTA. Intravenous esmolol 1-2 mg/kg was administered as a bolus whenever HR remained over 65 bpm just before imaging. The primary efficacy endpoint was HR <65 bpm during CCTA. The primary safety endpoint was symptomatic hypotension or bradycardia up to hospital discharge. During the study period CCTA was performed in 947 cases. In 86% of these, oral metoprolol was the only medication required to successfully reduce HR <60 bpm. Esmolol was used in the remaining 130 patients (14%). For esmolol-treated patients mean baseline and acquisition HR were 74±14 bpm and 63±9 bpm, respectively (p<0.001). The target HR of <65 bpm was achieved in 82 of the 130 esmolol-treated patients (63%). Considering the whole population, esmolol use led to a significant increase in the primary efficacy endpoint from 86% to 95% (p<0.001). Esmolol also resulted in a statistically, but not clinically, significant reduction in systolic blood pressure (144±22 to 115±17 mmHg; p<0.001). The combined primary safety endpoint was only observed in two (1.5%) patients. Despite optimal use of oral beta-blockers, 14% of patients needed intravenous esmolol for HR control. The pre-medication combination of oral metoprolol and on-demand administration of intravenous esmolol was safe and effective and enabled 95% of patients to be imaged with HR below 65 bpm. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Inter- and intrascanner variability of pulmonary nodule volumetry on low-dose 64-row CT: an anthropomorphic phantom study

PubMed Central

Xie, X; Willemink, M J; Zhao, Y; de Jong, P A; van Ooijen, P M A; Oudkerk, M; Greuter, M J W

2013-01-01

Objective: To assess inter- and intrascanner variability in volumetry of solid pulmonary nodules in an anthropomorphic thoracic phantom using low-dose CT. Methods: Five spherical solid artificial nodules [diameters 3, 5, 8, 10 and 12 mm; CT density +100 Hounsfield units (HU)] were randomly placed inside an anthropomorphic thoracic phantom in different combinations. The phantom was examined on two 64-row multidetector CT (64-MDCT) systems (CT-A and CT-B) from different vendors with a low-dose protocol. Each CT examination was performed three times. The CT examinations were evaluated twice by independent blinded observers. Nodule volume was semi-automatically measured by dedicated software. Interscanner variability was evaluated by Bland–Altman analysis and expressed as 95% confidence interval (CI) of relative differences. Intrascanner variability was expressed as 95% CI of relative variation from the mean. Results: No significant difference in CT-derived volume was found between CT-A and CT-B, except for the 3-mm nodules (p<0.05). The 95% CI of interscanner variability was within ±41.6%, ±18.2% and ±4.9% for 3, 5 and ≥8 mm nodules, respectively. The 95% CI of intrascanner variability was within ±28.6%, ±13.4% and ±2.6% for 3, 5 and ≥8 mm nodules, respectively. Conclusion: Different 64-MDCT scanners in low-dose settings yield good agreement in volumetry of artificial pulmonary nodules between 5 mm and 12 mm in diameter. Inter- and intrascanner variability decreases at a larger nodule size to a maximum of 4.9% for ≥8 mm nodules. Advances in knowledge: The commonly accepted cut-off of 25% to determine nodule growth has the potential to be reduced for ≥8 mm nodules. This offers the possibility of reducing the interval for repeated CT scans in lung cancer screenings. PMID:23884758

Correlation Between Findings of Multislice Helical Computed Tomography (CT), Endoscopic Examinations, Endovascular Procedures, and Surgery in Patients with Symptoms of Acute Gastrointestinal Bleeding.

PubMed

Konecki, Dariusz; Grabowska-Derlatka, Laretta; Pacho, Ryszard; Rowiński, Olgierd

2017-01-01

Endoscopic methods (gastroscopy and colonoscopy) are considered fundamental for the diagnosis of gastrointestinal bleeding. In recent years, multidetector computed tomography (MDCT) has also gained importance in diagnosing gastrointestinal bleeding, particularly in hemodynamically unstable patients and in cases with suspected lower gastrointestinal tract bleeding. CT can detect both the source and the cause of active gastrointestinal bleeding, thereby expediting treatment initiation. The study group consisted of 16 patients with clinical symptoms of gastrointestinal bleeding in whom features of active bleeding were observed on CT. In all patients, bleeding was verified by means of other methods such as endoscopic examinations, endovascular procedures, or surgery. The bleeding source was identified on CT in all 16 patients. In 14 cases (87.5%), bleeding was confirmed by other methods. CT is an efficient, fast, and readily available tool for detecting the location of acute gastrointestinal bleeding.

The complex nature of discordant severe calcified aortic valve disease grading: new insights from combined Doppler echocardiographic and computed tomographic study.

PubMed

Clavel, Marie-Annick; Messika-Zeitoun, David; Pibarot, Philippe; Aggarwal, Shivani R; Malouf, Joseph; Araoz, Phillip A; Michelena, Hector I; Cueff, Caroline; Larose, Eric; Capoulade, Romain; Vahanian, Alec; Enriquez-Sarano, Maurice

2013-12-17

With concomitant Doppler echocardiography and multidetector computed tomography (MDCT) measuring aortic valve calcification (AVC) load, this study aimed at defining: 1) independent physiologic/structural determinants of aortic valve area (AVA)/mean gradient (MG) relationship; 2) AVC thresholds best associated with severe aortic stenosis (AS); and 3) whether, in AS with discordant MG, severe calcified aortic valve disease is generally detected. Aortic stenosis with discordant markers of severity, AVA in severe range but low MG, is a conundrum, unresolved by outcome studies. Patients (n = 646) with normal left ventricular ejection fraction AS underwent Doppler echocardiography and AVC measurement by MDCT. On the basis of AVA-indexed-to-body surface area (AVAi) and MG, patients were categorized as concordant severity grading (CG) with moderate AS (AVAi >0.6 cm²/m², MG <40 mm Hg), severe AS (AVAi ≤0.6 cm²/m², MG ≥ 40 mm Hg), discordant-severity-grading (DG) with low-MG (AVAi ≤0.6 cm(2)/m(2), MG <40 mm Hg), or high-MG (AVAi >0.6 cm(2)/m(2), MG ≥40 mm Hg). The MG (discordant in 29%) was strongly determined by AVA and flow but also independently and strongly influenced by AVC-load (p < 0.0001) and systemic arterial compliance (p < 0.0001). The AVC-load (median [interquartile range]) was similar within patients with DG (low-MG: 1,619 [965 to 2,528] arbitrary units [AU]; high-MG: 1,736 [1,209 to 2,894] AU; p = 0.49), higher than CG-moderate-AS (861 [427 to 1,519] AU; p < 0.0001) but lower than CG-severe-AS (2,931 [1,924 to 4,292] AU; p < 0.0001). The AVC-load thresholds separating severe/moderate AS were defined in CG-AS with normal flow (stroke-volume-index >35 ml/m(2)). The AVC-load, absolute or indexed, identified severe AS accurately (area under the curve ≥0.89, sensitivity ≥86%, specificity ≥79%) in men and women. Upon application of these criteria to DG-low MG, at least one-half of the patients were identified as severe calcified aortic valve disease, irrespective of flow. Among patients with AS, MG is often discordant from AVA and is determined by multiple factors, valvular (AVC) and non-valvular (arterial compliance) independently of flow. The AVC-load by MDCT, strongly associated with AS severity, allows diagnosis of severe calcified aortic valve disease. At least one-half of the patients with discordant low gradient present with heavy AVC-load reflective of severe calcified aortic valve disease, emphasizing the clinical yield of AVC quantification by MDCT to diagnose and manage these complex patients. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Evaluation of the Elekta Symmetry ™ 4D IGRT system by using a moving lung phantom

NASA Astrophysics Data System (ADS)

Shin, Hun-Joo; Kim, Shin-Wook; Kay, Chul Seung; Seo, Jae-Hyuk; Lee, Gi-Woong; Kang, Ki-Mun; Jang, Hong Seok; Kang, Young-nam

2015-07-01

Purpose: 4D cone-beam computed tomography (CBCT) is a beneficial tool for the treatment of movable tumors because it can help us to understand where the tumors are actually located and it has a precise treatment plan. However, general CBCT images have a limitation in that they cannot perfectly perform a sophisticated registration. On the other hand, the Symmetry TM 4D image-guided radiation therapy (IGRT) system of Elekta offers a 4D CBCT registration option. In this study, we evaluated the usefulness of Symmetry TM . Method and Materials: Planning CT images of the CIRS moving lung phantom were acquired 4D multi-detector CT (MDCT), and the images were sorted as 10 phases from 0% phase to 90% phase. The thickness of the CT images was 1 mm. Acquired MDCT images were transferred to the contouring software, and a virtual target was generated. A one-arc volumetric-modulated arc therapy (VMAT) plan was performed by using the treatment planning system on the virtual target. Finally, the movement of the phantom was verified by using the XVI Symmetry TM system. Results: The physical movement of the CIRS moving lung phantom was ±10.0 mm in the superiorinferior direction, ±1.0 mm in the lateral direction, and ±2.5 mm in the anterior-posterior direction. The movement of the phantom was measured from the 4D MDCT registration as ±10.2 mm in the superior-inferior direction, ±0.9 mm in the lateral direction, and ±2.45 mm in the anterior-posterior direction. The movement of the phantom was measured from the SymmetryTM registration as ±10.1 mm in the superior-inferior direction, ±0.9 mm in the lateral direction, and ±2.4 mm in the anterior-posterior direction. Conclusion: We confirmed that 4D CBCT is a beneficial tool for the treatment of movable tumors, and that the 4D registration of SymmetryTM can increase the precision of the registration when a movable tumor is the target of radiation treatment.

Estimating radiation dose to organs of patients undergoing conventional and novel multidetector CT exams using Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Angel, Erin

Advances in Computed Tomography (CT) technology have led to an increase in the modality's diagnostic capabilities and therefore its utilization, which has in turn led to an increase in radiation exposure to the patient population. As a result, CT imaging currently constitutes approximately half of the collective exposure to ionizing radiation from medical procedures. In order to understand the radiation risk, it is necessary to estimate the radiation doses absorbed by patients undergoing CT imaging. The most widely accepted risk models are based on radiosensitive organ dose as opposed to whole body dose. In this research, radiosensitive organ dose was estimated using Monte Carlo based simulations incorporating detailed multidetector CT (MDCT) scanner models, specific scan protocols, and using patient models based on accurate patient anatomy and representing a range of patient sizes. Organ dose estimates were estimated for clinical MDCT exam protocols which pose a specific concern for radiosensitive organs or regions. These dose estimates include estimation of fetal dose for pregnant patients undergoing abdomen pelvis CT exams or undergoing exams to diagnose pulmonary embolism and venous thromboembolism. Breast and lung dose were estimated for patients undergoing coronary CTA imaging, conventional fixed tube current chest CT, and conventional tube current modulated (TCM) chest CT exams. The correlation of organ dose with patient size was quantified for pregnant patients undergoing abdomen/pelvis exams and for all breast and lung dose estimates presented. Novel dose reduction techniques were developed that incorporate organ location and are specifically designed to reduce close to radiosensitive organs during CT acquisition. A generalizable model was created for simulating conventional and novel attenuation-based TCM algorithms which can be used in simulations estimating organ dose for any patient model. The generalizable model is a significant contribution of this work as it lays the foundation for the future of simulating TCM using Monte Carlo methods. As a result of this research organ dose can be estimated for individual patients undergoing specific conventional MDCT exams. This research also brings understanding to conventional and novel close reduction techniques in CT and their effect on organ dose.

Systems for Lung Volume Standardization during Static and Dynamic MDCT-based Quantitative Assessment of Pulmonary Structure and Function

PubMed Central

Fuld, Matthew K.; Grout, Randall; Guo, Junfeng; Morgan, John H.; Hoffman, Eric A.

2013-01-01

Rationale and Objectives Multidetector-row Computed Tomography (MDCT) has emerged as a tool for quantitative assessment of parenchymal destruction, air trapping (density metrics) and airway remodeling (metrics relating airway wall and lumen geometry) in chronic obstructive pulmonary disease (COPD) and asthma. Critical to the accuracy and interpretability of these MDCT-derived metrics is the assurance that the lungs are scanned during a breath-hold at a standardized volume. Materials and Methods A computer monitored turbine-based flow meter system was developed to control patient breath-holds and facilitate static imaging at fixed percentages of the vital capacity. Due to calibration challenges with gas density changes during multi-breath xenon-CT an alternative system was required. The design incorporated dual rolling seal pistons. Both systems were tested in a laboratory environment and human subject trials. Results The turbine-based system successfully controlled lung volumes in 32/37 subjects, having a linear relationship for CT measured air volume between repeated scans: for all scans, the mean and confidence interval of the differences (scan1-scan2) was −9 ml (−169, 151); for TLC alone 6 ml (−164, 177); for FRC alone, −23 ml (−172, 126). The dual-piston system successfully controlled lung volume in 31/41 subjects. Study failures related largely to subject non-compliance with verbal instruction and gas leaks around the mouthpiece. Conclusion We demonstrate the successful use of a turbine-based system for static lung volume control and demonstrate its inadequacies for dynamic xenon-CT studies. Implementation of a dual-rolling seal spirometer has been shown to adequately control lung volume for multi-breath wash-in xenon-CT studies. These systems coupled with proper patient coaching provide the tools for the use of CT to quantitate regional lung structure and function. The wash-in xenon-CT method for assessing regional lung function, while not necessarily practical for routine clinical studies, provides for a dynamic protocol against which newly emerging single breath, dual-energy xenon-CT measures can be validated. PMID:22555001

Systems for lung volume standardization during static and dynamic MDCT-based quantitative assessment of pulmonary structure and function.

PubMed

Fuld, Matthew K; Grout, Randall W; Guo, Junfeng; Morgan, John H; Hoffman, Eric A

2012-08-01

Multidetector-row computed tomography (MDCT) has emerged as a tool for quantitative assessment of parenchymal destruction, air trapping (density metrics), and airway remodeling (metrics relating airway wall and lumen geometry) in chronic obstructive pulmonary disease (COPD) and asthma. Critical to the accuracy and interpretability of these MDCT-derived metrics is the assurance that the lungs are scanned during a breathhold at a standardized volume. A computer monitored turbine-based flow meter system was developed to control patient breathholds and facilitate static imaging at fixed percentages of the vital capacity. Because of calibration challenges with gas density changes during multibreath xenon CT, an alternative system was required. The design incorporated dual rolling seal pistons. Both systems were tested in a laboratory environment and human subject trials. The turbine-based system successfully controlled lung volumes in 32/37 subjects, having a linear relationship for CT measured air volume between repeated scans: for all scans, the mean and confidence interval of the differences (scan1-scan2) was -9 mL (-169, 151); for total lung capacity alone 6 mL (-164, 177); for functional residual capacity alone, -23 mL (-172, 126). The dual-piston system successfully controlled lung volume in 31/41 subjects. Study failures related largely to subject noncompliance with verbal instruction and gas leaks around the mouthpiece. We demonstrate the successful use of a turbine-based system for static lung volume control and demonstrate its inadequacies for dynamic xenon CT studies. Implementation of a dual-rolling seal spirometer has been shown to adequately control lung volume for multibreath wash-in xenon CT studies. These systems coupled with proper patient coaching provide the tools for the use of CT to quantitate regional lung structure and function. The wash-in xenon CT method for assessing regional lung function, although not necessarily practical for routine clinical studies, provides for a dynamic protocol against which newly emerging single breath, dual-energy xenon CT measures can be validated. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT.

PubMed

Gay, F; Pavia, Y; Pierrat, N; Lasalle, S; Neuenschwander, S; Brisse, H J

2014-01-01

To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. • Iterative reconstruction helps lower radiation exposure levels in children undergoing CT. • Adaptive statistical iterative reconstruction (ASIR) significantly increases SNR without impairing spatial resolution. • For abdomen and chest CT, ASIR allows at least a 30 % dose reduction.

The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms

NASA Astrophysics Data System (ADS)

Brisse, H. J.; Brenot, J.; Pierrat, N.; Gaboriaud, G.; Savignoni, A.; DeRycke, Y.; Neuenschwander, S.; Aubert, B.; Rosenwald, J.-C.

2009-04-01

This study assessed and compared various image quality indices in order to manage the dose of pediatric abdominal MDCT protocols and to provide guidance on dose reduction. PMMA phantoms representing average body diameters at birth, 1 year, 5 years, 10 years and 15 years of age were scanned in a four-channel MDCT with a standard pediatric abdominal CT protocol. Image noise (SD, standard deviation of CT number), noise derivative (ND, derivative of the function of noise with respect to dose) and contrast-to-noise ratio (CNR) were measured. The 'relative' low-contrast detectability (rLCD) was introduced as a new quantity to adjust LCD to the various phantom diameters on the basis of the LCD1% assessed in a Catphan® phantom and a constant central absorbed dose. The required variations of CTDIvol16 with respect to phantom size were analyzed in order to maintain each image quality index constant. The use of a fixed SD or CNR level leads to major dose ratios between extreme patient sizes (factor 22.7 to 44 for SD, 31.7 to 51.5 for CNR2.8%), whereas fixed ND and rLCD result in acceptable dose ratios ranging between factors of 2.9 and 3.9 between extreme phantom diameters. For a 5-9 mm rLCD1%, adjusted ND values range between -0.84 and -0.11 HU mGy-1. Our data provide guidance on dose reduction on the basis of patient dimensions and the required rLCD (e.g., to get a constant 7 mm rLCD1% for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol16 values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

Diagnostic accuracy of 256-row multidetector CT coronary angiography with prospective ECG-gating combined with fourth-generation iterative reconstruction algorithm in the assessment of coronary artery bypass: evaluation of dose reduction and image quality.

PubMed

Ippolito, Davide; Fior, Davide; Franzesi, Cammillo Talei; Riva, Luca; Casiraghi, Alessandra; Sironi, Sandro

2017-12-01

Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose. To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol. Seventy-four non-obese patients with known coronary disease treated with artery bypass grafting were prospectively enrolled. All the patients underwent 256 MDCT (Brilliance iCT, Philips) CTCA using low-dose protocol (100 kV; 800 mAs; rotation time: 0.275 s) combined with prospective ECG-triggering acquisition and fourth-generation IR technique (iDose 4 ; Philips); all the lengths of the bypass graft were included in the evaluation. A control group of 42 similar patients was evaluated with a standard retrospective ECG-gated CTCA (100 kV; 800 mAs).On both CT examinations, ROIs were placed to calculate standard deviation of pixel values and intra-vessel density. Diagnostic quality was also evaluated using a 4-point quality scale. Despite the statistically significant reduction of radiation dose evaluated with DLP (study group mean DLP: 274 mGy cm; control group mean DLP: 1224 mGy cm; P value < 0.001). No statistical differences were found between PGA group and RGH group regarding intra-vessel density absolute values and SNR. Qualitative analysis, evaluated by two radiologists in "double blind", did not reveal any significant difference in diagnostic quality of the two groups. The development of high-speed MDCT scans combined with modern IR allows an accurate evaluation of CABG with prospective ECG-gating protocols in a single breath hold, obtaining a significant reduction in radiation dose.

SU-F-207-01: Comparison of Beam Characteristics and Organ Dose From Four Commercial Multidetector Computed Tomography Scanners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohno, T; Araki, F

2015-06-15

Purpose: To compare dosimetric properties and patient organ doses from four commercial multidetector CT (MDCT) using Monte Carlo (MC) simulation based on the absorbed dose measured using a Farmer chamber and cylindrical water phantoms according to AAPM TG-111. Methods: Four commercial MDCT were modeled using the GMctdospp (IMPS, Germany) based on the EGSnrc user code. The incident photon spectrum and bowtie filter for MC simulations were determined so that calculated values of aluminum half-value layer (Al-HVL) and off-center ratio (OCR) profile in air agreed with measured values. The MC dose was calibrated from absorbed dose measurements using a Farmer chambermore » and cylindrical water phantoms. The dose distributions of head, chest, and abdominal scan were calculated using patient CT images and mean organ doses were evaluated from dose volume histograms. Results: The HVLs at 120 kVp of Brilliance, LightSpeed, Aquilion, and SOMATOM were 9.1, 7.5, 7.2, and 8.7 mm, respectively. The calculated Al-HVLs agreed with measurements within 0.3%. The calculated and measured OCR profiles agreed within 5%. For adult head scans, mean doses for eye lens from Brilliance, LightSpeed, Aquilion, and SOMATOM were 21.7, 38.5, 47.2 and 28.4 mGy, respectively. For chest scans, mean doses for lung from Brilliance, LightSpeed, Aquilion, and SOMATOM were 21.1, 26.1, 35.3 and 24.0 mGy, respectively. For adult abdominal scans, the mean doses for liver from Brilliance, LightSpeed, Aquilion, and SOMATOM were 16.5, 21.3, 22.7, and 18.0 mGy, respectively. The absorbed doses increased with decreasing Al-HVL. The organ doses from Aquilion were two greater than those from Brilliance in head scan. Conclusion: MC dose distributions based on absorbed dose measurement in cylindrical water phantom are useful to evaluate individual patient organ doses.« less

Systolic hypertension and progression of aortic valve calcification in patients with aortic stenosis: results from the PROGRESSA study.

PubMed

Tastet, Lionel; Capoulade, Romain; Clavel, Marie-Annick; Larose, Éric; Shen, Mylène; Dahou, Abdellaziz; Arsenault, Marie; Mathieu, Patrick; Bédard, Élisabeth; Dumesnil, Jean G; Tremblay, Alexe; Bossé, Yohan; Després, Jean-Pierre; Pibarot, Philippe

2017-01-01

Hypertension is highly prevalent in patients with aortic stenosis (AS) and is associated with worse outcomes. The current prospective study assessed the impact of systolic hypertension (SHPT) on the progression of aortic valve calcification (AVC) measured by multidetector computed tomography (MDCT) in patients with AS. The present analysis includes the first series of 101 patients with AS prospectively recruited in the PROGRESSA study. Patients underwent comprehensive Doppler echocardiography and MDCT exams at baseline and after 2-year follow-up. AVC and coronary artery calcification (CAC) were measured using the Agatston method. Patients with SHPT at baseline (i.e. systolic blood pressure ≥140 mmHg; n = 37, 37%) had faster 2-year AVC progression compared with those without SHPT (i.e. systolic blood pressure <140 mmHg) (AVC median [25th percentile-75th percentile]: +370 [126-824] vs. +157 [58-303] AU; P = 0.007, respectively). Similar results were obtained with the analysis of AVC progression divided by the cross-sectional area of the aortic annulus (AVC density : +96 [34-218] vs. +45 [14-82] AU/cm 2 , P = 0.01, respectively). In multivariable analysis, SHPT remained significantly associated with faster progression of AVC or AVC density (all P = 0.001). There was no significant difference between groups with respect to progression of CAC (+39 [3-199] vs. +41 [0-156] AU, P = 0.88). This prospective study shows for the first time that SHPT is associated with faster AVC progression but not with CAC progression in AS patients. These findings provide further support for the elaboration of randomized clinical trials to assess the efficacy of antihypertensive medication to slow the stenosis progression in patients with AS. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Diagnostic accuracy and image quality of cardiac dual-source computed tomography in patients with arrhythmia.

PubMed

Tsiflikas, Ilias; Drosch, Tanja; Brodoefel, Harald; Thomas, Christoph; Reimann, Anja; Till, Alexander; Nittka, Daniel; Kopp, Andreas F; Schroeder, Stephen; Heuschmid, Martin; Burgstahler, Christof

2010-08-06

Cardiac multi-detector computed tomography (MDCT) permits accurate visualization of high-grade coronary artery stenosis. However, in patients with heart rate irregularities, MDCT was found to have limitations. Thus, the aim of the present study was to evaluate the diagnostic accuracy of a new dual-source computed tomography (DSCT) scanner generation with 83 ms temporal resolution in patients without stable sinus rhythm. 44 patients (31 men, mean age 67.5+/-9.2 years) without stable sinus rhythm and scheduled for invasive coronary angiography (ICA) because of suspected (n=17) or known coronary artery disease (CAD, n=27) were included in this study. All patients were examined with DSCT (Somatom Definition, Siemens). Besides assessment of total calcium score, all coronary segments were analyzed with regard to the presence of significant coronary artery lesions (>50%). The findings were compared to ICA in a blinded fashion. During CT examination, heart rhythm was as follows: 25 patients (57%) atrial fibrillation, 7 patients (16%) ventricular extrasystoles (two of them with atrial fibrillation), 4 patients (9%) supraventricular extrasystoles, 10 patients (23%) sinus arrhythmia (heart rate variability>10 bpm). Mean heart rate was 69+/-14 bpm, median 65 bpm. Mean Agatston score equivalent (ASE) was 762, ranging from 0 to 4949.7 ASE. Prevalence of CAD was 68% (30/44). 155 segments (27%) showed "step-ladder" artifacts and 28 segments (5%) could not be visualized by DSCT. Only 70 segments (12%) were completely imaged without any artifacts. Based on a coronary segment model, sensitivity was 73%, specificity 91%, positive predictive value 63%, and negative predictive value 94% for the detection of significant lesions (>or=50% diameter stenosis). Overall accuracy was 88%. In patients with heart rate irregularities, including patients with atrial fibrillation and a high prevalence of coronary artery disease, the diagnostic yield of dual-source computed tomography is still hampered due to a high number of segments with "step-ladder" artifacts. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Automated lobar quantification of emphysema in patients with severe COPD.

PubMed

Revel, Marie-Pierre; Faivre, Jean-Baptiste; Remy-Jardin, Martine; Deken, Valérie; Duhamel, Alain; Marquette, Charles-Hugo; Tacelli, Nunzia; Bakai, Anne-Marie; Remy, Jacques

2008-12-01

Automated lobar quantification of emphysema has not yet been evaluated. Unenhanced 64-slice MDCT was performed in 47 patients evaluated before bronchoscopic lung-volume reduction. CT images reconstructed with a standard (B20) and high-frequency (B50) kernel were analyzed using a dedicated prototype software (MevisPULMO) allowing lobar quantification of emphysema extent. Lobar quantification was obtained following (a) a fully automatic delineation of the lobar limits by the software and (b) a semiautomatic delineation with manual correction of the lobar limits when necessary and was compared with the visual scoring of emphysema severity per lobe. No statistically significant difference existed between automated and semiautomated lobar quantification (p > 0.05 in the five lobes), with differences ranging from 0.4 to 3.9%. The agreement between the two methods (intraclass correlation coefficient, ICC) was excellent for left upper lobe (ICC = 0.94), left lower lobe (ICC = 0.98), and right lower lobe (ICC = 0.80). The agreement was good for right upper lobe (ICC = 0.68) and moderate for middle lobe (IC = 0.53). The Bland and Altman plots confirmed these results. A good agreement was observed between the software and visually assessed lobar predominance of emphysema (kappa 0.78; 95% CI 0.64-0.92). Automated and semiautomated lobar quantifications of emphysema are concordant and show good agreement with visual scoring.

Statistical Characterization of MP3 Encoders for Steganalysis: ’CHAMP3’

DTIC Science & Technology

2004-04-27

compression exceeds those of typical stegano- graphic tools (e. g., LSB image embedding), the availability of commented source codes for MP3 encoders...developed by testing the approach on known and unknown reference data. 15. SUBJECT TERMS EOARD, Steganography , Digital Watermarking...Pages kbps Kilobits per Second LGPL Lesser General Public License LSB Least Significant Bit MB Megabyte MDCT Modified Discrete Cosine Transformation MP3

Ectopic Multinodular Goiter: Multidetector Computed Tomography Findings

PubMed Central

Karakaya, Afak Durur; Kantarci, Mecit; Yalcin, Ahmet; Demir, Berrin

2008-01-01

The thyroid is the first endocrine gland to form during embryogenesis. At this stage, incomplete or anomalous migration of thyroid tissue causes ectopic localization of the gland. In our case, a 55-year-old woman who was evaluated via ultrasonography (USG) and multi-detector computed tomography (MDCT) had no thyroid gland at the normal location, but did have ectopic thyroid tissue in the left submandibular and submental regions. PMID:25610021

Comparison of Intraoperative Portable CT Scanners in Skull Base and Endoscopic Sinus Surgery: Single Center Case Series

PubMed Central

Conley, David B.; Tan, Bruce; Bendok, Bernard R.; Batjer, H. Hunt; Chandra, Rakesh; Sidle, Douglas; Rahme, Rudy J.; Adel, Joseph G.; Fishman, Andrew J.

2011-01-01

Precise and safe management of complex skull base lesions can be enhanced by intraoperative computed tomography (CT) scanning. Surgery in these areas requires real-time feedback of anatomic landmarks. Several portable CT scanners are currently available. We present a comparison of our clinical experience with three portable scanners in skull base and craniofacial surgery. We present clinical case series and the participants were from the Northwestern Memorial Hospital. Three scanners are studied: one conventional multidetector CT (MDCT), two digital flat panel cone-beam CT (CBCT) devices. Technical considerations, ease of use, image characteristics, and integration with image guidance are presented for each device. All three scanners provide good quality images. Intraoperative scanning can be used to update the image guidance system in real time. The conventional MDCT is unique in its ability to resolve soft tissue. The flat panel CBCT scanners generally emit lower levels of radiation and have less metal artifact effect. In this series, intraoperative CT scanning was technically feasible and deemed useful in surgical decision-making in 75% of patients. Intraoperative portable CT scanning has significant utility in complex skull base surgery. This technology informs the surgeon of the precise extent of dissection and updates intraoperative stereotactic navigation. PMID:22470270

The role of multislice spiral computed tomography in the diagnosis and management of acute facial trauma in patients with multiple injuries.

PubMed

Nemsadze, G; Urushadze, O

2011-11-01

Using of mutislice spiral CT as first line examination for the diagnosis of Acute Facial trauma in the setting of Polytrauma reduces both: valuable time and cost of patient treatment. After a brief clinical examination, MDCT was performed depending on the area of injury, using a slice thickness of 0.65 mm. The obtained data were analyzed using 3D, MIP and Standard axial with Bone reconstruction protocols. 64 polytrauma patients were evaluated with both Anterior and Lateral craniography (plain skull X ray: AP and Lateral) and Multi Slice CT. Craniography detected only 18 cases of traumatic injuries of facial bones, but exact range of dislocation and accurate management plan could not be established. In the same 64 cases, Multislice CT revealed localization of all existed fractures, range of fragment dislocation, soft tissue damage and status of Paranasal sinus in 62 cases (96.8%). In two cases MS CT missed the facial fracture, in one case the examination was complicated because of bone thinness and numerous fracture fragments, in another multiple foreign body artifacts complicated the investigation. The study results show that, CT investigation based on our MDCT polytrauma protocol, detects all more or less serious facial bone injuries.

MRI of the lung: state of the art.

PubMed

Wielpütz, Mark; Kauczor, Hans-Ulrich

2012-01-01

Magnetic resonance imaging (MRI) of the lung is technically challenging due to the low proton density and fast signal decay of the lung parenchyma itself. Additional challenges consist of tissue loss, hyperinflation, and hypoxic hypoperfusion, e.g., in emphysema, a so-called "minus-pathology". However, pathological changes resulting in an increase of tissue ("plus-pathology"), such as atelectases, nodules, infiltrates, mucus, or pleural effusion, are easily depicted with high diagnostic accuracy. Although MRI is inferior or at best equal to multi-detector computed tomography (MDCT) for the detection of subtle morphological features, MRI now offers an increasing spectrum of functional imaging techniques such as perfusion assessment and measurement of ventilation and respiratory mechanics that are superior to what is possible with MDCT. Without putting patients at risk with ionizing radiation, repeated examinations allow for the evaluation of the course of lung disease and monitoring of the therapeutic response through quantitative imaging, providing a level of functional detail that cannot be obtained by any other single imaging modality. As such, MRI will likely be used for clinical applications beyond morphological imaging for many lung diseases. In this article, we review the technical aspects and protocol suggestions for chest MRI and discuss the role of MRI in the evaluation of nodules and masses, airway disease, respiratory mechanics, ventilation, perfusion and hemodynamics, and pulmonary vasculature.

Three-Dimensional Weighting in Cone Beam FBP Reconstruction and Its Transformation Over Geometries.

PubMed

Tang, Shaojie; Huang, Kuidong; Cheng, Yunyong; Niu, Tianye; Tang, Xiangyang

2018-06-01

With substantially increased number of detector rows in multidetector CT (MDCT), axial scan with projection data acquired along a circular source trajectory has become the method-of-choice in increasing clinical applications. Recognizing the practical relevance of image reconstruction directly from the projection data acquired in the native cone beam (CB) geometry, especially in scenarios wherein the most achievable in-plane resolution is desirable, we present a three-dimensional (3-D) weighted CB-FBP algorithm in such geometry in this paper. We start the algorithm's derivation in the cone-parallel geometry. Via changing of variables, taking the Jacobian into account and making heuristic and empirical assumptions, we arrive at the formulas for 3-D weighted image reconstruction in the native CB geometry. Using the projection data simulated by computer and acquired by an MDCT scanner, we evaluate and verify performance of the proposed algorithm for image reconstruction directly from projection data acquired in the native CB geometry. The preliminary data show that the proposed algorithm performs as well as the 3-D weighted CB-FBP algorithm in the cone-parallel geometry. The proposed algorithm is anticipated to find its utility in extensive clinical and preclinical applications wherein the reconstruction of images in the native CB geometry, i.e., the geometry for data acquisition, is of relevance.

Utility of double-contrast multi-detector CT scans to assess cartilage thickness after tibial plafond fracture

PubMed Central

Thomas, Thaddeus P.; Van Hofwegen, Christopher J.; Anderson, Donald D.; Brown, Thomas D.; Marsh, J. Lawrence

2010-01-01

The pathophysiology of post-traumatic osteoarthritis (PTOA) after intra-articular fractures is poorly understood. Pursuit of a better understanding of this disease is complicated by inability to accurately monitor its onset, progression and severity. Common radiographic methods used to assess PTOA do not provide sufficient image quality for precise cartilage measurements. Double-contrast MDCT is an alternative method that may be useful, since it produces high-quality images in normal ankles. The purpose of this study was to assess this technique’s performance in assessing cartilage maintenance in ankles with an intra-articular fracture. Thirty-six tibial plafond fractures were followed over two years, with thirty-one MDCTs being obtained four months after injury, and twenty-two MDCTs after two years. Unfortunately, clinical results with this technique were unreliable due to pathology (presumed arthrofibrosis) and technical problems (pooling of contrast). The arthrofibrosis that developed in many patients inhibited proper joint access and contrast infiltration, although high-quality images were obtained in eleven patients. In this patient subset, in which focal regions of cartilage degeneration could be visualized, thickness could be measured with a high degree of fidelity. While thus useful in selected instances, double-contrast MDCT was too unreliable to be recommended to assess these particular types of injuries. PMID:20634971

[Measurement of scatter radiation on MDCT equipment using an OSL dosimeter].

PubMed

Tomita, Hironobu; Morozumi, Kunihiko

2004-11-01

The recent introduction of multi-detector row computed tomography (MDCT) has made it possible to scan the entire abdomen within approximately 10 sec in procedures such as interventional radiology computed tomography (IVRCT), which are associated with operator exposure. Therefore, anxious patients and patients who are not able to remain still can be examined with an assistant. In the present study, radiation exposure to the assistant was estimated, and the distribution of scattered radiation near the gantry was measured using an optically stimulated luminescence (OSL) dosimeter. Simultaneous measurements were obtained using a direction storage (DIS) dosimeter for reference. The maximum value of 1.47 mSv per examination was obtained at the point closest to the gantry's center (50 cm from the center at a height of 150 cm above the floor) . In addition, scattered radiation decreased as the measurement point was moved further from the gantry's center, falling below the limit of detection (0.1 mSv or less) at 200 cm and at the sides of the gantry. OSL dosimeters are also employed as personal dosimeters, permitting reliable values to be obtained easily. They were found to be an effective tool for the measurement of scattered radiation, as in the present study, helping to provide better understanding of the distribution of scattered radiation within the CT room.

Detection of skeletal muscle metastases on initial staging of lung cancer: a retrospective case series.

PubMed

Bocchino, Marialuisa; Valente, Tullio; Somma, Francesco; de Rosa, Ilaria; Bifulco, Marco; Rea, Gaetano

2014-03-01

Estimation of skeletal muscle metastases (SMMs) at the time of diagnosis and/or initial staging of lung cancer. Retrospective evaluation of clinical charts and imaging data suggestive of SMMs of patients with histology-proved lung cancer over a 5-year period. SMMs were identified in 46 out of 1,754 patients. Single and multiple (62.9% of cases) SMMs were detected by total body multi-detector computed tomography (MDCT). They were associated with poorly differentiated (43%) and advanced adenocarcinomas (52%) without clinically relevant symptoms and/or signs. Psoas and buttock muscles were most frequently involved (33.3%). MDCT findings consisted of well-defined homogeneously hyperdense oval masses (31%), lesions with ring-like enhancement and central hypoattenuation (68%), or large abscess-like necrotic lesions (24%). Sonography revealed well-defined hypoechoic masses (41.6%), ill-defined hypoechoic lesions (33.3%), or anechoic areas with a necrotic centre (25%). Positron emission tomography revealed that all SMMs were metabolically active. SMMs are uncommon but not negligible in lung cancer, with an estimated prevalence of 2.62% in our series. Although histology remains the recommended method, use of high-performance imaging techniques and increased clinical suspicion may improve their early detection. Efforts addressing their effect on the natural history of lung cancer are needed.

Quantitative computer-aided diagnostic algorithm for automated detection of peak lesion attenuation in differentiating clear cell from papillary and chromophobe renal cell carcinoma, oncocytoma, and fat-poor angiomyolipoma on multiphasic multidetector computed tomography.

PubMed

Coy, Heidi; Young, Jonathan R; Douek, Michael L; Brown, Matthew S; Sayre, James; Raman, Steven S

2017-07-01

To evaluate the performance of a novel, quantitative computer-aided diagnostic (CAD) algorithm on four-phase multidetector computed tomography (MDCT) to detect peak lesion attenuation to enable differentiation of clear cell renal cell carcinoma (ccRCC) from chromophobe RCC (chRCC), papillary RCC (pRCC), oncocytoma, and fat-poor angiomyolipoma (fp-AML). We queried our clinical databases to obtain a cohort of histologically proven renal masses with preoperative MDCT with four phases [unenhanced (U), corticomedullary (CM), nephrographic (NP), and excretory (E)]. A whole lesion 3D contour was obtained in all four phases. The CAD algorithm determined a region of interest (ROI) of peak lesion attenuation within the 3D lesion contour. For comparison, a manual ROI was separately placed in the most enhancing portion of the lesion by visual inspection for a reference standard, and in uninvolved renal cortex. Relative lesion attenuation for both CAD and manual methods was obtained by normalizing the CAD peak lesion attenuation ROI (and the reference standard manually placed ROI) to uninvolved renal cortex with the formula [(peak lesion attenuation ROI - cortex ROI)/cortex ROI] × 100%. ROC analysis and area under the curve (AUC) were used to assess diagnostic performance. Bland-Altman analysis was used to compare peak ROI between CAD and manual method. The study cohort comprised 200 patients with 200 unique renal masses: 106 (53%) ccRCC, 32 (16%) oncocytomas, 18 (9%) chRCCs, 34 (17%) pRCCs, and 10 (5%) fp-AMLs. In the CM phase, CAD-derived ROI enabled characterization of ccRCC from chRCC, pRCC, oncocytoma, and fp-AML with AUCs of 0.850 (95% CI 0.732-0.968), 0.959 (95% CI 0.930-0.989), 0.792 (95% CI 0.716-0.869), and 0.825 (95% CI 0.703-0.948), respectively. On Bland-Altman analysis, there was excellent agreement of CAD and manual methods with mean differences between 14 and 26 HU in each phase. A novel, quantitative CAD algorithm enabled robust peak HU lesion detection and discrimination of ccRCC from other renal lesions with similar performance compared to the manual method.

First performance evaluation of software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine at CT.

PubMed

Scholtz, Jan-Erik; Wichmann, Julian L; Kaup, Moritz; Fischer, Sebastian; Kerl, J Matthias; Lehnert, Thomas; Vogl, Thomas J; Bauer, Ralf W

2015-03-01

To evaluate software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine on CT in terms of accuracy, potential for time savings and workflow improvement. 77 patients (28 women, 49 men, mean age 65.3±14.4 years) with known or suspected spinal disorders (degenerative spine disease n=32; disc herniation n=36; traumatic vertebral fractures n=9) underwent 64-slice MDCT with thin-slab reconstruction. Time for automatic labeling of the thoracolumbar spine and reconstruction of double-angulated axial images of the pathological vertebrae was compared with manually performed reconstruction of anatomical aligned axial images. Reformatted images of both reconstruction methods were assessed by two observers regarding accuracy of symmetric depiction of anatomical structures. In 33 cases double-angulated axial images were created in 1 vertebra, in 28 cases in 2 vertebrae and in 16 cases in 3 vertebrae. Correct automatic labeling was achieved in 72 of 77 patients (93.5%). Errors could be manually corrected in 4 cases. Automatic labeling required 1min in average. In cases where anatomical aligned axial images of 1 vertebra were created, reconstructions made by hand were significantly faster (p<0.05). Automatic reconstruction was time-saving in cases of 2 and more vertebrae (p<0.05). Both reconstruction methods revealed good image quality with excellent inter-observer agreement. The evaluated software for automatic labeling and anatomically aligned, double-angulated axial image reconstruction of the thoracolumbar spine on CT is time-saving when reconstructions of 2 and more vertebrae are performed. Checking results of automatic labeling is necessary to prevent errors in labeling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Co-registered perfusion SPECT/CT: utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates.

PubMed

Takenaka, Daisuke; Ohno, Yoshiharu; Koyama, Hisanobu; Nogami, Munenobu; Onishi, Yumiko; Matsumoto, Keiko; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro

2010-06-01

To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates. Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1s (FEV(1)) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome. Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (-0.60

Correlation Between Findings of Multislice Helical Computed Tomography (CT), Endoscopic Examinations, Endovascular Procedures, and Surgery in Patients with Symptoms of Acute Gastrointestinal Bleeding

PubMed Central

Konecki, Dariusz; Pacho, Ryszard; Rowiński, Olgierd

2017-01-01

Summary Background Endoscopic methods (gastroscopy and colonoscopy) are considered fundamental for the diagnosis of gastrointestinal bleeding. In recent years, multidetector computed tomography (MDCT) has also gained importance in diagnosing gastrointestinal bleeding, particularly in hemodynamically unstable patients and in cases with suspected lower gastrointestinal tract bleeding. CT can detect both the source and the cause of active gastrointestinal bleeding, thereby expediting treatment initiation. Material/Methods The study group consisted of 16 patients with clinical symptoms of gastrointestinal bleeding in whom features of active bleeding were observed on CT. In all patients, bleeding was verified by means of other methods such as endoscopic examinations, endovascular procedures, or surgery. Results The bleeding source was identified on CT in all 16 patients. In 14 cases (87.5%), bleeding was confirmed by other methods. Conclusions CT is an efficient, fast, and readily available tool for detecting the location of acute gastrointestinal bleeding. PMID:29662594

Variability of surface and center position radiation dose in MDCT: Monte Carlo simulations using CTDI and anthropomorphic phantoms

PubMed Central

Zhang, Di; Savandi, Ali S.; Demarco, John J.; Cagnon, Chris H.; Angel, Erin; Turner, Adam C.; Cody, Dianna D.; Stevens, Donna M.; Primak, Andrew N.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

2009-01-01

The larger coverage afforded by wider z-axis beams in multidetector CT (MDCT) creates larger cone angles and greater beam divergence, which results in substantial surface dose variation for helical and contiguous axial scans. This study evaluates the variation of absorbed radiation dose in both cylindrical and anthropomorphic phantoms when performing helical or contiguous axial scans. The approach used here was to perform Monte Carlo simulations of a 64 slice MDCT. Simulations were performed with different radiation profiles (simulated beam widths) for a given collimation setting (nominal beam width) and for different pitch values and tube start angles. The magnitude of variation at the surface was evaluated under four different conditions: (a) a homogeneous CTDI phantom with different combinations of pitch and simulated beam widths, (b) a heterogeneous anthropomorphic phantom with one measured beam collimation and various pitch values, (c) a homogeneous CTDI phantom with fixed beam collimation and pitch, but with different tube start angles, and (d) pitch values that should minimize variations of surface dose—evaluated for both homogeneous and heterogeneous phantoms. For the CTDI phantom simulations, peripheral dose patterns showed variation with percent ripple as high as 65% when pitch is 1.5 and simulated beam width is equal to the nominal collimation. For the anterior surface dose on an anthropomorphic phantom, the percent ripple was as high as 40% when the pitch is 1.5 and simulated beam width is equal to the measured beam width. Low pitch values were shown to cause beam overlaps which created new peaks. Different x-ray tube start angles create shifts of the peripheral dose profiles. The start angle simulations showed that for a given table position, the surface dose could vary dramatically with minimum values that were 40% of the peak when all conditions are held constant except for the start angle. The last group of simulations showed that an “ideal” pitch value can be determined which reduces surface dose variations, but this pitch value must take into account the measured beam width. These results reveal the complexity of estimating surface dose and demonstrate a range of dose variability at surface positions for both homogeneous cylindrical and heterogeneous anthropomorphic phantoms. These findings have potential implications for small-sized dosimeter measurements in phantoms, such as with TLDs or small Farmer chambers. PMID:19378763

Hilar cholangiocarcinoma: Cross sectional evaluation of disease spectrum

PubMed Central

Mahajan, Mangal S; Moorthy, Srikanth; Karumathil, Sreekumar P; Rajeshkannan, R; Pothera, Ramchandran

2015-01-01

Although hilar cholangiocarcinoma is relatively rare, it can be diagnosed on imaging by identifying its typical pattern. In most cases, the tumor appears to be centered on the right or left hepatic duct with involvement of the ipsilateral portal vein, atrophy of hepatic lobe on that side, and invasion of adjacent liver parenchyma. Multi-detector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) are commonly used imaging modalities to assess the longitudinal and horizontal spread of tumor. PMID:25969643

Interrupted Aortic Arch Associated with Absence of Left Common Carotid Artery: Imaging with MDCT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onbas, Omer; Olgun, Hasim; Ceviz, Naci

2006-06-15

Interrupted aortic arch (IAA) is a rare severe congenital heart defect defined as complete luminal and anatomic discontinuity between ascending and descending aorta. Although its association with various congenital heart defects has been reported, absence of left common carotid artery (CCA) in patients with IAA has not been reported previously. We report a case of IAA associated with the absence of left CCA which was clearly shown on multidetector-row spiral CT.

Radiological protection in computed tomography and cone beam computed tomography.

PubMed

Rehani, M M

2015-06-01

The International Commission on Radiological Protection (ICRP) has sustained interest in radiological protection in computed tomography (CT), and ICRP Publications 87 and 102 focused on the management of patient doses in CT and multi-detector CT (MDCT) respectively. ICRP forecasted and 'sounded the alarm' on increasing patient doses in CT, and recommended actions for manufacturers and users. One of the approaches was that safety is best achieved when it is built into the machine, rather than left as a matter of choice for users. In view of upcoming challenges posed by newer systems that use cone beam geometry for CT (CBCT), and their widened usage, often by untrained users, a new ICRP task group has been working on radiological protection issues in CBCT. Some of the issues identified by the task group are: lack of standardisation of dosimetry in CBCT; the false belief within the medical and dental community that CBCT is a 'light', low-dose CT whereas mobile CBCT units and newer applications, particularly C-arm CT in interventional procedures, involve higher doses; lack of training in radiological protection among clinical users; and lack of dose information and tracking in many applications. This paper provides a summary of approaches used in CT and MDCT, and preliminary information regarding work just published for radiological protection in CBCT. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Coronary artery calcification score by multislice computed tomography predicts the outcome of dobutamine cardiovascular magnetic resonance imaging.

PubMed

Janssen, Caroline H C; Kuijpers, Dirkjan; Vliegenthart, Rozemarijn; Overbosch, Jelle; van Dijkman, Paul R M; Zijlstra, Felix; Oudkerk, Matthijs

2005-06-01

The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive patients clinically suspected of myocardial ischemia with an inconclusive diagnosis of myocardial ischemia, dobutamine CMR was performed and the CAC score was determined. The CAC score was obtained by 16-row multidetector compued tomography (MDCT) and was calculated according to the method of Agatston. The CAC score and the results of the dobutamine CMR were correlated and the positive predictive value (PPV) and the negative predictive value (NPV) of the CAC score for dobutamine CMR were calculated. A total of 114 (87%) of the patients were eligible for this study. There was a significant correlation between the CAC score and dobutamine CMR (p<0.001). Patients with a CAC score of less than 11 showed no signs of inducible ischemia during dobutamine CMR. For a CAC score of less than 101, the NPV and the PPV of the CAC score for the outcome of dobutamine CMR were, respectively, 0.96 and 0.29. In patients with an inconclusive diagnosis of myocardial ischemia a MDCT CAC score of less than 11 reliably rules out myocardial ischemia detected by dobutamine CMR.

Role of multidetector computed tomography in evaluating incidentally detected breast lesions.

PubMed

Moschetta, Marco; Scardapane, Arnaldo; Lorusso, Valentina; Rella, Leonarda; Telegrafo, Michele; Serio, Gabriella; Angelelli, Giuseppe; Ianora, Amato Antonio Stabile

2015-01-01

Computed tomography (CT) does not represent the primary method for the evaluation of breast lesions; however, it can detect breast abnormalities, even when performed for other reasons related to thoracic structures. The aim of this study is to evaluate the potential benefits of 320-row multidetector CT (MDCT) in evaluating and differentiating incidentally detected breast lesions by using vessel probe and 3D analysis software with net enhancement value. Sixty-two breast lesions in 46 patients who underwent 320-row chest CT examination were retrospectively evaluated. CT scans were assessed searching for the presence, location, number, morphological features, and density of breast nodules. Net enhancement was calculated by subtracting precontrast density from the density obtained by postcontrast values. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT were calculated for morphological features and net enhancement. Thirty of 62 lesions were found to be malignant at histological examination and 32 were found to be benign. When morphological features were considered, the sensitivity, specificity, accuracy, PPV, and NPV of CT were 87%, 100%, 88%, 100%, and 50%, respectively. Based on net enhancement, CT reached a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 94%, 97%, 94%, and 100%, respectively. MDCT allows to recognize and characterize breast lesions based on morphological features. Net enhancement can be proposed as an additional accurate feature of CT.

CBCT-based bone quality assessment: are Hounsfield units applicable?

PubMed Central

Jacobs, R; Singer, S R; Mupparapu, M

2015-01-01

CBCT is a widely applied imaging modality in dentistry. It enables the visualization of high-contrast structures of the oral region (bone, teeth, air cavities) at a high resolution. CBCT is now commonly used for the assessment of bone quality, primarily for pre-operative implant planning. Traditionally, bone quality parameters and classifications were primarily based on bone density, which could be estimated through the use of Hounsfield units derived from multidetector CT (MDCT) data sets. However, there are crucial differences between MDCT and CBCT, which complicates the use of quantitative gray values (GVs) for the latter. From experimental as well as clinical research, it can be seen that great variability of GVs can exist on CBCT images owing to various reasons that are inherently associated with this technique (i.e. the limited field size, relatively high amount of scattered radiation and limitations of currently applied reconstruction algorithms). Although attempts have been made to correct for GV variability, it can be postulated that the quantitative use of GVs in CBCT should be generally avoided at this time. In addition, recent research and clinical findings have shifted the paradigm of bone quality from a density-based analysis to a structural evaluation of the bone. The ever-improving image quality of CBCT allows it to display trabecular bone patterns, indicating that it may be possible to apply structural analysis methods that are commonly used in micro-CT and histology. PMID:25315442

Image quality comparison between single energy and dual energy CT protocols for hepatic imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Yuan, E-mail: yuanyao@stanford.edu; Pelc, Nor

Purpose: Multi-detector computed tomography (MDCT) enables volumetric scans in a single breath hold and is clinically useful for hepatic imaging. For simple tasks, conventional single energy (SE) computed tomography (CT) images acquired at the optimal tube potential are known to have better quality than dual energy (DE) blended images. However, liver imaging is complex and often requires imaging of both structures containing iodinated contrast media, where atomic number differences are the primary contrast mechanism, and other structures, where density differences are the primary contrast mechanism. Hence it is conceivable that the broad spectrum used in a dual energy acquisition maymore » be an advantage. In this work we are interested in comparing these two imaging strategies at equal-dose and more complex settings. Methods: We developed numerical anthropomorphic phantoms to mimic realistic clinical CT scans for medium size and large size patients. MDCT images based on the defined phantoms were simulated using various SE and DE protocols at pre- and post-contrast stages. For SE CT, images from 60 kVp through 140 with 10 kVp steps were considered; for DE CT, both 80/140 and 100/140 kVp scans were simulated and linearly blended at the optimal weights. To make a fair comparison, the mAs of each scan was adjusted to match the reference radiation dose (120 kVp, 200 mAs for medium size patients and 140 kVp, 400 mAs for large size patients). Contrast-to-noise ratio (CNR) of liver against other soft tissues was used to evaluate and compare the SE and DE protocols, and multiple pre- and post-contrasted liver-tissue pairs were used to define a composite CNR. To help validate the simulation results, we conducted a small clinical study. Eighty-five 120 kVp images and 81 blended 80/140 kVp images were collected and compared through both quantitative image quality analysis and an observer study. Results: In the simulation study, we found that the CNR of pre-contrast SE image mostly increased with increasing kVp while for post-contrast imaging 90 kVp or lower yielded higher CNR images, depending on the differential iodine concentration of each tissue. Similar trends were seen in DE blended CNR and those from SE protocols. In the presence of differential iodine concentration (i.e., post-contrast), the CNR curves maximize at lower kVps (80–120), with the peak shifted rightward for larger patients. The combined pre- and post-contrast composite CNR study demonstrated that an optimal SE protocol has better performance than blended DE images, and the optimal tube potential for SE scan is around 90 kVp for a medium size patients and between 90 and 120 kVp for large size patients (although low kVp imaging requires high x-ray tube power to avoid photon starvation). Also, a tin filter added to the high kVp beam is not only beneficial for material decomposition but it improves the CNR of the DE blended images as well. The dose adjusted CNR of the clinical images also showed the same trend and radiologists favored the SE scans over blended DE images. Conclusions: Our simulation showed that an optimized SE protocol produces up to 5% higher CNR for a range of clinical tasks. The clinical study also suggested 120 kVp SE scans have better image quality than blended DE images. Hence, blended DE images do not have a fundamental CNR advantage over optimized SE images.« less

Development of a Radiation Dose Reporting Software for X-ray Computed Tomography (CT)

NASA Astrophysics Data System (ADS)

Ding, Aiping

X-ray computed tomography (CT) has experienced tremendous technological advances in recent years and has established itself as one of the most popular diagnostic imaging tools. While CT imaging clearly plays an invaluable role in modern medicine, its rapid adoption has resulted in a dramatic increase in the average medical radiation exposure to the worldwide and United States populations. Existing software tools for CT dose estimation and reporting are mostly based on patient phantoms that contain overly simplified anatomies insufficient in meeting the current and future needs. This dissertation describes the development of an easy-to-use software platform, “VirtualDose”, as a service to estimate and report the organ dose and effective dose values for patients undergoing the CT examinations. “VirtualDose” incorporates advanced models for the adult male and female, pregnant women, and children. To cover a large portion of the ignored obese patients that frequents the radiology clinics, a new set of obese male and female phantoms are also developed and applied to study the effects of the fat tissues on the CT radiation dose. Multi-detector CT scanners (MDCT) and clinical protocols, as well as the most recent effective dose algorithms from the International Commission on Radiological Protection (ICRP) Publication 103 are adopted in “VirtualDose” to keep pace with the MDCT development and regulatory requirements. A new MDCT scanner model with both body and head bowtie filter is developed to cover both the head and body scanning modes. This model was validated through the clinical measurements. A comprehensive slice-by-slice database is established by deriving the data from a larger number of single axial scans simulated on the patient phantoms using different CT bowtie filters, beam thicknesses, and different tube voltages in the Monte Carlo N-Particle Extended (MCNPX) code. When compared to the existing CT dose software packages, organ dose data in this software provides a better CT dose assessment by using anatomically realistic patient phantoms. All the related organ doses are incorporated into a standardized database compiled using Microsoft Structured Query Language (SQL) server 2008. Organ doses from contiguous axial or helical scans defined by a specific protocol can be rapidly obtained from the database. A next-generation software architecture and Active Server Pages (ASP) .NET framework are adopted to create a browser-hosted application to improve the user interactivity and reporting functionality including scanning parameter selection and organ dose reporting. “VirtualDose” has been developed as a web-based CT dose reporting platform to facilitate several important features including: (1) easy access via Internet; (2) no need for installation on the local computer; (3) a user-friendly, dynamic, browser-hosted graphical user interface; (4) use of advanced patient models for the adult male and female, pregnant women, children, and obese patient models; (5) adoption of modern CT scanners and protocols, as well as the most recent ICRP 103 effective dose algorithms; and (6) flexibility to manage and easily upgrade without impacting user’s usage.

Objective performance assessment of five computed tomography iterative reconstruction algorithms.

PubMed

Omotayo, Azeez; Elbakri, Idris

2016-11-22

Iterative algorithms are gaining clinical acceptance in CT. We performed objective phantom-based image quality evaluation of five commercial iterative reconstruction algorithms available on four different multi-detector CT (MDCT) scanners at different dose levels as well as the conventional filtered back-projection (FBP) reconstruction. Using the Catphan500 phantom, we evaluated image noise, contrast-to-noise ratio (CNR), modulation transfer function (MTF) and noise-power spectrum (NPS). The algorithms were evaluated over a CTDIvol range of 0.75-18.7 mGy on four major MDCT scanners: GE DiscoveryCT750HD (algorithms: ASIR™ and VEO™); Siemens Somatom Definition AS+ (algorithm: SAFIRE™); Toshiba Aquilion64 (algorithm: AIDR3D™); and Philips Ingenuity iCT256 (algorithm: iDose4™). Images were reconstructed using FBP and the respective iterative algorithms on the four scanners. Use of iterative algorithms decreased image noise and increased CNR, relative to FBP. In the dose range of 1.3-1.5 mGy, noise reduction using iterative algorithms was in the range of 11%-51% on GE DiscoveryCT750HD, 10%-52% on Siemens Somatom Definition AS+, 49%-62% on Toshiba Aquilion64, and 13%-44% on Philips Ingenuity iCT256. The corresponding CNR increase was in the range 11%-105% on GE, 11%-106% on Siemens, 85%-145% on Toshiba and 13%-77% on Philips respectively. Most algorithms did not affect the MTF, except for VEO™ which produced an increase in the limiting resolution of up to 30%. A shift in the peak of the NPS curve towards lower frequencies and a decrease in NPS amplitude were obtained with all iterative algorithms. VEO™ required long reconstruction times, while all other algorithms produced reconstructions in real time. Compared to FBP, iterative algorithms reduced image noise and increased CNR. The iterative algorithms available on different scanners achieved different levels of noise reduction and CNR increase while spatial resolution improvements were obtained only with VEO™. This study is useful in that it provides performance assessment of the iterative algorithms available from several mainstream CT manufacturers.

Iodine-125 Seeds Strand for Treatment of Tumor Thrombus in Inferior Vena Cava: An Experimental Study in a Rabbit Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wen, E-mail: wenzhangxiao@126.com; Yan, Zhiping, E-mail: Yan.zhiping@zs-hospital.sh.cn; Luo, Jianjun, E-mail: luo.jianjun@zs-hospital.sh.cn

Objective: The purpose of this study was to establish an animal model of implanted inferior vena cava tumor thrombus (IVCTT) and to evaluate the effect of linear iodine-125 seeds strand in treating implanted IVCTT. Methods: Tumor cell line VX{sub 2} was inoculated subcutaneously into New Zealand rabbit to develop the parent tumor. The tumor strip was inoculated into inferior vena cava (IVC) to establish the IVCTT model. The IVCTT was confirmed by multidetector computed tomography (MDCT) after 2 weeks. Twelve rabbits with IVCTT were randomly divided into two groups. Treatment group (group T; n = 6) underwent Iodine-125 seeds brachytherapy,more » and the control group (group C; n = 6) underwent blank seeds strand. The blood laboratory examination (including blood routine examination, hepatic and renal function), body weight, survival time, and IVCTT volume by MDCT were monitored. All rabbits were dissected postmortem, and the therapeutic effects were evaluated on the basis of histopathology. The proliferating cell nuclear antigen index (PI) and apoptosis index (AI) of IVCTT were compared between two groups. T test, Wilcoxon rank test, and Kaplan-Meier survival curve analysis were used. Results: The success rate of establishing IVCTT was 100 %. The body weight loss and cachexia of rabbits in group C appeared earlier than in group T. Body weight in the third week, the mean survival time, PI, AI in groups T and C were 2.23 {+-} 0.12 kg, 57.83 {+-} 8.68 days, (16.73 {+-} 5.18 %), (29.47 {+-} 7.18 %), and 2.03 {+-} 0.13 kg, 43.67 {+-} 5.28 days, (63.01 {+-} 2.01 %), (6.02 {+-} 2.93 %), respectively. There were statistically significant differences between group T and group C (P < 0.05). The IVCTT volume of group T was remarkably smaller than that of group C. Conclusions: Injecting and suspensory fixing VX2 tumor strip into IVC is a reliable method to establish IVCTT animal model. The linear Iodine-125 seeds strand brachytherapy was a safe and effective method for treating IVCTT in rabbit model.« less

Multidetector CT diagnosis of massive hemobilia due to gallbladder polyposis in a child with metachromatic leukodystrophy.

PubMed

Wanner, Matthew R; Karmazyn, Boaz; Fan, Rong

2015-12-01

Hemobilia secondary to gallbladder polyposis is rare in children but has been reported in a few children with metachromatic leukodystrophy. We present a case with preoperative multidetector computed tomography (MDCT) diagnosis of massive hemobilia caused by gallbladder polyposis in a patient with metachromatic leukodystrophy. Our report highlights the importance of both awareness of the association of gallbladder polyposis with other syndromes such as metachromatic leukodystrophy as well as the possibility of this entity presenting with life-threatening bleeding.

Association of Dyslipidemia and Sex With Coronary Artery Calcium Assessed by Coronary Computed Tomography Angiography.

PubMed

Asami, Masahiko; Yamaji, Kyohei; Aoki, Jiro; Tanimoto, Shuzou; Watanabe, Mika; Horiuchi, Yu; Furui, Koichi; Kato, Nahoko; Hara, Kazuhiro; Tanabe, Kengo

2017-10-21

Previous studies reporting that statin increases coronary artery calcium (CAC) were conducted exclusively on patients with statin as a prevention, regardless of the presence or absence of dyslipidemia. The impact of sex on CAC has not been fully evaluated. We aimed to determine the association of dyslipidemia and sex with CAC using 320-row multi-detector computed tomography (MDCT).Of the 356 consecutive patients who underwent coronary MDCT, 251 patients were enrolled, after excluding those with prior stenting and/or coronary bypass grafting or images showing motion artifacts. The primary outcome measures were the percent calcium volume (PCV) and percent atheroma volume (PAV) per coronary vessel.Multivariable analyses indicated that PCV was significantly higher in dyslipidemia patients without statins than in the subjects without dyslipidemia [partial regression coefficient (PRC): 2.59, 95% confidence interval (CI): 0.83 to 4.34, P = 0.004]. In contrast, PCV was similar in dyslipidemia patients taking statins and those without dyslipidemia (PRC: -1.09, 95% CI: -2.82 to 0.65, P = 0.22). There was no significant difference in PCV between men and women, although women exhibited a significantly lower PAV (PRC: -2.87, 95% CI: -4.54 to -1.20, P = 0.001).In low-risk patients, these results could be translated into hypotheses, which should be tested in future prospective studies. Furthermore, there was no significant difference in CAC between men and women, but women had lower PAV than men.

Prevalence of myocardial bridging detected with 64-slice multidetector coronary computed tomography angiography in asymptomatic adults.

PubMed

Atar, Eli; Kornowski, Ran; Fuchs, Shmuell; Naftali, Noa; Belenky, Alexander; Bachar, Gil N

2007-10-01

Myocardial bridging is a congenital condition in which a segment of an epicardial artery has an intramural course within the myocardium. The aim of the present study was to evaluate the prevalence of myocardial bridging and the ability of 64-slice coronary computed tomography angiography to identify myocardial bridging in asymptomatic adults. One hundred sixty-nine consecutive asymptomatic subjects underwent 64-row multidetector computed tomography (MDCT) of the coronary arteries. Two experienced CT radiologists identified myocardial bridging >1 mm in thickness, by consensus. We examined the frequency of myocardial bridging and evaluated the length, thickness, and coronary wall lesions. Myocardial bridges were found in 28 (17%) of 165 subjects. Twenty-one subjects (75%) had 1 bridge and 7 subjects (25%) had 2, for a total of 35 myocardial bridges. Twenty-one bridges (60%) were located in the left anterior descending, 8.5% in the diagonal branch, and 2.8% in the circumflex arteries. The segment beneath the myocardial bridge was always free of coronary wall plaques, but the arterial segment proximal to it had significant coronary wall plaques in 24 cases (68.6%). We found that the incidence of myocardial bridging in asymptomatic adults is 7%, which is in agreement with some pathologic studies in the literature. Our study shows that MDCT of the coronary arteries is a reliable and noninvasive technique, which can accurately locate the site of myocardial bridging, and measure its thickness, course, and length.

Noncalcified coronary plaque in systemic lupus erythematosus.

PubMed

Kiani, Adnan N; Vogel-Claussen, Jens; Magder, Laurence S; Petri, Michelle

2010-03-01

To study noncalcified coronary plaque (NCP) in systemic lupus erythematosus (SLE). Sixty-four-slice coronary multidetector computed tomography (MDCT) was performed in 39 consecutive patients with SLE. MDCT scans were evaluated semiquantitatively by a radiologist using dedicated software. The presence or absence of NCP in each coronary artery was assessed. Patients with mixed plaque (calcified and noncalcified portions) were included in the NCP group. The patient group was 90% women, 64% Caucasian, 31% African American, 5% other; mean age 50.5 +/- 9.6 years. Fifty-four percent (21/39) had NCP. Seventy-six percent (16/21) of those with NCP also had coronary calcium (range 0.7 to 1264.1 Agatston units). In univariate analysis, NCP was associated with age (p = 0.01), current nonsteroidal antiinflammatory drug (NSAID) use (p = 0.04), hormone replacement therapy (p = 0.02), current use of immunosuppressive drugs (p = 0.02), current low serum C3 level (p = 0.07), current physician's global assessment of activity (PGA; p = 0.05), and low-density lipoprotein cholesterol (p = 0.04). NCP was not associated with other risk factors for atherosclerosis, including total serum cholesterol, high sensitivity C-reactive protein, and lipoprotein(a). Unlike coronary calcium, which is not associated with SLE activity measures or with active serologies, NCP is more common in patients with SLE with current, 3-, and 6-month activity by PGA. NCP was also associated with the need for current NSAID or immunosuppressive therapy. NCP is an important part of the total atherosclerotic burden in SLE.

Determination of the chemical composition of human renal stones with MDCT: influence of the surrounding media

NASA Astrophysics Data System (ADS)

Grosjean, Romain; Sauer, Benoît; Guerra, Rui; Kermarrec, Isabelle; Ponvianne, Yannick; Winninger, Daniel; Daudon, Michel; Blum, Alain; Felblinger, Jacques; Hubert, Jacques

2007-03-01

The selection of the optimal treatment method for urinary stones diseases depends on the chemical composition of the stone and its corresponding fragility. MDCT has become the most used modality to determine rapidly and accurately the presence of stones when evaluating urinary lithiasis treatment. That is why several studies have tempted to determine the chemical composition of the stones based on the stone X-ray attenuation in-vitro and invivo. However, in-vitro studies did not reproduce the normal abdominal wall and fat, making uncertain the standardization of the obtained values. The aim of this study is to obtain X-ray attenuation values (in Hounsfield Units) of the six more frequent types of human renal stones (n=217) and to analyze the influence of the surrounding media on these values. The stones were first placed in a jelly, which X-ray attenuation is similar to that of the human kidney (30 HU at 120 kV). They were then stuck on a grid, scanned in a water tank and finally scanned in the air. Significant differences in CT-attenuation values were obtained with the three different surrounding media (jelly, water, air). Furthermore there was an influence of the surrounding media and consequently discrepancies in determination of the chemical composition of the renal stones. Consequently, CT-attenuation values found in in-vitro studies cannot really be considered as a reference for the determination of the chemical composition except if the used phantom is an anthropomorphic one.

Anatomical variations of hepatic arterial system, coeliac trunk and renal arteries: an analysis with multidetector CT angiography.

PubMed

Ugurel, M S; Battal, B; Bozlar, U; Nural, M S; Tasar, M; Ors, F; Saglam, M; Karademir, I

2010-08-01

The purpose of our investigation was to determine the anatomical variations in the coeliac trunk-hepatic arterial system and the renal arteries in patients who underwent multidetector CT (MDCT) angiography of the abdominal aorta for various reasons. A total of 100 patients were analysed retrospectively. The coeliac trunk, hepatic arterial system and renal arteries were analysed individually and anatomical variations were recorded. Statistical analysis of the relationship between hepatocoeliac variations and renal artery variations was performed using a chi(2) test. There was a coeliac trunk trifurcation in 89% and bifurcation in 8% of the cases. Coeliac trunk was absent in 1%, a hepatosplenomesenteric trunk was seen in 1% and a splenomesenteric trunk was present in 1%. Hepatic artery variation was present in 48% of patients. Coeliac trunk and/or hepatic arterial variation was present in 23 (39.7%) of the 58 patients with normal renal arteries, and in 27 (64.3%) of the 42 patients with accessory renal arteries. There was a statistically significant correlation between renal artery variations and coeliac trunk-hepatic arterial system variations (p = 0.015). MDCT angiography permits a correct and detailed evaluation of hepatic and renal vascular anatomy. The prevalence of variations in the coeliac trunk and/or hepatic arteries is increased in people with accessory renal arteries. For that reason, when undertaking angiographic examinations directed towards any single organ, the possibility of variations in the vascular structure of other organs should be kept in mind.

[In vivo anatomical study of inferior attachment of renal fascia in adult with acute pancreatitis as shown on multidetector computed tomography].

PubMed

Qi, Rui; Zhou, Xiangping; Yu, Jianqun; Li, Zhenlin

2014-04-01

This study aims to explore the inferior adhesion of the renal fascia (RF), and the inferior connectivity of the perirenal spaces (PS) with multidetector computed tomography (MDCT), and to investigate the diagnostic value of CT for showing this anatomy. From May to July 2012, eighty-two patients with acute pancreatitis presented in our hospital were enrolled into this study and underwent contrast-enhanced CT scans. All the image data were used to perform three dimensional reconstruction to show the inferior attachment of RF and the inferior connectivity of PS. The fusion of anterior renal fascia (ARF) and posterior renal fascia (PRF) next to the plane of iliac fossa were found on the left in 71.95% (59/82) cases, and on the right in 75.61% (62/82). In these cases, bilateral perirenal spaces, and anterior and posterior pararenal spaces were not found to be connected with each other. No fusion of ARF and PRF below the level of bilateral kidneys occurred on the left side in 28.05% (23/82) cases and on the right side in 24.39% (20/82). In these patients, the PS extended to the extraperitoneal space of the pelvic cavity and further to the inguinal region, and bilateral anterior and posterior pararenal spaces were not found to be connected with each other. Three-dimensional reconstruction on contrast-enhanced MDCT could be a valuable procedure for depicting inferior attachment of RF, and the inferior connectivity of PS.

Blunt chest trauma--an audit of injuries diagnosed by the MDCT examination.

PubMed

Turkalj, Ivan; Petrović, Kosta; Stojanović, Sanja; Petrović, Djordje; Brakus, Alma; Ristić, Jelena

2014-02-01

Multidetector computed tomography (MDCT) characterised by speed and precision is increasingly accessible in emergency wards. The aim of our study was to determine the most common injuries to the chest region, as well as type associated extrathoracic injuries, and the treatment outcome. This prospective study included 61 patients with blunt trauma who were submitted to computed tomography (CT) of the thorax. The number of injuries was evaluated by organs and organ systems of the chest. The cause of the injury, the length and the outcome of the treatment, and the presence of injuries in other regions were assessed. Chest injuries were associated with injuries to other regions in 80.3% cases, predominantly injuries to extremities or pelvic bones in 54.1% cases, followed by head injuries in 39.3% patients. Associated thoracic injuries were present in 90.9% of patients with lethal outcome. Lung parenchymal lesions, pleural effusions and rib fractures were the most common injuries affecting 77.1%, 65.6% and 63.9% of the cases, respectively. Blunt chest trauma is a significant problem affecting predominantly males in their forties and it is usually caused by a motor vehicle accident. In case of pneumomediastinum or mediastinal haematoma, the use of 3D reconstructions is advised for diagnosing possible tracheobronchial ruptures and thoracic aorta injuries. Increased resolution of CT scanners yielded a large number of findings that are occult on radiography, especially in the event of lung parenchymal and pleural injuries. However, none imaging modality can replace surgical judgement.

Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

NASA Astrophysics Data System (ADS)

Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

2016-03-01

The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p < 10-4). These results demonstrate that biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

WNK4 inhibits NCC protein expression through MAPK ERK1/2 signaling pathway.

PubMed

Zhou, Bo; Wang, Dexuan; Feng, Xiuyan; Zhang, Yiqian; Wang, Yanhui; Zhuang, Jieqiu; Zhang, Xuemei; Chen, Guangping; Delpire, Eric; Gu, Dingying; Cai, Hui

2012-03-01

WNK [with no lysine (K)] kinase is a subfamily of serine/threonine kinases. Mutations in two members of this family (WNK1 and WNK4) cause pseudohypoaldosteronism type II featuring hypertension, hyperkalemia, and metabolic acidosis. WNK1 and WNK4 were shown to regulate sodium chloride cotransporter (NCC) activity through phosphorylating SPAK and OSR1. Previous studies including ours have also shown that WNK4 inhibits NCC function and its protein expression. A recent study reported that a phorbol ester inhibits NCC function via activation of extracellular signal-regulated kinase (ERK) 1/2 kinase. In the current study, we investigated whether WNK4 affects NCC via the MAPK ERK1/2 signaling pathway. We found that WNK4 increased ERK1/2 phosphorylation in a dose-dependent manner in mouse distal convoluted tubule (mDCT) cells, whereas WNK4 mutants with the PHA II mutations (E562K and R1185C) lost the ability to increase the ERK1/2 phosphorylation. Hypertonicity significantly increased ERK1/2 phosphorylation in mDCT cells. Knock-down of WNK4 expression by siRNA resulted in a decrease of ERK1/2 phosphorylation. We further showed that WNK4 knock-down significantly increases the cell surface and total NCC protein expressions and ERK1/2 knock-down also significantly increases cell surface and total NCC expression. These data suggest that WNK4 inhibits NCC through activating the MAPK ERK1/2 signaling pathway.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

PubMed Central

Tamada, Kiichi; Ushio, Jun; Sugano, Kentaro

2011-01-01

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension. PMID:21611097

CT-angiography protocol with low dose radiation and low volume contrast medium for non-cardiac chest pain

PubMed Central

Ozkurt, Huseyin; Tokgoz, Safiye; Karabay, Esra; Ucan, Berna; Akdogan, Melek Pala; Basak, Muzaffer

2014-01-01

Aim To evaluate the diagnostic quality of a new multiple detector-row computed tomography angiography (MDCT-A) protocol using low dose radiation and low volume contrast medium techniques for evaluation of non-cardiac chest pain. Methods Forty-five consecutive patients with clinically suspected noncardiac chest pain and requiring contrast-enhanced chest computed tomography (CT) were examined. The patients were assigned to the protocol, with 80 kilovolt (peak) (kV[p]) and 150 effective milliampere-second (eff mA-s). In our study group, 40 mL of low osmolar contrast material was administered at 3.0 mL/s. Results In the study group, four patients with pulmonary embolism, four with pleural effusion, two with ascending aortic aneurysm and eight patients with pneumonic consolidation were detected. The mean attenuation of the pulmonary truncus and ascendant aortic locations was considered 264±44 and 249±51 HU, respectively. The mean effective radiation dose was 0.83 mSv for MDCT-A. Conclusions Pulmonary artery and the aorta scanning simultaneously was significantly reduced radiation exposure with the mentioned dose saving technique. Additionally, injection of low volume (40 cc) contrast material may reduce the risk of contrast induced nephropathy, therefore, facilitate the diagnostic approach. This technique can be applied to all cases and particularly patients at high risk of contrast induced nephropathy due to its similar diagnostic quality with a low dose and high levels of arteriovenous enhancement simultaneously. PMID:25392818

Impact of Indoxyl Sulfate on Coronary Plaques in Patients on Hemodialysis.

PubMed

Asami, Masahiko; Tanabe, Kengo; Ito, Shunsuke; Yoshida, Eri; Aoki, Jiro; Tanimoto, Shuzou; Horiuchi, Yu; Yoshida, Masayuki

2018-05-30

Serum indoxyl sulfate (IS; a uremic toxin) levels, which are significantly higher in patients with chronic kidney disease, including those undergoing hemodialysis, than in the robust, are associated with both cardiovascular disease (CVD) and CVD-related mortality. Furthermore, coronary artery calcium (CAC) is an independent predictor of cardiovascular events in patients undergoing hemodialysis. This study aimed to interpret the association between serum IS levels and coronary plaque burden (CPB) or CAC.A total of 30 consecutive patients on hemodialysis, who underwent 320-row coronary multidetector computed tomography (MDCT) angiography for suspected coronary artery disease, were enrolled in this prospective study. Coronary artery percent atheroma volume (a CPB marker) and percent calcium volume (a CAC marker) assessed using MDCT were evaluated. Furthermore, various oxidative and inflammatory markers typified by serum IS levels at a dialysis-free day were measured. Using these data, we investigated correlation between the inflammatory marker IS and CPB or CAC.Multivariable analysis indicated that serum IS levels were positively correlated with CAC [partial regression coefficient, 2.89; 95% confidence interval (CI), 0.35-5.43; P = 0.03] but not with CPB, even after adjustment for cofounders. Composite cardiovascular events, namely, as all-cause death, non-fatal myocardial infarction, disabling stroke, and hospital admission for other cardiovascular events, were reported to be 50% in all patients (95% CI, 32.1-67.9).In patients undergoing hemodialysis, serum IS levels were significantly associated with CAC but not with CPB.

[Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

PubMed

Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

2007-03-20

In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

Imaging investigation of pancreatic cystic lesions and proposal for therapeutic guidelines

PubMed Central

Hilendarov, Atanas D; Deenichin, Georgi Petrov; Velkova, Kichka Georgieva

2012-01-01

AIM: To propose a diagnostic algorithm for preoperatively predicting the need for surgical intervention. METHODS: The study included 56 patients (27 men and 29 women) with a final diagnosis of cystic pancreatic lesions. The following materials were used: ultrasonic equipment with 3.5 and 7 MHz linear, convex and biopsical transducers. Multidetector computed tomography (MDCT) investigations were performed using a 16-slice scanner. Images were obtained following the oral administration of 200 mL water and 100 mL intravenous iopamidol (300 mg/mL) administered by pump injector at a rate of 3 mL/s (40 and 60 s post-injection, respectively) using 0.5 mm detectors, reconstructed at 1 mm (pancreatic phase) or 2 mm (portal venous phase) increments. The table feed was 10 mm per rotation. Images were acquired in the pancreatic and portal venous phases of contrast enhancement. The “Chiba” needles 18, 20, 22, 23 G and an automatic aspiration system were used in conjunction with the following methods of guiding the interventional procedures: (1)“free-hand” biopsy and puncture method under ultrasound (US) or computed tomography (CT) control; (2) guiding method using biopsical transducer. RESULTS: All 56 patients in this study underwent at least two cuts imaging survey methods, such as US, CT or magnetic resonance imaging (MRI). The most common preoperative diagnostic examination was US scan - 56 patients (100%). MDCT studies were conducted in 49 (87.50%) and MRI in 13 (23.21%). More than half of patients surveyed (37) underwent some type of interventional procedure: 25-fine-needle aspiration and 29-fine needle aspiration biopsy (FNAB), as part of the examination. Thirty-four patients of all 56 patients underwent surgery because of histological evidence of malignancy after the FNAB for cystic lesions of the pancreas. Distal pancreatectomy with splenectomy was the most common operative approach in 13 patients, followed by Whipple resection in 11 and distal pancreatectomy without splenectomy in 7. Three patients were treated with total pancreatectomy due to the presence of a multifocal mucinous neoplasm. Comparing the diagnostic results of US examination with those of MDCT examination and histological verification true positive results were found in 31 patients, true negative in 11 patients, false positive in 5 and false negative in 9 patients. Accordingly we estimated the power of the diagnostic imaging methods for cystic lesions of the pancreas. A specificity of 68.75%, sensitivity of 79.48%, accuracy of 75.00%, positive predictive value of 86.11% and negative predictive value of 55% were obtained. The power increased after applying invasive procedures with immunohistochemical analysis of CEA and P-53 (Fig. 4). In 15 patients with cytological feature of malignant tumour cells, the tumour markers were positive. In our opinion the higher the percentage of reacting cells the higher the percent of malignancy. In patients with clear symptoms and/or clear imaging features of malignant or premalignant cystic neoplasm, the need for surgery was confirmed by histological verification in 34 (60.71%) of cases. CONCLUSION: By using the proposed algorithm, cystic mucinous tumors of the pancreas were detected and proper operative interventions would have been rendered with fewer diagnostic examinations. PMID:22937216

Fully automated lobe-based airway taper index calculation in a low dose MDCT CF study over 4 time-points

NASA Astrophysics Data System (ADS)

Weinheimer, Oliver; Wielpütz, Mark O.; Konietzke, Philip; Heussel, Claus P.; Kauczor, Hans-Ulrich; Brochhausen, Christoph; Hollemann, David; Savage, Dasha; Galbán, Craig J.; Robinson, Terry E.

2017-02-01

Cystic Fibrosis (CF) results in severe bronchiectasis in nearly all cases. Bronchiectasis is a disease where parts of the airways are permanently dilated. The development and the progression of bronchiectasis is not evenly distributed over the entire lungs - rather, individual functional units are affected differently. We developed a fully automated method for the precise calculation of lobe-based airway taper indices. To calculate taper indices, some preparatory algorithms are needed. The airway tree is segmented, skeletonized and transformed to a rooted acyclic graph. This graph is used to label the airways. Then a modified version of the previously validated integral based method (IBM) for airway geometry determination is utilized. The rooted graph, the airway lumen and wall information are then used to calculate the airway taper indices. Using a computer-generated phantom simulating 10 cross sections of airways we present results showing a high accuracy of the modified IBM. The new taper index calculation method was applied to 144 volumetric inspiratory low-dose MDCT scans. The scans were acquired from 36 children with mild CF at 4 time-points (baseline, 3 month, 1 year, 2 years). We found a moderate correlation with the visual lobar Brody bronchiectasis scores by three raters (r2 = 0.36, p < .0001). The taper index has the potential to be a precise imaging biomarker but further improvements are needed. In combination with other imaging biomarkers, taper index calculation can be an important tool for monitoring the progression and the individual treatment of patients with bronchiectasis.

A Numerical Study of Heat and Water Vapor Transfer in MDCT-Based Human Airway Models

PubMed Central

Wu, Dan; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long

2014-01-01

A three-dimensional (3D) thermo-fluid model is developed to study regional distributions of temperature and water vapor in three multi-detector row computed-tomography (MDCT)-basedhuman airwayswith minute ventilations of 6, 15 and 30 L/min. A one-dimensional (1D) model is also solved to provide necessary initial and boundary conditionsforthe 3D model. Both 3D and 1D predicted temperature distributions agree well with available in vivo measurement data. On inspiration, the 3D cold high-speed air stream is split at the bifurcation to form secondary flows, with its cold regions biased toward the inner wall. The cold air flowing along the wall is warmed up more rapidly than the air in the lumen center. The repeated splitting pattern of air streams caused by bifurcations acts as an effective mechanism for rapid heat and mass transfer in 3D. This provides a key difference from the 1D model, where heating relies largely on diffusion in the radial direction, thus significantly affecting gradient-dependent variables, such as energy flux and water loss rate. We then propose the correlations for respective heat and mass transfer in the airways of up to 6 generations: Nu=3.504(ReDaDt)0.277, R = 0.841 and Sh=3.652(ReDaDt)0.268, R = 0.825, where Nu is the Nusselt number, Sh is the Sherwood number, Re is the branch Reynolds number, Da is the airway equivalent diameter, and Dt is the tracheal equivalentdiameter. PMID:25081386

The CT image standardization based on the verified PSF

NASA Astrophysics Data System (ADS)

Wada, Shinichi; Ohkubo, Masaki; Kunii, Masayuki; Matsumoto, Toru; Murao, Kohei; Awai, Kazuo; Ikeda, Mitsuru

2007-03-01

This study discusses a method of CT image quality standardization that uses a point-spread function (PSF) in MDCT. CT image I(x,y,z) is represented by the following formula: I(x,y,z) = O(x,y,z)***PSF(x,y,z). Standardization was performed by measuring the three-dimensional (3-D) PSFs of two CT images with different image qualities. The image conversion method was constructed and tested using the 3-D PSFs and CT images of the CT scanners of three different manufacturers. The CT scanners used were Lightspeed QX/i, Somatom Volume Zoom, and Brilliance-40. To obtain the PSF(x,y) of these CT scanners, the line spread functions of the respective reconstruction kernels were measured using a phantom described by J.M. Boone. The kernels for each scanner were: soft, standard, lung, bone, and bone plus (GE); B20f, B40f, B41f, B50f, and B60f (Siemens); and B, C, D, E, and L (Philips). Slice sensitivity profile (SSP) were measured using a micro-disk phantom (50 μm* φ1 mm) with 5 mm slice thickness and beam pitch of 1.5 (GE, Siemens) and 0.626 (Philips). 3-D PSF was verified using an MDCT QA phantom. Real chest CT images were converted to images with contrasting standard image quality. Comparison between the converted CT image and the original standard image showed good agreement. The usefulness of the image conversion method is discussed using clinical CT images acquired by CT scanners produced by different manufacturers.

Brief communication: timing of spheno-occipital closure in modern Western Australians.

PubMed

Franklin, Daniel; Flavel, Ambika

2014-01-01

The spheno-occipital synchondrosis is a craniofacial growth centre between the occipital and sphenoid bones-its ossification persists into adolescence, which for the skeletal biologist, means it has potential application for estimating subadult age. Based on previous research the timing of spheno-occipital fusion is widely variable between and within populations, with reports of complete fusion in individuals as young as 11 years of age and nonfusion in adults. The aim of this study is, therefore, to examine this structure in a mixed sex sample of Western Australian individuals that developmentally span late childhood to adulthood. The objective is to develop statistically quantified age estimation standards based on scoring the degree of spheno-occipital fusion. The sample comprises multidetector computed tomography (MDCT) scans of 312 individuals (169 male; 143 female) between 5 and 25 years of age. Each MDCT scan is visualized in a standardized sagittal plane using three-dimensional oblique multiplanar reformatting. Fusion status is scored according to a four-stage system. Transition analysis is used to calculate age ranges for each defined stage and determine the mean age for transition between an unfused, fusing and fused status. The maximum likelihood estimates for the transition from open to fusing in the endocranial half is 14.44 years (male) and 11.42 years (female); transition from fusion in the ectocranial half to complete fusion is 16.16 years (male) and 13.62 years (female). This study affirms the potential value of assessing the degree of fusion in the spheno-occipital synchondrosis as an indicator of skeletal age. Copyright © 2013 Wiley Periodicals, Inc.

Incidence of three-rooted mandibular first molars among contemporary Japanese individuals determined using multidetector computed tomography.

PubMed

Ishii, Namiko; Sakuma, Ayaka; Makino, Yohsuke; Torimitsu, Suguru; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Hoshioka, Yumi; Iwase, Hirotaro; Saitoh, Hisako

2016-09-01

The purpose of this study was to determine the incidence of three-rooted mandibular first molars in a contemporary Japanese population using multidetector computed tomography (MDCT) and examine whether this characteristic root form may be useful for identification purposes. Prior to their forensic autopsies, we obtained MDCT scans of 365 cadavers (255 males, 110 females) with mandibular first molars on both sides. Altogether, 730 mandibular first molars were examined morphologically on reconstructed CT images, and the incidence of three-rooted molars was recorded. The results were analyzed statistically to determine sex and left-right differences using the chi-square test. In all, 189 (25.9%) of the 730 mandibular first molars had three roots: 79 (31.0%) in the 255 males and 35 (31.8%) in the 110 females. No statistically significant difference was found between the sexes. In the 39 individuals who had unilateral three-rooted mandibular first molars, 7 (17.9%) were on the left side and 32 (82.1%) were on the right side, indicating a statistically significant predominance on the right side. The incidence of three-rooted mandibular first molars in contemporary Japanese individuals was 25.9%, with no statistically significant sex difference, but in the case of unilateral three-rooted teeth, with a statistically significant predominance on the right side. Our study found that Japanese and northeastern Asians have a high incidence of the three-rooted mandibular first molars among individuals of Mongolian origin; this finding may be a useful screening tool for identification of unknown individuals. Copyright © 2016. Published by Elsevier Ireland Ltd.

Cone beam CT of the musculoskeletal system: clinical applications.

PubMed

Posadzy, Magdalena; Desimpel, Julie; Vanhoenacker, Filip

2018-02-01

The aim of this pictorial review is to illustrate the use of CBCT in a broad spectrum of musculoskeletal disorders and to compare its diagnostic merit with other imaging modalities, such as conventional radiography (CR), Multidetector Computed Tomography (MDCT) and Magnetic Resonance Imaging. Cone Beam Computed Tomography (CBCT) has been widely used for dental imaging for over two decades. Current CBCT equipment allows use for imaging of various musculoskeletal applications. Because of its low cost and relatively low irradiation, CBCT may have an emergent role in making a more precise diagnosis, assessment of local extent and follow-up of fractures and dislocations of small bones and joints. Due to its exquisite high spatial resolution, CBCT in combination with arthrography may be the preferred technique for detection and local staging of cartilage lesions in small joints. Evaluation of degenerative joint disorders may be facilitated by CBCT compared to CR, particularly in those anatomical areas in which there is much superposition of adjacent bony structures. The use of CBCT in evaluation of osteomyelitis is restricted to detection of sequestrum formation in chronic osteomyelitis. Miscellaneous applications include assessment of (symptomatic) variants, detection and characterization of tumour and tumour-like conditions of bone. • Review the spectrum of MSK disorders in which CBCT may be complementary to other imaging techniques. • Compare the advantages and drawbacks of CBCT compared to other imaging techniques. • Define the present and future role of CBCT in musculoskeletal imaging.

Measuring radiation dose in computed tomography using elliptic phantom and free-in-air, and evaluating iterative metal artifact reduction algorithm

NASA Astrophysics Data System (ADS)

Morgan, Ashraf

The need for an accurate and reliable way for measuring patient dose in multi-row detector computed tomography (MDCT) has increased significantly. This research was focusing on the possibility of measuring CT dose in air to estimate Computed Tomography Dose Index (CTDI) for routine quality control purposes. New elliptic CTDI phantom that better represent human geometry was manufactured for investigating the effect of the subject shape on measured CTDI. Monte Carlo simulation was utilized in order to determine the dose distribution in comparison to the traditional cylindrical CTDI phantom. This research also investigated the effect of Siemens health care newly developed iMAR (iterative metal artifact reduction) algorithm, arthroplasty phantom was designed and manufactured that purpose. The design of new phantoms was part of the research as they mimic the human geometry more than the existing CTDI phantom. The standard CTDI phantom is a right cylinder that does not adequately represent the geometry of the majority of the patient population. Any dose reduction algorithm that is used during patient scan will not be utilized when scanning the CTDI phantom, so a better-designed phantom will allow the use of dose reduction algorithms when measuring dose, which leads to better dose estimation and/or better understanding of dose delivery. Doses from a standard CTDI phantom and the newly-designed phantoms were compared to doses measured in air. Iterative reconstruction is a promising technique in MDCT dose reduction and artifacts correction. Iterative reconstruction algorithms have been developed to address specific imaging tasks as is the case with Iterative Metal Artifact Reduction or iMAR which was developed by Siemens and is to be in use with the companys future computed tomography platform. The goal of iMAR is to reduce metal artifact when imaging patients with metal implants and recover CT number of tissues adjacent to the implant. This research evaluated iMAR capability of recovering CT numbers and reducing noise. Also, the use of iMAR should allow using lower tube voltage instead of 140 KVp which is used frequently to image patients with shoulder implants. The evaluations of image quality and dose reduction were carried out using an arthroplasty phantom.

Quantitative CT: technique dependence of volume estimation on pulmonary nodules

NASA Astrophysics Data System (ADS)

Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Colsher, James; Amurao, Maxwell; Samei, Ehsan

2012-03-01

Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.

[The role of multidetector computer tomography in diagnosis of acute pancreatitis].

PubMed

Lohanikhina, K Iu; Hordiienko, K P; Kozarenko, T M

2014-10-01

With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%.

Multidetector computed tomography diagnosis of gastric volvulus through the foramen of Morgagni.

PubMed

Lecouvet, S; Coulier, B; Pierard, F; Gogoase, M; Coppens, J P; Van Hoof, M

2014-01-01

Morgagni hernia is considered to be the rarest form of all diaphragmatic hernias. It develops through a congenital defect in the retrosternal area. Usually asymptomatic, this entity can lead to life-threatening complications such as incarceration, strangulation or volvulus of the herniated viscus. We hereby report a rare case of organoaxial gastric volvulus producing through the foramen of Morgagni in a 78-year-old woman. The full diagnosis was made by upper gastro-intestinal series and multidetector computed tomography (MDCT). The basic anatomy, physiopathology, diagnostic methods, complications and surgical treatment of Morgagni hernia are briefly reviewed.

[New methods for the evaluation of bone quality. Assessment of bone structural property using imaging.

PubMed

Ito, Masako

Structural property of bone includes micro- or nano-structural property of the trabecular and cortical bone, and macroscopic geometry. Radiological technique is useful to analyze the bone structural property;multi-detector row CT(MDCT)or high-resolution peripheral QCT(HR-pQCT)is available to analyze human bone in vivo . For the analysis of hip geometry, CT-based hip structure analysis(HSA)is available as well as DXA-based HSA. These structural parameters are related to biomechanical property, and these assessment tools provide information of pathological changes or the effects of anti-osteoporotic agents on bone.

CT triage for lung malignancy: coronal multiplanar reformation versus images in three orthogonal planes.

PubMed

Kusk, Martin Weber; Karstoft, Jens; Mussmann, Bo Redder

2015-11-01

Generation of multiplanar reformation (MPR) images has become automatic on most modern computed tomography (CT) scanners, potentially increasing the workload of the reporting radiologists. It is not always clear if this increases diagnostic performance in all clinical tasks. To assess detection performance using only coronal multiplanar reformations (MPR) when triaging patients for lung malignancies with CT compared to images in three orthogonal planes, and to evaluate performance comparison of novice and experienced readers. Retrospective study of 63 patients with suspicion of lung cancer, scanned on 64-slice multidetector computed tomography (MDCT) with images reconstructed in three planes. Coronal images were presented to four readers, two novice and two experienced. Readers decided whether the patients were suspicious for malignant disease, and indicated their confidence on a five-point scale. Sensitivity and specificity on per-patient basis was calculated with regards to a reference standard of histological diagnosis, and compared with the original report using McNemar's test. Receiver operating characteristic (ROC) curves were plotted to compare the performance of the four readers, using the area under the curve (AUC) as figure of merit. No statistically significant difference of sensitivity and specificity was found for any of the readers when compared to the original reports. ROC analysis yielded AUCs in the range of 0.92-0.93 for all readers with no significant difference. Inter-rater agreement was substantial (kappa = 0.72). Sensitivity and specificity were comparable to diagnosis using images in three planes. No significant difference was found between experienced and novice readers. © The Foundation Acta Radiologica 2014.

CT dose reduction using Automatic Exposure Control and iterative reconstruction: A chest paediatric phantoms study.

PubMed

Greffier, Joël; Pereira, Fabricio; Macri, Francesco; Beregi, Jean-Paul; Larbi, Ahmed

2016-04-01

To evaluate the impact of Automatic Exposure Control (AEC) on radiation dose and image quality in paediatric chest scans (MDCT), with or without iterative reconstruction (IR). Three anthropomorphic phantoms representing children aged one, five and 10-year-old were explored using AEC system (CARE Dose 4D) with five modulation strength options. For each phantom, six acquisitions were carried out: one with fixed mAs (without AEC) and five each with different modulation strength. Raw data were reconstructed with Filtered Back Projection (FBP) and with two distinct levels of IR using soft and strong kernels. Dose reduction and image quality indices (Noise, SNR, CNR) were measured in lung and soft tissues. Noise Power Spectrum (NPS) was evaluated with a Catphan 600 phantom. The use of AEC produced a significant dose reduction (p<0.01) for all anthropomorphic sizes employed. According to the modulation strength applied, dose delivered was reduced from 43% to 91%. This pattern led to significantly increased noise (p<0.01) and reduced SNR and CNR (p<0.01). However, IR was able to improve these indices. The use of AEC/IR preserved image quality indices with a lower dose delivered. Doses were reduced from 39% to 58% for the one-year-old phantom, from 46% to 63% for the five-year-old phantom, and from 58% to 74% for the 10-year-old phantom. In addition, AEC/IR changed the patterns of NPS curves in amplitude and in spatial frequency. In chest paediatric MDCT, the use of AEC with IR allows one to obtain a significant dose reduction while maintaining constant image quality indices. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Multidetector CT features of pulmonary focal ground-glass opacity: differences between benign and malignant

PubMed Central

Fan, L; Liu, S-Y; Li, Q-C; Yu, H; Xiao, X-S

2012-01-01

Objective To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT). Methods 82 pathologically or clinically confirmed fGGOs were retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ2 test, Fisher's exact test or Mann–Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy. Results There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively. Conclusion An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant. PMID:22128130

Automated diagnosis of interstitial lung diseases and emphysema in MDCT imaging

NASA Astrophysics Data System (ADS)

Fetita, Catalin; Chang Chien, Kuang-Che; Brillet, Pierre-Yves; Prêteux, Françoise

2007-09-01

Diffuse lung diseases (DLD) include a heterogeneous group of non-neoplasic disease resulting from damage to the lung parenchyma by varying patterns of inflammation. Characterization and quantification of DLD severity using MDCT, mainly in interstitial lung diseases and emphysema, is an important issue in clinical research for the evaluation of new therapies. This paper develops a 3D automated approach for detection and diagnosis of diffuse lung diseases such as fibrosis/honeycombing, ground glass and emphysema. The proposed methodology combines multi-resolution 3D morphological filtering (exploiting the sup-constrained connection cost operator) and graph-based classification for a full characterization of the parenchymal tissue. The morphological filtering performs a multi-level segmentation of the low- and medium-attenuated lung regions as well as their classification with respect to a granularity criterion (multi-resolution analysis). The original intensity range of the CT data volume is thus reduced in the segmented data to a number of levels equal to the resolution depth used (generally ten levels). The specificity of such morphological filtering is to extract tissue patterns locally contrasting with their neighborhood and of size inferior to the resolution depth, while preserving their original shape. A multi-valued hierarchical graph describing the segmentation result is built-up according to the resolution level and the adjacency of the different segmented components. The graph nodes are then enriched with the textural information carried out by their associated components. A graph analysis-reorganization based on the nodes attributes delivers the final classification of the lung parenchyma in normal and ILD/emphysematous regions. It also makes possible to discriminate between different types, or development stages, among the same class of diseases.

Features of cranio-maxillofacial trauma in the massive Sichuan earthquake: analysis of 221 cases with multi-detector row CT.

PubMed

Chu, Zhi-gang; Yang, Zhi-gang; Dong, Zhi-hui; Chen, Tian-wu; Zhu, Zhi-yu; Deng, Wen; Xiao, Jia-he

2011-10-01

In a massive earthquake, cranio-maxillofacial trauma was common. The present study was to determine the features of cranio-maxillofacial trauma sustained in the massive Sichuan earthquake by multi-detector row computed tomography (MDCT). The study included 221 consecutive patients (123 males and 98 females; age range, 1-83 years; median age, 35 years) with cranio-maxillofacial trauma in the Sichuan earthquake, who underwent cranio-maxillofacial MDCT scans. The image data were retrospectively reviewed focusing on the injuries of the cranio-maxillofacial soft tissue, facial bones and cranium. All patients had soft tissue injuries frequently with foreign bodies. Ninety-seven (43.9%) patients had fractures (1.5 involved sites per patient, range from 1 to 8) including single cranial fractures in 36 (37.1%) cases, single maxillofacial fractures were seen in 48 (49.5%) and cranio-maxillofacial fractures in 13 (13.4%). Single bone fracture was more common than multiple bone fractures (p<0.05). Nasal, ethmoid bones and the orbits were the most commonly involved sites of the craniofacial region. Thirty-eight (17.2%) patients had intracranial injuries, the commonest being subarachnoid haemorrhage and the commonest sites were the temporal and frontal regions. Coexisting intracranial injuries were more common in patients with cranial fractures than in patients with maxillofacial fractures (p<0.05). Our results indicate that the cranio-maxillofacial trauma arising from the massive Sichuan earthquake had some characteristic features, and a significant number of individuals had the potential for combined cranial and maxillofacial injuries, successful management of which required a multidisciplinary approach. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Usefulness of computed tomography in pre-surgical evaluation of maxillo-facial pathology with rapid prototyping and surgical pre-planning by virtual reality.

PubMed

Toso, Francesco; Zuiani, Chiara; Vergendo, Maurizio; Salvo, Iolanda; Robiony, Massimo; Politi, Massimo; Bazzocchi, Massimo

2005-01-01

To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomic and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, surgery has been preformed on 12 patients after simulation of the procedure on the stereolithographyc model. The solid prototypes constructed in the difficult cases were sufficiently detailed despite problems related to the artefacts generated by dental fillings an d prostheses. In the remaining cases the MPR/3D images were sufficiently detailed for surgical planning. The surgical results were excellent in all patients who underwent surgery, and the surgeons were satisfied with the improvement in quality and the reduction in time required for the procedure. MDCT enables rapid prototyping using solid replication, which was very helpful in maxillo-facial surgery, despite problems related to artifacts due to dental fillings and prosthesis within the acquisition field; solutions for this problem are work in progress. The protocol used for communication between the different laboratories was valid and reproducible.

Radiation dose from MDCT using Monte Carlo simulations: estimating fetal dose due to pulmonary embolism scans accounting for overscan

NASA Astrophysics Data System (ADS)

Angel, E.; Wellnitz, C.; Goodsitt, M.; DeMarco, J.; Cagnon, C.; Ghatali, M.; Cody, D.; Stevens, D.; McCollough, C.; Primak, A.; McNitt-Gray, M.

2007-03-01

Pregnant women with shortness of breath are increasingly referred for CT Angiography to rule out Pulmonary Embolism (PE). While this exam is typically focused on the lungs, extending scan boundaries and overscan can add to the irradiated volume and have implications on fetal dose. The purpose of this work was to estimate radiation dose to the fetus when various levels of overscan were encountered. Two voxelized models of pregnant patients derived from actual patient anatomy were created based on image data. The models represent an early (< 7 weeks) and late term pregnancy (36 weeks). A previously validated Monte Carlo model of an MDCT scanner was used that takes into account physical details of the scanner. Simulated helical scans used 120 kVp, 4x5 mm beam collimation, pitch 1, and varying beam-off locations (edge of the irradiated volume) were used to represent different protocols plus overscan. Normalized dose (mGy/100mAs) was calculated for each fetus. For the early term and the late term pregnancy models, fetal dose estimates for a standard thoracic PE exam were estimated to be 0.05 and 0.3 mGy/100mAs, respectively, increasing to 9 mGy/100mAs when the beam-off location was extended to encompass the fetus. When performing PE exams to rule out PE in pregnant patients, the beam-off location may have a large effect on fetal dose, especially for late term pregnancies. Careful consideration of ending location of the x-ray beam - and not the end of image data - could result in significant reduction in radiation dose to the fetus.

LINKING LUNG AIRWAY STRUCTURE TO PULMONARY FUNCTION VIA COMPOSITE BRIDGE REGRESSION

PubMed Central

Chen, Kun; Hoffman, Eric A.; Seetharaman, Indu; Jiao, Feiran; Lin, Ching-Long; Chan, Kung-Sik

2017-01-01

The human lung airway is a complex inverted tree-like structure. Detailed airway measurements can be extracted from MDCT-scanned lung images, such as segmental wall thickness, airway diameter, parent-child branch angles, etc. The wealth of lung airway data provides a unique opportunity for advancing our understanding of the fundamental structure-function relationships within the lung. An important problem is to construct and identify important lung airway features in normal subjects and connect these to standardized pulmonary function test results such as FEV1%. Among other things, the problem is complicated by the fact that a particular airway feature may be an important (relevant) predictor only when it pertains to segments of certain generations. Thus, the key is an efficient, consistent method for simultaneously conducting group selection (lung airway feature types) and within-group variable selection (airway generations), i.e., bi-level selection. Here we streamline a comprehensive procedure to process the lung airway data via imputation, normalization, transformation and groupwise principal component analysis, and then adopt a new composite penalized regression approach for conducting bi-level feature selection. As a prototype of composite penalization, the proposed composite bridge regression method is shown to admit an efficient algorithm, enjoy bi-level oracle properties, and outperform several existing methods. We analyze the MDCT lung image data from a cohort of 132 subjects with normal lung function. Our results show that, lung function in terms of FEV1% is promoted by having a less dense and more homogeneous lung comprising an airway whose segments enjoy more heterogeneity in wall thicknesses, larger mean diameters, lumen areas and branch angles. These data hold the potential of defining more accurately the “normal” subject population with borderline atypical lung functions that are clearly influenced by many genetic and environmental factors. PMID:28280520

Life-threatening gastrointestinal system bleeding in Hodgkin disease: multidetector CT findings and review of the literature.

PubMed

Akpinar, Erhan; Türkbey, Bariş; Cil, Barbaros Erhan; Canyiğit, Murat; Dündar, Ziya; Balkanci, Ferhun

2007-06-01

Acute lower gastrointestinal system (GIS) bleeding is a life-threatening condition. Immediate determination of the origin of the bleeding is crucial, since hemostatic management must be initiated as rapidly as possible. Colonoscopy, radionuclide studies, and conventional angiography are considered the most important methods for assessing the origin of the bleeding. There are few published reports about the feasibility of computed tomography (CT) in acute GIS bleeding. We present multidetector CT (MDCT) findings in a case of Hodgkin disease status one month post-chemotherapy (CHOP protocol; cyclophosphamide, doxorubicin, vincristine, prednisone) that presented with acute lower GIS bleeding.

Multidetector computed tomography findings of central bronchopleural fistulas as sequelae of tuberculosis, chemo radiation and trauma: A report of three cases

PubMed Central

Yuksekkaya, Ruken; Ozturk, Banu; Celikyay, Fatih; Sade, Recep; Kupeli, Mustafa; Yeginsu, Ali

2013-01-01

A bronchopleural fistula (BPF) is defined as a direct pathway between the bronchial tree or lung parenchyma and the pleural space. Herein, we describe the clinical findings and imaging results of BPFs in three cases. The patients' medical histories revealed that the first had recurrent pulmonary tuberculosis, the second had small-cell lung cancer (SCLC) and had previously undergone chemoradiotherapy, and the third had trauma. Multidetector computed tomography (MDCT) showed clear communication between the airways and pleural spaces which was sufficient for a proper diagnosis without performing a bronchoscopy. PMID:26029624

Virtual Whipple: preoperative surgical planning with volume-rendered MDCT images to identify arterial variants relevant to the Whipple procedure.

PubMed

Brennan, Darren D; Zamboni, Giulia; Sosna, Jacob; Callery, Mark P; Vollmer, Charles M V; Raptopoulos, Vassilios D; Kruskal, Jonathan B

2007-05-01

The purposes of this study were to combine a thorough understanding of the technical aspects of the Whipple procedure with advanced rendering techniques by introducing a virtual Whipple procedure and to evaluate the utility of this new rendering technique in prediction of the arterial variants that cross the anticipated surgical resection plane. The virtual Whipple is a novel technique that follows the complex surgical steps in a Whipple procedure. Three-dimensional reconstructed angiographic images are used to identify arterial variants for the surgeon as part of the preoperative radiologic assessment of pancreatic and ampullary tumors.

Comparison of image features calculated in different dimensions for computer-aided diagnosis of lung nodules

NASA Astrophysics Data System (ADS)

Xu, Ye; Lee, Michael C.; Boroczky, Lilla; Cann, Aaron D.; Borczuk, Alain C.; Kawut, Steven M.; Powell, Charles A.

2009-02-01

Features calculated from different dimensions of images capture quantitative information of the lung nodules through one or multiple image slices. Previously published computer-aided diagnosis (CADx) systems have used either twodimensional (2D) or three-dimensional (3D) features, though there has been little systematic analysis of the relevance of the different dimensions and of the impact of combining different dimensions. The aim of this study is to determine the importance of combining features calculated in different dimensions. We have performed CADx experiments on 125 pulmonary nodules imaged using multi-detector row CT (MDCT). The CADx system computed 192 2D, 2.5D, and 3D image features of the lesions. Leave-one-out experiments were performed using five different combinations of features from different dimensions: 2D, 3D, 2.5D, 2D+3D, and 2D+3D+2.5D. The experiments were performed ten times for each group. Accuracy, sensitivity and specificity were used to evaluate the performance. Wilcoxon signed-rank tests were applied to compare the classification results from these five different combinations of features. Our results showed that 3D image features generate the best result compared with other combinations of features. This suggests one approach to potentially reducing the dimensionality of the CADx data space and the computational complexity of the system while maintaining diagnostic accuracy.

Reducing radiation dose to selected organs by selecting the tube start angle in MDCT helical scans: A Monte Carlo based study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Di; Zankl, Maria; DeMarco, John J.

Purpose: Previous work has demonstrated that there are significant dose variations with a sinusoidal pattern on the peripheral of a CTDI 32 cm phantom or on the surface of an anthropomorphic phantom when helical CT scanning is performed, resulting in the creation of ''hot'' spots or ''cold'' spots. The purpose of this work was to perform preliminary investigations into the feasibility of exploiting these variations to reduce dose to selected radiosensitive organs solely by varying the tube start angle in CT scans. Methods: Radiation dose to several radiosensitive organs (including breasts, thyroid, uterus, gonads, and eye lenses) resulting from MDCTmore » scans were estimated using Monte Carlo simulation methods on voxelized patient models, including GSF's Baby, Child, and Irene. Dose to fetus was also estimated using four pregnant female models based on CT images of the pregnant patients. Whole-body scans were simulated using 120 kVp, 300 mAs, both 28.8 and 40 mm nominal collimations, and pitch values of 1.5, 1.0, and 0.75 under a wide range of start angles (0 deg. - 340 deg. in 20 deg. increments). The relationship between tube start angle and organ dose was examined for each organ, and the potential dose reduction was calculated. Results: Some organs exhibit a strong dose variation, depending on the tube start angle. For small peripheral organs (e.g., the eye lenses of the Baby phantom at pitch 1.5 with 40 mm collimation), the minimum dose can be 41% lower than the maximum dose, depending on the tube start angle. In general, larger dose reductions occur for smaller peripheral organs in smaller patients when wider collimation is used. Pitch 1.5 and pitch 0.75 have different mechanisms of dose reduction. For pitch 1.5 scans, the dose is usually lowest when the tube start angle is such that the x-ray tube is posterior to the patient when it passes the longitudinal location of the organ. For pitch 0.75 scans, the dose is lowest when the tube start angle is such that the x-ray tube is anterior to the patient when it passes the longitudinal location of the organ. Conclusions: Helical MDCT scanning at pitch 1.5 and pitch 0.75 results in ''cold spots'' and ''hot spots'' that are created both at surface and in-depth locations within patients. For organs that have a relatively small longitudinal extent, dose can vary considerably with different start angles. While current MDCT systems do not provide the user with the ability to control the tube start angle, these results indicate that in these specific situations (pitch 1.5 or pitch 0.75, small organs and especially small patients), there could be significant dose savings to organs if that functionality would be provided.« less

Novel Mahalanobis-based feature selection improves one-class classification of early hepatocellular carcinoma.

PubMed

Thomaz, Ricardo de Lima; Carneiro, Pedro Cunha; Bonin, João Eliton; Macedo, Túlio Augusto Alves; Patrocinio, Ana Claudia; Soares, Alcimar Barbosa

2018-05-01

Detection of early hepatocellular carcinoma (HCC) is responsible for increasing survival rates in up to 40%. One-class classifiers can be used for modeling early HCC in multidetector computed tomography (MDCT), but demand the specific knowledge pertaining to the set of features that best describes the target class. Although the literature outlines several features for characterizing liver lesions, it is unclear which is most relevant for describing early HCC. In this paper, we introduce an unconstrained GA feature selection algorithm based on a multi-objective Mahalanobis fitness function to improve the classification performance for early HCC. We compared our approach to a constrained Mahalanobis function and two other unconstrained functions using Welch's t-test and Gaussian Data Descriptors. The performance of each fitness function was evaluated by cross-validating a one-class SVM. The results show that the proposed multi-objective Mahalanobis fitness function is capable of significantly reducing data dimensionality (96.4%) and improving one-class classification of early HCC (0.84 AUC). Furthermore, the results provide strong evidence that intensity features extracted at the arterial to portal and arterial to equilibrium phases are important for classifying early HCC.

Magnesium intake is inversely associated with coronary artery calcification: the Framingham Heart Study.

PubMed

Hruby, Adela; O'Donnell, Christopher J; Jacques, Paul F; Meigs, James B; Hoffmann, Udo; McKeown, Nicola M

2014-01-01

The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying cardiovascular disease. Little is known about the association of magnesium intake and atherosclerotic calcification in humans. We examined cross-sectional associations of self-reported total (dietary and supplemental) magnesium intake estimated by food frequency questionnaire with CAC and AAC in participants of the Framingham Heart Study who were free of cardiovascular disease and underwent Multi-Detector Computed Tomography (MDCT) of the heart and abdomen (n = 2,695; age: 53 ± 11 years), using multivariate-adjusted Tobit regression. CAC and AAC were quantified using modified Agatston scores (AS). Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, fasting insulin, total-to-high-density lipoprotein cholesterol ratio, use of hormone replacement therapy (women only), menopausal status (women only), treatment for hyperlipidemia, hypertension, cardiovascular disease prevention, or diabetes, as well as self-reported intake of calcium, vitamins D and K, saturated fat, fiber, alcohol, and energy. Secondary analyses included logistic regressions of CAC and AAC outcomes as cut-points (AS >0 and AS ≥90th percentile for age and sex), as well as sex-stratified analyses. In fully adjusted models, a 50-mg/day increment in self-reported total magnesium intake was associated with 22% lower CAC (p < 0.001) and 12% lower AAC (p = 0.07). Consistent with these observations, the odds of having any CAC were 58% lower (p trend: <0.001) and any AAC were 34% lower (p trend: 0.01), in those with the highest compared to those with the lowest magnesium intake. Stronger inverse associations were observed in women than in men. In community-dwelling participants free of cardiovascular disease, self-reported magnesium intake was inversely associated with arterial calcification, which may play a contributing role in magnesium's protective associations in stroke and fatal coronary heart disease. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Magnesium Intake Is Inversely Associated With Coronary Artery Calcification

PubMed Central

Hruby, Adela; O'Donnell, Christopher J.; Jacques, Paul F.; Meigs, James B.; Hoffmann, Udo; McKeown, Nicola M.

2014-01-01

OBJECTIVES The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). BACKGROUND Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying cardiovascular disease. Little is known about the association of magnesium intake and atherosclerotic calcification in humans. METHODS We examined cross-sectional associations of self-reported total (dietary and supplemental) magnesium intake estimated by food frequency questionnaire with CAC and AAC in participants of the Framingham Heart Study who were free of cardiovascular disease and underwent Multi-Detector Computed Tomography (MDCT) of the heart and abdomen (n = 2,695; age: 53 ± 11 years), using multivariate-adjusted Tobit regression. CAC and AAC were quantified using modified Agatston scores (AS). Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, fasting insulin, total-to-high-density lipoprotein cholesterol ratio, use of hormone replacement therapy (women only), menopausal status (women only), treatment for hyperlipidemia, hypertension, cardiovascular disease prevention, or diabetes, as well as self-reported intake of calcium, vitamins D and K, saturated fat, fiber, alcohol, and energy. Secondary analyses included logistic regressions of CAC and AAC outcomes as cut-points (AS >0 and AS ≥90th percentile for age and sex), as well as sex-stratified analyses. RESULTS In fully adjusted models, a 50-mg/day increment in self-reported total magnesium intake was associated with 22% lower CAC (p < 0.001) and 12% lower AAC (p = 0.07). Consistent with these observations, the odds of having any CAC were 58% lower (p trend: <0.001) and any AAC were 34% lower (p trend: 0.01), in those with the highest compared to those with the lowest magnesium intake. Stronger inverse associations were observed in women than in men. CONCLUSIONS In community-dwelling participants free of cardiovascular disease, self-reported magnesium intake was inversely associated with arterial calcification, which may play a contributing role in magnesium's protective associations in stroke and fatal coronary heart disease. PMID:24290571

Mental foramen and lingual vascular canals of mandible on MDCT images: anatomical study and review of the literature.

PubMed

Direk, Filiz; Uysal, Ismihan Ilknur; Kivrak, Ali Sami; Fazliogullari, Zeliha; Unver Dogan, Nadire; Karabulut, Ahmet Kagan

2018-03-01

The mental foramen and lingual vascular canals are related to vessels and nerves in the mandibular body. The aim of the present study was to determine the number and location of these structures and to make measurements of them. The archived Multidetector Computed Tomography images of 100 adult (15- to 70-year-old) patients were evaluated retrospectively. The diameters of the mental foramens and their distances from the front, back, upper and lower reference points were measured. The distribution of mental foramens with respect to the teeth was also researched. The presence of lingual vascular canals, and the number of median and lateral canals was determined, and the length of the median lingual vascular canals measured. All measurement parameters were analyzed by gender, side and age group. Eleven patients demonstrated a total of 15 accessory mental foramen. Median lingual vascular canals were observed in 100% of cases, with lateral lingual vascular canals determined in 32%. Significant differences were observed in the results of different gender groups (P < 0.05); in contrast, no significant difference was observed related with age or side. Accessory mental foramen was determined mostly in males, and unilaterally on the right side; also, the distances of mental foramen, except the distance from the back border of the mandible (P < 0.05), were found to be higher, bilaterally, in males. Variation of mental foramen, as well as the presence, position and size of lingual vascular canals can be clearly investigated by multidetector computed tomography. A preoperative knowledge of the positions of neurovascular and bone structures is very important for preventing complications that may occur during or after operations.

Post-traumatic hepatic arterial pseudoaneurysm and arterioportal shunt.

PubMed

Maes, J; D'Archambeau, O; Snoeckx, A; Op de Beeck, B; Voormolen, M; Parizel, P M

2010-01-01

The authors report the case of a 21-year-old man who suffered from a blunt abdominal trauma. Initial imaging revealed a liver laceration at the right lobe, a perirenal hematoma of the right kidney and a hematoma of the right adrenal gland. Follow-up MDCT-scan on day 10 after admission showed at the arterial-phase contrast-enhanced study perfusion alterations and two hepatic pseudoaneurysms. The diagnosis of pseudoaneurysm was confirmed and treated angiographically with superselective coil embolization. A follow-up CT-scan on day 17 showed at a nontreated area an arterioportal shunt and a wedge-shaped transient hepatic parenchymal enhancement. This was confirmed angiographically and subsequently treated with coil embolization.

Imaging in lung transplants: Checklist for the radiologist.

PubMed

Madan, Rachna; Chansakul, Thanissara; Goldberg, Hilary J

2014-10-01

Post lung transplant complications can have overlapping clinical and imaging features, and hence, the time point at which they occur is a key distinguisher. Complications of lung transplantation may occur along a continuum in the immediate or longer postoperative period, including surgical and mechanical problems due to size mismatch and vascular as well as airway anastomotic complication, injuries from ischemia and reperfusion, acute and chronic rejection, pulmonary infections, and post-transplantation lymphoproliferative disorder. Life expectancy after lung transplantation has been limited primarily by chronic rejection and infection. Multiple detector computed tomography (MDCT) is critical for evaluation and early diagnosis of complications to enable selection of effective therapy and decrease morbidity and mortality among lung transplant recipients.

Functional MR Imaging Techniques in Oncology in the Era of Personalized Medicine.

PubMed

Benz, Matthias R; Vargas, Hebert Alberto; Sala, Evis

2016-02-01

DW and DCE MR imaging contribute significantly to diagnosis, treatment planning, response assessment, and prognosis in personalized cancer medicine. Nevertheless, the need for further standardization of these techniques needs to be addressed. Whole-body DW MR imaging is an exciting field; however, future studies need to investigate in more depth the biologic significance of the findings depicted, their prognostic relevance, and cost-effectiveness in comparison with MDCT and PET/CT. New MR imaging probes, such as targeted or activatable contrast agents and dynamic nuclear hyperpolarization, show great promise to further improve the care of patients with cancer in the near future. Copyright © 2016 Elsevier Inc. All rights reserved.

Discordance between Prevalent Vertebral Fracture and Vertebral Strength Estimated by the Finite Element Method Based on Quantitative Computed Tomography in Patients with Type 2 Diabetes Mellitus

PubMed Central

2015-01-01

Background Bone fragility is increased in patients with type 2 diabetes mellitus (T2DM), but a useful method to estimate bone fragility in T2DM patients is lacking because bone mineral density alone is not sufficient to assess the risk of fracture. This study investigated the association between prevalent vertebral fractures (VFs) and the vertebral strength index estimated by the quantitative computed tomography-based nonlinear finite element method (QCT-based nonlinear FEM) using multi-detector computed tomography (MDCT) for clinical practice use. Research Design and Methods A cross-sectional observational study was conducted on 54 postmenopausal women and 92 men over 50 years of age, all of whom had T2DM. The vertebral strength index was compared in patients with and without VFs confirmed by spinal radiographs. A standard FEM procedure was performed with the application of known parameters for the bone material properties obtained from nondiabetic subjects. Results A total of 20 women (37.0%) and 39 men (42.4%) with VFs were identified. The vertebral strength index was significantly higher in the men than in the women (P<0.01). Multiple regression analysis demonstrated that the vertebral strength index was significantly and positively correlated with the spinal bone mineral density (BMD) and inversely associated with age in both genders. There were no significant differences in the parameters, including the vertebral strength index, between patients with and without VFs. Logistic regression analysis adjusted for age, spine BMD, BMI, HbA1c, and duration of T2DM did not indicate a significant relationship between the vertebral strength index and the presence of VFs. Conclusion The vertebral strength index calculated by QCT-based nonlinear FEM using material property parameters obtained from nondiabetic subjects, whose risk of fracture is lower than that of T2DM patients, was not significantly associated with bone fragility in patients with T2DM. This discordance may indirectly suggest that patients with T2DM have deteriorated bone material compared with nondiabetic subjects, a potential cause of bone fragility in T2DM patients. PMID:26642210

Pancreatic Carcinoma: the Disease that Kills

PubMed Central

Kabashi, Serbeze; Dedushi, Kreshnike; Ramadani, Naser; Mucaj, Sefedin; Hoxhaj, Asrtrit; Jerliu, Naim

2016-01-01

The purpose of this case report is to demonstrate the clinical symptoms and laboratory changes that have occurred very late and were very few in number even the imaging studies performed at that time showed an intensive local tumor growth associated with the wide infiltration of the both adjacent and distant upper abdominal structures. A 71-year-old male patient who was a chronic alcohol abuser and ex smoker (quit smoking 8 years earlier) presented with symptoms of mild pain on epigastric region that irradiated toward the back and significant weight loss. The initial ultrasonography (US) examination was performed, followed by the lab tests and multidetector computed tomography (MDCT) examination. The diagnostic studies confirmed the presence of the pancreatic’s body mass. The ordered laparoscopic evaluation established definitive diagnosis. Initial US examination showed heterogeneous pseudo-cystic changes and slight edema of the pancreatic parenchyma associated with the multiple oval hyperechogenic lesions of liver - the signs highly suggestive of secondary metastatic deposits. The other imaging findings that were obtained with the use of the MDCT confirmed the presence of an expansive primary process of the body of the pancreas associated with the secondary metastatic changes in liver. In addition, the consecutive lymphadenopathy was revealed along hepatoduodenal ligament, retropancreatic region and intraperitoneal compartment. Tumor markers resulted with the high values of the AFP of 2.3, CA19-9 of 423.0 U/mL, and CEA of 219.0 ng/mL. The specimen of the tumor tissue taken during laparoscopic biopsy was sent for histologic examination and the final result was “metastatic adenocarcinoma of pancreas”. Pancreatic body carcinoma has always been associated with poor prognosis because diagnosis is made at the advanced stage of the disease. Therefore, poor prognosis might be improved if early diagnosis could be made. Recent researches confirmed genetic predisposition for this disease at certain group of patients and this “high risk” group has to be followed up with regular imaging studies and lab analysis. PMID:28983357

Pancreatic Carcinoma: the Disease that Kills.

PubMed

Kabashi, Serbeze; Dedushi, Kreshnike; Ramadani, Naser; Mucaj, Sefedin; Hoxhaj, Asrtrit; Jerliu, Naim

2016-02-01

The purpose of this case report is to demonstrate the clinical symptoms and laboratory changes that have occurred very late and were very few in number even the imaging studies performed at that time showed an intensive local tumor growth associated with the wide infiltration of the both adjacent and distant upper abdominal structures. A 71-year-old male patient who was a chronic alcohol abuser and ex smoker (quit smoking 8 years earlier) presented with symptoms of mild pain on epigastric region that irradiated toward the back and significant weight loss. The initial ultrasonography (US) examination was performed, followed by the lab tests and multidetector computed tomography (MDCT) examination. The diagnostic studies confirmed the presence of the pancreatic's body mass. The ordered laparoscopic evaluation established definitive diagnosis. Initial US examination showed heterogeneous pseudo-cystic changes and slight edema of the pancreatic parenchyma associated with the multiple oval hyperechogenic lesions of liver - the signs highly suggestive of secondary metastatic deposits. The other imaging findings that were obtained with the use of the MDCT confirmed the presence of an expansive primary process of the body of the pancreas associated with the secondary metastatic changes in liver. In addition, the consecutive lymphadenopathy was revealed along hepatoduodenal ligament, retropancreatic region and intraperitoneal compartment. Tumor markers resulted with the high values of the AFP of 2.3, CA19-9 of 423.0 U/mL, and CEA of 219.0 ng/mL. The specimen of the tumor tissue taken during laparoscopic biopsy was sent for histologic examination and the final result was "metastatic adenocarcinoma of pancreas". Pancreatic body carcinoma has always been associated with poor prognosis because diagnosis is made at the advanced stage of the disease. Therefore, poor prognosis might be improved if early diagnosis could be made. Recent researches confirmed genetic predisposition for this disease at certain group of patients and this "high risk" group has to be followed up with regular imaging studies and lab analysis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamoureux, R; Sinclair, L; Mench, A

Purpose: To introduce and investigate effective diameter ratios as a new patient metric for use in computed tomography protocol selection as a supplement to patient-specific size parameter data. Methods: The metrics of outer effective diameter and inner effective diameter were measured for 7 post-mortem subjects scanned with a standardized chest/abdomen/pelvis (CAP) protocol on a 320-slice MDCT scanner. The outer effective diameter was calculated by obtaining the anterior/posterior and lateral dimensions of the imaged anatomy at the middle of the scan range using Effective Diameter= SQRT(AP height*Lat Width). The inner effective diameter was calculated with the same equation using the APmore » and Lat dimensions of the anatomy excluding the adipose tissue. The ratio of outer to inner effective diameter was calculated for each subject. A relationship to BMI, weight, and CTDI conversion coefficients was investigated. Results: For the largest subject with BMI of 43.85 kg/m2 and weight of 255 lbs the diameter ratio was calculated as 1.33. For the second largest subject with BMI of 33.5 kg/m2 and weight of 192.4 lbs the diameter ratio was measured as 1.43, indicating a larger percentage of adipose tissue in the second largest subject’s anatomical composition. For the smallest subject at BMI of 17.4 kg/m2 and weight of 86 lbs a similar tissue composition was indicated as a subject with BMI of 24.2 kg/m2 and weight of 136 lbs as they had the same diameter ratios of 1.11. Conclusion: The diameter ratio proves to contain information about anatomical composition that the BMI and weight alone do not. The utility of this metric is still being examined but could prove useful for determining MDCT techniques and for giving a more in depth detail of the composition of a patient’s body habitus.« less

Image overlay navigation by markerless surface registration in gastrointestinal, hepatobiliary and pancreatic surgery.

PubMed

Sugimoto, Maki; Yasuda, Hideki; Koda, Keiji; Suzuki, Masato; Yamazaki, Masato; Tezuka, Tohru; Kosugi, Chihiro; Higuchi, Ryota; Watayo, Yoshihisa; Yagawa, Yohsuke; Uemura, Shuichiro; Tsuchiya, Hironori; Azuma, Takeshi

2010-09-01

We applied a new concept of "image overlay surgery" consisting of the integration of virtual reality (VR) and augmented reality (AR) technology, in which dynamic 3D images were superimposed on the patient's actual body surface and evaluated as a reference for surgical navigation in gastrointestinal, hepatobiliary and pancreatic surgery. We carried out seven surgeries, including three cholecystectomies, two gastrectomies and two colectomies. A Macintosh and a DICOM workstation OsiriX were used in the operating room for image analysis. Raw data of the preoperative patient information obtained via MDCT were reconstructed to volume rendering and projected onto the patient's body surface during the surgeries. For accurate registration, OsiriX was first set to reproduce the patient body surface, and the positional coordinates of the umbilicus, left and right nipples, and the inguinal region were fixed as physiological markers on the body surface to reduce the positional error. The registration process was non-invasive and markerlesss, and was completed within 5 min. Image overlay navigation was helpful for 3D anatomical understanding of the surgical target in the gastrointestinal, hepatobiliary and pancreatic anatomies. The surgeon was able to minimize movement of the gaze and could utilize the image assistance without interfering with the forceps operation, reducing the gap from the VR. Unexpected organ injury could be avoided in all procedures. In biliary surgery, the projected virtual cholangiogram on the abdominal wall could advance safely with identification of the bile duct. For early gastric and colorectal cancer, the small tumors and blood vessels, which usually could not be found on the gastric serosa by laparoscopic view, were simultaneously detected on the body surface by carbon dioxide-enhanced MDCT. This provided accurate reconstructions of the tumor and involved lymph node, directly linked with optimization of the surgical procedures. Our non-invasive markerless registration using physiological markers on the body surface reduced logistical efforts. The image overlay technique is a useful tool when highlighting hidden structures, giving more information.

Imaging in chronic obstructive pulmonary disease.

PubMed

Shaker, Saher B; Dirksen, Asger; Bach, Karen S; Mortensen, Jann

2007-06-01

Chronic obstructive pulmonary disease (COPD) is divided into pulmonary emphysema and chronic bronchitis (CB). Emphysema is defined patho-anatomically as "permanent enlargement of airspaces distal to the terminal bronchiole, accompanied by the destruction of their walls, and without obvious fibrosis" (1). These lesions are readily identified and quantitated using computed tomography (CT), whereas the accompanying hyperinflation is best detected on plain chest X-ray, especially in advanced disease. The diagnosis of CB is clinical and relies on the presence of productive cough for 3 months in 2 or more successive years. The pathological changes of mucosal inflammation and bronchial wall thickening have been more difficult to identify with available imaging techniques. However, recent studies using Multi-detector row CT (MDCT) reported more reproducible assessment of air wall thickening.

High resolution multidetector CT aided tissue analysis and quantification of lung fibrosis

NASA Astrophysics Data System (ADS)

Zavaletta, Vanessa A.; Karwoski, Ronald A.; Bartholmai, Brian; Robb, Richard A.

2006-03-01

Idiopathic pulmonary fibrosis (IPF, also known as Idiopathic Usual Interstitial Pneumontis, pathologically) is a progressive diffuse lung disease which has a median survival rate of less than four years with a prevalence of 15-20/100,000 in the United States. Global function changes are measured by pulmonary function tests and the diagnosis and extent of pulmonary structural changes are typically assessed by acquiring two-dimensional high resolution CT (HRCT) images. The acquisition and analysis of volumetric high resolution Multi-Detector CT (MDCT) images with nearly isotropic pixels offers the potential to measure both lung function and structure. This paper presents a new approach to three dimensional lung image analysis and classification of normal and abnormal structures in lungs with IPF.

Assessment of vascular invasion by bone and soft tissue tumours of the limbs: usefulness of MDCT angiography.

PubMed

Thévenin, Fabrice S; Drapé, Jean-Luc; Biau, David; Campagna, Raphaël; Richarme, Delphine; Guerini, Henri; Chevrot, Alain; Larousserie, Frédérique; Babinet, Antoine; Anract, Philippe; Feydy, Antoine

2010-06-01

To evaluate the accuracy of computed tomography angiography (CTA) in predicting arterial encasement by limb tumours, by comparing CTA with surgical findings (gold standard). Preoperative CTA images of 55 arteries in 48 patients were assessed for arterial status: cross-sectional CTA images were scored as showing a fat plane between artery and tumour (score 0), slight contact between artery and tumour (score 1), partial arterial encasement (score 2) or total arterial encasement (score 3). Reformatted CTA images were assessed for arterial displacement, rigid wall, stenosis or occlusion. At surgery, arteries were classified as free or surgically encased; 45 arteries were free and 10 were surgically encased. Multivariate logistic regression identified the axial CTA score as a relevant predictor for arterial encasement and subsequent vascular intervention during surgery. All sites where CTA showed a fat plane between the tumour and the artery were classified as free at surgery (n = 28/28). The sensitivity of total arterial encasement on CTA (score 3) was 90%, specificity 93%, accuracy 93% and positive likelihood ratio 13.5. CTA evidence of total arterial encasement is a highly specific indication of arterial encasement. The presence of fat between the tumour and the artery on CTA rules out arterial involvement at surgery.

Experimental benchmarking of a Monte Carlo dose simulation code for pediatric CT

NASA Astrophysics Data System (ADS)

Li, Xiang; Samei, Ehsan; Yoshizumi, Terry; Colsher, James G.; Jones, Robert P.; Frush, Donald P.

2007-03-01

In recent years, there has been a desire to reduce CT radiation dose to children because of their susceptibility and prolonged risk for cancer induction. Concerns arise, however, as to the impact of dose reduction on image quality and thus potentially on diagnostic accuracy. To study the dose and image quality relationship, we are developing a simulation code to calculate organ dose in pediatric CT patients. To benchmark this code, a cylindrical phantom was built to represent a pediatric torso, which allows measurements of dose distributions from its center to its periphery. Dose distributions for axial CT scans were measured on a 64-slice multidetector CT (MDCT) scanner (GE Healthcare, Chalfont St. Giles, UK). The same measurements were simulated using a Monte Carlo code (PENELOPE, Universitat de Barcelona) with the applicable CT geometry including bowtie filter. The deviations between simulated and measured dose values were generally within 5%. To our knowledge, this work is one of the first attempts to compare measured radial dose distributions on a cylindrical phantom with Monte Carlo simulated results. It provides a simple and effective method for benchmarking organ dose simulation codes and demonstrates the potential of Monte Carlo simulation for investigating the relationship between dose and image quality for pediatric CT patients.

2013 ACC/AHA versus 2004 NECP ATP III Guidelines in the Assignment of Statin Treatment in a Korean Population with Subclinical Coronary Atherosclerosis.

PubMed

Jung, Chang Hee; Lee, Min Jung; Kang, Yu Mi; Yang, Dong Hyun; Kang, Joon-Won; Kim, Eun Hee; Park, Duk-Woo; Park, Joong-Yeol; Kim, Hong-Kyu; Lee, Woo Je

2015-01-01

The usefulness of the 2013 ACC/AHA guidelines for the management of blood cholesterol in the Asian population remains controversial. In this study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines is better aligned with the presence of subclinical coronary atherosclerosis detected by CCTA (coronary computed tomography angiography) compared to the previously recommended 2004 NCEP ATP III guidelines. We collected the data from 5,837 asymptomatic subjects who underwent CCTA using MDCT during routine health examinations. Based on risk factor assessment and lipid data, we determined guideline-based eligibility for statin therapy according to the 2013 ACC/AHA and 2004 NCEP ATP III guidelines. We defined the presence and severity of subclinical coronary atherosclerosis detected in CCTA according to the presence of significant coronary artery stenosis (defined as >50% stenosis), plaques, and the degree of coronary calcification. As compared to the 2004 ATP III guidelines, a significantly higher proportion of subjects with significant coronary stenosis (61.8% vs. 33.8%), plaques (52.3% vs. 24.7%), and higher CACS (CACS >100, 63.6% vs. 26.5%) was assigned to statin therapy using the 2013 ACC/AHA guidelines (P < .001 for all variables). The area under the curves of the pooled cohort equation of the new guidelines in detecting significant stenosis, plaques, and higher CACS were significantly higher than those of the Framingham risk calculator. Compared to the previous ATP III guidelines, the 2013 ACC/AHA guidelines were more sensitive in identifying subjects with subclinical coronary atherosclerosis detected by CCTA in an Asian population.

2013 ACC/AHA versus 2004 NECP ATP III Guidelines in the Assignment of Statin Treatment in a Korean Population with Subclinical Coronary Atherosclerosis

PubMed Central

Kang, Yu Mi; Yang, Dong Hyun; Kang, Joon-Won; Kim, Eun Hee; Park, Duk-Woo; Park, Joong-Yeol; Kim, Hong-Kyu; Lee, Woo Je

2015-01-01

Background The usefulness of the 2013 ACC/AHA guidelines for the management of blood cholesterol in the Asian population remains controversial. In this study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines is better aligned with the presence of subclinical coronary atherosclerosis detected by CCTA (coronary computed tomography angiography) compared to the previously recommended 2004 NCEP ATP III guidelines. Methods We collected the data from 5,837 asymptomatic subjects who underwent CCTA using MDCT during routine health examinations. Based on risk factor assessment and lipid data, we determined guideline-based eligibility for statin therapy according to the 2013 ACC/AHA and 2004 NCEP ATP III guidelines. We defined the presence and severity of subclinical coronary atherosclerosis detected in CCTA according to the presence of significant coronary artery stenosis (defined as >50% stenosis), plaques, and the degree of coronary calcification. Results As compared to the 2004 ATP III guidelines, a significantly higher proportion of subjects with significant coronary stenosis (61.8% vs. 33.8%), plaques (52.3% vs. 24.7%), and higher CACS (CACS >100, 63.6% vs. 26.5%) was assigned to statin therapy using the 2013 ACC/AHA guidelines (P < .001 for all variables). The area under the curves of the pooled cohort equation of the new guidelines in detecting significant stenosis, plaques, and higher CACS were significantly higher than those of the Framingham risk calculator. Conclusions Compared to the previous ATP III guidelines, the 2013 ACC/AHA guidelines were more sensitive in identifying subjects with subclinical coronary atherosclerosis detected by CCTA in an Asian population. PMID:26372638

Dose reduction assessment in dynamic CT myocardial perfusion imaging in a porcine balloon-induced-ischemia model

NASA Astrophysics Data System (ADS)

Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

2014-03-01

We investigated the use of an advanced hybrid iterative reconstruction (IR) technique (iDose4, Philips Health- care) for low dose dynamic myocardial CT perfusion (CTP) imaging. A porcine model was created to mimic coronary stenosis through partial occlusion of the left anterior descending (LAD) artery with a balloon catheter. The severity of LAD occlusion was adjusted with FFR measurements. Dynamic CT images were acquired at end-systole (45% R-R) using a multi-detector CT (MDCT) scanner. Various corrections were applied to the acquired scans to reduce motion and imaging artifacts. Absolute myocardial blood flow (MBF) was computed with a deconvolution-based approach using singular value decomposition (SVD). We compared a high and a low dose radiation protocol corresponding to two different tube-voltage/tube-current combinations (80kV p/100mAs and 120kV p/150mAs). The corresponding radiation doses for these protocols are 7.8mSv and 34.3mSV , respectively. The images were reconstructed using conventional FBP and three noise-reduction strengths of the IR method, iDose. Flow contrast-to-noise ratio, CNRf, as obtained from MBF maps, was used to quantitatively evaluate the effect of reconstruction on contrast between normal and ischemic myocardial tissue. Preliminary results showed that the use of iDose to reconstruct low dose images provide better or comparable CNRf to that of high dose images reconstructed with FBP, suggesting significant dose savings. CNRf was improved with the three used levels of iDose compared to FBP for both protocols. When using the entire 4D dynamic sequence for MBF computation, a 77% dose reduction was achieved, while considering only half the scans (i.e., every other heart cycle) allowed even further dose reduction while maintaining relatively higher CNRf.

Upgrade to iterative image reconstruction (IR) in abdominal MDCT imaging: a clinical study for detailed parameter optimization beyond vendor recommendations using the adaptive statistical iterative reconstruction environment (ASIR).

PubMed

Mueck, F G; Körner, M; Scherr, M K; Geyer, L L; Deak, Z; Linsenmaier, U; Reiser, M; Wirth, S

2012-03-01

To compare the image quality of dose-reduced 64-row abdominal CT reconstructed at different levels of adaptive statistical iterative reconstruction (ASIR) to full-dose baseline examinations reconstructed with filtered back-projection (FBP) in a clinical setting and upgrade situation. Abdominal baseline examinations (noise index NI = 29; LightSpeed VCT XT, GE) were intra-individually compared to follow-up studies on a CT with an ASIR option (NI = 43; Discovery HD750, GE), n = 42. Standard-kernel images were calculated with ASIR blendings of 0 - 100 % in slice and volume mode, respectively. Three experienced radiologists compared the image quality of these 567 sets to their corresponding full-dose baseline examination (- 2: diagnostically inferior, - 1: inferior, 0: equal, + 1: superior, + 2: diagnostically superior). Furthermore, a phantom was scanned. Statistical analysis used the Wilcoxon - the Mann-Whitney U-test and the intra-class correlation (ICC). The mean CTDIvol decreased from 19.7 ± 5.5 to 12.2 ± 4.7 mGy (p < 0.001). The ICC was 0.861. The total image quality of the dose-reduced ASIR studies was comparable to the baseline at ASIR 50 % in slice (p = 0.18) and ASIR 50 - 100 % in volume mode (p > 0.10). Volume mode performed 73 % slower than slice mode (p < 0.01). After the system upgrade, the vendor recommendation of ASIR 50 % in slice mode allowed for a dose reduction of 38 % in abdominal CT with comparable image quality and time expenditure. However, there is still further dose reduction potential for more complex reconstruction settings. © Georg Thieme Verlag KG Stuttgart · New York.

Association between cardiovascular risk profiles and the presence and extent of different types of coronary atherosclerotic plaque as detected by multidetector computed tomography.

PubMed

Bamberg, Fabian; Dannemann, Nina; Shapiro, Michael D; Seneviratne, Sujith K; Ferencik, Maros; Butler, Javed; Koenig, Wolfgang; Nasir, Khurram; Cury, Ricardo C; Tawakol, Ahmed; Achenbach, Stephan; Brady, Thomas J; Hoffmann, Udo

2008-03-01

To assess the association between cardiovascular risk factors and extent of noncalcified- (NCAP), mixed- (MCAP), and calcified coronary atherosclerotic plaque (CAP). In this cross-sectional study, we included consecutive subjects who presented with chest pain but had no history of coronary artery disease (CAD) and did not develop acute coronary syndrome. Contrast-enhanced 64-slice coronary MDCT was performed to determine the presence of NCAP, MCAP, and CAP for each coronary segment. Among 195 patients (91 women, mean age: 54.6+/-12.0) exclusively NCAP was detected in 11 patients (5.6%). The extent of NCAP decreased and the extent of MCAP and CAP increased with age (P=0.06, P=0.02, and P=0.13, respectively). Hyperlipidemia and family history of CAD were associated with the extent of NCAP after adjusting for other risk factors (P=0.02 and P=0.04, respectively) or for the extent of MCAP and CAP (P=0.02 and P=0.05, respectively). Our data suggest that only a small proportion of individuals have exclusively NCAP and indicate that the relation of NCAP and CAP changes with age. Among individual risk factors, hyperlipidemia and family history of CAD may be associated with the extent of NCAP. Larger observational trials are necessary to confirm our findings.

Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma.

PubMed

Stengel, Dirk; Rademacher, Grit; Ekkernkamp, Axel; Güthoff, Claas; Mutze, Sven

2015-09-14

Ultrasonography (performed by means of a four-quadrant, focused assessment of sonography for trauma (FAST)) is regarded as a key instrument for the initial assessment of patients with suspected blunt abdominal and thoraco-abdominal trauma in the emergency department setting. FAST has a high specificity but low sensitivity in detecting and excluding visceral injuries. Proponents of FAST argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of unnecessary multi-detector computed tomography (MDCT) scans, and enable quicker triage to surgical and non-surgical care. Given the proven accuracy, increasing availability of, and indication for, MDCT among patients with blunt abdominal and multiple injuries, we aimed to compile the best available evidence of the use of FAST-based assessment compared with other primary trauma assessment protocols. To assess the effects of diagnostic algorithms using ultrasonography including in FAST examinations in the emergency department in relation to the early, late, and overall mortality of patients with suspected blunt abdominal trauma. The most recent search was run on 30th June 2015. We searched the Cochrane Injuries Group Specialised Register, The Cochrane Library, MEDLINE (OvidSP), EMBASE (OvidSP), ISI Web of Science (SCI-EXPANDED, SSCI, CPCI-S, and CPSI-SSH), clinical trials registers, and screened reference lists. Trial authors were contacted for further information and individual patient data. We included randomised controlled trials (RCTs). Participants were patients with blunt torso, abdominal, or multiple trauma undergoing diagnostic investigations for abdominal organ injury. The intervention was diagnostic algorithms comprising emergency ultrasonography (US). The control was diagnostic algorithms without US examinations (for example, primary computed tomography (CT) or diagnostic peritoneal lavage (DPL)). Outcomes were mortality, use of CT or invasive procedures (DPL, laparoscopy, laparotomy), and cost-effectiveness. Two authors (DS and CG) independently selected trials for inclusion, assessed methodological quality, and extracted data. Methodological quality was assessed using the Cochrane Collaboration risk of bias tool. Where possible, data were pooled and relative risks (RRs), risk differences (RDs), and weighted mean differences, each with 95% confidence intervals (CIs), were calculated by fixed-effect or random-effects models as appropriate. We identified four studies meeting our inclusion criteria. Overall, trials were of poor to moderate methodological quality. Few trial authors responded to our written inquiries seeking to resolve controversial issues and to obtain individual patient data. Strong heterogeneity amongst the trials prompted discussion between the review authors as to whether the data should or should not be pooled; we decided in favour of a quantitative synthesis to provide a rough impression about the effect sizes achievable with US-based triage algorithms. We pooled mortality data from three trials involving 1254 patients; the RR in favour of the FAST arm was 1.00 (95% CI 0.50 to 2.00). FAST-based pathways reduced the number of CT scans (random-effects model RD -0.52, 95% CI -0.83 to -0.21), but the meaning of this result was unclear. The experimental evidence justifying FAST-based clinical pathways in diagnosing patients with suspected abdominal or multiple blunt trauma remains poor. Because of strong heterogeneity between the trial results, the quantitative information provided by this review may only be used in an exploratory fashion. It is unlikely that FAST will ever be investigated by means of a confirmatory, large-scale RCT in the future. Thus, this Cochrane Review may be regarded as a review which provides the best available evidence for clinical practice guidelines and management recommendations. It can only be concluded from the few head-to-head studies that negative US scans are likely to reduce the incidence of MDCT scans which, given the low sensitivity of FAST (or reliability of negative results), may adversely affect the diagnostic yield of the trauma survey. At best, US has no negative impact on mortality or morbidity. Assuming that major blunt abdominal or multiple trauma is associated with 15% mortality and a CT-based diagnostic work-up is considered the current standard of care, 874, 3495, or 21,838 patients are needed per intervention group to demonstrate non-inferiority of FAST to CT-based algorithms with non-inferiority margins of 5%, 2.5%, and 1%, power of 90%, and a type-I error alpha of 5%.

High Intensity Focused Ultrasound Ablation of Pancreatic Neuroendocrine Tumours: Report of Two Cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orgera, Gianluigi, E-mail: gianluigi.orgera@ieo.it; Krokidis, Miltiadis; Monfardini, Lorenzo

2011-04-15

We describe the use of ultrasound-guided high-intensity focused ultrasound (HIFU) for ablation of two pancreatic neuroendocrine tumours (NETs; insulinomas) in two inoperable young female patients. Both suffered from episodes of severe nightly hypoglycemia that was not efficiently controlled by medical treatment. After HIFU ablation, local disease control and symptom relief were achieved without postinterventional complications. The patients remained free of symptoms during 9-month follow-up. The lesions appeared to be decreased in volume, and there was decreased enhancing pattern in the multidetector computed tomography control (MDCT). HIFU is likely to be a valid alternative for symptoms control in patients with pancreaticmore » NETs. However, currently the procedure should be reserved for inoperable patients for whom symptoms cannot be controlled by medical therapy.« less

Lateral topography for reducing effective dose in low-dose chest CT.

PubMed

Bang, Dong-Ho; Lim, Daekeon; Hwang, Wi-Sub; Park, Seong-Hoon; Jeong, Ok-man; Kang, Kyung Wook; Kang, Hohyung

2013-06-01

The purposes of this study were to assess radiation exposure during low-dose chest CT by using lateral topography and to compare the lateral topographic findings with findings obtained with anteroposterior topography alone and anteroposterior and lateral topography combined. From November 2011 to February 2012, 210 male subjects were enrolled in the study. Age, weight, and height of the men were recorded. All subjects were placed into one of three subgroups based on the type of topographic image obtained: anteroposterior topography, lateral topography, and both anteroposterior and lateral topography. Imaging was performed with a 128-MDCT scanner. CT, except for topography, was the same for all subjects. A radiologist analyzed each image, recorded scan length, checked for any insufficiencies in the FOV, and calculated the effective radiation dose. One-way analysis of variance and multiple comparisons were used to compare the effective radiation exposure and scan length between groups. The mean scan length in the anteroposterior topography group was significantly greater than that of the lateral topography group and the combined anteroposterior and lateral topography group (p < 0.001). The mean effective radiation dose for the lateral topography group (0.735 ± 0.033 mSv) was significantly lower than that for the anteroposterior topography group (0.763 ± 0.038 mSv) and the combined anteroposterior and lateral topography group (0.773 ± 0.038) (p < 0.001). Lateral topographic low-dose CT was associated with a lower effective radiation dose and scan length than either anteroposterior topographic low-dose chest CT or low-dose chest CT with both anteroposterior and lateral topograms.

Reduction in growth threshold for pulmonary metastases: an opportunity for volumetry and its impact on treatment decisions.

PubMed

Vogel, M N; Schmücker, S; Maksimovic, O; Hartmann, J; Claussen, C D; Horger, M

2012-07-01

This study compares tumour response assessment by automated CT volumetry and standard manual measurements regarding the impact on treatment decisions and patient outcome. 58 consecutive patients with 203 pulmonary metastases undergoing baseline and follow-up multirow detector CT (MDCT) under chemotherapy were assessed for response to chemotherapy. Tumour burden of pulmonary target lesions was quantified in three ways: (1) following response evaluation criteria in solid tumours (RECIST); (2) following the volume equivalents of RECIST (i.e. with a threshold of -65/+73%); and (3) using calculated limits for stable disease (SD). For volumetry, calculated limits had been set at ±38% prior to the study by repeated quantification of nodules scanned twice. Results were compared using non-weighted κ-values and were evaluated for their impact on treatment decisions and patient outcome. In 15 (17%) of the 58 patients, the results of response assessment were inconsistent with 1 of the 3 methods, which would have had an impact on treatment decisions in 8 (13%). Patient outcome regarding therapy response could be verified in 5 (33%) of the 15 patients with inconsistent measurement results and was consistent with both RECIST and volumetry in 1, with calculated limits in 3 and with none in 1. Diagnosis as to the overall response was consistent with RECIST in six patients, with volumetry in six and with calculated limits in eight cases. There is an impact of different methods for therapy response assessment on treatment decisions. A reduction of threshold for SD to ±30-40% of volume change seems reasonable when using volumetry.

Potential benefit of the CT adaptive statistical iterative reconstruction method for pediatric cardiac diagnosis

NASA Astrophysics Data System (ADS)

Miéville, Frédéric A.; Ayestaran, Paul; Argaud, Christophe; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Gudinchet, François; Bochud, François; Verdun, Francis R.

2010-04-01

Adaptive Statistical Iterative Reconstruction (ASIR) is a new imaging reconstruction technique recently introduced by General Electric (GE). This technique, when combined with a conventional filtered back-projection (FBP) approach, is able to improve the image noise reduction. To quantify the benefits provided on the image quality and the dose reduction by the ASIR method with respect to the pure FBP one, the standard deviation (SD), the modulation transfer function (MTF), the noise power spectrum (NPS), the image uniformity and the noise homogeneity were examined. Measurements were performed on a control quality phantom when varying the CT dose index (CTDIvol) and the reconstruction kernels. A 64-MDCT was employed and raw data were reconstructed with different percentages of ASIR on a CT console dedicated for ASIR reconstruction. Three radiologists also assessed a cardiac pediatric exam reconstructed with different ASIR percentages using the visual grading analysis (VGA) method. For the standard, soft and bone reconstruction kernels, the SD is reduced when the ASIR percentage increases up to 100% with a higher benefit for low CTDIvol. MTF medium frequencies were slightly enhanced and modifications of the NPS shape curve were observed. However for the pediatric cardiac CT exam, VGA scores indicate an upper limit of the ASIR benefit. 40% of ASIR was observed as the best trade-off between noise reduction and clinical realism of organ images. Using phantom results, 40% of ASIR corresponded to an estimated dose reduction of 30% under pediatric cardiac protocol conditions. In spite of this discrepancy between phantom and clinical results, the ASIR method is as an important option when considering the reduction of radiation dose, especially for pediatric patients.

Upgrade to iterative image reconstruction (IR) in MDCT imaging: a clinical study for detailed parameter optimization beyond vendor recommendations using the adaptive statistical iterative reconstruction environment (ASIR) Part2: The chest.

PubMed

Mueck, F G; Michael, L; Deak, Z; Scherr, M K; Maxien, D; Geyer, L L; Reiser, M; Wirth, S

2013-07-01

To compare the image quality in dose-reduced 64-row CT of the chest at different levels of adaptive statistical iterative reconstruction (ASIR) to full-dose baseline examinations reconstructed solely with filtered back projection (FBP) in a realistic upgrade scenario. A waiver of consent was granted by the institutional review board (IRB). The noise index (NI) relates to the standard deviation of Hounsfield units in a water phantom. Baseline exams of the chest (NI = 29; LightSpeed VCT XT, GE Healthcare) were intra-individually compared to follow-up studies on a CT with ASIR after system upgrade (NI = 45; Discovery HD750, GE Healthcare), n = 46. Images were calculated in slice and volume mode with ASIR levels of 0 - 100 % in the standard and lung kernel. Three radiologists independently compared the image quality to the corresponding full-dose baseline examinations (-2: diagnostically inferior, -1: inferior, 0: equal, + 1: superior, + 2: diagnostically superior). Statistical analysis used Wilcoxon's test, Mann-Whitney U test and the intraclass correlation coefficient (ICC). The mean CTDIvol decreased by 53 % from the FBP baseline to 8.0 ± 2.3 mGy for ASIR follow-ups; p < 0.001. The ICC was 0.70. Regarding the standard kernel, the image quality in dose-reduced studies was comparable to the baseline at ASIR 70 % in volume mode (-0.07 ± 0.29, p = 0.29). Concerning the lung kernel, every ASIR level outperformed the baseline image quality (p < 0.001), with ASIR 30 % rated best (slice: 0.70 ± 0.6, volume: 0.74 ± 0.61). Vendors' recommendation of 50 % ASIR is fair. In detail, the ASIR 70 % in volume mode for the standard kernel and ASIR 30 % for the lung kernel performed best, allowing for a dose reduction of approximately 50 %. © Georg Thieme Verlag KG Stuttgart · New York.

A Third-Generation Adaptive Statistical Iterative Reconstruction Technique: Phantom Study of Image Noise, Spatial Resolution, Lesion Detectability, and Dose Reduction Potential.

PubMed

Euler, André; Solomon, Justin; Marin, Daniele; Nelson, Rendon C; Samei, Ehsan

2018-06-01

The purpose of this study was to assess image noise, spatial resolution, lesion detectability, and the dose reduction potential of a proprietary third-generation adaptive statistical iterative reconstruction (ASIR-V) technique. A phantom representing five different body sizes (12-37 cm) and a contrast-detail phantom containing lesions of five low-contrast levels (5-20 HU) and three sizes (2-6 mm) were deployed. Both phantoms were scanned on a 256-MDCT scanner at six different radiation doses (1.25-10 mGy). Images were reconstructed with filtered back projection (FBP), ASIR-V with 50% blending with FBP (ASIR-V 50%), and ASIR-V without blending (ASIR-V 100%). In the first phantom, noise properties were assessed by noise power spectrum analysis. Spatial resolution properties were measured by use of task transfer functions for objects of different contrasts. Noise magnitude, noise texture, and resolution were compared between the three groups. In the second phantom, low-contrast detectability was assessed by nine human readers independently for each condition. The dose reduction potential of ASIR-V was estimated on the basis of a generalized linear statistical regression model. On average, image noise was reduced 37.3% with ASIR-V 50% and 71.5% with ASIR-V 100% compared with FBP. ASIR-V shifted the noise power spectrum toward lower frequencies compared with FBP. The spatial resolution of ASIR-V was equivalent or slightly superior to that of FBP, except for the low-contrast object, which had lower resolution. Lesion detection significantly increased with both ASIR-V levels (p = 0.001), with an estimated radiation dose reduction potential of 15% ± 5% (SD) for ASIR-V 50% and 31% ± 9% for ASIR-V 100%. ASIR-V reduced image noise and improved lesion detection compared with FBP and had potential for radiation dose reduction while preserving low-contrast detectability.

Association of aortic wall thickness on contrast-enhanced chest CT with major cerebro-cardiac events.

PubMed

Tresoldi, Silvia; Di Leo, Giovanni; Zoffoli, Elena; Munari, Alice; Primolevo, Alessandra; Cornalba, Gianpaolo; Sardanelli, Francesco

2014-11-01

There is a significant association between aortic atherosclerosis and previous major cardiovascular events. Particularly, thoracic aortic atherosclerosis is closely related to the degree of coronary and carotid artery disease. Thus, there is a rationale for screening the thoracic aorta in patients who undergo a chest computed tomography (CT) for any clinical question, in order to detect patients at increased risk of cerebro-cardiovascular (CCV) events. To estimate the association between either thoracic aortic wall thickness (AWT) or aortic total calcium score (ATCS) and CCV events. One hundred and forty-eight non-cardiac patients (78 men; 67 ± 12 years) underwent chest contrast-enhanced multidetector CT (MDCT). The AWT was measured at the level of the left atrium (AWTref) and at the maximum AWT (AWTmax). Correlation with clinical CCV patients' history was estimated. The value of AWTmax and of a semi-quantitative ATCS as a marker for CCV events was assessed using receiver-operating characteristic curve (ROC) analysis and multivariate regression analysis. Out of 148 patients, 59% reported sedentary lifestyle, 44% hypertension, 32% smoking, 23% hypercholesterolemia, 13% family history of cardiac disease, 12% diabetes, and 10% BMI ≥ 30 kg/m(2); 9% reported myocardial infarction, 8% aortic aneurism, 8% myocardial revascularization, and 2% ischemic stroke. Twenty-six percent of patients had a medium-to-high ATCS. Both AWTmax and AWTref correlated with hypertension and age (P < 0.002). At the ROC analysis, a 4.8 mm threshold was associated to a 90% specificity and an odds ratio of 6.3 (AUC = 0.735). Assuming as threshold the AWTmax median value (4.3 mm) of patients who suffered from at least one CCV event in their history, a negative predictive value of 90%, a RR of 3.6 and an OR of 6.3 were found. At the multivariate regression analysis, AWTmax was the only independent variable associated to the frequency of CCV events. Patients with increased thoracic AWTmax on chest MDCT could be considered at risk for CCV disease. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Characteristic image quality of a third generation dual-source MDCT scanner: Noise, resolution, and detectability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, Justin, E-mail: justin.solomon@duke.edu; Wilson, Joshua; Samei, Ehsan

2015-08-15

Purpose: The purpose of this work was to assess the inherent image quality characteristics of a new multidetector computed tomography system in terms of noise, resolution, and detectability index as a function of image acquisition and reconstruction for a range of clinically relevant settings. Methods: A multisized image quality phantom (37, 30, 23, 18.5, and 12 cm physical diameter) was imaged on a SOMATOM Force scanner (Siemens Medical Solutions) under variable dose, kVp, and tube current modulation settings. Images were reconstructed with filtered back projection (FBP) and with advanced modeled iterative reconstruction (ADMIRE) with iterative strengths of 3, 4, andmore » 5. Image quality was assessed in terms of the noise power spectrum (NPS), task transfer function (TTF), and detectability index for a range of detection tasks (contrasts of approximately 45, 90, 300, −900, and 1000 HU, and 2–20 mm diameter) based on a non-prewhitening matched filter model observer with eye filter. Results: Image noise magnitude decreased with decreasing phantom size, increasing dose, and increasing ADMIRE strength, offering up to 64% noise reduction relative to FBP. Noise texture in terms of the NPS was similar between FBP and ADMIRE (<5% shift in peak frequency). The resolution, based on the TTF, improved with increased ADMIRE strength by an average of 15% in the TTF 50% frequency for ADMIRE-5. The detectability index increased with increasing dose and ADMIRE strength by an average of 55%, 90%, and 163% for ADMIRE 3, 4, and 5, respectively. Assessing the impact of mA modulation for a fixed average dose over the length of the phantom, detectability was up to 49% lower in smaller phantom sections and up to 26% higher in larger phantom sections for the modulated scan compared to a fixed tube current scan. Overall, the detectability exhibited less variability with phantom size for modulated scans compared to fixed tube current scans. Conclusions: Image quality increased with increasing dose and decreasing phantom size. The CT system exhibited nonlinear noise and resolution properties, especially at very low-doses, large phantom sizes, and for low-contrast objects. Objective image quality metrics generally increased with increasing dose and ADMIRE strength, and with decreasing phantom size. The ADMIRE algorithm could offer comparable image quality at reduced doses or improved image quality at the same dose. The use of tube current modulation resulted in more consistent image quality with changing phantom size.« less

Intrathoracic Fat Measurements Using Multidetector Computed Tomography (MDCT): Feasibility and Reproducibility

PubMed Central

Stojanovska, Jadranka; Ibrahim, El-Sayed H.; Chughtai, Aamer R.; Jackson, Elizabeth A.; Gross, Barry H.; Jacobson, Jon A.; Tsodikov, Alexander; Daneshvar, Brian; Long, Benjamin D.; Chenevert, Thomas L.; Kazerooni, Ella A.

2017-01-01

Intrathoracic fat volume, more specifically, epicardial fat volume, is an emerging imaging biomarker of adverse cardiovascular events. The purpose of this work is to show the feasibility and reproducibility of intrathoracic fat volume measurement applied to contrast-enhanced multidetector computed tomography images. A retrospective cohort study of 62 subjects free of cardiovascular disease (55% females, age = 49 ± 11 years) conducted from 2008 to 2011 formed the study group. Intrathoracic fat volume was defined as all fat voxels measuring −50 to −250 Hounsfield Unit within the intrathoracic cavity from the level of the pulmonary artery bifurcation to the heart apex. The intrathoracic fat was separated into epicardial and extrapericardial fat by tracing the pericardium. The measurements were obtained by 2 readers and compared for interrater reproducibility. The fat volume measurements for the study group were 141 ± 72 cm3 for intrathoracic fat, 58 ± 27 cm3 for epicardial fat, and 84 ± 50 cm3 for extrapericardial fat. There was no statistically significant difference in intrathoracic fat volume measurements between the 2 readers, with correlation coefficients of 0.88 (P = .55) for intrathoracic fat volume and −0.12 (P = .33) for epicardial fat volume. Voxel-based measurement of intrathoracic fat, including the separation into epicardial and extrapericardial fat, is feasible and highly reproducible from multidetector computed tomography scans. PMID:28626797

Development and validation of a preoperative prediction model for colorectal cancer T-staging based on MDCT images and clinical information.

PubMed

Sa, Sha; Li, Jing; Li, Xiaodong; Li, Yongrui; Liu, Xiaoming; Wang, Defeng; Zhang, Huimao; Fu, Yu

2017-08-15

This study aimed to establish and evaluate the efficacy of a prediction model for colorectal cancer T-staging. T-staging was positively correlated with the level of carcinoembryonic antigen (CEA), expression of carbohydrate antigen 19-9 (CA19-9), wall deformity, blurred outer edges, fat infiltration, infiltration into the surrounding tissue, tumor size and wall thickness. Age, location, enhancement rate and enhancement homogeneity were negatively correlated with T-staging. The predictive results of the model were consistent with the pathological gold standard, and the kappa value was 0.805. The total accuracy of staging improved from 51.04% to 86.98% with the proposed model. The clinical, imaging and pathological data of 611 patients with colorectal cancer (419 patients in the training group and 192 patients in the validation group) were collected. A spearman correlation analysis was used to validate the relationship among these factors and pathological T-staging. A prediction model was trained with the random forest algorithm. T staging of the patients in the validation group was predicted by both prediction model and traditional method. The consistency, accuracy, sensitivity, specificity and area under the curve (AUC) were used to compare the efficacy of the two methods. The newly established comprehensive model can improve the predictive efficiency of preoperative colorectal cancer T-staging.

Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.

PubMed

Rosow, David E; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I; Mueller, Peter R; Fernández-del Castillo, Carlos; Warshaw, Andrew L; Thayer, Sarah P

2005-12-01

Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.

[Review of pre- and post-treatment multidetector computed tomography findings in abdominal aortic aneurysms].

PubMed

Casula, E; Lonjedo, E; Cerverón, M J; Ruiz, A; Gómez, J

2014-01-01

The increase in the frequency of abdominal aortic aneurysms (AAA) and the widely accepted use of endovascular aneurysm repair (EVAR) as a first-line treatment or as an alternative to conventional surgery make it necessary for radiologists to have thorough knowledge of the pre- and post-treatment findings. The high image quality provided by multidetector computed tomography (MDCT) enables CT angiography to play a fundamental role in the study of AAA and in planning treatment. The objective of this article is to review the cases of AAA in which CT angiography was the main imaging technique, so that radiologists will be able to detect the signs related to this disease, to diagnose it, to plan treatment, and to detect complications in the postoperative period. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

Vascular liver anatomy and main variants: what the radiologist must know.

PubMed

Seco, M; Donato, P; Costa, J; Bernardes, A; Caseiro-Alves, F

2010-01-01

Advances in surgical techniques are extremely demanding regarding the accuracy and level of detail expected for display of the vascular anatomy of the liver. Precise knowledge of the arterial, portal and hepatic vein territories are mandatory whenever a liver intervention is planned. Sectional anatomy can now be routinely performed on multidetector computed tomography (MDCT) with volumetric data and isotropic voxel display, by means of sub-millimetric slice thickness acquisition. The relevant vascular information can thus be gathered, reviewed and post-processed with unprecedented clarity, obviating the need for digital subtraction angiography. The scope of the present paper is to review the normal vascular liver anatomy, its most relevant variants including additional sources of vascular inflow. Apart from providing the surgeon with a detailed vascular and parenchymal roadmap knowledge of imaging findings may avoid potential confusion with pathologic processes.

CT differentiation of 1-2-cm gallbladder polyps: benign vs malignant.

PubMed

Song, E Rang; Chung, Woo-Suk; Jang, Hye Young; Yoon, Minjae; Cha, Eun Jung

2014-04-01

To evaluate MDCT findings of 1-2-cm sized gallbladder (GB) polyps for differentiation between benign and malignant polyps. Institutional review board approval was obtained, and informed consent was waived. Portal venous phase CT scans of 1-2-cm sized GB polyps caused by various pathologic conditions were retrospectively reviewed by two blinded observers. Among the 36 patients identified, 21 had benign polyps with the remaining 15 having malignant polyps. Size, margin, and shape of GB polyps were evaluated. Attenuation values of the polyps, including mean attenuation, maximum attenuation, and standard deviation, were recorded. As determined by visual inspection, the degree of polyp enhancement was evaluated. Using these CT findings, each of the two radiologists assessed and recorded individual diagnostic confidence for differentiating benign versus malignant polyps on a 5-point scale. The diagnostic performance of CT was evaluated using a receiver operating characteristic curve analysis. There was no significant difference in size between benign and malignant GB polyps. Ill-defined margin and sessile morphology were significantly associated with malignant polyp. There was a significant difference in mean and maximum attenuation values between benign and malignant GB polyps. Mean standard deviation value of malignant polyps was significantly higher than that of benign polyps. All malignant polyps showed either hyperenhancement or marked hyperenhancement. A z value for the diagnosis of malignant GB polyps was 0.905. Margin, shape, and enhancement degree are helpful in differentiating between benign and malignant polyps of 1-2-cm sizes.

A new cubic phantom for PET/CT dosimetry: Experimental and Monte Carlo characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belinato, Walmir; Silva, Rogerio M.V.; Souza, Divanizia N.

In recent years, positron emission tomography (PET) associated with multidetector computed tomography (MDCT) has become a diagnostic technique widely disseminated to evaluate various malignant tumors and other diseases. However, during PET/CT examinations, the doses of ionizing radiation experienced by the internal organs of patients may be substantial. To study the doses involved in PET/CT procedures, a new cubic phantom of overlapping acrylic plates was developed and characterized. This phantom has a deposit for the placement of the fluorine-18 fluoro-2-deoxy-D-glucose ({sup 18}F-FDG) solution. There are also small holes near the faces for the insertion of optically stimulated luminescence dosimeters (OSLD). Themore » holes for OSLD are positioned at different distances from the {sup 18}F-FDG deposit. The experimental results were obtained in two PET/CT devices operating with different parameters. Differences in the absorbed doses were observed in OSLD measurements due to the non-orthogonal positioning of the detectors inside the phantom. This phantom was also evaluated using Monte Carlo simulations, with the MCNPX code. The phantom and the geometrical characteristics of the equipment were carefully modeled in the MCNPX code, in order to develop a new methodology form comparison of experimental and simulated results, as well as to allow the characterization of PET/CT equipments in Monte Carlo simulations. All results showed good agreement, proving that this new phantom may be applied for these experiments. (authors)« less

Reduction in growth threshold for pulmonary metastases: an opportunity for volumetry and its impact on treatment decisions

PubMed Central

Vogel, M N; Schmücker, S; Maksimovic, O; Hartmann, J; Claussen, C D; Horger, M

2012-01-01

Objectives This study compares tumour response assessment by automated CT volumetry and standard manual measurements regarding the impact on treatment decisions and patient outcome. Methods 58 consecutive patients with 203 pulmonary metastases undergoing baseline and follow-up multirow detector CT (MDCT) under chemotherapy were assessed for response to chemotherapy. Tumour burden of pulmonary target lesions was quantified in three ways: (1) following response evaluation criteria in solid tumours (RECIST); (2) following the volume equivalents of RECIST (i.e. with a threshold of −65/+73%); and (3) using calculated limits for stable disease (SD). For volumetry, calculated limits had been set at ±38% prior to the study by repeated quantification of nodules scanned twice. Results were compared using non-weighted κ-values and were evaluated for their impact on treatment decisions and patient outcome. Results In 15 (17%) of the 58 patients, the results of response assessment were inconsistent with 1 of the 3 methods, which would have had an impact on treatment decisions in 8 (13%). Patient outcome regarding therapy response could be verified in 5 (33%) of the 15 patients with inconsistent measurement results and was consistent with both RECIST and volumetry in 1, with calculated limits in 3 and with none in 1. Diagnosis as to the overall response was consistent with RECIST in six patients, with volumetry in six and with calculated limits in eight cases. There is an impact of different methods for therapy response assessment on treatment decisions. Conclusion A reduction of threshold for SD to ±30–40% of volume change seems reasonable when using volumetry. PMID:22745205

Electrocardiogram abnormalities and coronary calcification in postmenopausal women.

PubMed

Sabour, Siamak; Grobbee, Diederick; Rutten, Annemarieke; Prokop, Mathias; Bartelink, Marie-Louise; van der Schouw, Yvonne; Bots, Michiel

2010-01-01

An electrocardiogram (ECG) can provide information on subclinical myocardial damage. The presence, and more importantly, the quantity of coronary artery calcification (CAC), relates well with the overall severity of the atherosclerotic process. A strong relation has been demonstrated between coronary calcium burden and the incidence of myocardial infarction, a relation independent of age. The aim of this study was to assess the relation of left ventricular hypertrophy (LVH) and ECG abnormalities with CAC. The study population comprised 566 postmenopausal women selected from a population-based cohort study. Information on LVH and repolarization abnormalities (T-axis and QRS-T angle) was obtained using electrocardiography. Modular ECG Analysis System (MEANS) was used to assess ECG abnormalities. The women underwent a multi detector-row computed tomography (MDCT) scan (Philips Mx 8000 IDT 16) to assess CAC. The Agatston score was used to quantify CAC; scores greater than zero were considered as the presence of coronary calcium. Logistic regression was used to assess the relation of ECG abnormality with coronary calcification. LVH was found in 2.7% (n = 15) of the women. The prevalence of T-axis abnormality was 6% (n = 34), whereas 8.5% (n = 48) had a QRS-T angle abnormality. CAC was found in 62% of the women. Compared to women with a normal T-axis, women with borderline or abnormal T-axes were 3.8 fold more likely to have CAC (95% CI: 1.4-10.2). Similarly, compared to women with a normal QRS-T angle, in women with borderline or abnormal QRS-T angle, CAC was 2.0 fold more likely to be present (95% CI: 1.0-4.1). Among women with ECG abnormalities reflecting subclinical ischemia, CAC is commonly found and may in part explain the increased coronary heart disease risk associated with these ECG abnormalities.

Comparison of Measured and Estimated CT Organ Doses for Modulated and Fixed Tube Current:: A Human Cadaver Study.

PubMed

Padole, Atul; Deedar Ali Khawaja, Ranish; Otrakji, Alexi; Zhang, Da; Liu, Bob; Xu, X George; Kalra, Mannudeep K

2016-05-01

The aim of this study was to compare the directly measured and the estimated computed tomography (CT) organ doses obtained from commercial radiation dose-tracking (RDT) software for CT performed with modulated tube current or automatic exposure control (AEC) technique and fixed tube current (mAs). With the institutional review board (IRB) approval, the ionization chambers were surgically implanted in a human cadaver (88 years old, male, 68 kg) in six locations such as liver, stomach, colon, left kidney, small intestine, and urinary bladder. The cadaver was scanned with routine abdomen pelvis protocol on a 128-slice, dual-source multidetector computed tomography (MDCT) scanner using both AEC and fixed mAs. The effective and quality reference mAs of 100, 200, and 300 were used for AEC and fixed mAs, respectively. Scanning was repeated three times for each setting, and measured and estimated organ doses (from RDT software) were recorded (N = 3*3*2 = 18). Mean CTDIvol for AEC and fixed mAs were 4, 8, 13 mGy and 7, 14, 21 mGy, respectively. The most estimated organ doses were significantly greater (P < 0.01) than the measured organ doses for both AEC and fixed mAs. At AEC, the mean estimated organ doses (for six organs) were 14.7 mGy compared to mean measured organ doses of 12.3 mGy. Similarly, at fixed mAs, the mean estimated organ doses (for six organs) were 24 mGy compared to measured organ doses of 22.3 mGy. The differences among the measured and estimated organ doses were higher for AEC technique compared to the fixed mAs for most organs (P < 0.01). The most CT organ doses estimated from RDT software are greater compared to directly measured organ doses, particularly when AEC technique is used for CT scanning. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.