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Sample records for 64-slice multidetector ct

  1. Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to "triage" patients' treatment.

    PubMed

    Agid, R; Lee, S K; Willinsky, R A; Farb, R I; terBrugge, K G

    2006-11-01

    To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm.

  2. 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

  3. 64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model.

    PubMed

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

    2011-03-01

    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. 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. 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. 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.

  4. Detection and quantification of coronary atherosclerotic plaque by 64-slice multidetector CT: a systematic head-to-head comparison with intravascular ultrasound.

    PubMed

    Papadopoulou, Stella-Lida; Neefjes, Lisan A; Schaap, Michiel; Li, Hui-Ling; Capuano, Ermanno; van der Giessen, Alina G; Schuurbiers, Johan C H; Gijsen, Frank J H; Dharampal, Anoeshka S; Nieman, Koen; van Geuns, Robert Jan; Mollet, Nico R; de Feyter, Pim J

    2011-11-01

    We evaluated the ability of 64-slice multidetector computed tomography (MDCT)-derived plaque parameters to detect and quantify coronary atherosclerosis, using intravascular ultrasound (IVUS) as the reference standard. In 32 patients, IVUS and 64-MDCT was performed. The MDCT and IVUS datasets of 44 coronary arteries were co-registered using a newly developed fusion technique and quantitative parameters were derived from both imaging modalities. The threshold of >0.5 mm of maximum wall thickness was used to establish plaque presence on MDCT and IVUS. We analyzed 1364 coregistered 1-mm coronary cross-sections and 255 segments of 5-mm length. Compared with IVUS, 64-MDCT enabled correct detection in 957 of 1109 cross-sections containing plaque (sensitivity 86%). In 180 of 255 cross-sections atherosclerosis was correctly excluded (specificity 71%). On the segmental level, MDCT detected 213 of 220 segments with any atherosclerotic plaque (sensitivity 96%), whereas the presence of any plaque was correctly ruled out in 28 of 32 segments (specificity 88%). Interobserver agreement for the detection of atherosclerotic cross-sections was moderate (Cohen's kappa coefficient K=0.51), but excellent for the atherosclerotic segments (K=1.0). Pearson's correlation coefficient for vessel plaque volumes measured by MDCT and IVUS was r=0.91 (p<0.001). Bland-Altman analysis showed a slight non-significant underestimation of any plaque volume by MDCT (p=0.5), with a trend to underestimate noncalcified and overestimate mixed/calcified plaque volumes (p=0.22 and p=0.87 respectively). MDCT is able to detect and quantify atherosclerotic plaque. Further improvement in CT resolution is necessary for more reliable assessment of very small and distal coronary plaques. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. A 64-slice multi-detector CT scan could evaluate the change of the left atrial appendage thrombi of the atrial fibrillation patient, which was reduced by warfarin therapy.

    PubMed

    Takeuchi, Hidekazu

    2011-08-19

    Curable cause of stroke is the left atrial appendage (LAA) thrombi of atrial fibrillation (AF) patients. Some AF patients have the LAA thrombi. It is very important to cure AF patients by warfarin. Transoesophageal echocardiography (TOE) is the usual clinical tool to detect the LAA thrombi. Recently, a 64-slice multi-detector CT (64-MDCT) scan enables us to display the LAA thrombi more easily than TOE. I reported a case that a 64-MDCT scan had been used successfully in displaying the change of the LAA thrombi reduced by warfarin therapy. The size of the LAA thrombi was reduced from 25.2 mm × 19.3 mm (figure 1) to 22.1 mm × 14.8 mm (figure 2) after the 3-month warfarin therapy. It was useful to estimate the LAA thrombi by a 64-MDCT scan to estimate LAA thrombi itself and the change of LAA thrombi to evaluate the effectiveness of warfarin therapy.

  6. Hemodialysis fistula occlusion: demonstration with 64-slice CT angiography.

    PubMed

    Neyman, Edward G; Johnson, Pamela T; Fishman, Elliot K

    2006-01-01

    The speed and resolution of 64-slice CT have resulted in new applications for CT angiography (CTA) owing to rapid data acquisition during the arterial phase, improved visualization of small vessels, and lengthened anatomic coverage. Extremity CT angiography is one such region. This case report shows the utility of multislice CTA for the evaluation of hemodialysis graft dysfunction.

  7. Comparison of 4- and 64-slice CT scanning in the diagnosis of pulmonary embolism.

    PubMed

    Douma, Renée A; Hofstee, Herman M A; Schaefer-Prokop, Cornelia; van Waesberghe, Jan Hein T M; Lely, Rutger J; Kamphuisen, Pieter W; Gerdes, Victor E A; Kramer, Mark H H; Büller, Harry R

    2010-01-01

    With the introduction of multi-detector row CT (MDCT), sensitivity to diagnose pulmonary embolism (PE) has greatly improved. The use of newer generation CT-scans may lead to a higher prevalence and a different distribution of PE. We compared 64-slice with 4-slice MDCT regarding prevalence and distribution of PE, the number of inconclusive test results and inter-reader variability. CT-scans from a random sample of 110 consecutive patients who underwent 4-slice CT-scanning were compared with 64-slice CT-scans from 107 patients from a second cohort. Three radiologists independently reassessed all CT-scans. Consensus was reached in case of disagreement between the readers. Final diagnosis of PE was categorised as central, segmental or subsegmental by the thrombus' most proximal end. The prevalence of PE was 24% (26/110, 95% confidence interval [CI] 17-32%) and 22% (24/107, 16-31%) for the 4-slice and 64-slice cohort, respectively. The prevalence of isolated subsegmental emboli was 2/26 (7.7%; 2.1-24%) and 5/24 (21%; 9.2-41%), respectively (p=0.424). The number of inconclusive scans was 10% in both cohorts, mostly due to movement artefacts and suboptimal intravascular contrast, respectively. The inter-reader agreement between the three readers was 0.70 for the 4-slice scans and 0.68 for the 64-slice scans. Although absolute prevalence of PE was equal in both cohorts, there was a trend towards more subsegmental PE with 64-slice CT. In a multi-reader setting, the number of inconclusive examinations was higher than quoted for clinical management studies, indicating that the diagnosis of PE with MDCT could be less straightforward than assumed.

  8. Comparative dosimetry of dental CBCT devices and 64-slice CT for oral and maxillofacial radiology.

    PubMed

    Ludlow, John B; Ivanovic, Marija

    2008-07-01

    This study compares 2 measures of effective dose, E(1990) and E(2007), for 8 dentoalveolar and maxillofacial cone-beam computerized tomography (CBCT) units and a 64-slice multidetector CT (MDCT) unit. Average tissue-absorbed dose, equivalent dose, and effective dose were calculated using thermoluminescent dosimeter chips in a radiation analog dosimetry phantom. Effective doses were derived using 1990 and the superseding 2007 International Commission on Radiological Protection (ICRP) recommendations. Large-field of view (FOV) CBCT E(2007) ranged from 68 to 1,073 microSv. Medium-FOV CBCT E(2007) ranged from 69 to 560 microSv, whereas a similar-FOV MDCT produced 860 microSv. The E(2007) calculations were 23% to 224% greater than E(1990). The 2007 recommendations of the ICRP, which include salivary glands, extrathoracic region, and oral mucosa in the calculation of effective dose, result in an upward reassessment of fatal cancer risk from oral and maxillofacial radiographic examinations. Dental CBCT can be recommended as a dose-sparing technique in comparison with alternative medical CT scans for common oral and maxillofacial radiographic imaging tasks.

  9. Performance evaluation of a 64-slice CT system with z-flying focal spot.

    PubMed

    Flohr, T; Stierstorfer, K; Raupach, R; Ulzheimer, S; Bruder, H

    2004-12-01

    The meanwhile established generation of 16-slice CT systems enables routine sub-millimeter imaging at short breath-hold times. Clinical progress in the development of multidetector row CT (MDCT) technology beyond 16 slices can more likely be expected from further improvement in spatial and temporal resolution rather than from a mere increase in the speed of volume coverage. We present an evaluation of a recently introduced 64-slice CT system (SOMATOM Sensation 64, Siemens AG, Forchheim, Germany), which uses a periodic motion of the focal spot in longitudinal direction (z-flying focal spot) to double the number of simultaneously acquired slices. This technique acquires 64 overlapping 0.6 mm slices per rotation. The sampling scheme corresponds to that of a 64 x 0.3 mm detector, with the goal of improved longitudinal resolution and reduced spiral artifacts. After an introduction to the detector design, we discuss the basics of z-flying focal spot technology (z-Sharp). We present phantom and specimen scans for performance evaluation. The measured full width at half maximum (FWHM) of the thinnest spiral slice is 0.65 mm. All spiral slice widths are almost independent of the pitch, with deviations of less than 0.1 mm from the nominal value. Using a high-resolution bar pattern phantom (CATPHAN, Phantom Laboratories, Salem, NY), the longitudinal resolution can be demonstrated to be up to 15 lp/cm at the isocenter independent of the pitch, corresponding to a bar diameter of 0.33 mm. Longitudinal resolution is only slightly degraded for off-center locations. At a distance of 100 mm from the isocenter, 14 lp/cm can be resolved in the z-direction, corresponding to a bar diameter of 0.36 mm. Spiral "windmill" artifacts presenting as hyper- and hypodense structures around osseous edges are effectively reduced by the z-flying focal spot technique. Cardiac scanning benefits from the short gantry rotation time of 0.33 s, providing up to 83 ms temporal resolution with 2-segment ECG

  10. A new method for experimental characterisation of scattered radiation in 64-slice CT scanner

    PubMed Central

    Akbarzadeh, A; Ay, MR; Ghadiri, H; Sarkar, S; Zaidi, H

    2010-01-01

    Purpose: The consummate 64-slice CT scanner that spawns a new generation of non-invasive diagnostic tool, however revolutionary, brings with it the incidental by-product that is scattered radiation. The extended detector aperture capability in the 64-slcie CT scanner allows the effects of scattered radiation to be more pronounced and therefore demands that the magnitude and spatial distribution of scatter component be addressed during the imaging process. To this end, corrective algorithms need to be formulated on a basis of a precise understanding of scatter distribution. Relative to a 64-slice CT scanner, here now a unique solution is based upon dedicated blockers operative within various detector rows, calculating scatter profiles and scatter to primary ratios (SPR). Materials and methods: A single dimension blocker array was installed beneath the collimator, and the extrapolated shadow area on the detectors revealed the scatter radiation after exposure. The experiment was conducted using a 64-slice CT scanner manufactured by GE Healthcare Technologies. Results: Variables such as tube voltage, phantom size and phantom-off centring on the scatter profile and the SPR was measured using the dedicated blocker method introduced above. When tube voltage is increased from 80kVp to 140kVp in a 21.5 cm water phantom, the SPR is found to reduce from 219.9 to 39.9 respectively. Conclusion: The method developed within this study is applicable to any measurement and is direct with minimal complexity. PMID:21611063

  11. A jumping left atrial thrombus connected to a pulmonary vein thrombus using transthoracic echocardiography and 64-slice multi-detector computed tomography.

    PubMed

    Takeuchi, Hidekazu

    2015-03-01

    Few studies have reported the differences between transthoracic echocardiography (TTE) and 64-slice multidetector CT (64-MDCT) in identifying left atrium (LA) thrombi. I report the case of a 70 year old man with coronary artery disease and angina who was diagnosed with a thrombus in the left lower pulmonary vein extending to the LA using a non-invasive 64-MDCT scan and TTE. TTE was unable to clearly identify a thrombus in the pulmonary veins, whereas a 64-MDCT scan identified a thrombus in the pulmonary vein but was unable to detect a moving thrombus attached to the mitral valves. The 64-MDCT images of LA thrombi are smaller than those of TTE and the video created using TTE demonstrated a moving thrombus connected to the mitral valve, which was underdiagnosed by a 64-MDCT scan. This case illustrates the complementary role for both TTE and 64-MDCT in the noninvasive diagnosis of left atrial-pulmonary vein thrombi.

  12. Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation.

    PubMed

    Carbone, Iacopo; Cannata, David; Algeri, Emanuela; Galea, Nicola; Napoli, Alessandro; De Zorzi, Andrea; Bosco, Giovanna; D'Agostino, Rita; Menezes, Leon; Catalano, Carlo; Passariello, Roberto; Francone, Marco

    2011-09-01

    Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. The study group comprised 12 patients (age 17.6 ± 2.9 years, mean ± SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 ± 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 ± 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.

  13. [Clinical value of 64-slice spiral 3-phase CT enhanced scanning for preoperative TNM staging assessment of gastric carcinoma].

    PubMed

    Zhong, Bao-yuan; Liu, Yan-xiu; Huang, Wen-feng; Liu, Qing-quan; Liu, Shao-qiang; Liu, Yao

    2012-07-01

    To explore the clinical value of 64-slice spiral 3-phase CT enhanced scanning for preoperative TNM staging assessment of gastric carcinoma. A retrospective study was performed to review the 64-slice spiral 3-phase CT enhanced scanning of 120 patients with gastric cancer diagnosed by biopsy prior to operation and postoperative pathological reports. All the findings were reviewed by two senior radiologic diagnosticians separately and compared with pathological findings. The accuracy of 64-slice spiral CT enhanced scan was 79.2%(95/120) for T staging, 66.7%(10/15) for T1, 66.7%(14/21) for T2, 84.0%(42/50) for T3, and 85.3%(29/34) for T4. For gastric wall with single layer and multiple layers, the accuracy of CT enhanced scanning was 59.4%(19/32) and 81.8%(72/88) for T staging, and the difference was statistically significant(P<0.05). The accuracy of 64-slice spiral CT enhanced scan was 73.9%(85/115) for N staging, 75.5%(37/49) for N0, 70.3%(26/37) for N1, 75.9%(22/29) for N2. The accuracy of 64-slice spiral CT enhanced scanning was 89.2% for M staging. 64-slice spiral CT 3-phase enhanced scanning can monitor the invasion, lymphatic metastasis, and distant metastasis of gastric cancer dynamically, which may become an important examination item for the preoperative evaluation of gastric cancer.

  14. Integrated assessment of coronary anatomy and myocardial perfusion using a retractable SPECT camera combined with 64-slice CT: initial experience.

    PubMed

    Thilo, Christian; Schoepf, U Joseph; Gordon, Leonie; Chiaramida, Salvatore; Serguson, Jill; Costello, Philip

    2009-04-01

    We evaluated a prototype SPECT system integrated with multidetector row CT (MDCT) for obtaining complementary information on coronary anatomy and hemodynamic lesion significance. Twenty-five consecutive patients with known or suspected coronary artery disease (CAD) underwent routine SPECT myocardial perfusion imaging (MPI). All patients also underwent repeat MPI with a mobile SPECT unit which could be attached to a 64-slice MDCT system. Coronary CT angiography (cCTA) was performed without repositioning the patient. Investigational MPI was compared with routine MPI for detection of myocardial perfusion defects (PD). Two observers diagnosed presence or absence of CAD based on MPI alone, cCTA alone, and based on combined MPI and cCTA with fused image display. In 22/24 patients investigative MPI corresponded with routine MPI (r = 0.80). Stenosis >or= 50% at cCTA was detected in 6/24 patients. Six out of 24 patients had PD at regular MPI. Three of these six patients had no significant stenosis at cCTA. Three out of 19 patients with normal MPI studies had significant stenosis at cCTA. Our initial experience indicates that the integration of SPECT MPI with cCTA is technically feasible and enables the comprehensive evaluation of coronary artery anatomy and myocardial perfusion with a single instrumental setup.

  15. Dosimetric and image quality assessment of different acquisition protocols of a novel 64-slice CT scanner

    NASA Astrophysics Data System (ADS)

    Vite, Cristina; Mangini, Monica; Strocchi, Sabina; Novario, Raffaele; Tanzi, Fabio; Carrafiello, Gianpaolo; Conte, Leopoldo; Fugazzola, Carlo

    2006-03-01

    Dose and image quality assessment in computed tomography (CT) are almost affected by the vast variety of CT scanners (axial CT, spiral CT, low-multislice CT (2-16), high-multislice CT (32-64)) and imaging protocols in use. Very poor information is at the moment available on 64 slices CT scanners. Aim of this work is to assess image quality related to patient dose indexes and to investigate the achievable dose reduction for a commercially available 64 slices CT scanner. CT dose indexes (weighted computed tomography dose index, CTDI w and Dose Length Product, DLP) were measured with a standard CT phantom for the main protocols in use (head, chest, abdomen and pelvis) and compared with the values displayed by the scanner itself. The differences were always below 7%. All the indexes were below the Diagnostic Reference Levels defined by the European Council Directive 97/42. Effective doses were measured for each protocol with thermoluminescent dosimeters inserted in an anthropomorphic Alderson Rando phantom and compared with the same values computed by the ImPACT CT Patient Dosimetry Calculator software code and corrected by a factor taking in account the number of slices (from 16 to 64). The differences were always below 25%. The effective doses range from 1.5 mSv (head) to 21.8 mSv (abdomen). The dose reduction system of the scanner was assessed comparing the effective dose measured for a standard phantom-man (a cylinder phantom, 32 cm in diameter) to the mean dose evaluated on 46 patients. The standard phantom was considered as no dose reduction reference. The dose reduction factor range from 16% to 78% (mean of 46%) for all protocols, from 29% to 78% (mean of 55%) for chest protocol, from 16% to 76% (mean of 42%) for abdomen protocol. The possibility of a further dose reduction was investigated measuring image quality (spatial resolution, contrast and noise) as a function of CTDI w. This curve shows a quite flat trend decreasing the dose approximately to 90% and a

  16. Diagnostic accuracy of 64-slice CT in the assessment of coronary stents.

    PubMed

    Cademartiri, F; Palumbo, A; Maffei, E; La Grutta, L; Runza, G; Pugliese, F; Midiri, M; Mollet, N R A; Meijboom, W B; Menozzi, A; Vignali, L; Reverberi, C; Ardissino, D; Krestin, G P

    2007-06-01

    The purpose of this study was to assess the diagnostic accuracy of 64-slice computed tomography (64-CT) coronary angiography in the detection of coronary in-stent restenosis. Ninety-five patients (72 men and 23 women, mean age 58+/-8 years) with previous percutaneous coronary intervention with stenting and suspected restenosis underwent 64-CT (Sensation 64, Siemens). The mean time between stent deployment and 64-CT was 6.1+/-4.2 months. The scan parameters were: slices 32 x 2, individual detector width 0.6 mm, rotation time 0.33 s, feed 3.84 mm/rotation, 120 kV, 900 mAs. After the intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml, Iomeron, Bracco) and a bolus chaser (40 ml of saline), the scan was completed in <12 s. All coronary segments with a stent were assessed on 64-CT by two observers in consensus and judged as: patent, with intimal hyperplasia (lumen reduction of <50%), with in-stent restenosis (> or =50%), or with in-stent occlusion (100%). The consensus reading was compared with conventional coronary angiography. Four patients were excluded because of insufficient image quality. In the remaining 91, we assessed 102 stents (31 RCA; 10 LM; 54 LAD; 7 CX). In 14 (13.7%) stents, in-stent restenosis (n=8) or in-stent occlusion (n=6) was found. Intimal hyperplasia was detected in 11 (10.8%) stents. The sensitivity and negative predictive value of 64-CT for in-stent occlusion were 100% and 100%, respectively, whereas for all stenoses, >50% they were 92.9% and 98.7%, respectively. We found that 64-CT has a high diagnostic accuracy for the detection of in-stent restenosis in a selected patient population.

  17. Diagnostic Capabilities of 64 Slice CT Coronography Compared to Classic in Coronary Disease Detection

    PubMed Central

    Sehovic, Sanja

    2013-01-01

    Introduction: Cardiovascular disease, among which the most common is coronary disease of the hearth are the main cause of death at middle aged persons in the majority of European countries. Percent of cardiovascular disease in overall mortality among our population is even more than 50%. Up to 55 years of live myocardial infarction is by 5-6 times more common among men, and up to age of 75 years that difference decreases to 2.5 times. Goal: The goal of this study is to determine the diagnostic value of 64 slices computerized tomography in detection of coronary disease compared to classic, invasive coronography. Material and methods: Study included 50 patients, of both genders, at average age of 60 years. Patients underwent CT coronography as well as classic coronography. Results: Our research prove that the sensitivity of MSCT coronography 92% with positive predictive value of 86%. Mayor difference was in the analysis of CX artery in the evaluation of significant and non-significant stenosis in application of these two methods. During the analysis of LAD and RCA artery there was no statistically significant difference in findings of these two methods. Conclusion: CT coronography is non-invasive, comfortable and reliable method in coronary disease diagnostics. Thanks to its high sensitivity and PPV it enables reliable exclusion of coronary disease and takes significant place in a cardiovascular diseases diagnostic algorithm. PMID:24167394

  18. Aortic valve stenosis: non-invasive preoperative evaluation using 64-slice CT angiography.

    PubMed

    Ciolina, F; Sedati, P; Zaccagna, F; Galea, N; Noce, V; Miraldi, F; Cavarretta, E; Francone, M; Carbone, I

    2015-10-01

    In patients affected by aortic valve stenosis (AS) it is mandatory to rule out coronary artery disease (CAD). The role of retrospectively ECG-gated 64-slice CT angiography (64-SCTA) was assessed in patients with AS referred for surgical valve replacement. Forty-two patients with AS underwent ECG-gated 64-SCTA of thoracic aorta, including the heart and coronary arteries, before surgical valve replacement. Images were evaluated by two independent readers and compared with surgical findings in terms of aortic valve calcification grading, valvular morphology, aortic valve annulus and sino-tubular junction diameters, and valvular area planimetry. Quantitative evaluation of cusps opening was also performed. Finally, the presence of CAD, thoracic aortic aneurysm and left ventricle hypertrophy were assessed. Visualization of the aortic valve without motion artefacts was possible in 38 patients (90.5%). Valvular morphology was correctly assessed in all cases (100%). 64-SCTA correctly determined aortic valve calcification grading and the aortic valve annulus and sinotubular junction diameters in 100% of cases. The aortic valve planimetric area was assessed in 38 cases (90.5%). Ascending aortic aneurysms requiring surgical replacement were detected in 12 patients (28.6%). Significant left ventricle hypertrophy was found in 30 patients (71%). Preoperative evaluation of patients undergoing surgical replacement for AS with 64-SCTA is feasible. 64-SCTA can rule out CAD and evaluate the status of the aortic valve and thoracic aorta in the same examination, obtaining relevant information for surgical planning.

  19. Evaluation of temporal windows for coronary artery bypass graft imaging with 64-slice CT.

    PubMed

    Desbiolles, Lotus; Leschka, Sebastian; Plass, André; Scheffel, Hans; Husmann, Lars; Gaemperli, Oliver; Garzoli, Elisabeth; Marincek, Borut; Kaufmann, Philipp A; Alkadhi, Hatem

    2007-11-01

    Temporal windows providing the best image quality of different segments and types of coronary artery bypass grafts (CABGs) with 64-slice computed tomography (CT) were evaluated in an experimental set-up. Sixty-four-slice CT with a rotation time of 330 ms was performed in 25 patients (four female; mean age 59.9 years). A total of 84 CABGs (62 individual and 22 sequential grafts) were evaluated, including 28 internal mammary artery (33.3%), one radial artery with sequential grafting (2.4%), and 54 saphenous vein grafts (64.3%). Ten data sets were reconstructed in 10% increments of the RR-interval. Each graft was separated into segments (proximal and distal anastomosis, and body), and CABG types were grouped according to target arteries. Two readers independently assessed image quality of each CABG segment in each temporal window. Diagnostic image quality was found with good inter-observer agreement (kappa=0.62) in 98.5% (202/205) of all graft segments. Image quality was significantly better for saphenous vein grafts versus arterial grafts (P<0.001) and for distal anastomosis to the right coronary compared with other target coronary arteries (P<0.05). Overall, best image quality was found at 60%. Image quality of proximal segments did not significantly vary with the temporal window, whereas for all other segments image quality was significantly better at 60% compared with other temporal windows (P<0.05). Sixty-four-slice CT provides best image quality of various segments and types of CABG at 60% of the RR-interval.

  20. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    PubMed

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (<1 years old) with CHD undergoing 128-slice CT prospective ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  1. Comparative evaluation of 64-slice CT angiography and digital subtraction angiography in assessing the cervicocranial vasculature.

    PubMed

    Klingebiel, Randolf; Kentenich, Max; Bauknecht, Hans-Christian; Masuhr, Florian; Siebert, Eberhard; Busch, Markus; Bohner, Georg

    2008-01-01

    Noninvasive 64-slice computed tomography angiography (64-MSCTA) closely approximates conventional catheter angiography (DSA) in terms of detail resolution. Retrospective evaluation of cervicocranial (cc) 64-MSCTA in comparison with DSA in patients with presumptive cc vascular disorders. Twenty-four 64-MSCTA studies (32 mm detector width, slice thickness 0.5 mm, 120 kv, 150 mAs, pitch 0.75) of patients with presumptive cc vascular pathology (13 men, 11 women, mean age 38.3 +/- 11.3 yrs, range 19-54 yrs) were assessed in comparison with DSA studies without abnormal findings in age-matched patients (11 men, 13 women, mean age 39.7 +/- 11.9 yrs, range 18-54 yrs). Study readings were performed in a blinded manner by two neuroradiologists with respect to image quality and assessibility of various cc vascular segments by using a five-point scale. Radiation exposure was calculated for 64-MSCTA. Each reader assessed 384/528 different vessel segments (64-MSCTA/DSA). Superior image quality was attributed to DSA with respect to the C1 ICA-C6 ICA, A3 ACA, and P3 PCA segments as well the AICA and SCA. 64-MSCTA was scored superior for C7 ICA and V4 VA segments. A significantly increased number ofnonassessable V2- and V3 VA segments in DSA studies was noted. The effective dose for 64-MSCTA amounted to 2.2 mSv. 64-MSCTA provides near-equivalent diagnostic information of the cc vasculature as compared with DSA. According to our results, DSA should be considered primarily when peripheral vessels (A3/P3) or ICA segments close to the skull base (C2-5) are of interest, such as in primary angiitis or stenoocclusive ICA disease, respectively.

  2. Diagnostic accuracy of standard axial 64-slice chest CT compared to cardiac MRI for the detection of cardiomyopathies.

    PubMed

    Murphy, David J; Lavelle, Lisa P; Gibney, Brian; O'Donohoe, Rory L; Rémy-Jardin, Martine; Dodd, Jonathan D

    2016-01-01

    To assess the diagnostic accuracy of standard axial chest CT compared with cardiac MRI for cardiomyopathies. The standard axial 64-slice chest CTs of 49 patients with cardiomyopathies and 27 controls were blindly assessed for the presence of a cardiomyopathy by two independent readers. Qualitative and quantitative analysis included assessment of: (i) interatrial septal thickness, (ii) left atrial diameter, (iii) myocardial hypertrophy, thinning or fat, (iv) myocardial and papillary muscle calcification, (v) papillary muscle thickness, (vi) calcified coronary artery segments, (vii) left ventricular (LV) diameter, (viii) interventricular septal thickness and (ix) right ventricular diameters. Cardiac MRI was the gold standard. There were 21 (42.9%) dilated, 16 (32.7%) hypertrophic, 8 (16.3%) ischaemic and 4 other (8.2%) (LV non-compaction × 2, amyloid, idiopathic restrictive) patients with cardiomyopathies. An LV diameter of 47 mm, interventricular septal thickness of 14 mm and coronary artery/papillary muscle calcification on axial chest CT best distinguished dilated, hypertrophic and ischaemic cardiomyopathies from controls, respectively; kappa = 0.45 (moderate interobserver agreement). The sensitivity (95% confidence interval), specificity, positive- and negative-predictive values (95% confidence interval) and diagnostic accuracy of chest CT in diagnosing cardiomyopathies were 68% (52-83), 100%, 100%, 66% (55-85) and 80%, respectively. Cardiomyopathies may be detected on standard chest CT with good sensitivity and high specificity. It is useful to assess for an underlying cardiomyopathy on standard chest CT, especially in a patient with unexplained dyspnoea.

  3. Myopericarditis diagnosed by a 64-slice coronary CT angiography "triple rule out" protocol

    PubMed Central

    Ku, Bon S.; Halpern, Ethan J.

    2010-01-01

    We report a case of myopericarditis in a 30-year-old male complaining of shortness of breath. In an emergency department (ED) setting, the symptoms of myopericarditis may overlap with many disease entities and can be a challenging diagnosis to make. However, with the use of a 64-section coronary CT angiography in a “triple rule out” (TRO) protocol, we were able to detect a large pericardial effusion surrounding the heart and moderate global hypokinesis in the setting of normal-sized heart chambers and normal coronary arteries. We were further able to exclude pulmonary embolism and thoracic dissection. This is the first reported case of diagnosing myopericarditis using a TRO protocol. It demonstrates the usefulness of TRO in making an emergent diagnosis of myopericarditis while excluding other life-threatening diseases that can lead to earlier appropriate ED disposition and care. PMID:21373320

  4. Diagnostic accuracy of standard axial 64-slice chest CT compared to cardiac MRI for the detection of cardiomyopathies

    PubMed Central

    Lavelle, Lisa P; Gibney, Brian; O'Donohoe, Rory L; Rémy-Jardin, Martine; Dodd, Jonathan D

    2016-01-01

    Objective: To assess the diagnostic accuracy of standard axial chest CT compared with cardiac MRI for cardiomyopathies. Methods: The standard axial 64-slice chest CTs of 49 patients with cardiomyopathies and 27 controls were blindly assessed for the presence of a cardiomyopathy by two independent readers. Qualitative and quantitative analysis included assessment of: (i) interatrial septal thickness, (ii) left atrial diameter, (iii) myocardial hypertrophy, thinning or fat, (iv) myocardial and papillary muscle calcification, (v) papillary muscle thickness, (vi) calcified coronary artery segments, (vii) left ventricular (LV) diameter, (viii) interventricular septal thickness and (ix) right ventricular diameters. Cardiac MRI was the gold standard. Results: There were 21 (42.9%) dilated, 16 (32.7%) hypertrophic, 8 (16.3%) ischaemic and 4 other (8.2%) (LV non-compaction × 2, amyloid, idiopathic restrictive) patients with cardiomyopathies. An LV diameter of 47 mm, interventricular septal thickness of 14 mm and coronary artery/papillary muscle calcification on axial chest CT best distinguished dilated, hypertrophic and ischaemic cardiomyopathies from controls, respectively; kappa = 0.45 (moderate interobserver agreement). The sensitivity (95% confidence interval), specificity, positive- and negative-predictive values (95% confidence interval) and diagnostic accuracy of chest CT in diagnosing cardiomyopathies were 68% (52–83), 100%, 100%, 66% (55–85) and 80%, respectively. Conclusion: Cardiomyopathies may be detected on standard chest CT with good sensitivity and high specificity. Advances in knowledge: It is useful to assess for an underlying cardiomyopathy on standard chest CT, especially in a patient with unexplained dyspnoea. PMID:26670156

  5. Non-invasive Detection of Aortic and Coronary Atherosclerosis in Homozygous Familial Hypercholesterolemia by 64 Slice Multi-detector Row Computed Tomography Angiography

    USDA-ARS?s Scientific Manuscript database

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector-row ...

  6. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    USDA-ARS?s Scientific Manuscript database

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  7. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    NASA Astrophysics Data System (ADS)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  8. Automatic alignment of myocardial perfusion PET and 64-slice coronary CT angiography on hybrid PET/CT

    PubMed Central

    Nakazato, Ryo; Dey, Damini; Alexánderson, Erick; Meave, Aloha; Jiménez, Moisés; Romero, Edgar; Jácome, Rodrigo; Peña, Marco; Berman, Daniel S.; Slomka, Piotr J.

    2012-01-01

    Background Hybrid PET/CT allows acquisition of cardiac PET and coronary CT angiography (CCTA) in one session. However, PET and CCTA, are acquired with differing breathing protocols and require software registration. We aimed to validate automatic correction for breathing misalignment between PET and CCTA acquired on hybrid scanner. Methods Single-session hybrid PET/CT studies of rest/stress 13N-ammonia PET and CCTA in 32 consecutive patients were considered. Automated registration of PET left ventricular (LV) surfaces with CCTA volumes was evaluated by comparison to expert manual alignment by 2 observers. Results The average initial misalignment between the position of LV on PET and CCTA was 27.2±11.8mm, 13.3±11.5mm, and 14.3±9.1mm in x, y, and z axes on rest, and 26.3±10.2mm, 11.1±9.5mm, and 11.7±7.1mm in x, y, and z axes on stress. The automated PET-CCTA co-registration had 95% agreement as judged visually. Compared to expert manual alignment, the translation errors of the algorithm were 5.3±2.8mm (rest) and 6.0±3.5mm (stress). 3D visualization of combined coronary vessel anatomy and hypoperfusion from PET could be made without further manual adjustments. Conclusion Software co-registration of CCTA and PET myocardial perfusion imaging on hybrid PET/CT scanners is necessary, but can be performed automatically, facilitating integrated 3D display on PET/CT. PMID:22419224

  9. Comparison of image characteristics of plaques in culprit coronary arteries by 64 slice CT and intravascular ultrasound in acute coronary syndromes.

    PubMed

    Takaoka, Hiroyuki; Ishibashi, Iwao; Uehara, Masae; Rubin, Geoffrey D; Komuro, Issei; Funabashi, Nobusada

    2012-10-04

    To evaluate plaque image characteristics in coronary artery culprit-lesions in subjects with acute coronary syndromes (ACS), we retrospectively compared coronary arterial images by 64-slice CT before conventional-coronary-angiogram with those by intravascular ultrasound (IVUS). Retrospective analysis of coronary arterial images from thirty-one subjects (26-males, mean age 59.3 ± 12.0 years) exhibiting acute symptoms with suspicion of ACS, where either (1) ECG was un-interpretable or (2) ECG was non diagnostic/cardiac biomarkers was equivocal; with significant stenosis on emergent 64 slice CT and subjects were finally diagnosed as having ACS confirmed by conventional-coronary-angiogram, followed by IVUS before coronary-intervention. After principal culprit-lesion components were classified into 1) thrombus, 2) soft plaques, and 3) fibrotic plaques by IVUS, corresponding culprit-lesion CT values were measured (two-observers). Nineteen and 12 of 31 subjects were finally diagnosed as unstable angina pectoris and non-ST elevation acute myocardial infarction respectively. Main culprit-lesion components of ACS were identified on MSCT in all subjects. Culprit-lesion CT values diagnosed as soft plaques by IVUS (n=6, 32.9 ± 8.7 HU) were not lower than those of thrombi (n=18, 43.2 ± 10.7 HU, p=0.268); both values were significantly lower than those of fibrotic plaques (n=7, 82.5 ± 22.6 HU) (both p<0.01). Calcification, spotty calcification, and positive arterial remodeling were observed in 67.7%, 61.3%, 58.1% (IVUS) and 58.1%, 51.6%, 74.2% (MSCT), respectively (all p=NS). CT value reproducibilities and culprit-lesion areas, were 0.87 and 0.86, respectively (two analyzers). 64-slice CT can non-invasively evaluate image characteristics in coronary artery culprit-lesions in ACS subjects accurately; this may help to differentiate soft plaques or thrombi generated by plaque rupture from fibrotic plaques. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Acute chest pain in emergency room. Preliminary findings with 40-64-slice CT ECG-gated of the whole chest.

    PubMed

    Coche, E

    2007-01-01

    ECG-gated MDCT of the entire chest represents the latest technical advance in the diagnostic work-up of atypical chest pain. The authors report their preliminary experience with the use of 40 and 64-slice CT in the emergency room and recommend to study only patients with moderate likelihood of coronary artery disease. ECG-gated MDCT of the entire chest will be preferentially performed on 64-slice MDCT rather than 40-slice MDCT because it enable to reduce the scan time (18 seconds versus 28 seconds acquisition time), the volume of contrast medium (82 mL + 15 mL versus 97 mL + 15 mL of highly concentrated contrast agent for a patient of 70 kgs) and radiation exposure (17 mSv versus 19 mSv). Approximately 1500 to 2000 of images are produced and need to be analysed on a dedicated workstation by a radiologist expert in cardiac and thoracic disorders. At the present time, only a few studies exist in the literature showing some promising results but further large clinical studies are needed before to implement such sophisticated protocol in emergency room.

  11. Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

    PubMed Central

    Matsuura, Noriaki; Yamamoto, Hideya; Kiguchi, Masao; Fujioka, Chikako; Kitagawa, Toshiro; Ito, Katsuhide

    2009-01-01

    Objective To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT. Materials and Methods One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD). Results The estimated effective dose was 1.5 ± 0.2 mSv. The mean heart rate was 63 ± 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 ± 4.5 kg/m2 (range, 15.5-42.3 kg/m2). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 ± 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level. Conclusion The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05). PMID:19568461

  12. Evaluation of organ doses and specific k effective dose of 64-slice CT thorax examination using an adult anthropomorphic phantom

    NASA Astrophysics Data System (ADS)

    Hashim, S.; Karim, M. K. A.; Bakar, K. A.; Sabarudin, A.; Chin, A. W.; Saripan, M. I.; Bradley, D. A.

    2016-09-01

    The magnitude of radiation dose in computed tomography (CT) depends on the scan acquisition parameters, investigated herein using an anthropomorphic phantom (RANDO®) and thermoluminescence dosimeters (TLD). Specific interest was in the organ doses resulting from CT thorax examination, the specific k coefficient for effective dose estimation for particular protocols also being determined. For measurement of doses representing five main organs (thyroid, lung, liver, esophagus and skin), TLD-100 (LiF:Mg, Ti) were inserted into selected holes in a phantom slab. Five CT thorax protocols were investigated, one routine (R1) and four that were modified protocols (R2 to R5). Organ doses were ranked from greatest to least, found to lie in the order: thyroid>skin>lung>liver>breast. The greatest dose, for thyroid at 25 mGy, was that in use of R1 while the lowest, at 8.8 mGy, was in breast tissue using R3. Effective dose (E) was estimated using three standard methods: the International Commission on Radiological Protection (ICRP)-103 recommendation (E103), the computational phantom CT-EXPO (E(CTEXPO)) method, and the dose-length product (DLP) based approach. E103 k factors were constant for all protocols, ~8% less than that of the universal k factor. Due to inconsistency in tube potential and pitch factor the k factors from CTEXPO were found to vary between 0.015 and 0.010 for protocols R3 and R5. With considerable variation between scan acquisition parameters and organ doses, optimization of practice is necessary in order to reduce patient organ dose.

  13. 64-Slice spiral CT perfusion combined with vascular imaging of acute ischemic stroke for assessment of infarct core and penumbra

    PubMed Central

    BAO, DANG-ZHEN; BAO, HUAN-YING; YAO, LI-ZHAI; PAN, YUN-GAO; ZHU, XIN-RUI; YANG, XIAO-SONG; WANG, HE; HUANG, YI-NING

    2013-01-01

    The aim of this study was to determine the value of computed tomography perfusion (CTP) parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time-to-peak (TP), in a clinical study of patients with stroke. Additionally, we determined which parameter or combination of parameters are reliable in detecting the presence of an infarct and penumbra. CTP was performed within 24 h of the onset of symptoms in 20 patients with possible stroke. Magnetic resonance imaging (MRI) was performed 3-7 days later and the threshold of the CTP was adjusted according to the results to provide CT images that correlated with the MRI; the MRI results were taken as the gold standard. CBV, CBF and TP contrast agent enhancement were calculated using the CT results. The CTP results were compared with the MRI findings. All CTP parameters were reliable in detecting the penumbra (P<0.001). In these parameters, changes of MTT were the most useful. CTP revealed various changes in CBF, CBV, MTT and TP in ischemic areas. CTP parameters were also reliable in detecting the infarct core (P<0.001). We determined that when detecting the penumbra, all CTP parameters are reliable, and when detecting cerebral ischemia, a combination of parameters should be used. PMID:23935734

  14. Experimental assessment of the influence of beam hardening filters on image quality and patient dose in volumetric 64-slice X-ray CT scanners.

    PubMed

    Ay, Mohammad Reza; Mehranian, Abolfazl; Maleki, Asghar; Ghadiri, Hossien; Ghafarian, Pardis; Zaidi, Habib

    2013-05-01

    Beam hardening filters have long been employed in X-ray Computed Tomography (CT) to preferentially absorb soft and low-energy X-rays having no or little contribution to image formation, thus allowing the reduction of patient dose and beam hardening artefacts. In this work, we studied the influence of additional copper (Cu) and aluminium (Al) flat filters on patient dose and image quality and seek an optimum filter thickness for the GE LightSpeed VCT 64-slice CT scanner using experimental phantom measurements. Different thicknesses of Cu and Al filters (0.5-1.6mm Cu, 0.5-4mm Al) were installed on the scanner's collimator. A planar phantom consisting of 13 slabs of Cu having different thicknesses was designed and scanned to assess the impact of beam filtration on contrast in the intensity domain (CT detector's output). To assess image contrast and image noise, a cylindrical phantom consisting of a polyethylene cylinder having 16 holes filled with different concentrations of K2HPO4 solution mimicking different tissue types was used. The GE performance and the standard head CT dose index (CTDI) phantoms were also used to assess image resolution characterized by the modulation transfer function (MTF) and patient dose defined by the weighted CTDI. A 100mm pencil ionization chamber was used for CTDI measurement. Finally, an optimum filter thickness was determined from an objective figure of merit (FOM) metric. The results show that the contrast is somewhat compromised with filter thickness in both the planar and cylindrical phantoms. The contrast of the K2HPO4 solutions in the cylindrical phantom was degraded by up to 10% for a 0.68mm Cu filter and 6% for a 4.14mm Al filter. It was shown that additional filters increase image noise which impaired the detectability of low density K2HPO4 solutions. It was found that with a 0.48mm Cu filter the 50% MTF value is shifted by about 0.77lp/cm compared to the case where the filter is not used. An added Cu filter with approximately

  15. Trapping volumetric measurement by multidetector CT in chronic obstructive pulmonary disease: Effect of CT threshold

    SciTech Connect

    Wang, Xiaohua; Yuan, Huishu; Duan, Jianghui; Du, Yipeng; Shen, Ning; He, Bei

    2013-08-15

    Purpose: The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD).Methods: Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and expiratory phase. CT thresholds of −950 Hu in inspiration and −950 to −890 Hu in expiration were used, after which trapping volumetric measurements were made using computer software. Trapping volume percentage (Vtrap%) under the different CT thresholds in the expiratory phase and below −950 Hu in the inspiratory phase was compared and correlated with lung function.Results: Mean Vtrap% was similar under −930 Hu in the expiratory phase and below −950 Hu in the inspiratory phase, being 13.18 ± 9.66 and 13.95 ± 6.72 (both lungs), respectively; this difference was not significant (P= 0.240). Vtrap% under −950 Hu in the inspiratory phase and below the −950 to −890 Hu threshold in the expiratory phase was moderately negatively correlated with the ratio of forced expiratory volume in one second to forced vital capacity and the measured value of forced expiratory volume in one second as a percentage of the predicted value.Conclusions: Trapping volumetric measurement with multidetector CT is a promising method for the quantification of COPD. It is important to know the effect of various CT thresholds on trapping volumetric measurements.

  16. 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

  17. Feasibility of extended-coverage perfusion and dynamic computer tomography (CT) angiography using toggling-table technique on 64-slice CT.

    PubMed

    Horiguchi, Jun; Kiura, Yoshihiro; Tanaka, Junpei; Fukuda, Hiroshi; Kiguchi, Masao; Fujioka, Chikako; Kurisu, Kaoru; Awai, Kazuo

    2011-07-01

    The major drawbacks of brain computed tomography (CT) perfusion are limited coverage in the z-axis, radiation exposure and the use of contrast medium, all of which increase when CT angiography (CTA) is performed with double acquisitions. The purpose of this study was to investigate the feasibility of the 'toggling-table' technique using a 40-mm detector. The clinical usefulness of CT perfusion and 4D-CTA (time-resolved 3D-CTA), as well as the time taken and radiation exposure, were assessed in 14 non-ischemic patients clinically indicated for CT perfusion and CTA. A perfusion map and 4D-CTA was successfully achieved in all patients. The total time needed for scanning and processing was approximately 30 min per examination. The 80-mm CT perfusion coverage and 4D-CTA images were advantageous for analyses of the anatomy and widely distributed lesions. The estimated effective radiation dose was 2.22 mSv, and the amount of contrast media was 40 mL. The 'toggling-table' technique acts as a 'one-stop-shop' protocol for perfusion mapping and 4D-CTA over a wide area, following a single contrast injection and scan. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  18. Body physique and heart rate variability determine the occurrence of stair-step artefacts in 64-slice CT coronary angiography with prospective ECG-triggering.

    PubMed

    Husmann, Lars; Herzog, Bernhard A; Burkhard, Nina; Tatsugami, Fuminari; Valenta, Ines; Gaemperli, Oliver; Wyss, Christophe A; Landmesser, Ulf; Kaufmann, Philipp A

    2009-07-01

    The purpose of this study was to describe and characterize the frequency and extent of stair-step artefacts in computed tomography coronary angiography (CTCA) with prospective electrocardiogram (ECG)-triggering and to identify their determinants. One hundred and forty three consecutive patients (55 women, mean age 57 +/- 13 years) underwent 64-slice CTCA using prospective ECG-triggering. Occurrence of stair-step artefacts in CTCA of the thoracic wall and the coronary arteries was determined and maximum offset was measured. If stair-step artefacts occurred in both cases, a difference between thoracic wall and coronary artery offset of 0.6 mm or greater was attributed to additional motion of the heart. Mean effective radiation dose was 2.1 +/- 0.7 mSv (range 1.0-3.5 mSv). Eighty-nine patients (62%) had stair-step artefacts in CTCA of the coronary arteries (mean offset of 1.7 +/- 1.1 mm), while only 77 patients had thoracic wall stair-step artefacts (mean offset of 1.0 +/- 0.3 mm; significantly different, P < 0.001). Stair-step artefacts in CTCA of the thoracic wall were determined by BMI and weight (P < 0.01), while artefacts in CTCA of the coronary arteries were associated with heart rate variability (P < 0.05). Stair-step artefacts in CTCA with prospective ECG-triggering are determined by (a) motion of the entire patient during table travel, particularly in large patients and (b) by motion of the heart, particularly when heart rates are variable.

  19. Multidetector CT of blunt thoracic trauma.

    PubMed

    Kaewlai, Rathachai; Avery, Laura L; Asrani, Ashwin V; Novelline, Robert A

    2008-10-01

    Thoracic injuries are significant causes of morbidity and mortality in trauma patients. These injuries account for approximately 25% of trauma-related deaths in the United States, second only to head injuries. Radiologic imaging plays an important role in the diagnosis and management of blunt chest trauma. In addition to conventional radiography, multidetector computed tomography (CT) is increasingly being used, since it can quickly and accurately help diagnose a wide variety of injuries in trauma patients. Furthermore, multiplanar and volumetric reformatted CT images provide improved visualization of injuries, increased understanding of trauma-related diseases, and enhanced communication between the radiologist and the referring clinician. (c) RSNA, 2008.

  20. Lymphoepithelial cyst of the pancreas--evaluation with multidetector CT.

    PubMed

    Neyman, Edward G; Georgiades, Christos S; Horton, Karen H; Lillemoe, Keith D; Fishman, Elliot K

    2005-01-01

    Lymphoepithelial cyst of the pancreas is a rare cystic pancreatic tumor. In this case report we provide the imaging perspective of the lesion including the role of multidetector CT (MDCT) and CT angiography and 3D imaging.

  1. Multidetector CT of emergent biliary pathologic conditions.

    PubMed

    Patel, Neel B; Oto, Aytekin; Thomas, Stephen

    2013-01-01

    Various biliary pathologic conditions can lead to acute abdominal pain. Specific diagnosis is not always possible clinically because many biliary diseases have overlapping signs and symptoms. Imaging can help narrow the differential diagnosis and lead to a specific diagnosis. Although ultrasonography (US) is the most useful imaging modality for initial evaluation of the biliary system, multidetector computed tomography (CT) is helpful when US findings are equivocal or when biliary disease is suspected. Diagnostic accuracy can be increased by optimizing the CT protocol and using multiplanar reformations to localize biliary obstruction. CT can be used to diagnose and stage acute cholecystitis, including complications such as emphysematous, gangrenous, and hemorrhagic cholecystitis; gallbladder perforation; gallstone pancreatitis; gallstone ileus; and Mirizzi syndrome. CT also can be used to evaluate acute biliary diseases such as biliary stone disease, benign and malignant biliary obstruction, acute cholangitis, pyogenic hepatic abscess, hemobilia, and biliary necrosis and iatrogenic complications such as biliary leaks and malfunctioning biliary drains and stents. Treatment includes radiologic, endoscopic, or surgical intervention. Familiarity with CT imaging appearances of emergent biliary pathologic conditions is important for prompt diagnosis and appropriate clinical referral and treatment.

  2. Comparison of transplenic multidetector CT portography to multidetector CT-angiography in normal dogs.

    PubMed

    Echandi, Rita L; Morandi, Federica; Daniel, William T; Paquette, Janet L; Daniel, Gregory B

    2007-01-01

    We evaluated transplenic injection of iodinated contrast medium for computed tomography (CT) assessment of the portal vasculature. Specific aims were to: (1) establish a protocol for transplenic transplenic CT portography using a 40-row multidetector scanner; (2) compare transplenic CT portography to dual-phase CT angiography in terms of image quality, opacification of the portal system, and contrast enhancement of the portal vasculature and liver; (3) compare personnel exposure during transplenic CT portography and transplenic portal scintigraphy. Seven juvenile dogs underwent transplenic portal scintigraphy, CT angiography, and transplenic CT portography. Transplenic portal scintigraphy and CT angiography were performed using previously established protocols. For transplenic CT portography, a 20- or 22 gauge needle attached to an extension set was placed into the splenic parenchyma using CT guidance. Iodinated contrast medium (175 mg I/ml) was administered, and CT acquisition was started at the time of the injection. Transplenic CT portography was simple, rapid and provided more intense enhancement of the splenic and portal veins, with a lower contrast medium dose (median dose: 525 mg I for transplenic CT portography, 7700 mg I for CT angiography), but caused inconsistent intrahepatic portal branches and parenchymal opacification due to streamlining and streak artifacts. Despite significantly lower attenuation values in the portal vein, CT angiography provided sufficient enhancement for vessel identification and more consistent parenchymal hepatic enhancement. Personnel radiation exposure rate was higher during transplenic CT portography (0.0725 mSv/min) compared with transplenic portal scintigraphy (0.000125 mSv/min). As transplenic CT portography requires an average injection time of 1 min per study; over 650 [corrected] studies must be performed before reaching the maximum permissible whole body dose of 0.05 [corrected] Sv.

  3. Multi-detector row CT as a "one-stop" examination in the preoperative evaluation of the morphology and function of living renal donors: preliminary study.

    PubMed

    Su, Chen; Yan, Chaogui; Guo, Yan; Zhou, Xuhui; Chen, Yaqing; Liu, Mingjuan; Wang, Wenjuan; Zhang, Xiaoling

    2011-02-01

    We designed to investigate the feasibility of multi-detector row computerized tomography (CT) as a "one-stop" examination for the simultaneous preoperative evaluation of the morphology and function of living renal donors. 21 living renal donors were examined by 64-slice spiral CT with a three-phase enhancement CT scan and two inserted dynamic scans. The maximum intensity projection (MIP), multi-planar reformation (MPR), and volume reconstruction (VR) procedures were performed to compare the renal parenchyma, renal vessels, and collecting system with operational findings. The known Patlak equation was used to calculate the glomerular filtration rate (GFR); exact GFR information was acquired by single photon emission computed tomography (SPECT). Our results as following, there were 3 cases of artery variation and 3 cases of vein variation. CT findings all corresponded with the operation, and the sensitivity, positive predictive value, specialty, and negative predictive value of CT were all 100%. The r of the GFR values estimated from CT is 0.894 (left) (P < 0.001) and 0.881 (right) (P < 0.001). In conclusions, our findings demonstrate that 64-slice spiral CT may offer a "one-stop" examination to replace SPECT in the preoperative evaluation of living renal donors to simultaneously provide information regarding both anatomy and the GFR of living renal donors.

  4. Low fingertip temperature rebound measured by digital thermal monitoring strongly correlates with the presence and extent of coronary artery disease diagnosed by 64-slice multi-detector computed tomography.

    PubMed

    Ahmadi, Naser; Nabavi, Vahid; Nuguri, Vivek; Hajsadeghi, Fereshteh; Flores, Ferdinand; Akhtar, Mohammad; Kleis, Stanley; Hecht, Harvey; Naghavi, Morteza; Budoff, Matthew

    2009-10-01

    Previous studies showed strong correlations between low fingertip temperature rebound measured by digital thermal monitoring (DTM) during a 5 min arm-cuff induced reactive hyperemia and both the Framingham Risk Score (FRS), and coronary artery calcification (CAC) in asymptomatic populations. This study evaluates the correlation between DTM and coronary artery disease (CAD) measured by CT angiography (CTA) in symptomatic patients. It also investigates the correlation between CTA and a new index of neurovascular reactivity measured by DTM. 129 patients, age 63 +/- 9 years, 68% male, underwent DTM, CAC and CTA. Adjusted DTM indices in the occluded arm were calculated: temperature rebound: aTR and area under the temperature curve aTMP-AUC. DTM neurovascular reactivity (NVR) index was measured based on increased fingertip temperature in the non-occluded arm. Obstructive CAD was defined as >or=50% luminal stenosis, and normal as no stenosis and CAC = 0. Baseline fingertip temperature was not different across the groups. However, all DTM indices of vascular and neurovascular reactivity significantly decreased from normal to non-obstructive to obstructive CAD [(aTR 1.77 +/- 1.18 to 1.24 +/- 1.14 to 0.94 +/- 0.92) (P = 0.009), (aTMP-AUC: 355.6 +/- 242.4 to 277.4 +/- 182.4 to 184.4 +/- 171.2) (P = 0.001), (NVR: 161.5 +/- 147.4 to 77.6 +/- 88.2 to 48.8 +/- 63.8) (P = 0.015)]. After adjusting for risk factors, the odds ratio for obstructive CAD compared to normal in the lowest versus two upper tertiles of FRS, aTR, aTMP-AUC, and NVR were 2.41 (1.02-5.93), P = 0.05, 8.67 (2.6-9.4), P = 0.001, 11.62 (5.1-28.7), P = 0.001, and 3.58 (1.09-11.69), P = 0.01, respectively. DTM indices and FRS combined resulted in a ROC curve area of 0.88 for the prediction of obstructive CAD. In patients suspected of CAD, low fingertip temperature rebound measured by DTM significantly predicted CTA-diagnosed obstructive disease.

  5. Intraindividual comparison of gadolinium- and iodine-enhanced 64-slice multidetector CT pulmonary angiography for the detection of pulmonary embolism in a porcine model.

    PubMed

    Henes, Frank Oliver Gerhard; Groth, Michael; Begemann, Philipp G C; Adam, Gerhard; Regier, Marc

    2011-06-01

    This study is an evaluation of the diagnostic accuracy of gadolinium-enhanced computed tomography pulmonary angiography (CTPA) for the detection of pulmonary embolism (PE) in comparison with iodine-enhanced CTPA. PE was induced in five anesthetized pigs by administration of blood clots through an 11-F catheter inside the jugular vein. Animals underwent CTPA in breathhold with i.v. bolus injection of 50 ml gadopentetate dimeglumine (0.4 mmol/kg, 4 ml/s). Subsequently, CTPA was performed using the same imaging parameters but under administration of 70 ml nonionic iodinated contrast material (400 mg/ml, 4 ml/s). All images were reconstructed with 1 mm slice thickness. A consensus readout of the iodium-enhanced CTPAs by both radiologists served as reference standard. Gadolinium-enhanced CTPAs were evaluated independently by two experienced radiologists, and differences in detection rate between both contrast agents were assessed on a per embolus basis using the Wilcoxon signed-rank test. Interobserver agreement was determined by calculation of қ values. PE was diagnosed independently by both readers in all five pigs by the use of gadolinium-enhanced CTPA. Out of 60 pulmonary emboli detected in the iodine-enhanced scans, 47 (78.3%; reader 1) and 44 (62.8%; reader 2) emboli were detected by the use of gadolinium. All 13 (100%) emboli in lobar arteries (by both readers) and 26 (reader 1) and 25 (reader 2) out of 27 emboli (96.3% and 92.6%) in segmental arteries were detected by the use of the gadolinium-enhanced CTPA. In subsegmental arteries, only 8 (40%; reader 1) and 6 (30%; reader 2) out of 20 emboli were detected by the gadolinium-enhanced CTPA. By comparing both scans on a per vessel basis (Wilcoxon test), Gd-enhanced CTPA was significantly inferior in emboli detection on subsegmental level (P < 0.0001). The interobserver agreement was excellent on lobar and segmental level (қ = 1.0 and 0.93, respectively), whereas readers only reached moderate agreement for PE evaluation on subsegmental level (қ = 0.56). Compared to conventional CTPA with iodinated contrast media, gadolinium-based contrast agents achieve an equivalent diagnostic accuracy in detection of PE down to segmental level. Gadolinium-enhanced CTPA may be considered as an alternative for the diagnostic workup of acute pulmonary embolism in patients with contraindications to iodinated contrast agents.

  6. Trabecular bone structure analysis in the osteoporotic spine using a clinical in vivo setup for 64-slice MDCT imaging: comparison to microCT imaging and microFE modeling.

    PubMed

    Issever, Ahi S; Link, Thomas M; Kentenich, Marie; Rogalla, Patrik; Schwieger, Karsten; Huber, Markus B; Burghardt, Andrew J; Majumdar, Sharmila; Diederichs, Gerd

    2009-09-01

    Assessment of trabecular microarchitecture may improve estimation of biomechanical strength, but visualization of trabecular bone structure in vivo is challenging. We tested the feasibility of assessing trabecular microarchitecture in the spine using multidetector CT (MDCT) on intact human cadavers in an experimental in vivo-like setup. BMD, bone structure (e.g., bone volume/total volume = BV/TV; trabecular thickness = Tb.Th; structure model index = SMI) and bone texture parameters were evaluated in 45 lumbar vertebral bodies using MDCT (mean in-plane pixel size, 274 microm(2); slice thickness, 500 microm). These measures were correlated with structure measures assessed with microCT at an isotropic spatial resolution of 16 microm and to microfinite element models (microFE) of apparent modulus and stiffness. MDCT-derived BMD and structure measures showed significant correlations to the density and structure obtained by microCT (BMD, R(2) = 0.86, p < 0.0001; BV/TV, R(2) = 0.64, p < 0.0001; Tb.Th, R(2) = 0.36, p < 0.01). When comparing microCT-derived measures with microFE models, the following correlations (p < 0.001) were found for apparent modulus and stiffness, respectively: BMD (R(2) = 0.58 and 0.66), BV/TV (R(2) = 0.44 and 0.58), and SMI (R(2) = 0.44 and 0.49). However, the overall highest correlation (p < 0.001) with microFE app. modulus (R(2) = 0.75) and stiffness (R(2) = 0.76) was achieved by the combination of QCT-derived BMD with the bone texture measure Minkowski Dimension. In summary, although still limited by its spatial resolution, trabecular bone structure assessment using MDCT is overall feasible. However, when comparing with microFE-derived bone properties, BMD is superior compared with single parameters for microarchitecture, and correlations further improve when combining with texture measures.

  7. New absorbed dose measurement with cylindrical water phantoms for multidetector CT

    NASA Astrophysics Data System (ADS)

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hioki, Kazunari; Tomiyama, Yuuki; Yamashita, Yusuke

    2015-06-01

    The aim of this study was to develop new dosimetry with cylindrical water phantoms for multidetector computed tomography (MDCT). The ionization measurement was performed with a Farmer ionization chamber at the center and four peripheral points in the body-type and head-type cylindrical water phantoms. The ionization was converted to the absorbed dose using a 60Co absorbed-dose-to-water calibration factor and Monte Carlo (MC) -calculated correction factors. The correction factors were calculated from MDCT (Brilliance iCT, 64-slice, Philips Electronics) modeled with GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. The spectrum of incident x-ray beams and the configuration of a bowtie filter for MDCT were determined so that calculated photon intensity attenuation curves for aluminum (Al) and calculated off-center ratio (OCR) profiles in air coincided with those measured. The MC-calculated doses were calibrated by the absorbed dose measured at the center in both cylindrical water phantoms. Calculated doses were compared with measured doses at four peripheral points and the center in the phantom for various beam pitches and beam collimations. The calibration factors and the uncertainty of the absorbed dose determined using this method were also compared with those obtained by CTDIair (CT dose index in air). Calculated Al half-value layers and OCRs in air were within 0.3% and 3% agreement with the measured values, respectively. Calculated doses at four peripheral points and the centers for various beam pitches and beam collimations were within 5% and 2% agreement with measured values, respectively. The MC-calibration factors by our method were 44-50% lower than values by CTDIair due to the overbeaming effect. However, the calibration factors for CTDIair agreed within 5% with those of our method after correction for the overbeaming effect. Our method makes it possible to directly measure the absorbed dose for MDCT and is more robust and accurate than the

  8. [Atypical appearance of pneumatosis intestinalis at multidetector CT].

    PubMed

    Lorusso, Valentina; Stabile Ianora, Antonio Amato; Rubini, Giuseppe; Losco, Matteo; Niccoli Asabella, Artor; Fonio, Paolo; Moschetta, Marco

    2012-11-01

    Pneumatosis intestinalis may be caused by bowel ischemia and may display different patterns of appearance. We report a case of pneumatosis intestinalis with an atypical target pattern, detected by multidetector computed tomography (CT) in a 66-year-old male presenting with acute abdominal syndrome. Abdominal CT scan showed a double gas collection within the wall of a jejunal segment, with a characteristic target air distribution. The patient was surgically treated and successfully discharged from our hospital with the diagnosis of acute bowel ischemia. The target air sign can be an initial CT finding of the typical pneumatosis intestinalis and it can be useful in the early diagnosis of bowel ischemia.

  9. [Multidetector CT for the assessment of the groin region].

    PubMed

    Stabile Ianora, Amato Antonio; Lorusso, Filomenamila; Niccoli Asabella, Artor; Di Maggio, Paola; Fonio, Paolo; Losco, Matteo; Rubini, Giuseppe

    2012-11-01

    Assessment of the complex anatomy of the groin region using different imaging modalities is important to identify those pathological conditions that may present with atypical symptoms. In obese patients or in the presence of complications, physical examination may be unremarkable and instrumental studies based on non-invasive techniques (e.g., ultrasounds) do not allow accurate assessment of this region. Multidetector CT scanning and reconstruction can provide useful information on inguinal canal anatomy and its related diseases, contributing to timely therapeutic interventions.

  10. Assessment of coronary stents by 64-slice computed tomography: in-stent lumen visibility and patency.

    PubMed

    Kong, Ling-Yan; Jin, Zheng-Yu; Zhang, Shu-Yang; Zhang, Zhu-Hua; Wang, Yi-Ning; Song, Lan; Zhang, Xiao-Na; Zhang, Yun-Qing

    2009-09-01

    To assess lumen visibility of coronary stents by 64-slice computed tomography (CT) coronary angiography, and determine the value of 64-slice CT in non-invasive detecting of in-stent restenosis after coronary artery stent implantation. Totally, 60 patients (54 males, aged 57.0+/-12.7 years) and 105 stents were investigated by 64-slice CT at a mean interval of 20.0+/-16.6 months after coronary stents implantation. Axial multi-planar reconstruction images of the stents and curved-planar reconstruction images through the median of the stents were reconstructed for evaluating stent image quality on a 5-point scale (1=excellent, 5=non-assessable), and stent lumen diameter was detected. Conventional coronary angiography was performed in 18 patients, and 32 stents were evaluated. Image quality was good to excellent on average (score 1.71+/-0.76). Stent image quality score was correlated to heart rate (r=0.281, P<0.01) and stent diameter (r=-0.480, P<0.001). All the stents were assessable in lumen visibility with an average visible lumen diameter percentage of 60.7%+/-13.6%. Visible lumen diameter percentage was correlated to heart rate (r=-0.193, P<0.05), stent diameter (r=0.403, P<0.001), and stent image quality score (r=-0.500, P<0.001). Visible lumen diameter percentage also varied depending on the stent type. In comparison with the conventional coronary angiography, 4 of 6 in-stent stenoses were correctly detected. The sensitivity and specificity for the detection of in-stent stenosis were 66.7% and 84.6%, respectively. Using a 64-slice CT, the stent lumen is partly visible in most of the stents. And 64-slice CT may be useful in the assessment of stent patency.

  11. Case series of 64 slice computed tomography-computed tomographic angiography with 3D reconstruction to diagnose symptomatic cerebral aneurysms: new standard of care?

    PubMed

    Jehle, Dietrich; Chae, Floria; Wai, Jonathan; Cloud, Sam; Pierce, David; Meyer, Michael

    2012-01-09

    CT angiography (CTA) has improved significantly over the past few years such that the reconstructed images of the cerebral arteries may now be equivalent to conventional digital angiography. The new technology of 64 slice multi-detector CTA can reconstruct detailed images that can reliably identify small cerebral aneurysms, even those <3mm. In addition, it is estimated that CT followed by lumbar puncture (LP) misses up to 4% of symptomatic aneurysms. We present a series of cases that illustrates how CT followed by CTA may be replacing CT-LP as the standard of care in working up patients for symptomatic cerebral aneurysms and the importance of performing three dimensional (3D) reconstructions. A series of seven cases of symptomatic cerebral aneurysms were identified that illustrate the sensitivity of CT-CTA versus CT-LP and the importance of 3D reconstruction in identifying these aneurysms. Surgical treatment was recommended for 6 of the 7 patients with aneurysms and strict hypertension control was recommended for the seventh patient. Some of these patients demonstrated subarachnoid hemorrhage on presentation while others had negative LPs. A number of these patients with negative LPs were clearly symptomatic from their aneurysms. At least one of these cerebral aneurysms was not apparent on CTA without 3D reconstruction. 3D reconstruction of CTA is crucial to adequately identify cerebral aneurysms. This case series helps reinforce the importance of 3D reconstruction. There is some data to suggest that 64 slice CT-CTA may be equivalent or superior to CT-LP in the detection of symptomatic cerebral aneurysms.

  12. Case series of 64 slice computed tomography-computed tomographic angiography with 3D reconstruction to diagnose symptomatic cerebral aneurysms: new standard of care?

    PubMed Central

    Jehle, Dietrich; Chae, Floria; Wai, Jonathan; Cloud, Sam; Pierce, David; Meyer, Michael

    2012-01-01

    CT angiography (CTA) has improved significantly over the past few years such that the reconstructed images of the cerebral arteries may now be equivalent to conventional digital angiography. The new technology of 64 slice multi-detector CTA can reconstruct detailed images that can reliably identify small cerebral aneurysms, even those <3mm. In addition, it is estimated that CT followed by lumbar puncture (LP) misses up to 4% of symptomatic aneurysms. We present a series of cases that illustrates how CT followed by CTA may be replacing CT-LP as the standard of care in working up patients for symptomatic cerebral aneurysms and the importance of performing three dimensional (3D) reconstructions. A series of seven cases of symptomatic cerebral aneurysms were identified that illustrate the sensitivity of CT-CTA versus CT-LP and the importance of 3D reconstruction in identifying these aneurysms. Surgical treatment was recommended for 6 of the 7 patients with aneurysms and strict hypertension control was recommended for the seventh patient. Some of these patients demonstrated subarachnoid hemorrhage on presentation while others had negative LPs. A number of these patients with negative LPs were clearly symptomatic from their aneurysms. At least one of these cerebral aneurysms was not apparent on CTA without 3D reconstruction. 3D reconstruction of CTA is crucial to adequately identify cerebral aneurysms. This case series helps reinforce the importance of 3D reconstruction. There is some data to suggest that 64 slice CT-CTA may be equivalent or superior to CT-LP in the detection of symptomatic cerebral aneurysms. PMID:22593806

  13. [Gatrointestinal imaging with multidetector CT and MRI].

    PubMed

    Lorusso, Filomenamila; Fonio, Paolo; Scardapane, Arnaldo; Giganti, Melchiore; Rubini, Giuseppe; Ferrante, Annunziata; Stabile Ianora, Amato Antonio

    2012-11-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are important diagnostic tools for evaluating gastrointestinal disorders. A rigorous examination protocol is needed to achieve the best results. This paper describes the technical issues of CT and MRI for the study of gastrointestinal tracts (esophagus, stomach, small and large bowel).

  14. Radiation dose reduction in multidetector CT in fracture evaluation.

    PubMed

    Yi, Jung Woo; Park, Hee Jin; Lee, So Yeon; Rho, Myung Ho; Hong, Hyun Pyo; Choi, Yoon Jung; Kim, Mi Sung

    2017-08-01

    To evaluate whether multidetector CT with low-dose radiation (low-dose CT) of joints can be useful when evaluating fractures. Our study included CT scans of 398 patients, 103 shoulder cases, 109 wrist cases, 98 pelvis cases and 88 ankle cases. There were 191 females and 207 males. The low-dose CTs were performed using identical voltage and parameters with the exception of decreased (half of standard dose) tube current. Low-dose and standard-dose images were compared with regards to objective image quality, subjective evaluation of image quality and diagnostic performance for the fractures. There was no significant difference of image noise between standard-dose CT and low-dose CT in every joint (p > 0.05). Each mean value of subjective score did not show significant difference according to the dosage of the CT scan. There were no statistically significant differences in the sensitivity (96-100%), specificity (95.2-100%) or accuracy (97.9-100%) between standard-dose CT and low-dose CT (p values, 0.1336-1.000). The evaluation of extremities for fractures using low-dose CT can reduce radiation exposure by about 50% compared with standard-dose CT without affecting image quality or diagnostic performance. Advances in knowledge: Low-dose CT of the extremities (shoulder, pelvis, ankle and wrist) can reduce radiation dose by about 50% compared with standard-dose CT and does not significantly affect image quality or diagnostic performance in fracture detection.

  15. Multidetector CT in children: current concepts and dose reduction strategies

    PubMed Central

    van Dam, Ingrid M.; van der Molen, Aart J.

    2010-01-01

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks (“as low as reasonably achievable” principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols. PMID:20535463

  16. Multidetector CT in children: current concepts and dose reduction strategies.

    PubMed

    Nievelstein, Rutger A J; van Dam, Ingrid M; van der Molen, Aart J

    2010-08-01

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks ("as low as reasonably achievable" principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols.

  17. Multi-detector row CT of pancreatic islet cell tumors.

    PubMed

    Horton, Karen M; Hruban, Ralph H; Yeo, Charles; Fishman, Elliot K

    2006-01-01

    Pancreatic islet cell tumors (ICTs) are neuroendocrine neoplasms that produce and secrete hormones to a variable degree. These neoplasms can present a diagnostic challenge, both clinically and radiologically. ICTs can be classified as either syndromic or nonsyndromic on the basis of their clinical manifestations. Multi-detector row computed tomography (CT) plays an important role in the diagnosis and staging of both syndromic and nonsyndromic ICTs. In general, syndromic ICTs are less than 3 cm in size. They are typically hyperenhancing and are usually best seen on CT scans obtained during the arterial phase. Nonsyndromic ICTs tend to be larger than syndromic ICTs at presentation and are more likely to be cystic or necrotic. It is important for the radiologist to be familiar with appropriate CT protocol for the evaluation of patients with suspected pancreatic ICT and to understand the variable CT appearances of these neoplasms. (c) RSNA, 2006.

  18. Accessory Spleen: Prevalence and Multidetector CT Appearance.

    PubMed

    Rashid, Sameeah Abdulrahman

    2014-07-01

    The aim of this study was to evaluate the prevalence and computed tomography (CT) appearances of accessory spleens in hospital-based patients, and to measure and make comparisons between accessory spleen size and density. A cross-sectional study was carried out in a diagnostic center in Erbil, Iraq during January-December, 2012. Biphasic abdominal CT images of 334 consecutive patients with different age groups were evaluated for the presence of an accessory spleen, and if identified, it was further analysed for shape, diameter, density, number, and location. Patients with inadequate CT techniques, splenectomy, hematological disorders, and widespread lesions in the abdomen were excluded from this study. Of the 334 patients (198 female, 136 male), with a mean age of 47.2 years (SD 15.7), 82 accessory spleens were detected in 63 patients (18.8%). Their mean diameter was 14.7 mm (range 3-79 mm), 68% were round in shape and 75.6% were medial to the main spleen. Sixty percent of the cases showed a single accessory spleen and 40% had more than one (up to 4 detected). A significant difference in the mean diameter of accessory spleens between similar and different densities than the main spleen was observed (P = 0.018), 71 accessory spleens (mean diameter = 15.97 mm) displayed similar densities to the main spleen, while 11 (mean diameter = 7.09 mm) were hypodense or hyperdense to the main spleen. The prevalence of an accessory spleen is high, and should be considered by radiologists during abdominal CT scan reporting.

  19. Diagnostic Imaging of Pulmonary Thromboembolism by Multidetector-row CT

    PubMed Central

    2010-01-01

    For diagnosis of pulmonary thromboembolism, multidetector-row computed tomography (CT) is a minimally invasive imaging technique that can be performed rapidly with high sensitivity and specificity, and has been increasingly employed as the imaging modality of first choice for this disease. Since deep vein thrombosis in the legs, which is important as a thrombus source, can be evaluated immediately after the diagnosis of pulmonary thromboembolism, this diagnostic method is considered to provide important information when deciding on a comprehensive therapeutic strategy for this disease. PMID:23555409

  20. Multidetector CT Findings of Bowel Transection in Blunt Abdominal Trauma

    PubMed Central

    Cho, Hyun Suk; Hong, Hye-Suk; Park, Mee Hyun; Ha, Hong Il; Yang, Ik; Lee, Yul; Jung, Ah Young; Hwang, Ji-Young

    2013-01-01

    Objective Though a number of CT findings of bowel and mesenteric injuries in blunt abdominal trauma are described in literature, no studies on the specific CT signs of a transected bowel have been published. In the present study we describe the incidence and new CT signs of bowel transection in blunt abdominal trauma. Materials and Methods We investigated the incidence of bowel transection in 513 patients admitted for blunt abdominal trauma who underwent multidetector CT (MDCT). The MDCT findings of 8 patients with a surgically proven complete bowel transection were assessed retrospectively. We report novel CT signs that are unique for transection, such as complete cutoff sign (transection of bowel loop), Janus sign (abnormal dual bowel wall enhancement, both increased and decreased), and fecal spillage. Results The incidence of bowel transection in blunt abdominal trauma was 1.56%. In eight cases of bowel transection, percentage of CT signs unique for bowel transection were as follows: complete cutoff in 8 (100%), Janus sign in 6 (100%, excluding duodenal injury), and fecal spillage in 2 (25%). The combination of complete cutoff and Janus sign were highly specific findings in patients with bowel transection. Conclusion Complete cut off and Janus sign are the unique CT findings to help detect bowel transection in blunt abdominal trauma and recognition of these findings enables an accurate and prompt diagnosis for emergency laparotomy leading to reduced mortality and morbidity. PMID:23901318

  1. Multidetector CT and three-dimensional CT angiography of upper extremity arterial injury.

    PubMed

    Fritz, Jan; Efron, David T; Fishman, Elliot K

    2015-06-01

    Successful management of upper extremity arterial injury requires fast and accurate diagnosis. The rate of limb preservation depends on the location, severity, and time of ischemia. Indications for diagnostic imaging depend on the mechanism and type of injury, clinical signs, cardiovascular stability, and clinical suspicion. Because of ease of access, speed, and high accuracy for this diagnosis, multidetector computed tomographic (MDCT) angiography is often used as the first line imaging modality. MDCT systems with 64 slice configuration and more afford high temporal and spatial high-resolution, isotropic data acquisition and integration with whole-body trauma MDCT protocols. The use of individual injection timing protocols ensures high diagnostic image quality. Several strategies are available to reduce radiation exposure. Direct MDCT angiography findings of arterial injuries include active extravasation, luminal narrowing, lack of luminal contrast opacification, filling defect, arteriovenous fistula, and pseudoaneurysm. Important descriptors are location and length of defect, degree of luminal narrowing, and presence of distal arterial supply reconstitution. Proximal arterial injuries include the subclavian, axillary, and brachial arteries. Distal arterial injuries include the ulnar and radial arteries, as well as the palmar arterial arches. Concomitant venous injury, musculoskeletal injury, and nerve damage are common. In this exhibit, we outline the role of MDCT angiography in the diagnosis and management of upper extremity arterial injury, discuss strategies for MDCT angiography acquisition and concepts of data visualization, and illustrate various types of injuries.

  2. Assessment of trabecular bone structure of the calcaneus using multi-detector CT: correlation with microCT and biomechanical testing.

    PubMed

    Diederichs, Gerd; Link, Thomas M; Kentenich, Marie; Schwieger, Karsten; Huber, Markus B; Burghardt, Andrew J; Majumdar, Sharmila; Rogalla, Patrik; Issever, Ahi S

    2009-05-01

    The prediction of bone strength can be improved when determining bone mineral density (BMD) in combination with measures of trabecular microarchitecture. The goal of this study was to assess parameters of trabecular bone structure and texture of the calcaneus by clinical multi-detector row computed tomography (MDCT) in an experimental in situ setup and to correlate these parameters with microCT (microCT) and biomechanical testing. Thirty calcanei in 15 intact cadavers were scanned using three different protocols on a 64-slice MDCT scanner with an in-plane pixel size of 208 microm and 500 microm slice thickness. Bone cores were harvested from each specimen and microCT images with a voxel size of 16 microm were obtained. After image coregistration, trabecular bone structure and texture were evaluated in identical regions on the MDCT images. After data acquisition, uniaxial compression testing was performed. Significant correlations between MDCT- and microCT-derived measures of bone volume fraction (BV/TV), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) were found (range, R(2)=0.19-0.65, p<0.01 or 0.05). The MDCT-derived parameters of volumetric BMD, app. BV/TV, app. Tb.Th and app. Tb.Sp were capable of predicting 60%, 63%, 53% and 25% of the variation in bone strength (p<0.01). When combining those measures with one additional texture index (either GLCM, TOGLCM or MF.euler), prediction of mechanical competence was significantly improved to 86%, 85%, 71% and 63% (p<0.01). In conclusion, this study showed the feasibility of trabecular microarchitecture assessment using MDCT in an experimental setup simulating the clinical situation. Multivariate models of BMD or structural parameters combined with texture indices improved prediction of bone strength significantly and might provide more reliable estimates of fracture risk in patients.

  3. Scenes from the past: initial investigation of early jurassic vertebrate fossils with multidetector CT.

    PubMed

    Bolliger, Stephan A; Ross, Steffen; Thali, Michael J; Hostettler, Bernhard; Menkveld-Gfeller, Ursula

    2012-01-01

    The study of fossils permits the reconstruction of past life on our planet and enhances our understanding of evolutionary processes. However, many fossils are difficult to recognize, being encased in a lithified matrix whose tedious removal is required before examination is possible. The authors describe the use of multidetector computed tomography (CT) in locating, identifying, and examining fossil remains of crocodilians (Mesosuchia) embedded in hard shale, all without removing the matrix. In addition, they describe how three-dimensional (3D) reformatted CT images provided details that were helpful for extraction and preparation. Multidetector CT can help experienced paleontologists localize and characterize fossils in the matrix of a promising rock specimen in a nondestructive manner. Moreover, with its capacity to generate highly accurate 3D images, multidetector CT can help determine whether the fossils warrant extraction and can assist in planning the extraction process. Thus, multidetector CT may well become an invaluable tool in the field of paleoradiology.

  4. Cam-type deformities: Concepts, criteria, and multidetector CT features.

    PubMed

    Mellado, J M; Radi, N

    2015-01-01

    Interpreting imaging studies of a painful hip requires detailed knowledge of the regional anatomy. Some variants of the proximal femur, such as cam-type deformities, can course asymptomatically or cause femoroacetabular impingement. The principal numerical criterion for defining cam-type deformities, the alpha angle, has some limitations. In this article, we review the anatomic variants of the anterior aspect of the proximal femur, focusing on cam-type deformities. Using diagrams and multidetector CT images, we describe the parameters that are useful for characterizing these deformities in different imaging techniques. We also discuss the potential correspondence of imaging findings of cam-type deformities with the terms coined by anatomists and anthropologists to describe these phenomena. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  5. Multidetector CT of pulmonary cavitation: filling in the holes.

    PubMed

    Mortensen, K H; Babar, J L; Balan, A

    2015-04-01

    Pulmonary cavitation causes significant morbidity and mortality. Early diagnosis of the presence and aetiology of a cavity is therefore crucial in order to avoid further demise in both the localized pulmonary and systemic disorders that may manifest with pulmonary cavity formation. Multidetector CT has become the principal diagnostic technique for detecting pulmonary cavitation and its complications. This review provides an overview of the aetiologies and their imaging findings using this technique. Combining a literature review with case illustration, a synopsis of the different imaging features and constellations is provided, which may suggest a particular cause and aid the differentiation from diseases with similar findings. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  6. Imaging of patent foramen ovale with 64-section multidetector CT.

    PubMed

    Saremi, Farhood; Channual, Stephanie; Raney, Aidan; Gurudevan, Swaminatha V; Narula, Jagat; Fowler, Steven; Abolhoda, Amir; Milliken, Jeffrey C

    2008-11-01

    To investigate the feasibility of 64-section multidetector computed tomography (CT) by using CT angiography (a) to demonstrate anatomic detail of the interatrial septum pertinent to the patent foramen ovale (PFO), and (b) to visually detect left-to-right PFO shunts and compare these findings in patients who also underwent transesophageal echocardiography (TEE). In this institutional review board-approved HIPAA-compliant study, electrocardiographically gated coronary CT angiograms in 264 patients (159 men, 105 women; mean age, 60 years) were reviewed for PFO morphologic features. The length and diameter of the opening of the PFO tunnel, presence of atrial septal aneurysm (ASA), and PFO shunts were evaluated. A left-to-right shunt was assigned a grade according to length of contrast agent jet (grade 1, 1 cm to 2 cm; grade 3, >2 cm). In addition, 23 patients who underwent both modalities were compared (Student t test and linear regression analysis). A difference with P < .05 was significant. A flap valve, seen in 101 (38.3%) patients, was patent at the entry into the right atrium (PFO) in 62 patients (61.4% of patients with flap valve, 23.5% of total patients). A left-to-right shunt was detected in 44 (16.7% of total) patients (grade 1, 61.4%; grade 2, 34.1%; grade 3, 4.5%). No shunt was seen in patients without a flap valve. Mean length of PFO tunnel was 7.1 mm in 44 patients with a shunt and 12.1 mm in 57 patients with a flap valve without a shunt (P < .0001). In patients with a tunnel length of 6 mm or shorter, 92.6% of the shunts were seen. ASA was seen in 11 (4.2%) patients; of these patients, a shunt was seen in seven (63.6%). In 23 patients who underwent CT angiography and TEE, both modalities showed a PFO shunt in seven. Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in

  7. The validity of investigating occult hip fractures using multidetector CT

    PubMed Central

    Williams, Huw L M; Carpenter, Eleanor C; Lyons, Kathleen

    2016-01-01

    Objective: 10% of all hip fractures are occult on plain radiography, requiring further investigation to ascertain the diagnosis. MRI is presently the gold standard investigation, but frequently has disadvantages of time delay, resulting in increased hospital stay and mortality. Our aim was to establish whether multidetector CT (MDCT) is an appropriate first-line investigation of occult femoral neck (NOF) fractures. Methods: From 2013, we elected to use MDCT as the first-line investigation in patients believed to have an NOF fracture with negative plain films. These were reported by consultant musculoskeletal radiologists. We retrospectively analysed the data of consecutive patients presenting to the University Hospital of Wales, over 30 months with a clinical suspicion of a hip fracture. Results: 1443 patients were admitted during the study period. 209 (14.5%) patients had negative plain films requiring further investigation to exclude an NOF fracture, of which 199 patients had a CT. 93 patients had no fracture and 20 patients had isolated greater trochanter fractures. None of these patients progressed to develop an intracapsular femoral neck fracture at 4-month follow-up, although one patient sustained an extracapsular fracture following a high-energy fall whilst admitted. 26 femoral neck fractures were diagnosed on CT, whilst the remaining 60 patients were diagnosed with other pelvic ring fractures. Conclusion: When interpreted by experienced radiologists, MDCT has both sensitivity and specificity of 100%. Advances in knowledge: We recommend the use of MDCT as a safe and appropriate first-line investigation for NOF fractures. PMID:26838948

  8. Multidetector CT angiography in evaluation of prosthetic heart valve dysfunction.

    PubMed

    Habets, Jesse; Mali, Willem P T M; Budde, Ricardo P J

    2012-01-01

    Prosthetic heart valves (PHVs) are commonly implanted to replace diseased native heart valves. PHV dysfunction is an infrequent but potentially life-threatening condition. In daily clinical practice, transthoracic and transesophageal echocardiography and fluoroscopy are the imaging modalities used for diagnostic evaluation of suspected PHV dysfunction. These modalities may not allow determination of the cause of PHV dysfunction, mostly because of acoustic shadowing. Multidetector computed tomographic (CT) angiography is a promising complementary technique for evaluation of PHVs, especially in patients with PHV obstruction and endocarditis. The CT image quality of PHVs mainly depends on their composition, with most causing only limited artifacts. Retrospectively electrocardiographically gated acquisition is advisable for PHV imaging because it enables dynamic leaflet evaluation and anatomic assessment in both systole and diastole. For accurate image interpretation, dedicated reconstruction in plane with and perpendicular to the PHV leaflets is mandatory. Besides PHV assessment, CT also provides information on the coronary arteries, the location and patency of bypass grafts, the dimensions of the aorta, and the distance between the sternum and right ventricle, information valuable for planning repeat surgery. To achieve the optimal diagnostic yield in PHV imaging, multidisciplinary cooperation between the departments of cardiology, cardiothoracic surgery, and radiology is crucial.

  9. In the workup of patients with obscure gastrointestinal bleed, does 64-slice MDCT have a role?

    PubMed

    Kulkarni, Chinmay; Moorthy, Srikanth; Sreekumar, Kp; Rajeshkannan, R; Nazar, Pk; Sandya, Cj; Sivasubramanian, S; Ramchandran, Pv

    2012-01-01

    The purpose was to prospectively determine the sensitivity of 64-slice MDCT in detecting and diagnosing the cause of obscure gastrointestinal bleed (OGIB). Our study included 50 patients (male 30, female 20) in the age range of 3-82 years (average age: 58.52 years) who were referred to our radiology department as part of their workup for clinically evident gastrointestinal (GI) bleed or as part of workup for anemia (with and without positive fecal occult blood test). All patients underwent conventional upper endoscopy and colonoscopy before undergoing CT scan. Following a noncontrast scan, all patients underwent triple-phase contrast CT scan using a 64-slice CT scan system. The diagnostic performance of 64-slice MDCT was compared to the results of capsule endoscopy, 99m-technetium-labeled red blood cell scintigraphy (99mTc-RBC scintigraphy), digital subtraction angiography, and surgery whenever available. CT scan showed positive findings in 32 of 50 patients. The sensitivity, specificity, positive predictive value, and negative predictive values of MDCT for detection of bleed were 72.2%, 42.8%, 81.2%, and 44.4%, respectively. Capsule endoscopy was done in 15 patients and was positive in 10 patients; it had a sensitivity of 71.4%. Eleven patients had undergone 99mTc-RBC scintigraphy prior to CT scan, and the result was positive in seven patients (sensitivity 70%). Digital subtraction angiography was performed in only eight patients and among them all except one patient showed findings consistent with the lesions detected on MDCT. MDCT is a sensitive and noninvasive tool that allows rapid detection and localization of OGIB. It can be used as the first-line investigation in patients with negative endoscopy and colonoscopy studies. MDCT and capsule endoscopy have complementary roles in the evaluation of OGIB.

  10. Multidetector CT angiography for acute gastrointestinal bleeding: technique and findings.

    PubMed

    Artigas, José M; Martí, Milagros; Soto, Jorge A; Esteban, Helena; Pinilla, Inmaculada; Guillén, Eugenia

    2013-01-01

    Acute gastrointestinal bleeding is a common reason for emergency department admissions and an important cause of morbidity and mortality. Factors that complicate its clinical management include patient debility due to comorbidities; intermittence of hemorrhage; and multiple sites of simultaneous bleeding. Its management, therefore, must be multidisciplinary and include emergency physicians, gastroenterologists, and surgeons, as well as radiologists for diagnostic imaging and interventional therapy. Upper gastrointestinal tract bleeding is usually managed endoscopically, with radiologic intervention reserved as an alternative to be used if endoscopic therapy fails. Endoscopy is often less successful in the management of acute lower gastrointestinal tract bleeding, where colonoscopy may be more effective. The merits of performing bowel cleansing before colonoscopy in such cases might be offset by the resultant increase in response time and should be weighed carefully against the deficits in visualization and diagnostic accuracy that would result from performing colonoscopy without bowel preparation. In recent years, multidetector computed tomographic (CT) angiography has gained acceptance as a first-line option for the diagnosis and management of lower gastrointestinal tract bleeding. In selected cases of upper gastrointestinal tract bleeding, CT angiography also provides accurate information about the presence or absence of active bleeding, its source, and its cause. This information helps shorten the total diagnostic time and minimizes or eliminates the need for more expensive and more invasive procedures. © RSNA, 2013.

  11. Variations of the popliteal artery branching with multidetector CT angiography.

    PubMed

    Yanik, Bahar; Bulbul, Erdogan; Demirpolat, Gulen

    2015-04-01

    To date the anatomy of the popliteal artery variations using multidetector-row computed tomography angiography (MD CTA) was not assessed. The objective of this study is to establish 3D CT anatomy of the popliteal artery variations. A total of 126 lower limbs that underwent CTA using 64-detector MDCT were retrospectively reviewed. The anatomical variations of the distal popliteal artery branching were assessed. Ninety-seven lower limbs (83.6%) had the usual branching pattern (type 1 A) with tibialis anterior artery (TA) arising first followed by the tibial-peroneal trunk, which then gives rise to the tibialis posterior artery (TP) and peroneal artery. Variations in popliteal branching pattern were seen in 19 (16.4%) limbs. The commonest variation was first branch of the TP in 5 (4.4%) of the limbs (type 1 C) or high origin with anterior course of popliteus muscle of the TA in 5 (4.4%) limbs (type 2 A II). Many variations exist in the running patterns of the branching pattern of the popliteal artery. Knowledge of the branching pattern of the popliteal artery will be beneficial to radiologist for the evaluation of CT angiograms and interventional vascular procedures, and to vascular surgeons for various surgical approaches. MD CTA provides noninvasive means of assessing distal popliteal artery variations.

  12. Classification of lung area using multidetector-row CT images

    NASA Astrophysics Data System (ADS)

    Mukaibo, Tsutomu; Kawata, Yoshiki; Niki, Noboru; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki

    2002-05-01

    Recently, we can get high quality images in the short time for the progress of X-ray CT scanner. And the three dimensional (3-D) analysis of pulmonary organs using multidetector-row CT (MDCT) images, is expected. This paper presents a method for classifying lung area into each lobe using pulmonary MDCT images of the whole lung area. It is possible to recognize the position of nodule by classifying lung area into these lobes. The structure of lungs differs on the right one and left one. The right lung is divided into three domains by major fissure and minor fissure. And, the left lung is divided into two domains by major fissure. Watching MDCT images carefully, we find that the surroundings of fissures have few blood vessels. Therefore, lung area is classified by extraction of the domain that the distance from pulmonary blood vessels is large and connective search of these extracted domains. These extraction and search are realized by 3-D weighted Hough transform.

  13. Recent technologic advances in multi-detector row cardiac CT.

    PubMed

    Halliburton, Sandra Simon

    2009-11-01

    Recent technical advances in multi-detector row CT have resulted in lower radiation dose, improved temporal and spatial resolution, decreased scan time, and improved tissue differentiation. Lower radiation doses have resulted from the use of pre-patient z collimators, the availability of thin-slice axial data acquisition, the increased efficiency of ECG-based tube current modulation, and the implementation of iterative reconstruction algorithms. Faster gantry rotation and the simultaneous use of two x-ray sources have led to improvements in temporal resolution, and gains in spatial resolution have been achieved through application of the flying x-ray focal-spot technique in the z-direction. Shorter scan times have resulted from the design of detector arrays with increasing numbers of detector rows and through the simultaneous use of two x-ray sources to allow higher helical pitch. Some improvement in tissue differentiation has been achieved with dual energy CT. This article discusses these recent technical advances in detail.

  14. Intercostal Artery Supplying Hepatocellular Carcinoma: Demonstration of a Tumor Feeder by C-arm CT and Multidetector Row CT

    SciTech Connect

    Kim, Hyo-Cheol Chung, Jin Wook; Lee, In Joon; An, Sangbu; Seong, Nak Jong; Son, Kyu Ri; Jae, Hwan Jun; Park, Jae Hyung

    2011-02-15

    This study was designed to describe tumor feeders from the intercostal artery supplying hepatocellular carcinoma (HCC) on C-arm CT and multidetector row CT. From March 2008 to May 2009, C-arm CT of the intercostal artery was prospectively performed in 24 HCC patients. Two interventional radiologists, who performed C-arm CT, evaluated tumor feeders on C-arm CT and multidetector row CT scans by consensus. In total, 35 intercostal arteries were examined by C-arm CT. All tumor feeders except one showed a sharp upward turn at or near the costochondral junction. On axial C-arm CT images, all tumor feeders were observed as an enhancing dot in the upper intercostal space along the diaphragm. On multidetector CT scans, 17 tumor feeders were observed and 18 were not. Tumor feeders from the intercostal artery are observed as an enhancing dot along the diaphragm on C-arm CT and can be seen on multidetector row CT in approximately half of patients.

  15. Multidetector CT of Surgically Proven Blunt Bowel and Mesenteric Injury.

    PubMed

    Bates, David D B; Wasserman, Michael; Malek, Anita; Gorantla, Varun; Anderson, Stephan W; Soto, Jorge A; LeBedis, Christina A

    2017-01-01

    Blunt traumatic injury is one of the leading causes of morbidity and mortality in the United States. Unintentional injury represents the leading cause of death in the United States for all persons between the ages of 1 and 44 years. In the setting of blunt abdominal trauma, the reported rate of occurrence of bowel and mesenteric injuries ranges from 1% to 5%. Despite the relatively low rate of blunt bowel and mesenteric injury in patients with abdominal and pelvic trauma, delays in diagnosis are associated with increased rates of sepsis, a prolonged course in the intensive care unit, and increased mortality. During the past 2 decades, as multidetector computed tomography (CT) has emerged as an essential tool in emergency radiology, several direct and indirect imaging features have been identified that are associated with blunt bowel and mesenteric injury. The imaging findings in cases of blunt bowel and mesenteric injury can be subtle and may be seen in the setting of multiple complex injuries, such as multiple solid-organ injuries and spinal fractures. Familiarity with the various imaging features of blunt bowel and mesenteric injury, as well as an understanding of their clinical importance with regard to the care of the patient, is essential to making a timely diagnosis. Once radiologists are familiar with the spectrum of findings of blunt bowel and mesenteric injury, they will be able to make timely diagnoses that will lead to improved patient outcomes. (©)RSNA, 2017.

  16. Determinants of aortic bioprosthetic valve calcification assessed by multidetector CT.

    PubMed

    Mahjoub, Haïfa; Mathieu, Patrick; Larose, Eric; Dahou, Abdelaziz; Sénéchal, Mario; Dumesnil, Jean-Gaston; Després, Jean-Pierre; Pibarot, Philippe

    2015-03-01

    Cusp calcification is the main mechanism leading to bioprosthetic heart valve (BPV) failure. Recent studies suggest that BPV calcification is an active rather than passive process probably modulated by several mechanisms including lipid-mediated inflammation and dysfunctional phosphocalcic metabolism. To identify the clinical and metabolic determinants of BPV calcification assessed by multidetector CT (MDCT). Presence of BPV calcification was assessed by MDCT in 194 patients who had undergone aortic valve replacement. A calcification score was individually calculated and expressed in mm(3). Patients also underwent a clinical evaluation, a Doppler echocardiographic exam, and a plasma lipid and phosphocalcic profile. 46 patients (24%) had BPV calcification (cusp calcification score >0 mm(3)). After adjustment for age, gender, and time interval since BPV implantation, increased calcium-phosphorus product (OR 1.11, 95% CI 1.01 to 1.23 per 1 unit; p=0.02) and the presence of prosthesis-patient mismatch (OR 3.67, 95% CI 1.25 to 10.6; p=0.01) were the strongest independent factors associated with BPV calcification. Calcium supplement intake, age and female gender were independently associated with increased calcium-phosphorus product. This study suggests that higher calcium-phosphorus product and prosthesis-patient mismatch promote BPV calcification. Furthermore, this study reports that calcium supplements, which are extensively prescribed in elderly patients, are independently associated with higher calcium-phosphorus product. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. Aortic valve area assessment: multidetector CT compared with cine MR imaging and transthoracic and transesophageal echocardiography.

    PubMed

    Pouleur, Anne-Catherine; le Polain de Waroux, Jean-Benoît; Pasquet, Agnès; Vanoverschelde, Jean-Louis J; Gerber, Bernhard L

    2007-09-01

    To prospectively compare the accuracy of multidetector computed tomographic (CT) measurements of the aortic valve area (AVA) with transesophageal echocardiography (TEE) and cine magnetic resonance (MR) measurements of this area for preoperative examination of patients undergoing cardiac surgery, with transthoracic echocardiography (TTE) as the reference standard. After giving informed consent for the institutional review board-approved study protocol, 48 patients (33 men, 15 women; mean age, 62 years+/-13 [standard deviation]) with (n=27) or without (n=21) aortic stenosis underwent multidetector CT, cine MR, TTE, and TEE before undergoing cardiac surgery. AVAs derived with manual planimetry by using cine short-axis multidetector CT, MR, and TEE images obtained through the aortic valve were compared among each other and with AVAs measured by using continuity equation TTE at regression and Bland-Altman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that of TTE by using kappa statistics and receiver operating characteristic curves. Multidetector CT-derived AVA correlated highly with MR-derived (r=0.98, P<.001), TEE-derived (r=0.98, P<.001), and TTE-derived (r=0.96, P<.001) AVA. Multidetector CT planimetry AVAs (mean AVA+/-standard deviation, 2.5 cm2+/-1.7) were not significantly different from MR planimetry (2.4 cm2+/-1.8, P>.99) or TEE planimetery (2.5 cm2+/-1.7, P=.21) AVAs, but they were significantly larger than TTE-derived AVAs (2.0 cm2+/-1.5, P<.001). With TTE as the reference standard, multidetector CT correctly (kappa=0.88, P<.001) depicted all 21 normal, six of eight mildly stenotic (AVA>or=1.2 cm2 and <2.0 cm2), seven of eight moderately stenotic (AVA>or= 0.8 cm2 and <1.2 cm2), and 10 of 11 severely stenotic (AVA<0.8 cm2) valves. It also correctly depicted all 14 bicuspid valves identified with TEE, eight of which were missed with TTE. Multidetector CT enables accurate noninvasive assessment of the

  18. Carotid stenosis evaluation by 64-slice CTA: comparison of NASCET, ECST and CC grading methods.

    PubMed

    Kılıçkap, Gülsüm; Ergun, Elif; Başbay, Elif; Koşar, Pınar; Kosar, Uğur

    2012-06-01

    Purpose is to evaluate the intraobserver and interobserver variability of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST) and Common Carotid (CC) methods, which are used to measure the degree of ICA stenosis, using 64-slice CT angiography and to compare the measurements made by these three methods. 88 cases (111 carotid arteries) were included in the study. Carotid CTA was performed by a 64 slice scanner (Toshiba, Aqullion 64).Two radiologists measured the degree of carotid stenosis by using NASCET, ECST and CC methods. Intraobserver and interobserver variability of each method was determined by intraclass correlation coefficient (ICC), Bland-Altman plots and kappa and linear weighted kappa statistics. The relation between the measurements was assessed by correlation coefficient (with linear and quadratic methods). Correlation coefficients showed that there is linear correlation between the measurements made by the three methods. The degree of stenosis measured with the NASCET method had the lowest value, while the corresponding values measured with the ECST and CC methods were close to each other. ICC and Bland-Altman plots showed high intra and inter observer agreement for NASCET, ECST and CC methods whereas kappa statistics showed moderate to substantial agreement. CC method had slightly higher agreement when compared with the other two methods. Intra and interobserver agreement is high for NASCET, ECST and CC methods however CC method has a slightly higher reproducibility. There is linear correlation between the measurements made by the three methods.

  19. Slope on proximal tibiofibular articular surface with 3-D reconstruction by 64-slice computed tomography on human.

    PubMed

    Zhang, Yin-wang; Deng, Hong-zhen; Zhu, Hai-bo; Zhu, Yi; Zhu, Jian-ming

    2012-05-01

    Using 64-slice spiral CT to reconstruct virtual knee joints of adults, we measured the gradient of proximal tibia-fibular joint and compared this result with bare joint measurement. We then discuss the accuracy of these measurements using a 64-slice spiral CT. Two hundred healthy adults were selected, including 100 males and 100 females, aged from 18 to 90 years. The gradient of the longitudinal axis of the fibula and the articular surface, and the angle of horizon of the proximal tibia-fibular articular surface and the horizontal line were measured by using a 64-slice spiral CT scan. The angle between the longitudinal axis of the fibula and the articular surface (angle A) was 56.80° ± 6.59°, both the left and the right fibula showed no significant difference (t = 0.308, P = 0.758). The angle between horizontal line and the articular surface (angle B) was 32.80° ± 6.49°. The regression or correlation analysis findings showed that there is a negative relationship (r = -0.952, P = 0.000), and there is significant difference (t = 51.87, P < 0.01) between the angle A and the angle B. The measurement value of using 64-slice spiral CT to reconstruct the slope of proximal tibia-fibular joints has no difference compared to the measurement value of the slope of bare proximal tibia-fibular joints. It is a precise, convenient method and is easy to apply for clinical study. © 2012 Tianjin Hospital and Blackwell Publishing Asia Pty Ltd.

  20. A new approach to the assessment of lumen visibility of coronary artery stent at various heart rates using 64-slice MDCT

    PubMed Central

    Groen, J. M.; van Ooijen, P. M. A.; Oudkerk, M.

    2007-01-01

    Coronary artery stent lumen visibility was assessed as a function of cardiac movement and temporal resolution with an automated objective method using an anthropomorphic moving heart phantom. Nine different coronary stents filled with contrast fluid and surrounded by fat were scanned using 64-slice multi-detector computed tomography (MDCT) at 50–100 beats/min with the moving heart phantom. Image quality was assessed by measuring in-stent CT attenuation and by a dedicated tool in the longitudinal and axial plane. Images were scored by CT attenuation and lumen visibility and compared with theoretical scoring to analyse the effect of multi-segment reconstruction (MSR). An average increase in CT attenuation of 144 ± 59 HU and average diminished lumen visibility of 29 ± 12% was observed at higher heart rates in both planes. A negative correlation between image quality and heart rate was non-significant for the majority of measurements (P > 0.06). No improvement of image quality was observed in using MSR. In conclusion, in-stent CT attenuation increases and lumen visibility decreases at increasing heart rate. Results obtained with the automated tool show similar behaviour compared with attenuation measurements. Cardiac movement during data acquisition causes approximately twice as much blurring compared with the influence of temporal resolution on image quality. Electronic supplementary material The online version of this article (doi:10.1007/s00330-007-0568-8) contains supplementary material, which is available to authorized users. PMID:17429648

  1. 64-Slice Computed Tomographic Angiography for the Diagnosis of Intermediate Risk Coronary Artery Disease

    PubMed Central

    2010-01-01

    Magnetic Resonance Imaging for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Pease note that two related evidence-based analyses of non-invasive cardiac imaging technologies for the assessment of myocardial viability are also available on the MAS website: Positron Emission Tomography for the Assessment of Myocardial Viability: An Evidence-Based Analysis Magnetic Resonance Imaging for the Assessment of Myocardial Viability: an Evidence-Based Analysis The Toronto Health Economics and Technology Assessment Collaborative has also produced an associated economic report entitled: The Relative Cost-effectiveness of Five Non-invasive Cardiac Imaging Technologies for Diagnosing Coronary Artery Disease in Ontario [Internet]. Available from: http://theta.utoronto.ca/reports/?id=7 Objective The objective of this report is to determine the accuracy of computed tomographic angiography (CTA) compared to the more invasive option of coronary angiography (CA) in the detection of coronary artery disease (CAD) in stable (non-emergent) symptomatic patients. CT Angiography CTA is a cardiac imaging test that assesses the presence or absence, as well as the extent, of coronary artery stenosis for the diagnosis of CAD. As such, it is a test of cardiac structure and anatomy, in contrast to the other cardiac imaging modalities that assess cardiac function. It is, however, unclear as to whether cardiac structural features alone, in the absence cardiac function information, are sufficient to determine the presence or absence of intermediate pretest risk of CAD. CTA technology is changing rapidly with increasing scan speeds and anticipated reductions in radiation exposure. Initial scanners based on 4, 8, 16, 32, and 64 slice machines have been available since the end of 2004. Although 320-slice machines are now available, these are not widely diffused and the existing published evidence is specific to 64-slice scanners. In general, CTA allows for 3-dimensional (3D) viewing of the

  2. Analyzing coronary artery disease in patients with low CAC scores by 64-slice MDCT.

    PubMed

    Lu, Nan-Han; Yeh, Lee-Ren; Chen, Tai-Been; Huang, Yung-Hui; Kuo, Chung-Ming; Ding, Hueisch-Jy

    2012-01-01

    Coronary artery calcification (CAC) scores are widely used to determine risk for Coronary Artery Disease (CAD). A CAC score does not have the diagnostic accuracy needed for CAD. This work uses a novel efficient approach to predict CAD in patients with low CAC scores. The study group comprised 86 subjects who underwent a screening health examination, including laboratory testing, CAC scanning, and cardiac angiography by 64-slice multidetector computed tomographic angiography. Eleven physiological variables and three personal parameters were investigated in proposed model. Logistic regression was applied to assess the sensitivity, specificity, and accuracy of when using individual variables and CAC score. Meta-analysis combined physiological and personal parameters by logistic regression. The diagnostic sensitivity of the CAC score was 14.3% when the CAC score was ≤30. Sensitivity increased to 57.13% using the proposed model. The statistically significant variables, based on beta values and P values, were family history, LDL-c, blood pressure, HDL-c, age, triglyceride, and cholesterol. The CAC score has low negative predictive value for CAD. This work applied a novel prediction method that uses patient information, including physiological and society parameters. The proposed method increases the accuracy of CAC score for predicting CAD.

  3. Penetrating wounds to the torso: evaluation with triple-contrast multidetector CT.

    PubMed

    Lozano, J Diego; Munera, Felipe; Anderson, Stephan W; Soto, Jorge A; Menias, Christine O; Caban, Kim M

    2013-01-01

    Penetrating injuries account for a large percentage of visits to emergency departments and trauma centers worldwide. Emergency laparotomy is the accepted standard of care in patients with a penetrating torso injury who are not hemodynamically stable and have a clinical indication for exploratory laparotomy, such as evisceration or gastrointestinal bleeding. Continuous advances in technology have made computed tomography (CT) an indispensable tool in the evaluation of many patients who are hemodynamically stable, have no clinical indication for exploratory laparotomy, and are candidates for conservative treatment. Multidetector CT may depict the trajectory of a penetrating injury and help determine what type of intervention is necessary on the basis of findings such as active arterial extravasation and major vascular, hollow viscus, or diaphragmatic injuries. Because multidetector CT plays an increasing role in the evaluation of patients with penetrating wounds to the torso, the radiologists who interpret these studies should be familiar with the CT findings that mandate intervention.

  4. Internal Hernias in the Era of Multidetector CT: Correlation of Imaging and Surgical Findings.

    PubMed

    Doishita, Satoshi; Takeshita, Tohru; Uchima, Yasutake; Kawasaki, Masayasu; Shimono, Taro; Yamashita, Akiyoshi; Sugimoto, Michiko; Ninoi, Teruhisa; Shima, Hideki; Miki, Yukio

    2016-01-01

    Clinical diagnosis of internal hernias is challenging because of their nonspecific signs and symptoms. Many types of internal hernias have been defined: paraduodenal, small bowel mesentery-related, greater omentum-related, lesser sac, transverse mesocolon-related, pericecal, sigmoid mesocolon-related, falciform ligament, pelvic internal, and Roux-en-Y anastomosis-related. An internal hernia is a surgical emergency that can develop into intestinal strangulation and ischemia. Accurate preoperative diagnosis is crucial for appropriate management. Multidetector computed tomography (CT), with its thin-section axial images, high-quality multiplanar reformations, and three-dimensional images, currently plays an essential role in preoperative diagnosis of internal hernias. The diagnostic approach to internal hernias at multidetector CT includes detecting an intestinal closed loop, identifying the hernia orifice, and analyzing abnormal displacement of surrounding structures and key vessels around the hernia orifice and hernia sac. At each step, multidetector CT can depict pathognomonic findings. A saclike appearance suggests an intestinal closed loop in several types of internal hernias. Convergence, engorgement, and twisting of mesenteric vessels in the hernia orifice can be seen clearly at multidetector CT, especially with use of multiplanar reformations. For definitive diagnosis of an internal hernia, analysis of displacement of anatomic landmarks around the hernia orifice is particularly important, and thin-section images provide the required information. Detailed knowledge of the anatomy, etiology, and imaging landmarks of the various hernia types is also necessary. Familiarity with the appearances of internal hernias at multidetector CT allows accurate and specific preoperative diagnosis. (©)RSNA, 2015.

  5. Multidetector CT: what do we do with all the images generated?

    PubMed

    Strickland, N H

    2004-01-01

    Multidetector spiral CT technology generates much more acquisition data than the previous generation of single detector spiral CT machines, and permits more sophisticated and better quality post-processing options, which in turn generate even more imaging data. Such large quantities of data have repercussions upon the mode of image interpretation (hard copy vs soft copy), the speed of data transmission and the storage of these data.

  6. Multidetector CT and postprocessing in planning and assisting in minimally invasive bronchoscopic airway interventions.

    PubMed

    Nair, Arjun; Godoy, Myrna C; Holden, Emma L; Madden, Brendan P; Chua, Felix; Ost, David E; Roos, Justus E; Naidich, David P; Vlahos, Ioannis

    2012-01-01

    A widening spectrum of increasingly advanced bronchoscopic techniques is available for the diagnosis and treatment of various bronchopulmonary diseases. The evolution of computed tomography (CT)-multidetector CT in particular-has paralleled these advances. The resulting development of two-dimensional and three-dimensional (3D) postprocessing techniques has complemented axial CT interpretation in providing more anatomically familiar information to the pulmonologist. Two-dimensional techniques such as multiplanar recontructions and 3D techniques such as virtual bronchoscopy can provide accurate guidance for increasing yield in transbronchial needle aspiration and transbronchial biopsy of mediastinal and hilar lymph nodes. Sampling of lesions located deeper within the lung periphery via bronchoscopic pathways determined at virtual bronchoscopy are also increasingly feasible. CT fluoroscopy for real-time image-guided sampling is now widely available; electromagnetic navigation guidance is being used in select centers but is currently more costly. Minimally invasive bronchoscopic techniques for restoring airway patency in obstruction caused by both benign and malignant conditions include mechanical strategies such as airway stent insertion and ablative techniques such as electrocauterization and cryotherapy. Multidetector CT postprocessing techniques provide valuable information for planning and surveillance of these treatment methods. In particular, they optimize the evaluation of dynamic obstructive conditions such as tracheobronchomalacia, especially with the greater craniocaudal coverage now provided by wide-area detectors. Multidetector CT also provides planning information for bronchoscopic treatment of bronchopleural fistulas and bronchoscopic lung volume reduction for carefully selected patients with refractory emphysema.

  7. Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

    PubMed

    Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

    2006-01-01

    In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution.

  8. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography.

    PubMed

    Einstein, Andrew J; Henzlova, Milena J; Rajagopalan, Sanjay

    2007-07-18

    Computed tomography coronary angiography (CTCA) has become a common diagnostic test, yet there are little data on its associated cancer risk. The recent Biological Effects of Ionizing Radiation (BEIR) VII Phase 2 report provides a framework for estimating lifetime attributable risk (LAR) of cancer incidence associated with radiation exposure from a CTCA study, using the most current data available on health effects of radiation. To determine the LAR of cancer incidence associated with radiation exposure from a 64-slice CTCA study and to evaluate the influence of age, sex, and scan protocol on cancer risk. Organ doses from 64-slice CTCA to standardized phantom (computational model) male and female patients were estimated using Monte Carlo simulation methods, using standard spiral CT protocols. Age- and sex-specific LARs of individual cancers were estimated using the approach of BEIR VII and summed to obtain whole-body LARs. Whole-body and organ LARs of cancer incidence. Organ doses ranged from 42 to 91 mSv for the lungs and 50 to 80 mSv for the female breast. Lifetime cancer risk estimates for standard cardiac scans varied from 1 in 143 for a 20-year-old woman to 1 in 3261 for an 80-year-old man. Use of simulated electrocardiographically controlled tube current modulation (ECTCM) decreased these risk estimates to 1 in 219 and 1 in 5017, respectively. Estimated cancer risks using ECTCM for a 60-year-old woman and a 60-year-old man were 1 in 715 and 1 in 1911, respectively. A combined scan of the heart and aorta had higher LARs, up to 1 in 114 for a 20-year-old woman. The highest organ LARs were for lung cancer and, in younger women, breast cancer. These estimates derived from our simulation models suggest that use of 64-slice CTCA is associated with a nonnegligible LAR of cancer. This risk varies markedly and is considerably greater for women, younger patients, and for combined cardiac and aortic scans.

  9. Dual-energy CT revisited with multidetector CT: review of principles and clinical applications.

    PubMed

    Karçaaltıncaba, Muşturay; Aktaş, Aykut

    2011-09-01

    Although dual-energy CT (DECT) was first conceived in the 1970s, it was not widely used for CT indications. Recently, the simultaneous acquisition of volumetric dual-energy data has been introduced using multidetector CT (MDCT) with two X-ray tubes and rapid kVp switching (gemstone spectral imaging). Two major advantages of DECT are material decomposition by acquiring two image series with different kVp and the elimination of misregistration artifacts. Hounsfield unit measurements by DECT are not absolute and can change depending on the kVp used for an acquisition. Typically, a combination of 80/140 kVp is used for DECT, but for some applications, 100/140 kVp is preferred. In this study, we summarized the clinical applications of DECT and included images that were acquired using the dual-source CT and rapid kVp switching. In general, unenhanced images can be avoided by using DECT for body and neurological applications; iodine can be removed from the image, and a virtual, non-contrast (water) image can be obtained. Neuroradiological applications allow for the removal of bone and calcium from the carotid and brain CT angiography. Thorax applications include perfusion imaging in patients with pulmonary thromboemboli and other chest diseases, xenon ventilation-perfusion imaging and solitary nodule characterization. Cardiac applications include dual-energy cardiac perfusion, viability and cardiac iron detection. The removal of calcific plaques from arteries, bone removal and aortic stent graft evaluation may be achieved in the vascular system. Abdominal applications include the detection and characterization of liver and pancreas masses, the diagnosis of steatosis and iron overload, DECT colonoscopy and CT cholangiography. Urinary system applications are urinary calculi characterization (uric acid vs. non-uric acid), renal cyst characterization and mass characterization. Musculoskeletal applications permit the differentiation of gout from pseudogout and a reduction of

  10. Multidetector CT (MD-CT) in the diagnosis of uncertain open globe injuries.

    PubMed

    Hoffstetter, P; Schreyer, A G; Schreyer, C I; Jung, E M; Heiss, P; Zorger, N; Framme, C

    2010-02-01

    To evaluate the significance of multislice CT for the diagnosis of uncertain penetrating globe injuries. Based on a retrospective chart review between 2002 and 2007, we identified 59 patients presenting with severe ocular trauma with uncertain rupture of the globe due to massive subconjunctival and/or anterior chamber hemorrhage. The IOP (intraocular pressure) was within normal range in all patients. High resolution multidetector CT (MD-CT) scans (16 slice scans) with axial and coronar reconstructions were performed in all patients. The affected eye was examined for signs of penetrating injury such as abnormal eye shape, scleral irregularities, lens dislocation or intravitreal hemorrhages. Four experienced radiologists read the CT scans independently. Beside the diagnosis, the relevant morphological criteria and the optimal plane orientation (axial or coronar) were specified. The sensitivity, specificity, and negative and positive predictive value were calculated. Additionally the interobserver variability was determined by applying the Cohen's kappa test. Surgical sclera inspections were performed in all cases as a standard of reference. The evaluations of the CT examination were compared with the surgery reports. 59 patients were evaluated (42 men, 17 women). The mean age was 29 years (range 7 - 91). In 17 patients a rupture of the globe was diagnosed during surgery. 12 of these 17 penetrating injuries (70.6 %) were classified correctly by MDCT, 5 of the 17 (29.4 %) were not detectable. 42 patients did not have an open globe injury. 41 of these patients were diagnosed correctly negative by MDCT, and one patient was classified false positive. This results in a sensitivity of 70 % with a specificity of 98 %. There was high inter-rater agreement with kappa values between 0.89 - 0.96. Most discrepancies were caused by wrong negative findings. The most frequent morphologic criteria for open globe injury were the deformation (n = 10) and the volume reduction (n = 7) of

  11. Multidetector CT and dentascan software: dosimetric evaluation and technique improvement.

    PubMed

    Fanucci, E; Leporace, M; Di Costanzo, G; Fiaschetti, V; Simonetti, G

    2006-02-01

    The development of new operative techniques in oral and maxillofacial surgery within the last few years has led to an increasing demand for Dentascan examination, also in paediatric patients. It is necessary to modify acquisition parameters to reduce the absorbed dose. The aim of this study was to define a Dentascan protocol in which a reduced X-ray dose could be used. Dosimeters were applied to the eyes, mouth, parotid glands, thyroid and back of the neck of an anthropomorphic Plexiglas phantom that underwent multidetector computed tomography (MDCT) Dentascan examinations. Both 120kV and 80 kV were used to study the mandibular and maxillary arches. Examinations obtained with the 80 kV protocol showed a ten-fold reduction in the absorbed dose, without affecting image quality. We suggest a Dentascan protocol that reduces the X-ray dose administered to the patient while ensuring the same high diagnostic accuracy.

  12. Fish bone foreign bodies in the pharynx and upper esophagus: evaluation with 64-slice MDCT.

    PubMed

    Park, Soyeon; Choi, Dae Seob; Shin, Hwa Seon; Cho, Jae Min; Jeon, Kyung Nyeo; Bae, Kyung-Soo; Koh, Eun Ha; Park, Jung Je

    2014-02-01

    Fish bone (FB) is one of the common causes of foreign body impaction in the pharynx and esophagus. To investigate the efficacy of 64-slice multidetector computed tomography (MDCT) for the evaluation of pharynx and upper esophageal FB foreign bodies. Sixty-six patients with suspected FB foreign body ingestion were examined by plain radiography (n = 40) and unenhanced MDCT (n = 66). We analyzed the presence, location, size, shape, and lying position of the foreign bodies. On MDCT, 46 foreign bodies were detected. Among them, 45 were confirmed by endoscopy. The sensitivity of MDCT for the detection of foreign bodies was 100%, which was superior to that of the plain radiography (51.7%). The location of the foreign bodies was most common in the upper esophagus (n = 22, 47.8%), followed by pharyngoesophageal junction (n = 10, 21.7%), transjunctional (n = 7, 15.2%), hypopharynx (n = 5, 10.9%), and oropharynx (n = 2, 4.3%). Their longest length was 5.3-40.1 mm (mean, 21.3 mm). Thirty-three FBs (71.7%) were linear and 13 (28.3%) were flat in shape. They showed transverse (n = 23, 50.0%), parallel (n = 13, 28.3%), and oblique positions (n = 10, 21.7%) to the long axis of the pharynx and esophagus, respectively. MDCT is useful for the evaluation of the pharynx and upper esophageal FB foreign bodies.

  13. Multidetector CT of carpal injuries: anatomy, fractures, and fracture-dislocations.

    PubMed

    Kaewlai, Rathachai; Avery, Laura L; Asrani, Ashwin V; Abujudeh, Hani H; Sacknoff, Richard; Novelline, Robert A

    2008-10-01

    Fractures and dislocations of the carpal bones are more common in young active patients. These injuries can lead to pain, dysfunction, and loss of productivity. Conventional radiography remains the primary imaging modality for evaluation of suspected carpal fractures and dislocations. However, multidetector computed tomography (CT) is playing an increasingly important role, especially in the following situations: (a) when results from initial radiographs are negative in patients with suspected carpal fractures, (b) when initial radiographic findings are indeterminate, and (c) when knowledge of the extent of carpal fractures or dislocations is required before surgical treatment. The advantages of multidetector CT include quick and accurate diagnosis with availability in most emergency centers. Multidetector CT can easily display the extent of carpal fractures and dislocations, often depicting fractures that are occult at radiography. In addition, with multiplanar (two-dimensional) and volumetric (three-dimensional) reformation, pathologic conditions and anatomic relationships are better perceived. This information can be easily conveyed to orthopedic and trauma surgeons and can be crucial for surgical treatment and planning. (c) RSNA, 2008.

  14. Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis.

    PubMed

    Holly, Brian P; Steenburg, Scott D

    2011-01-01

    Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.

  15. Multi-detector CT in the paediatric urinary tract.

    PubMed

    Damasio, M B; Darge, K; Riccabona, M

    2013-07-01

    The use of paediatric multi-slice CT (MSCT) is rapidly increasing worldwide. As technology advances its application in paediatric care is constantly expanding with an increasing need for radiation dose control and appropriate utilization. Recommendations on how and when to use CT for assessment of the paediatric urinary tract appear to be an important issue. Therefore the European Society of Paediatric Radiology (ESPR) uroradiology task force and European Society of Urogenital Radiology (ESUR) paediatric working groups created a proposal for performing renal CT in children that has recently been published. The objective of this paper is to discuss paediatric urinary tract CT (uro-CT) in more detail and depth. The specific aim is not only to offer general recommendations on clinical indications and optimization processes of paediatric CT examination, but also to address various childhood characteristics and phenomena that facilitate understanding the different approach and use of uro-CT in children compared to adults. According to ALARA principles, paediatric uro-CT should only be considered for selected indications provided high-level comprehensive US is not conclusive and alternative non-ionizing techniques such as MR are not available or appropriate. Optimization of paediatric uro-CT protocols (considering lower age-adapted kV and mAs) is mandatory, and the number of phases and acquisition series should be kept as few as possible.

  16. Penetrating diaphragmatic injury: accuracy of 64-section multidetector CT with trajectography.

    PubMed

    Dreizin, David; Borja, Maria J; Danton, Gary H; Kadakia, Kevin; Caban, Kim; Rivas, Luis A; Munera, Felipe

    2013-09-01

    To (a) determine the diagnostic performance of 64-section multidetector computed tomography (CT) trajectography for penetrating diaphragmatic injury (PDI), (b) determine the diagnostic performance of classic signs of diaphragmatic injury at 64-section multidetector CT, and (c) compare the performance of these signs with that of trajectography. This HIPAA-compliant retrospective study had institutional review board approval, with a waiver of the informed consent requirement. All patients who had experienced penetrating thoracoabdominal trauma, who had undergone preoperative 64-section multidetector CT of the chest and abdomen, and who had surgical confirmation of findings during a 2.5-year period were included in this study (25 male patients, two female patients; mean age, 32.6 years). After a training session, four trauma radiologists unaware of the surgical outcome independently reviewed all CT studies and scored the probability of PDI on a six-point scale. Collar sign, dependent viscera sign, herniation, contiguous injury on both sides of the diaphragm, discontinuous diaphragm sign, and transdiaphragmatic trajectory were evaluated for sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). Accuracies were determined and receiver operating characteristic curves were analyzed. Sensitivities for detection of PDI by using 64-section multidetector CT with postprocessing software ranged from 73% to 100%, specificities ranged from 50% to 92%, NPVs ranged from 71% to 100%, PPVs ranged from 68% to 92%, and accuracies ranged from 70% to 89%. Discontinuous diaphragm, herniation, collar, and dependent viscera signs were highly specific (92%-100%) but nonsensitive (0%-60%). Contiguous injury was generally more sensitive (80%-93% vs 73%-100%) but less specific (50%-67% vs 83%-92%) than transdiaphragmatic trajectory when patients with multiple entry wounds were included in the analysis. Transdiaphragmatic trajectory was a much more

  17. 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.

  18. Lymphoplasmacytic sclerosing pancreatitis (autoimmune pancreatitis): evaluation with multidetector CT.

    PubMed

    Kawamoto, Satomi; Siegelman, Stanley S; Hruban, Ralph H; Fishman, Elliot K

    2008-01-01

    Lymphoplasmacytic sclerosing pancreatitis is a form of chronic pancreatitis characterized by a mixed inflammatory infiltrate that centers on the pancreatic ducts. It is a cause of benign pancreatic disease that can clinically mimic pancreatic cancer. Preoperative detection of lymphoplasmacytic sclerosing pancreatitis is important because patients usually respond to steroid therapy. Patients with lymphoplasmacytic sclerosing pancreatitis are often referred for computed tomography (CT) when they are suspected of having a pancreatic or biliary neoplasm; therefore, it is important to search for potential findings suggestive of lymphoplasmacytic sclerosing pancreatitis when typical findings of a pancreatic or biliary neoplasm are not found. Typical CT findings include diffuse or focal enlargement of the pancreas without dilatation of the main pancreatic duct. Focal enlargement is most commonly seen in the head of the pancreas, and the involved pancreas on contrast material-enhanced CT images may be iso-attenuating relative to the rest of the pancreas, or hypo-attenuating, especially during the early postcontrast phase. Thickening and contrast enhancement of the wall of the common bile duct and gallbladder may reflect inflammatory infiltrate and fibrosis associated with lymphoplasmacytic sclerosing pancreatitis. There are several features seen at CT that may help to differentiate lymphoplasmacytic sclerosing pancreatitis from pancreatic cancer, such as diffuse enlargement of the pancreas with minimal peripancreatic stranding in patients with obstructive jaundice, an absence of significant pancreatic atrophy, and an absence of significant main pancreatic duct dilatation. When these findings are encountered, clinical, other imaging, and serologic data should be evaluated.

  19. Dedicated multi-detector CT of the esophagus: spectrum of diseases.

    PubMed

    Ba-Ssalamah, Ahmed; Zacherl, Johannes; Noebauer-Huhmann, Iris Melanie; Uffmann, Martin; Matzek, Wolfgang Karl; Pinker, Katja; Herold, Christian; Schima, Wolfgang

    2009-01-01

    Multi-detector computed tomography (CT) offers new opportunities in the imaging of the gastrointestinal tract. Its ability to cover a large volume in a very short scan time, and in a single breath hold with thin collimation and isotropic voxels, allows the imaging of the entire esophagus with high-quality multiplanar reformation and 3D reconstruction. Proper distention of the esophagus and stomach (by oral administration of effervescent granules and water) and optimally timed administration of intravenous contrast material are required to detect and characterize disease. In contrast to endoscopy and double-contrast studies of the upper GI tract, CT provides information about both the esophageal wall and the extramural extent of disease. Preoperative staging of esophageal carcinoma appears to be the main indication for MDCT. In addition, MDCT allows detection of other esophageal malignancies, such as lymphoma and benign esophageal tumors, such as leiomyma. A diagnosis of rupture or fistula of the esophagus can be firmly established using MDCT. Furthermore, miscellaneous esophageal conditions, such as achalasia, esophagitis, diverticula, and varices, are incidental findings and can also be visualized with hydro-multi-detector CT. Multi-detector CT is a valuable tool for the evaluation of esophageal wall disease and serves as an adjunct to endoscopy.

  20. [Multidetector row CT in assessment of coronary artery calcification on hemodialisis].

    PubMed

    Caro, P; Delgado, R; Dapena, F; Núñez, A

    2007-01-01

    Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive and progresses more rapidly in CKD than in general population. They are also considered a marker of coronary heart disease, with high prevalence and functional significance. It suggests that detection and surveillance may be worthwhile in general clinical practice. New non-invasive image techniques, like Multi-detector row CT, a type of spiral scanner, assess density and volume of calcification at multiple sites and allow quantitative scoring of vascular calcification using calcium scores analogous to those from electron-beam CT. We have assessed and quantified coronary artery calcification with 16 multidetector row CT in 44 patients on hemodialysis and their relationship with several cardiovascular risk factors. Coronary artery calcification prevalence was of 84 % with mean calcium score of 1580 +/- 2010 ( r 0-9844) with calcium score > 400 in 66% of patients. It was usually multiple, affecting more than two vessels in more than 50%. In all but one patient, left anterior descending artery was involved with higher calcium score level at right coronary artery. Advanced age, male, diabetes, smoking, more morbidity, cerebrovascular disease previous, and calcium-binders phosphate and analogous vitamin D treatment would seem to be associated with coronary artery calcification. Coronary artery calcification is very frequent and extensive, usually multiple and associated to modifiable risk factors in hemodialysis patients. Multi-detector-row CT seems an effective, suitable, readily applicable method to assess and quantify coronary artery calcification.

  1. Multidetector CT for Evaluation of the Extrapleural Space.

    PubMed

    Santamarina, Mario G; Beddings, Ignacio; Lermanda Holmgren, Guillermo V; Opazo Sanchez, Hector; Volpacchio, Mariano M

    2017-01-01

    The extrapleural space (EPS) is an anatomic space at the periphery of the chest that can be involved in a number of disease processes. This space lies between the inner surface of the ribs and the parietal pleura and contains adipose tissue, loose connective tissue, lymph nodes, vessels, endothoracic fascia, and the innermost intercostal muscle. It is often overlooked on cross-sectional imaging studies and almost invariably overlooked on conventional radiographic studies. At conventional radiography, the EPS occasionally can be seen when there is extrapleural fat proliferation, which might be confused with pleural thickening or pleural effusion. Knowledge of the normal anatomy of the EPS depicted at computed tomography (CT) and of the relationship of the EPS with parenchymal, pleural, and chest wall processes is key to the detection of extrapleural abnormalities. Disease entities that most commonly affect the EPS include chronic inflammatory disorders, infection, trauma, and neoplasms. Chronic inflammatory conditions and infectious processes of the lungs and pleurae induce adipocyte proliferation adjacent to the inflamed tissue, resulting in increased extrapleural fat. Chest wall trauma with extrapleural hematoma formation causes characteristic CT findings that enable differentiation of the extrapleural hematoma from hemothorax and warrant a different treatment approach. Extrapleural air is commonly seen in patients with pneumomediastinum and should be distinguished from pneumothorax because it requires a different treatment approach. Intrathoracic neoplasms can cause an increase in the attenuation of normal extrapleural fat owing to pleural inflammation, lymphatic obstruction, lymphangitic spread, or direct invasion by tumor. The normal and pathologic appearances of the EPS, as depicted at thoracic CT, and the differential diagnosis of findings in the EPS are reviewed. (©)RSNA, 2017.

  2. Multidetector CT of expected findings and complications after contemporary inguinal hernia repair surgery

    PubMed Central

    Tonolini, Massimo

    2016-01-01

    Inguinal hernia repair (IHR) with prosthetic mesh implantation is the most common procedure in general surgery, and may be performed using either an open or laparoscopic approach. This paper provides an overview of contemporary tension-free IHR techniques and materials, and illustrates the expected postoperative imaging findings and iatrogenic injuries. Emphasis is placed on multidetector CT, which represents the ideal modality to comprehensively visualize the operated groin region and deeper intra-abdominal structures. CT consistently depicts seroma, mesh infections, hemorrhages, bowel complications and urinary bladder injuries, and thus generally provides a consistent basis for therapeutic choice. Since radiologists are increasingly requested to investigate suspected iatrogenic complications, this paper aims to provide an increased familiarity with early CT studies after IHR, including complications and normal postoperative appearances such as focal pseudolesions, in order to avoid misinterpretation and inappropriate management. PMID:27460285

  3. Noninvasive imaging of coronary arteries: current and future role of multi-detector row CT.

    PubMed

    Schoenhagen, Paul; Halliburton, Sandra S; Stillman, Arthur E; Kuzmiak, Stacie A; Nissen, Steven E; Tuzcu, E Murat; White, Richard D

    2004-07-01

    While invasive imaging techniques, especially selective conventional coronary angiography, will remain vital to planning and guiding catheter-based and surgical treatment of significantly stenotic coronary lesions, the comprehensive and serial assessment of asymptomatic or minimally symptomatic stages of coronary artery disease (CAD) for preventive purposes will eventually need to rely on noninvasive imaging techniques. Cardiovascular imaging with tomographic modalities, including computed tomography (CT) and magnetic resonance imaging, has great potential for providing valuable information. This review article will describe the current and future role of cardiac CT, and in particular that of multi-detector row CT, for imaging of atherosclerotic and other pathologic changes of the coronary arteries. It will describe how tomographic coronary imaging may eventually supplement traditional angiographic techniques in understanding the patterns of atherosclerotic CAD development.

  4. Calcified plaque: measurement of area at thin-section flat-panel CT and 64-section multidetector CT and comparison with histopathologic findings.

    PubMed

    Sarwar, Ammar; Rieber, Johannes; Mooyaart, Eline A Q; Seneviratne, Sujith K; Houser, Stuart L; Bamberg, Fabian; Raffel, O Christopher; Gupta, Rajiv; Kalra, Mannudeep K; Pien, Homer; Lee, Hang; Brady, Thomas J; Hoffmann, Udo

    2008-10-01

    The purpose of this study was to assess the blooming artifacts in ex vivo coronary arteries at multidetector computed tomography (CT) and flat-panel-volume CT by comparing measured areas of calcified plaque with respect to the reference standard of histopathologic findings. Three ex vivo hearts were scanned with multidetector CT and flat-panel-volume CT after institutional review board approval. The area of calcified plaque was measured at histopathologic examination, multidetector CT, and flat-panel-volume CT. The plaque area was overestimated at multidetector CT by 400% (4.61/1.15) on average, and the predicted difference between the measurements was significant (3.46 mm(2), P = .018). The average overestimation of plaque area at flat-panel-volume CT was twofold (214% [2.18/1.02]), and the predicted difference was smaller (1.16 mm(2), P = .08). The extent of the blooming artifact in visualizing calcified coronary plaque is reduced by using flat-panel-volume CT. (c) RSNA, 2008.

  5. Virtual anthropology and forensic identification using multidetector CT.

    PubMed

    Dedouit, F; Savall, F; Mokrane, F-Z; Rousseau, H; Crubézy, E; Rougé, D; Telmon, N

    2014-04-01

    Virtual anthropology is made possible by modern cross-sectional imaging. Multislice CT (MSCT) can be used for comparative bone and dental identification, reconstructive identification and lesion identification. Comparative identification, the comparison of ante- and post-mortem imaging data, can be performed on both teeth and bones. Reconstructive identification, a considerable challenge for the radiologist, identifies the deceased by determining sex, geographical origin, stature and age at death. Lesion identification combines virtual autopsy and virtual anthropology. MSCT can be useful in palaeopathology, seeking arthropathy, infection, oral pathology, trauma, tumours, haematological disorders, stress indicators or occupational stress in bones and teeth. We examine some of the possibilities offered by this new radiological subspeciality that adds a new dimension to the work of the forensic radiologist. A multidisciplinary approach is crucial and involves communication and data exchange between radiologists, forensic pathologists, anthropologists and radiographers.

  6. Virtual anthropology and forensic identification using multidetector CT

    PubMed Central

    Savall, F; Mokrane, F-Z; Rousseau, H; Crubézy, E; Rougé, D; Telmon, N

    2014-01-01

    Virtual anthropology is made possible by modern cross-sectional imaging. Multislice CT (MSCT) can be used for comparative bone and dental identification, reconstructive identification and lesion identification. Comparative identification, the comparison of ante- and post-mortem imaging data, can be performed on both teeth and bones. Reconstructive identification, a considerable challenge for the radiologist, identifies the deceased by determining sex, geographical origin, stature and age at death. Lesion identification combines virtual autopsy and virtual anthropology. MSCT can be useful in palaeopathology, seeking arthropathy, infection, oral pathology, trauma, tumours, haematological disorders, stress indicators or occupational stress in bones and teeth. We examine some of the possibilities offered by this new radiological subspeciality that adds a new dimension to the work of the forensic radiologist. A multidisciplinary approach is crucial and involves communication and data exchange between radiologists, forensic pathologists, anthropologists and radiographers. PMID:24234584

  7. Assessment of non-invasive chronic fungal rhinosinusitis by cone beam CT: comparison with multidetector CT findings.

    PubMed

    Yamauchi, Tomohiko; Tani, Akiko; Yokoyama, Shuji; Ogawa, Hiroshi

    2017-08-09

    To investigate the accuracy of cone beam CT (CBCT) to diagnose non-invasive chronic fungal rhinosinusitis. Preoperative CT evaluation of non-invasive chronic fungal rhinosinusitis was performed by CBCT (3D Accuitomo 170(®)) and traditional multidetector CT (MDCT) (Aquilion 32(®)) in 13 and 38 patients with non-invasive chronic fungal maxillary sinusitis, respectively, in different facilities. Detection of intrasinus calcification was compared between these two groups. Detection of intrasinus calcification in patients with non-invasive chronic fungal maxillary sinusitis was higher in the MDCT group (84.2%) than the CBCT group (46.2%). CBCT is inferior to MDCT in detection of intrasinus calcification in patients with non-invasive chronic fungal maxillary sinusitis. CBCT is frequently used in the screening of the paranasal lesion, but it is not enough to evaluate non-invasive chronic fungal maxillary sinusitis alone. Retrospective study.

  8. Visual claudicatio: diagnosis with 64-slice computed tomography.

    PubMed

    Cademartiri, Filippo; Maffei, Erica; Palumbo, Alessandro; Mollet, Nico R; van der Lugt, Aad; Crisi, Girolamo

    2007-06-01

    We present a case of a 78-year-old male referred presented to our institution with amaurosis fugax after walking 20 steps ("visual claudicatio"). Duplex ultrasound was not able to visualize the carotid arteries. Multislice computed tomography (Sensation 64 Cardiac, Siemens, Germany) of the cerebro-vascular circulation was performed from its origin at the level of the aortic arch to the circle of Willis. The investigation demonstrated a complete occlusion of both common carotid arteries at their origin and a severe origo stenosis of both vertebral arteries. An important collateral circulation of the vertebral arteries through the minor vessels of the neck was also displayed. Both comunicans posterior arteries were small but patent. The intra-cranial arteries were patent. Multislice CT of the cerebro-vascular circulation is an optimal tool for a comprehensive evaluation when duplex ultrasound fails.

  9. Quantitative measurement of radiofrequency volumetric tissue reduction by multidetector CT in patients with inferior turbinate hypertrophy.

    PubMed

    Bahadir, Osman; Kosucu, Polat

    2012-12-01

    To objectively assess the efficacy of radiofrequency thermal ablation of inferior turbinate hypertrophy. Thirty-five patients with nasal obstruction secondary to inferior turbinate hypertrophy were prospectively enrolled. Radiofrequency energy was delivered to four sites in each inferior turbinate. Patients were evaluated before and 8 weeks after intervention. Subjective evaluation of nasal obstruction was performed using a visual analogue scale (VAS), and objective evaluation of the turbinate volume reduction was calculated using multidetector CT. Volumetric measurements of the preoperative inferior turbinate were compared with postoperative values on both sides. The great majority of patients (91.4%) exhibited subjective postoperative improvement. Mean obstruction (VAS) improved significantly from 7.45±1.48 to 3.54±1.96. Significant turbinate volume reduction was achieved by the surgery on both right and left sides [(preoperative vs. postoperative, right: 6.55±1.62cm(3) vs. 5.10±1.47cm(3), (P<0.01); left: 6.72±1.53cm(3) vs. 5.00±1.37cm(3), (P<0.01)] respectively. Radiofrequency is a safe and effective surgical procedure in reducing turbinate volume in patients with inferior turbinate hypertrophy. Multidetector CT is an objective method of assessment in detecting radiofrequency turbinate volume reduction. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Multidetector CT in emergency radiology: acute and generalized non-traumatic abdominal pain

    PubMed Central

    Paolantonio, Pasquale; Rengo, Marco; Ferrari, Riccardo

    2016-01-01

    Multidetector CT (MDCT) is an imaging technique that provides otherwise unobtainable information in the diagnostic work-up of patients presenting with acute abdominal pain. A correct working diagnosis depends essentially on understanding the individual patient's clinical data and laboratory findings. In haemodynamically stable patients with acute severe and generalized abdominal pain, MDCT is now the preferred imaging test and gives invaluable diagnostic information, also in unstable patients after stabilization. In this descriptive review, we focus our attention on acute, severe and generalized or undifferentiated non-traumatic abdominal pain. The main differential diagnoses are acute pancreatitis, gastrointestinal perforation, ruptured abdominal aneurysm and acute mesenteric ischaemia. We will provide radiologist readers with a technical guide to optimize MDCT imaging protocols and list the major CT signs essential to reach a correct diagnosis and guide the best treatment. PMID:26689097

  11. Mandibular arteriovenous malformation: A rare life-threatening condition depicted on multidetector CT angiography

    PubMed Central

    Dwivedi, Amit Nandan Dhar; Pandey, Anubha; Kumar, Ishan; Agarwal, Arjit

    2014-01-01

    Arteriovenous malformation (AVM) of the mandible is a rare and potentially life-threatening condition which can lead to massive hemorrhage. The following is a description where a large mandibular AVM presented with torrential bleeding following tooth extraction for caries. An orthopantomogram (OPG) was performed which was suggestive of aneurysmal bone cyst or ameloblastoma. A computed tomography (CT) angiography revealed a large mandibular AVM with submandibular extension. It is important for both clinicians and radiologist to be aware of this type of lesion that can have life-threatening complications. It is important to define the anatomical location and the feeder vessels of the entity in detail preoperatively. This communication highlights the common differential and use of multidetector CT (MDCT) angiography along with other imaging modalities to prevent a fatal hemorrhage and arrive at a correct diagnosis. PMID:24959049

  12. 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.

  13. Radiation dose in 320-slice multidetector cardiac CT: a single center experience of evolving dose minimization.

    PubMed

    Tung, Matthew K; Cameron, James D; Casan, Joshua M; Crossett, Marcus; Troupis, John M; Meredith, Ian T; Seneviratne, Sujith K

    2013-01-01

    Minimization of radiation exposure remains an important subject that occurs in parallel with advances in scanner technology. We report our experience of evolving radiation dose and its determinants after the introduction of 320-multidetector row cardiac CT within a single tertiary cardiology referral service. Four cohorts of consecutive patients (total 525 scans), who underwent cardiac CT at defined time points as early as 2008, are described. These include a cohort just after scanner installation, after 2 upgrades of the operating system, and after introduction of an adaptive iterative image reconstruction algorithm. The proportions of nondiagnostic coronary artery segments and studies with nondiagnostic segments were compared between cohorts. Significant reductions were observed in median radiation doses in all cohorts compared with the initial cohort (P < .001). Median dose-length product fell from 944 mGy · cm (interquartile range [IQR], 567.3-1426.5 mGy · cm) to 156 mGy · cm (IQR, 99.2-265.0 mGy · cm). Although the proportion of prospectively triggered scans has increased, reductions in radiation dose have occurred independently of distribution of scan formats. In multiple regression that combined all groups, determinants of dose-length product were tube output, the number of cardiac cycles scanned, tube voltage, scan length, scan format, body mass index, phase width, and heart rate (adjusted R(2) = 0.85, P < .001). The proportion of nondiagnostic coronary artery segments was slightly increased in group 4 (2.9%; P < .01). While maintaining diagnostic quality in 320-multidetector row cardiac CT, the radiation dose has decreased substantially because of a combination of dose-reduction protocols and technical improvements. Continued minimization of radiation dose will increase the potential for cardiac CT to expand as a cardiac imaging modality. Copyright © 2013 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  14. Detection of hypervascular hepatocellular carcinoma: Comparison of multi-detector CT with digital subtraction angiography and Lipiodol CT

    PubMed Central

    Zheng, Xiao-Hua; Guan, Yong-Song; Zhou, Xiang-Ping; Huang, Juan; Sun, Long; Li, Xiao; Liu, Yuan

    2005-01-01

    AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA) and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC). METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules. RESULTS: The three imaging techniques had the same sensitivity in detecting nodules >20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules <10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (χ2 = 11.3, P = 0.005<0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16 (χ2 = 9.09, P = 0.005<0.01 vs Lipiodol CT and χ2 = 29.03, P = 0.005<0.01vs HAP-MDCT). However, six nodules <10 mm in diameter were detected only by Lipiodol CT. CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC. PMID:15633215

  15. Detection of vascular injuries in patients with blunt pelvic trauma by using 64-channel multidetector CT.

    PubMed

    Kertesz, Jennifer L; Anderson, Stephan W; Murakami, Akira M; Pieroni, Sabrina; Rhea, James T; Soto, Jorge A

    2009-01-01

    Vascular injuries are a major source of morbidity and mortality in patients with blunt pelvic trauma. Digital subtraction angiography (DSA) has traditionally been used to detect pelvic arterial injuries and to treat active arterial hemorrhage. Improvements in the technology of computed tomography (CT) have facilitated the implementation of CT angiography, which is beginning to replace DSA in the evaluation of patients with acute trauma. Pelvic CT angiography can reliably depict various pelvic arterial injuries and can help differentiate arterial hemorrhage from venous hemorrhage on the basis of multiphasic acquisitions, a method that may be used to tailor the subsequent clinical approach. With the use of a 64-channel multidetector CT scanner, multiphasic pelvic CT angiography can be integrated into the evaluation of trauma patients by using 1.25-mm reconstructed section thickness, pitch of 1:0.987, and gantry revolution time of 0.5 second to achieve near-isotropic results. A standard dose of 100 mL intravenous contrast material is injected at a rate of 5 mL/sec, and 30 mL saline solution, also at 5 mL/sec, is injected as a "chasing" bolus to follow the contrast material. (c) RSNA, 2009.

  16. Normal or abnormal? Demystifying uterine and cervical contrast enhancement at multidetector CT.

    PubMed

    Yitta, Silaja; Hecht, Elizabeth M; Mausner, Elizabeth V; Bennett, Genevieve L

    2011-01-01

    Computed tomography (CT) is not generally advocated as the first-line imaging examination for disorders of the female pelvis. However, multidetector CT is often the modality of choice for evaluating nongynecologic pelvic abnormalities, particularly in emergent settings, in which all the pelvic organs are invariably assessed. Incidental findings of uterine and cervical contrast enhancement in such settings may easily be mistaken for abnormalities, given the broad spectrum of anatomic variants and enhancement patterns that may be seen in the normal uterus and cervix. The authors' review of CT and magnetic resonance (MR) imaging enhancement patterns, augmented by case examples from their clinical radiology practice, provides a solid foundation for understanding the spectrum of normal uterine and cervical appearances and avoiding potential pitfalls in the diagnosis of benign cervical lesions, adenomyosis, infection, malignancy, and postpartum effects. This information should help radiologists more confidently differentiate between normal and abnormal CT findings and, when CT findings are not definitive, offer appropriate recommendations for follow-up ultrasonography or MR imaging.

  17. Influence of z overscanning on normalized effective doses calculated for pediatric patients undergoing multidetector CT examinations

    SciTech Connect

    Tzedakis, Antonis; Damilakis, John; Perisinakis, Kostas; Karantanas, Apostolos; Karabekios, Spiros; Gourtsoyiannis, Nicholas

    2007-04-15

    The purpose of this study was to evaluate the effect of z overscanning on normalized effective dose for pediatric patients undergoing multidetector-computed tomography (CT) examinations. Five commercially available mathematical anthropomorphic phantoms representing newborn, 1-, 5-, 10-, and 15-year-old patients and the Monte Carlo N-Particle (MCNP, version 4C2) radiation transport code were employed in the current study to simulate pediatric CT exposures. For all phantoms, axial and helical examinations at 120 kV tube voltage were simulated. Scans performed at 80 kV were also simulated. Sex-specific normalized effective doses were estimated for four standard CT examinations i.e., head-neck, chest, abdomen-pelvis, and trunk, for all pediatric phantoms. Data for both axial and helical mode acquisition were obtained. In the helical mode, z overscanning was taken into account. The validity of the Monte Carlo results was verified by comparison with dose data obtained using thermoluminescence dosimetry and a physical pediatric anthropomorphic phantom simulating a 10-year-old child. In all cases normalized effective dose values were found to increase with increasing z overscanning. The percentage differences in normalized data between axial and helical scans may reach 43%, 70%, 36%, and 26% for head-neck, chest, abdomen-pelvis, and trunk studies, respectively. Normalized data for female pediatric patients was in general higher compared to male patients for all ages, examined regions, and z overscanning values. For both male and female children, the normalized effective dose values were reduced as the age was increased. For the same typical exposure conditions, dose values decreased when lower tube voltage was used; for a 1-year-old child, for example, the effective dose was 3.8 times lower when 80 kV instead of 120 kV was used. Normalized data for the estimation of effective dose to pediatric patients undergoing standard axial and helical CT examinations on an

  18. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography

    PubMed Central

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-01-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH. PMID:22932061

  19. [Role of multidetector CT in the evaluation of large bowel obstruction].

    PubMed

    Scardapane, Arnaldo; Rubini, Giuseppe; Lorusso, Filomenamila; Fonio, Paolo; Suriano, Claudia; Giganti, Melchiore; Stabile Ianora, Amato Antonio

    2012-11-01

    The aim of the study was to assess the accuracy of multidetector CT (MDCT) with MPR reformation in the evaluation of large bowel obstruction. Thirty-one patients were evaluated retrospectively in a blinded fashion by two radiologists. All patients underwent MDCT with multiplanar reformation (MPR). The two radiologists interpreted independently the axial images and then the reconstructions. Each patient received a score from 1 (absent occlusion) to 5 (confirmed occlusion). The results were compared with surgical findings. Both axial and MPR images showed a very high accuracy in the diagnosis of bowel obstruction with a significant advantage of MPRs over native images and without any difference between the two radiologists. MDCT is an accurate technique in the evaluation of large bowel obstruction and use of MPRs facilitates the interpretation of imaging findings.

  20. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography.

    PubMed

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-11-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.

  1. Multidetector CT angiography influences the choice of treatment for blunt carotid artery injury

    PubMed Central

    Beliaev, Andrei M; Civil, Ian

    2014-01-01

    A 43-year-old woman presented with a 2 h history of left neck pain after striking her neck against a marble bench while playing with her son. The patient was screened for blunt cerebrovascular injury (BCVI) and a left carotid bruit was identified. Subsequently, she underwent multidetector CT angiography (MCTA) of the aortic arch and neck vessels, which demonstrated a flow-limiting dissection of the left common carotid artery (CCA). The patient was started on heparin infusion and underwent an emergency operation. At surgery, a circumferential intimal dissection was excised and the arteriotomy defect closed with an autologous venous patch. This case emphasises the importance of adequately examining patients with direct injury to the neck, screening relevant patients for BCVI and investigating them with MCTA that influences the choice of a treatment option. PMID:25103313

  2. Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects.

    PubMed

    Anzidei, M; Napoli, A; Zini, C; Kirchin, M A; Catalano, C; Passariello, R

    2011-08-01

    Small bowel neoplasms, including adenocarcinoma, carcinoid tumour, lymphoma and gastrointestinal stromal tumours, represent a small percentage of gastrointestinal cancers, yet are among those with the poorest prognosis compared with other gastrointestinal malignancies. Unclear clinical scenarios and difficult radiological diagnosis often delay treatment with negative effects on patient survival. Recently, multidetector CT (MDCT) and MRI have been introduced as feasible and accurate diagnostic techniques for the identification and staging of small bowel neoplasms. These techniques are gradually replacing conventional barium radiography as the tool of choice. However, the inherent technical and physiological challenges of small bowel imaging require a familiarity with patient preparation and scan protocols. Adequate knowledge of the histopathology and natural evolution of small bowel neoplasms is also important for differential diagnosis. The aim of this article is to review MDCT and MRI protocols for the evaluation of small bowel tumours and to provide a concise yet comprehensive guide to the most relevant imaging features relative to histopathology.

  3. Comparison of air kerma between C-arm CT and 64-multidetector-row CT using a phantom.

    PubMed

    Hosokawa, Seiki; Kawai, Nobuyuki; Sato, Morio; Minamiguchi, Hiroki; Nakai, Motoki; Murotani, Kazuhiro; Nishioku, Tadayoshi; Shirai, Shintaro; Sonomura, Tetsuo

    2014-05-01

    To compare air kerma after scanning a phantom with C-arm CT and with 64-multidetector row CT (64MDCT). A phantom was scanned using parameters based on data of ten patients with hepatocellular carcinoma who had C-arm CT during hepatic arteriography and 64MDCT during arterial portography. Radiation monitors were used to measure air kerma ten times at each of five points: the center (A), top (B), left side (C), bottom (D), and right side (E). For C-arm CT vs. 64MDCT, air kerma after scanning was 10.5 ± 0.2 vs. 6.4 ± 0.0 for A, 1.5 ± 0.0 vs. 11.6 ± 0.2 for B, 37.1 ± 0.2 vs. 11.1 ± 0.1 for C, 55.6 ± 1.0 vs. 10.6 ± 0.1 for D, and 40.5 ± 0.5 vs. 11.7 ± 0.1 for E, respectively. Air kerma for A, B, C, D, and E was 1.64, 0.13, 3.34, 5.24, and 3.46 times greater for C-arm CT than for 64MDCT, respectively. Using the same scanning parameters as for clinical cases, air kerma values were greater with C-arm CT than with 64MDCT; at the dorsal side of the phantom, they were 5.24 times greater with C-arm CT compared with 64MDCT.

  4. Bronchial anatomy of left lung: a study of multi-detector row CT.

    PubMed

    Zhao, Xinya; Ju, Yuanrong; Liu, Cheng; Li, Jianfeng; Huang, Min; Sun, Jian; Wang, Tao

    2009-02-01

    Familiarity with prevailing pattern and variations in the bronchial tree is not only essential for the anatomist to explain bronchial variation in bronchial specimens, but also useful for guiding bronchoscopy and instructing pulmonary segmental resection. The purpose of this study was designed to demonstrate various branching patterns of left lung with 3D images, with special attention given to identify the major types at transverse thin-section CT. Two hundred and sixteen patients with routine thorax scans were enrolled. The images of bronchial tree, virtual bronchoscopy were reconstructed using post-processing technique of multi-detector row CT. We attempted to classify the segmental bronchi by interpreting the post-processing images, and identified them in transverse thin-section CT. Our results showed that the segmental bronchial ramifications of the left superior lobe were classified into three types mainly, i.e., common stem of apical and posterior segmental bronchi (64%, 138/216); trifurcation (23%, 50/216); common stem of apical and anterior segmental bronchi (10%, 22/216), and they could be identified at two typical sections of transverse thin-section CT. There were two major types in left basal segmental bronchi, i.e., bifurcation (75%, 163/216), trifurcation (18%, 39/216), and they could also be identified at two typical sections of transverse thin-section CT. In conclusion, our study have offered simplified branching patterns of bronchi and demonstrated various unusual bronchial branching patterns perfectly with 3D images, and have also revealed how to identify the main branching patterns in transverse thin-section CT.

  5. Automated multidetector row CT dataset segmentation with an interactive watershed transform (IWT) algorithm: Part 2. Body CT angiographic and orthopedic applications.

    PubMed

    Johnson, Pamela T; Hahn, Horst K; Heath, David G; Fishman, Elliot K

    2008-12-01

    The preceding manuscript describes the principles behind the Interactive Watershed Transform (IWT) segmentation tool. The purpose of this manuscript is to illustrate the clinical utility of this editing technique for body multidetector row computed tomography (MDCT) imaging. A series of cases demonstrates clinical applications where automated segmentation of skeletal structures with IWT is most useful. Both CT angiography and orthopedic applications are presented.

  6. Beam hardening artifacts by dental implants: Comparison of cone-beam and 64-slice computed tomography scanners

    PubMed Central

    Esmaeili, Farzad; Johari, Masume; Haddadi, Pezhman

    2013-01-01

    Background: Cone beam computed tomography (CBCT) is an alternative to a computed tomography (CT) scan, which is appropriate for a wide range of craniomaxillofacial indications. The long-term use of metallic materials in dentistry means that artifacts caused by metallic restorations in the oral cavity should be taken into account when utilizing CBCT and CT scanners. The aim of this study was to quantitatively compare the beam hardening artifacts produced by dental implants between CBCT and a 64-Slice CT scanner. Materials and Methods: In this descriptive study, an implant drilling model similar to the human mandible was used in the present study. The implants (Dentis) were placed in the canine, premolar and molar areas. Three series of scans were provided from the implant areas using Somatom Sensation 64-slice and NewTom VGi (CBCT) CT scanners. Identical images were evaluated by three radiologists. The artifacts in each image were determined based on pre-determined criteria. Kruskal-Wallis test was used to compare mean values; Mann-Whitney U test was used for two-by-two comparisons when there was a statistical significance (P < 0.05). Results: The images of the two scanners had similar resolutions in axial sections (P = 0.299). In coronal sections, there were significant differences in the resolutions of the images produced by the two scanners (P < 0.001), with a higher resolution in the images produced by NewTom VGi scanner. On the whole, there were significant differences between the resolutions of the images produced by the two CT scanners (P < 0.001), with higher resolution in the images produced by NewTom VGi scanner in comparison to those of Somatom Sensation. Conclusion: Given the high quality of the images produced by NewTom VGi and the lower costs in comparison to CT, the use of the images of this scanner in dental procedures is recommended, especially in patients with extensive restorations, multiple prostheses and previous implants. PMID:24019808

  7. Multidetector CT appearance of the pelvis after cesarean delivery: normal and abnormal acute findings

    PubMed Central

    Gui, Benedetta; Danza, Francesco Maria; Valentini, Anna Lia; Laino, Maria Elena; Caruso, Alessandro; Carducci, Brigida; Rodolfino, Elena; Devicienti, Ersilia; Bonomo, Lorenzo

    2016-01-01

    Cesarean section (CS) may have several acute complications that can occur in the early postoperative period. The most common acute complications are hematomas and hemorrhage, infection, ovarian vein thrombosis, uterine dehiscence and rupture. Pelvic hematomas usually occur at specific sites and include bladder flap hematoma (between the lower uterine segment and the bladder) and subfascial or rectus sheath hematoma (rectus sheath or prevescical space). Puerperal hemorrhage can be associated with uterine dehiscence or rupture. Pelvic infections include endometritis, abscess, wound infection, and retained product of conception. Radiologists play an important role in the diagnosis and management of postoperative complications as a result of increasing use of multidetector CT in emergency room. The knowledge of normal and abnormal postsurgical anatomy and findings should facilitate the correct diagnosis so that the best management can be chosen for the patient, avoiding unnecessary surgical interventions and additional treatments. In this article we review the surgical cesarean technique and imaging CT technique followed by description of normal and abnormal post-CS CT findings. PMID:27756714

  8. Multidetector CT appearance of the pelvis after cesarean delivery: normal and abnormal acute findings.

    PubMed

    Gui, Benedetta; Danza, Francesco Maria; Valentini, Anna Lia; Laino, Maria Elena; Caruso, Alessandro; Carducci, Brigida; Rodolfino, Elena; Devicienti, Ersilia; Bonomo, Lorenzo

    2016-01-01

    Cesarean section (CS) may have several acute complications that can occur in the early postoperative period. The most common acute complications are hematomas and hemorrhage, infection, ovarian vein thrombosis, uterine dehiscence and rupture. Pelvic hematomas usually occur at specific sites and include bladder flap hematoma (between the lower uterine segment and the bladder) and subfascial or rectus sheath hematoma (rectus sheath or prevescical space). Puerperal hemorrhage can be associated with uterine dehiscence or rupture. Pelvic infections include endometritis, abscess, wound infection, and retained product of conception. Radiologists play an important role in the diagnosis and management of postoperative complications as a result of increasing use of multidetector CT in emergency room. The knowledge of normal and abnormal postsurgical anatomy and findings should facilitate the correct diagnosis so that the best management can be chosen for the patient, avoiding unnecessary surgical interventions and additional treatments. In this article we review the surgical cesarean technique and imaging CT technique followed by description of normal and abnormal post-CS CT findings.

  9. Relationship between indexed epicardial fat volume and coronary plaque volume assessed by cardiac multidetector CT

    PubMed Central

    You, Seulgi; Sun, Joo Sung; Park, Seon Young; Baek, Yoolim; Kang, Doo Kyoung

    2016-01-01

    Abstract We explored whether baseline indexed epicardial fat volume (EFVi) and serial changes in EFVi were associated with increase in coronary plaque volume as assessed by multidetector computed tomography. We retrospectively reviewed 87 patients with coronary artery plaque, identified during either baseline or follow-up cardiac computed tomography (CT) examinations. Each plaque volume was measured in volumetric units using a semiautomatic software tool. EFVi was quantified by calculating the total volume of epicardial tissue of CT density −190 to −30 HU, indexed to the body surface area. Clinical cardiovascular risk factors were extracted by medical record review at the time of the cardiac CT examinations. The relationship between EFVi and coronary plaque volume was explored by regression analysis. Although the EFVi did not change significantly from baseline to the time of the follow-up CT (65.7 ± 21.8 vs 66.0 ± 21.8 cm3/m3, P = 0.620), the plaque volumes were increased significantly on the follow-up CT scans. The annual change in EFVi was not accompanied by a parallel change in coronary plaque volume (P = 0.096–0.500). On univariate analysis, smoking, hypercholesterolemia, 10-year coronary heart disease risk, obesity, and baseline EFVi predicted rapid increases in lipid-rich and fibrous plaque volumes. On multivariate analysis, baseline EFVi (odds ratio = 1.029, P = 0.016) was an independent predictor of a rapid increase in lipid-rich plaque volume. EFVi was shown to be an independent predictor of a rapid increase in lipid-rich plaque volume. However, changes in EFVi were not associated with parallel changes in coronary plaque volume. PMID:27399137

  10. Evaluation of accuracy of 3D reconstruction images using multi-detector CT and cone-beam CT

    PubMed Central

    Kim, Mija; YI, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul

    2012-01-01

    Purpose This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). Materials and Methods MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. Results All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Conclusion Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements. PMID:22474645

  11. A multidetector CT angiography study of variations in the circle of Willis in a Chinese population.

    PubMed

    Li, Qi; Li, Jialun; Lv, Fajin; Li, Kewei; Luo, Tianyou; Xie, Peng

    2011-03-01

    The circle of Willis is a major collateral circulation that has an important role in ischemic events. The purpose of our study was to investigate the collateral circulation in a Chinese population with 64-section multidetector CT angiography (CTA). A total of 170 patients who underwent 64-section CT angiography at The First Affiliated Hospital of Chongqing Medical University were included in our study. The morphological variations in the anterior and posterior circle of Willis were assessed in each patient. A total of 160 patients were included in the final analysis, of whom 126 (79%) demonstrated a complete anterior circle of Willis, and 50 (31%) had a complete posterior circle of Willis. A complete circle of Willis was seen in 43 of 160 participants (27%). A fetal-type posterior circle of Willis was seen in 15 (9.4%) patients. This is the first report of a CTA study of collateral circulation in a Chinese population. A higher prevalence of compromised posterior collaterals was observed in this Chinese population compared to Western and Japanese populations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Contrast enhanced multi-detector CT and MR findings of a well-differentiated pancreatic vipoma.

    PubMed

    Camera, Luigi; Severino, Rosa; Faggiano, Antongiulio; Masone, Stefania; Mansueto, Gelsomina; Maurea, Simone; Fonti, Rosa; Salvatore, Marco

    2014-10-28

    Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography (CT) or magnetic resonance (MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved by somatostatin-receptor scintigraphy (SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR (Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT (Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure (3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis.

  13. 64-Slice spiral computed tomography and three-dimensional reconstruction in the diagnosis of cystic pancreatic tumors

    PubMed Central

    WEN, ZHAOXIA; YAO, FENGQING; WANG, YUXING

    2016-01-01

    The present study aimed to describe the characteristics of cystic pancreatic tumors using computed tomography (CT) and to evaluate the diagnostic accuracy (DA) of post-imaging three-dimensional (3D) reconstruction. Clinical and imaging data, including multi-slice spiral CT scans, enhanced scans and multi-faceted reconstruction, from 30 patients with pathologically confirmed cystic pancreatic tumors diagnosed at the Linyi People's Hospital between August 2008 and June 2014 were retrospectively analyzed. Following the injection of Ultravist® 300 contrast agent, arterial, portal venous and parenchymal phase scans were obtained at 28, 60 and 150 sec, respectively, and 3D reconstructions of the CT images were generated. The average age of the patients was 38.4 years (range, 16–77 years), and the cohort included 5 males and 25 females (ratio, 1:5). The patients included 8 cases of mucinous cystadenoma (DA), 80%]; 9 cases of cystadenocarcinoma (DA, 84%); 6 cases of serous cystadenoma (DA, 100%); 3 cases of solid pseudopapillary tumor (DA, 100%); and 4 cases of intraductal papillary mucinous neoplasm (DA, 100%). 3D reconstructions of CT images were generated and, in the 4 cases of intraductal papillary mucinous neoplasm, the tumor was connected to the main pancreatic duct and multiple mural nodules were detected in one of these cases. The DA of the 3D-reconstructed images of cystic pancreatic tumors was 89.3%. The 64-slice spiral CT and 3D-reconstructed CT images facilitated the visualization of cystic pancreatic tumor characteristics, in particular the connections between the tumor and the main pancreatic duct. In conclusion, the 3D reconstruction of multi-slice CT data may provide an important source of information for the surgical team, in combination with the available clinical data. PMID:27073473

  14. Acetabular Cartilage Thickness: Accuracy of Three-Dimensional Reconstructions from Multidetector CT Arthrograms in a Cadaver Study1

    PubMed Central

    Allen, Bryce C; Peters, Christopher L.; Brown, Nicholas A. T.; Anderson, Andrew E.

    2010-01-01

    Purpose: To prospectively quantify the accuracy of hip cartilage thickness estimated from three-dimensional (3D) surfaces, generated by segmenting multidetector computed tomographic (CT) arthrograms by using direct physical measurements of cartilage thickness as the reference standard. Materials and Methods: Four fresh-frozen cadaver hip joints from two male donors, ages 43 and 46 years, were obtained; institutional review board approval for cadaver research was also obtained. Sixteen holes were drilled perpendicular to the cartilage of four cadaveric acetabula (two specimens). Hip capsules were surgically closed, injected with contrast material, and scanned by using multidetector CT. After scanning, 5.3-mmcores were harvested concentrically at each drill hole and cartilage thickness was measured with a microscope. Cartilage was reconstructed in 3D by using commercial software. Segmentations were repeated by two authors. Reconstructed cartilage thickness was determined by using a published algorithm. Bland-Altman plots and linear regression were used to assess accuracy. Repeatability was quantified by using the coefficient of variation, intraclass correlation coefficient (ICC), repeatability coefficient, and percentage variability. Results: Cartilage was reconstructed to a bias of −0.13 mm and a repeatability coefficient of ±0.46 mm. Regression of the scatterplots indicated a tendency for multidetector CT to overestimate thickness. Intra- and interobserver repeatability were very good. For intraobserver correlation, the coefficient of variation was 14.80%, the ICC was 0.88, the repeatability coefficient was 0.55 mm, and the percentage variability was 11.77%. For interobserver correlation, the coefficient of variation was 13.47%, the ICC was 0.90, the repeatability coefficient was 0.52 mm, and the percentage variability was 11.63%. Conclusion: Assuming that an accuracy of approximately ±0.5 mm is sufficient, reconstructions of cartilage geometry from

  15. Acute appendicitis: comparison of low-dose and standard-dose unenhanced multi-detector row CT.

    PubMed

    Keyzer, Caroline; Tack, Denis; de Maertelaer, Viviane; Bohy, Pascale; Gevenois, Pierre Alain; Van Gansbeke, Daniel

    2004-07-01

    To prospectively compare low- and standard-dose unenhanced multi-detector row computed tomography (CT) in patients suspected of having acute appendicitis. Ninety-five consecutive patients underwent two unenhanced multi-detector row CT examinations with 4 x 2.5-mm collimation, 120 kVp, and 30 and 100 effective mAs. Two radiologists independently read the images obtained at each dose during two sessions. Readers recorded visualization of the appendix and presence of gas in its lumen, appendicolith, periappendiceal fat stranding, cecal wall thickening, and abscess or phlegmon to measure the diameter of the appendix and to propose diagnosis (appendicitis or alternative). Data were compared according to dose and reader, with definite diagnosis established on basis of surgical findings (n = 37) or clinical follow-up. chi(2) tests and logistic regression were used. Measurement agreements were assessed with Cohen kappa statistics. Twenty-nine patients had a definite diagnosis of appendicitis. No difference was observed between the frequency of visualization of the appendix (P =.874) neither in its mean diameter (P =.101-.696, according to readers and sessions) nor in the readers' overall diagnosis (P =.788) at each dose. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each sign were not different between doses. Fat stranding, appendicolith, and diameter were the most predictive signs, regardless of dose, yielding approximately 90% of correct diagnoses. The ability to propose a correct alternative diagnosis was not influenced by the dose. Low-dose unenhanced multi-detector row CT has similar diagnostic performance as standard-dose unenhanced multi-detector row CT for the diagnosis of acute appendicitis. Copyright RSNA, 2004

  16. Accuracy of linear intraoral measurements using cone beam CT and multidetector CT: a tale of two CTs

    PubMed Central

    Patcas, R; Markic, G; Müller, L; Ullrich, O; Peltomäki, T; Kellenberger, C J; Karlo, C A

    2012-01-01

    Objectives The aim was to compare the accuracy of linear bone measurements of cone beam CT (CBCT) with multidetector CT (MDCT) and validate intraoral soft-tissue measurements in CBCT. Methods Comparable views of CBCT and MDCT were obtained from eight intact cadaveric heads. The anatomical positions of the gingival margin and the buccal alveolar bone ridge were determined. Image measurements (CBCT/MDCT) were performed upon multiplanar reformatted data sets and compared with the anatomical measurements; the number of non-assessable sites (NASs) was evaluated. Results Radiological measurements were accurate with a mean difference from anatomical measurements of 0.14 mm (CBCT) and 0.23 mm (MDCT). These differences were statistically not significant, but the limits of agreement for bone measurements were broader in MDCT (−1.35 mm; 1.82 mm) than in CBCT (−0.93 mm; 1.21 mm). The limits of agreement for soft-tissue measurements in CBCT were smaller (−0.77 mm; 1.07 mm), indicating a slightly higher accuracy. More NASs occurred in MDCT (14.5%) than in CBCT (8.3%). Conclusions CBCT is slightly more reliable for linear measurements than MDCT and less affected by metal artefacts. CBCT accuracy of linear intraoral soft-tissue measurements is similar to the accuracy of bone measurements. PMID:22554987

  17. Multi-detector row CT scanning in Paleoanthropology at various tube current settings and scanning mode.

    PubMed

    Badawi-Fayad, J; Yazbeck, C; Balzeau, A; Nguyen, T H; Istoc, A; Grimaud-Hervé, D; Cabanis, E- A

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required.

  18. Multidetector CT: a new gold standard in the diagnosis of pulmonary embolism? State of the art and diagnostic algorithms.

    PubMed

    Russo, V; Piva, T; Lovato, L; Fattori, R; Gavelli, G

    2005-01-01

    From the early 90s, spiral CT technology has considerably changed the diagnostic capability of Pulmonary Embolism (PE), giving a direct vision of intravascular thrombi. Further technological progress has strengthened its diagnostic impact leading to an essential role in clinical practice. The advent of Multi-Detector CT (MDCT) has subsequently increased the reliability of this technique to the point of undermining the role of pulmonary angiography as the gold standard and occupying a central position in diagnostic algorithms. The aim of this paper is to appraise this evolution by means of a meta-analysis of the relevant literature from 1995 to 2004. The review of the literature showed the sensitivity and specificity of CT to have increased from 37-94% and 81-100% (single-detector CT) to 87-94% and 94-100% (4-channel multidetector CT), especially thanks to the possibility of depicting subsegmental clots, with an interobserver agreement of 0.63-0.94 (k). CT is one of the most reliable and effective methods in the diagnosis is PE, with the advantage of being extremely fast and providing alternative diagnoses. Recent improvements in MDCT technology confers the highest value of diagnostic accuracy with respect to other imaging modalities such as scintigraphy, angiography, MRI, D-dimer assay and Doppler US.

  19. 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

    2016-12-20

    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/.

  20. Cirsoid Aneurysm of Coronary Arteries Associated with Arterioventricular Fistula Evaluated by 64-Multidetector CT Coronary Angiography: Depiction of a Case

    SciTech Connect

    Marrone, Gianluca Mamone, Giuseppe; Milazzo, Mariapina; Caruso, Settimo; Baravoglia, Cesar Hernandez; Vitulo, Patrizio; Gridelli, Bruno; Luca, Angelo

    2009-05-15

    A female patient with severe pulmonary hypertension was admitted for lung transplant evaluation. As an incidental finding, the chest CT showed diffuse and dilated coronaries, not detected at previous echocardiography. A coronary CT angiography was then performed using a 64-multidetector computed tomography (MDCT) scanner to better evaluate the coronary tree. The images obtained after postprocessing demonstrated tremendously aneurysmatic and tortuous coronary arteries and the presence of a septal branch deepening into the myocardium and penetrating the right ventricle cavity, forming an abnormal arterioventricular fistula. A causal relation between the aneurysms and the fistula is suspected.

  1. Multidetector CT cystography for imaging colovesical fistulas and iatrogenic bladder leaks.

    PubMed

    Tonolini, Massimo; Bianco, Roberto

    2012-04-01

    Multidetector computed tomography (MDCT) cystography currently represents the modality of choice to image the urinary bladder in traumatized patients. In this review we present our experience with MDCT cystography applications outside the trauma setting, particularly for diagnosing bladder fistulas and leaks. A detailed explanation is provided concerning exam preparation, acquisition technique, image reconstruction and interpretation. Colovesical fistulas most commonly occur as a complication of sigmoid diverticular disease, and often remain occult after extensive diagnostic work-up including cystoscopy and contrast-enhanced CT. We consistently achieved accurate preoperative visualization of colovesical fistulas using MDCT cystography. Urinary leaks and injuries represent a non-negligible occurrence after pelvic surgery, particularly obstetric and gynaecological procedures: in our experience MDCT cystography is useful to investigate iatrogenic bladder leaks or fistulas. In our opinion, MDCT cystography should be recommended as the first line modality for direct visualization or otherwise confident exclusion of both spontaneous enterovesical fistulas and bladder injuries following instrumentation procedures, obstetric or surgical interventions. Main Messages • Explanation of exam preparation, acquisition technique, image reconstruction and interpretation. • Preoperative visualization of colovesical fistulas, usually secondary to sigmoid diverticulitis. • Visualization or exclusion of iatrogenic bladder injuries following instrumentation or surgery.

  2. Paratracheal air cysts: prevalence and relevance to pulmonary emphysema and bronchiectasis using thoracic multidetector CT.

    PubMed

    Boyaci, Nurefsan; Sen Dokumaci, Dilek; Karakas, Ekrem; Yalcin, Funda; Oney Kurnaz, Ayse Gul

    2015-01-01

    We aimed to determine the prevalence of paratracheal air cysts (PTACs) and the relationship of PTACs with emphysema and bronchiectasis through retrospective analysis of multidetector computed tomography (MDCT) findings. MDCT findings of 1027 consecutive patients who underwent routine thorax examination between January 2012 and January 2013 were evaluated retrospectively for the presence of PTACs. Localization of the PTACs, as well as their size, shape, and relationship with the trachea were examined. Presence of emphysema and bronchiectasis was recorded, and bronchiectasis severity index was calculated when present. We randomly selected 80 patients who had no visible PTACs as the control group. The findings of patients with and without PTACs were compared. PTACs were determined in 82 of 1027 patients (8%), in 8.8% of females and 7.3% of males. The presence of PTACs was determined to be independent of gender (P = 0.361). Eighty-one PTACs (98.8%) were located in the right side of the trachea and 56.1% had a tracheal connection. The presence of PTACs significantly correlated with the presence and severity of bronchiectasis (P = 0.001 and P = 0.005 respectively). There was no significant relationship between the presence of PTACs and the presence of emphysema on CT images (P = 0.125). The prevalence of PTACs was determined as 8% in this study. There was significant association between PTACs and bronchiectasis.

  3. Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT

    SciTech Connect

    Flohr, T. G.; Stierstorfer, K.; Suess, C.; Schmidt, B.; Primak, A. N.; McCollough, C. H.

    2007-05-15

    We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the z-axis direction for a routine medical multi-detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the z-axis direction in combination with tantalum grids that are inserted in front of the multi-row detector to reduce the aperture of the detector elements both in-plane and in the z-axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of 0.4 mm (measured full width at half maximum=0.45 mm) can be reconstructed in spiral mode on a CT system with a detector configuration of 32x0.6 mm. The measured 2% value of the in-plane modulation transfer function (MTF) is 20.4 lp/cm, the measured 2% value of the longitudinal (z axis) MTF is 21.5 lp/cm. In a resolution phantom with metal line pair test patterns, spatial resolution of 20 lp/cm can be demonstrated both in the scan plane and along the z axis. This corresponds to an object size of 0.25 mm that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade-off for the clinical benefit brought about by the improved spatial resolution.

  4. Paratracheal air cysts on thoracic multidetector CT: incidence, morphological characteristics and relevance to pulmonary emphysema.

    PubMed

    Bae, H-J; Kang, E-Y; Yong, H S; Kim, Y K; Woo, O H; Oh, Y-W; Doo, K W

    2013-01-01

    To determine the incidence, morphological characteristics and relevance of paratracheal air cysts (PTACs) with pulmonary emphysema, as seen on thoracic multidetector CT (MDCT). The CT images of 854 consecutive patients who underwent thoracic MDCT during a period of 2 months at our institution were reviewed. 538 of the patients were male and 316 were female. The incidence, size and shape of the PTACs and their relation to pulmonary emphysema were retrospectively analysed. Among the 854 patients, 69 (8.1%) had PTACs. 37 (6.9%) of the 538 male patients and 32 (10.1%) of the 316 female patients had PTACs. The highest prevalence of PTACs (25 patients, 11.2%) was found in those who were in the sixth decade of life. 48 (69.6%) PTACs measured 3-10 mm at the longest diameter and 33 (47.8%) were elongated on the coronal section images. 12 (17.4%) patients with PTACs had underlying gross morphological emphysema. The relationship between the presence of PTACs and the presence of emphysema and the relationship between the presence of PTACs and the severity of emphysema were not statistically significant. The size of PTACs showed an inverse relation to the severity of emphysema. The incidence of PTACs was estimated to be much higher than that of previous studies. There was a slight female predilection for PTACs, most commonly found in the sixth decade of life; PTACs mostly measured 3-10 mm and were elongated in shape. The relation of PTACs to gross morphological emphysema was low. PTACs are not correlated with the presence of emphysema on MDCT.

  5. Evaluation of bone substitute materials: comparison of flat-panel based volume CT to conventional multidetector CT.

    PubMed

    Sauerbier, Sebastian; Duttenhoefer, Fabian; Sachlos, Elefterios; Haberstroh, Jörg; Scheifele, Christian; Wrbas, Karl-Thomas; Voss, Pit Jacob; Veigel, Egle; Smedek, Jörg; Ganter, Philip; Tuna, Taskin; Gutwald, Ralf; Palmowski, Moritz

    2013-10-01

    Over the last decade tissue engineering has emerged as a key factor in bone regeneration within the field of cranio-maxillofacial surgery. Despite this in vivo analysis of tissue-engineered-constructs to monitor bone rehabilitation are difficult to conduct. Novel high-resolving flat-panel based volume CTs (fp-VCT) are increasingly used for imaging bone structures. This study compares the potential value of novel fp-VCT with conventional multidetector CT (MDCT) based on a sheep sinus floor elevation model. Calcium-hydroxyapatite reinforced collagen scaffolds were populated with autologous osteoblasts and implanted into sheep maxillary sinus. After 8, 16 and 24 weeks MDCT and fp-VCT scans were performed to investigate the volume of the augmented area; densities of cancellous and compact bone were assessed as comparative values. fp-VCT imaging resulted in higher spatial resolution, which was advantageous when separating closely related anatomical structures (i.e. trabecular and compact bone, biomaterials). Fp-VCT facilitated imaging of alterations occurring in test specimens over time. fp-VCTs therefore displayed high volume coverage, dynamic imaging potential and superior performance when investigating superfine bone structures and bone remodelling of biomaterials. Thus, fp-VCTs may be a suitable instrument for intraoperative imaging and future in vivo tissue-engineering studies.

  6. Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting.

    PubMed

    Hayter, Robert G; Rhea, James T; Small, Andrew; Tafazoli, Faranak S; Novelline, Robert A

    2006-03-01

    To retrospectively review the authors' experience with multi-detector row computed tomography (CT) for detection of aortic dissection in the emergency setting. The investigation was institutional review board approved, did not require informed patient consent, and was HIPAA compliant. In 373 clinical evaluations in the emergency setting, 365 patients suspected of having aortic dissection and/or other aortic disorders underwent multidetector CT. Criteria for acute aortic disorder were confirmed by using surgical and pathologic diagnoses or findings at clinical follow-up and any subsequent imaging as the reference standard. Positive cases were characterized according to type of disorder interpreted. Resulting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by using two-way contingency tables. All cases found to be negative for acute aortic disorders were grouped according to alternative CT findings. Sixty-seven (18.0%) of the 373 cases were interpreted as positive for acute aortic disorder. One hundred twelve acute aortic disorders were identified in these 67 cases: 23 acute aortic dissections, 14 acute aortic intramural hematomas, 20 acute penetrating aortic ulcers, 44 new or enlarging aortic aneurysms, and 11 acute aortic ruptures. Three hundred five (81.8%) cases were interpreted as negative for acute aortic disorder. In 48 negative cases, multidetector CT depicted alternative findings that accounted for the clinical presentation. Of these, three included both acute aortic disorders and alternative findings, and 45 included only alternative findings. One (0.3%) case was indeterminate for acute aortic disorder. Overall, 112 findings were interpreted as positive for acute aortic disorder, an alternative finding, or both at CT. No interpretations were false-positive, one was false-negative, 67 were true-positive, and 304 were true-negative. Sensitivity, specificity, PPV, NPV, and accuracy were

  7. An ancient Roman bowl embedded in a soil sample: surface shaded three dimensional display using data from a multi-detector CT.

    PubMed

    De Maeseneer, M; Buls, N; Cleeren, N; Lenchik, L; De Mey, J

    2006-01-01

    We present an unusual application of multidetector CT and shaded surface rendering in the investigation of a soil sample, containing an ancient Roman bronze bowl. The CT findings were of fundamental importance in helping the archaeologists study the bronze bowl from the soil sample.

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

    SciTech Connect

    Damilakis, John; Tzedakis, Antonis; Perisinakis, Kostas; Papadakis, Antonios E.

    2010-12-15

    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, simulating 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

  9. Multidetector-row CT with a 64-row amorphous silicon flat panel detector

    NASA Astrophysics Data System (ADS)

    Shapiro, Edward G.; Colbeth, Richard E.; Daley, Earl T.; Job, Isaias D.; Mollov, Ivan P.; Mollov, Todor I.; Pavkovich, John M.; Roos, Pieter G.; Star-Lack, Josh M.; Tognina, Carlo A.

    2007-03-01

    A unique 64-row flat panel (FP) detector has been developed for sub-second multidetector-row CT (MDCT). The intent was to explore the image quality achievable with relatively inexpensive amorphous silicon (a-Si) compared to existing diagnostic scanners with discrete crystalline diode detectors. The FP MDCT system is a bench-top design that consists of three FP modules. Each module uses a 30 cm x 3.3 cm a-Si array with 576 x 64 photodiodes. The photodiodes are 0.52 mm x 0.52 mm, which allows for about twice the spatial resolution of most commercial MDCT scanners. The modules are arranged in an overlapping geometry, which is sufficient to provide a full-fan 48 cm diameter scan. Scans were obtained with various detachable scintillators, e.g. ceramic Gd IIO IIS, particle-in-binder Gd IIO IIS:Tb and columnar CsI:Tl. Scan quality was evaluated with a Catphan-500 performance phantom and anthropomorphic phantoms. The FP MDCT scans demonstrate nearly equivalent performance scans to a commercial 16-slice MDCT scanner at comparable 10 - 20 mGy/100mAs doses. Thus far, a high contrast resolution of 15 lp/cm and a low contrast resolution of 5 mm @ 0.3 % have been achieved on 1 second scans. Sub-second scans have been achieved with partial rotations. Since the future direction of MDCT appears to be in acquiring single organ coverage per scan, future efforts are planned for increasing the number of detector rows beyond the current 64- rows.

  10. Using air bronchograms on multi-detector CT to predict the invasiveness of small lung adenocarcinoma.

    PubMed

    Zhang, Yu; Qiang, Jin Wei; Shen, Yan; Ye, Jian Ding; Zhang, Jie; Zhu, Lei

    2016-03-01

    To investigate the prevalence of multidetector CT (MDCT) air bronchograms and their value in predicting the invasiveness of lung adenocarcinomas. MDCT scans of 606 nodules in 582 patients with a lung adenocarcinoma less than 2cm in diameter confirmed by surgery and pathology were reviewed. Air bronchograms were classified into three patterns: type I, bronchus with intact lumen; type II, bronchus with dilated or tortuous lumen; and type III, bronchus with obstructed lumen. Air bronchograms were demonstrated on MDCT in 210 of 606 (34.7%) lung adenocarcinomas with 16.6% (35/211) preinvasive lesions (PL), 30.5% (50/164) minimally invasive adenocarcinoma (MIA), and 54.1% (125/231) invasive adenocarcinoma (IAC) (P=0.000); 18.3% (44/240) pure ground-glass nodules (GGNs), 44.2% (137/310) mixed GGNs, and 51.8% (29/56) solid nodules (P=0.000). Type I was slightly more common in MIA (36/164, 22.0%) than IAC (40/231, 17.3%) and PL (30/211, 14.2%) but without differences among them (P=0.147). Type II (PL: 5/211, 2.4%; MIA: 13/164, 7.9%; IAC: 53/231, 22.9%) and type III (PL: 0/211; MIA: 1/164, 0.6%; IAC: 32/231, 13.9%) were observed more frequently with increasing lung adenocarcinoma invasiveness (both P=0.000). The prevalence and patterns of air bronchograms on MDCT can predict the invasiveness of small lung adenocarcinomas. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Costs and clinical outcomes after coronary multidetector CT angiography in patients without known coronary artery disease: comparison to myocardial perfusion SPECT.

    PubMed

    Min, James K; Kang, Ning; Shaw, Leslee J; Devereux, Richard B; Robinson, Matthew; Lin, Fay; Legorreta, Antonio P; Gilmore, Amanda

    2008-10-01

    To assess costs and clinical outcomes in individuals without known coronary artery disease (CAD) who underwent multidetector computed tomographic (CT) angiography compared with those in matched patients who underwent myocardial perfusion single photon emission computed tomography (SPECT). Data were captured from a deidentified, HIPAA-compliant data warehouse. We examined 1-year CAD costs (additional diagnostic coronary testing, CAD hospitalization, and coronary procedural and revascularization costs) and clinical outcomes in individuals without known CAD who underwent multidetector CT (n = 1647) compared with those in a matched cohort of patients who underwent myocardial perfusion SPECT (n = 6588). Cox proportional hazards models were employed for clinical outcome measures, including CAD hospitalization, myocardial infarction, and angina. Adjusted CAD costs in the multidetector CT group were 25.9% lower than in the myocardial perfusion SPECT group, by an average of $1075 (95% confidence interval [CI]: $243, $2570) per patient. Those in the multidetector CT group were more likely to undergo downstream testing with myocardial perfusion SPECT (odds ratio, 6.65; 95% CI: 5.05, 8.75; P < .001), while those in the myocardial perfusion SPECT group were more likely to undergo downstream testing with invasive angiography (odds ratio, 6.25; 95% CI: 4.35, 9.09; P < .001). The multidetector CT group was less likely to undergo coronary revascularization (hazard ratio, 0.76; 95% CI: 0.75, 0.77; P < .001) than the myocardial perfusion SPECT group. There was no significant difference between multidetector CT and myocardial perfusion SPECT groups for rates of myocardial infarction (0.4% for both) or CAD hospitalization (0.7% vs 1.1%, respectively), while rates of angina were significantly lower in the multidetector CT group (4.3% vs 6.4%, P < .001). Individuals without known CAD who underwent multidetector CT as an initial diagnostic test, compared with those who underwent

  12. High pitch CT in triple rule-out studies: Radiation dose and image quality compared to multidetector CT.

    PubMed

    Fernández del Valle, A; Delgado Sánchez-Gracián, C; Oca Pernas, R; Grande Astorquiza, A; Bustos Fiore, A; Trinidad López, C; Tardáguila de la Fuente, G

    2015-01-01

    To compare the image quality and radiation dose from high pitch dual source CT (128-DSCT) versus those from retrospective acquisition with 64-row multidetector CT (64-MDCT) in triple rule-out studies. We retrospectively studied 60 patients with acute chest pain: 30 with a retrospective EKG acquisition with 64-MDCT and 30 with high pitch 128-DSCT. We quantitatively analyzed the image quality by calculating the vascular density, muscular density (DM), noise, vascular density/noise ratio (VDNR), and contrast/noise ratio (CNR). We qualitatively evaluated the artifacts in the vena cava, aorta, and coronary arteries. We estimated the effective dose (ED) of radiation by means of the dose-length product. There were no significant differences between 128-DSCT and 64-MDCT in the vascular density. The VDNR and CNR were higher on 128-DSCT than on 64-MDCT in the aorta (VDNR: 28.9 ± 11.7 vs. 20 ± 5.5; CNR: 24.4 ± 10.9 vs. 16.8 ± 5.4; P<.01), in the pulmonary arteries (VDNR: 25.5 ± 10 vs. 20.6 ± 6.5; CNR: 24.5 ± 5.4 vs. 17.4 ± 6.4; P<.01), and in the coronary arteries (VDNR: 25.9 ± 8.2 vs. 18.9 ± 4.9; CNR: 24.9 ± 8.2 vs. 15.6 ± 4.6; P<.01). There were fewer artifacts in the coronary arteries on 128-DSCT than on 64-MDCT (3 vs. 34 nondiagnostic segments; P<.001), and the ED in 128-DSCT was lower than in 64-MDCT (13.77 ± 4 vs. 2.77 ± 0.6 mSv; P<.001). In triple rule-out studies, high pitch 128-DSCT delivers a lower dose of radiation and provides better image quality than retrospective acquisition with 64-MDCT. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  13. Evaluation of reperfused myocardial infarction by low-dose multidetector computed tomography using prospective electrocardiography (ECG)-triggering: comparison with magnetic resonance imaging.

    PubMed

    Gweon, Hye Mi; Kim, Sang Jin; Kim, Tae Hoon; Lee, Sang Min; Hong, Yoo Jin; Rim, Se-Joong; Hong, Bum Ki; Min, Phil Ki; Yoon, Young Won; Kwon, Hyuck Moon

    2010-09-01

    To evaluate the potential of prospective electrocardiography (ECG)- gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction. Seventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images. Total mean radiation dose was 7.7 +/- 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 +/- 10% vs. 22 +/- 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 +/- 17.8% vs. 4.3 +/- 2.1%, p < 0.001). Prospective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.

  14. A new 3-D diagnosis strategy for duodenal malignant lesions using multidetector row CT, CT virtual duodenoscopy, duodenography, and 3-D multicholangiography.

    PubMed

    Sata, N; Endo, K; Shimura, K; Koizumi, M; Nagai, H

    2007-01-01

    Recent advances in multidetector row computed tomography (MD-CT) technology provide new opportunities for clinical diagnoses of various diseases. Here we assessed CT virtual duodenoscopy, duodenography, and three-dimensional (3D) multicholangiography created by MD-CT for clinical diagnosis of duodenal malignant lesions. The study involved seven cases of periduodenal carcinoma (four ampullary carcinomas, two duodenal carcinomas, one pancreatic carcinoma). Biliary contrast medium was administered intravenously, followed by intravenous administration of an anticholinergic agent and oral administration of effervescent granules for expanding the upper gastrointestinal tract. Following intravenous administration of a nonionic contrast medium, an upper abdominal MD-CT scan was performed in the left lateral position. Scan data were processed on a workstation to create CT virtual duodenoscopy, duodenography, 3D multicholangiography, and various postprocessing images, which were then evaluated for their effectiveness as preoperative diagnostic tools. Carcinoma location and extent were clearly demonstrated as defects or colored low-density areas in 3-D multicholangiography images and as protruding lesions in virtual duodenography and duodenoscopy images. These findings were confirmed using multiplanar or curved planar reformation images. In conclusion, CT virtual duodenoscopy, doudenography, 3-D multicholangiography, and various images created by MD-CT alone provided necessary and adequate preoperative diagnostic information.

  15. Diagnostic Performance of Gadoxetic Acid-enhanced Liver MR Imaging versus Multidetector CT in the Detection of Dysplastic Nodules and Early Hepatocellular Carcinoma.

    PubMed

    Kim, Bo Ram; Lee, Jeong Min; Lee, Dong Ho; Yoon, Jeong Hee; Hur, Bo Yun; Suh, Kyung Suk; Yi, Nam-Joon; Lee, Kyung Boon; Han, Joon Koo

    2017-10-01

    Purpose To compare the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging with that of contrast material-enhanced multidetector computed tomography (CT) in the detection of borderline hepatocellular nodules in patients with liver cirrhosis and to determine the Liver Imaging Reporting and Data System (LI-RADS) categories of these detected nodules. Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Sixty-eight patients with pathologically proven dysplastic nodules (DNs) (low-grade DNs, n = 20; high-grade DNs, n = 17), early hepatocellular carcinomas (HCCs) (n = 42), or progressed HCCs (n = 33) underwent gadoxetic acid-enhanced MR imaging and multidetector CT. An additional 57 patients without any DNs or HCCs in the explanted livers were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale and assigned LI-RADS categories by using imaging findings. Jackknife alternative free-response receiver operating characteristics (JAFROC) software was used to compare the diagnostic accuracy of each modality in lesion detection. Results Reader-averaged figures of merit estimated with JAFROC software to detect hepatocellular nodules were 0.774 for multidetector CT and 0.842 for MR imaging (P = .002). Readers had significantly higher detection sensitivity for early HCCs with MR imaging than with multidetector CT (78.6% vs 52.4% [P = .001], 71.4% vs 50.0% [P = .011], and 73.8% vs 50.0% [P = .001], respectively). A high proportion of overall detected early HCCs at multidetector CT (59.4%) and MR imaging (72.3%) were categorized as LI-RADS category 4. Most early HCCs (76.2%) and high-grade DNs (82.4%) demonstrated hypointensity on hepatobiliary phase images. In total, 30 more LI-RADS category 4 early HCCs were identified with MR imaging than with multidetector CT across all readers

  16. Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen.

    PubMed

    Taylor, Stuart A; Halligan, Steve; Bartram, Clive I; Morgan, Paul R; Talbot, Ian C; Fry, Nicola; Saunders, Brian P; Khosraviani, Kirosh; Atkin, Wendy

    2003-10-01

    To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening. A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection. The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P <.001). The effective radiation dose, calculated with a Monte Carlo simulation, was 1.4-10.0 mSv. Detection of small polyps (<5 mm) with multi-detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose

  17. Cervical spine clearance in the traumatically injured patient: is multidetector CT scanning sufficient alone? Clinical article.

    PubMed

    Chew, Brandon G; Swartz, Christopher; Quigley, Matthew R; Altman, Daniel T; Daffner, Richard H; Wilberger, James E

    2013-11-01

    Clearance of the cervical spine in patients who have sustained trauma remains a contentious issue. Clinical examination alone is sufficient in neurologically intact patients without neck pain. Patients with neck pain or those with altered mental status or a depressed level of consciousness require further radiographic evaluation. However, no consensus exists as to the appropriate imaging modality. Some advocate multidetector CT (MDCT) scanning alone, but this has been criticized because MDCT is not sensitive in detecting ligamentous injuries that can often only be identified on MRI. Patients were identified retrospectively from a prospectively maintained database at a Level I trauma center. All patients admitted between January 2004 and June 2011 who had a cervical MDCT scan interpreted by a board-certified radiologist as being without evidence of acute traumatic injury and who also had a cervical MRI study obtained during the same hospital admission were included. Data collected included patient demographics, mechanism of injury, Glasgow Coma Scale score at the time of MRI, the indication for and findings on MRI, and the number, type, and indication for cervical spine procedures. A total of 1004 patients were reviewed, of whom 614 were male, with an overall mean age of 47 years. The indication for MRI was neck pain in 662 patients, altered mental status in 467, and neurological signs or symptoms in 157. The MRI studies were interpreted as normal in 645 patients, evidencing ligamentous injury alone in 125, and showing nonspecific degenerative changes in the remaining patients. Of the 125 patients with ligamentous injuries, 66 (52.8%) had documentation of clearance (29 clinical, 37 with flexion-extension radiographs). Another 32 patients were presumed to be self-cleared, bringing the follow-up rate to 82% (98 of 119). Five patients died prior to clearance, and 1 patient was transferred to another facility prior to clearance. Based on these data, the 95% confidence

  18. Digital medical technology based on 64-slice computed tomography in hepatic surgery.

    PubMed

    Fang, Chi-hua; Huang, Yan-peng; Chen, Mian-ling; Lu, Chao-min; Li, Xiao-feng; Qiu, Wen-feng

    2010-05-05

    With the rapid development of computer technology, digital medicine has become a new direction in surgery. The application of digital medicine in hepatic surgery is still at the early stage and less reported in the literature. The aim of this study was to apply digital medical technology in the context of hepatic surgery. Data from 64-slice helical computed tomography of 17 patients, including 13 with hepatocellular carcinoma and 4 with hepatic hemangioma, were imported into independently developed medical image software program, segmentation and three-dimensional reconstruction were performed. The three-dimensional models were then processed with the FreeForm Modeling System. We used virtual surgical instruments to perform surgery on the models. Simulated surgeries included six hepatic segmentectomies, four left hemihepatectomies, three right hemihepatectomies for hepatocellular carcinoma, one hepatic segmentectomy, two stripping surgeries, and one irregular segmentectomy combined with stripping surgery for hemangioma. For resections involving more than three hepatic segments, total and residual functional hepatic volumes were measured before and after simulation surgery, and the resection ratio was calculated. The anatomy of the models was distinct and was used to localize lesions. We used virtual surgical instruments to perform simulated surgeries and used the models to optimize actual surgeries. We were able to minimize resection volume as well as surgical risk. Digital medical technology is helpful in the diagnosis of hepatic disease and in optimizing surgical plans. Three-dimensional models can decrease surgical risk and help prevent postoperative hepatic failure.

  19. Evaluation of Deep Vein Thrombosis with Multidetector Row CT after Orthopedic Arthroplasty: a Prospective Study for Comparison with Doppler Sonography

    PubMed Central

    Byun, Sung Su; Kim, Youn Jeong; Chun, Yong Sun; Park, Chul Hi; Kim, Won-Hong

    2008-01-01

    Objective This prospective study evaluated the ability of indirect 16-row multidetector CT venography, in comparison with Doppler sonography, to detect deep vein thrombosis after total hip or knee replacement. Materials and Methods Sixty-two patients had undergone orthopedic replacement surgery on a total of 30 hip joints and 54 knee joints. The CT venography (scan delay time: 180 seconds; slice thickness/increment: 2/1.5 mm) and Doppler sonography were performed 8 to 40 days after surgery. We measured the z-axis length of the beam hardening artifact that degraded the image quality so that the presence of deep vein thrombosis couldn't be evaluated on the axial CT images. The incidence and location of deep vein thrombosis was analyzed. The diagnostic performance of the CT venograms was evaluated and compared with that of Doppler sonography as a standard of reference. Results The z-axis length (mean±standard deviation) of the beam hardening artifact was 4.5 ± 0.8 cm in the arthroplastic knees and 3.9 ± 2.9 cm in the arthroplastic hips. Deep vein thrombosis (DVT) was found in the popliteal or calf veins on Doppler sonography in 30 (48%) of the 62 patients. The CT venography has a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 90%, 97%, 96%, 91% and 94%, respectively. Conclusion The ability of CT venography to detect DVT was comparable to that of Doppler sonography despite of beam hardening artifact. Therefore, CT venography is feasible to use as an alternative modality for evaluating postarthroplasty patients. PMID:18253077

  20. Three-dimensional echocardiography in various types of heart disease: a comparison study of magnetic resonance imaging and 64-slice computed tomography in a real-world population.

    PubMed

    Squeri, Angelo; Censi, Stefano; Reverberi, Claudio; Gaibazzi, Nicola; Baldelli, Marco; Binno, Simone Maurizio; Properzi, Enrico; Bosi, Stefano

    2017-03-01

    Accurate quantification of left ventricular (LV) volumes [end-diastolic volume (EDV) and end-systolic volume (ESV)] and ejection fraction (EF) is of critical importance. The development of real-time three-dimensional echocardiography (RT3DE) has shown better correlation than two-dimensional (2D) echocardiography with magnetic resonance imaging (MRI) measurements. The aim of our study was to assess the accuracy of RT3DE and 64-slice computed tomography (CT) in the evaluation of LV volumes and function using MRI as the reference standard in a real-world population with various types of heart disease with different chamber geometry. The study population consisted of 66 patients referred for cardiac MRI for various pathologies. All patients underwent cardiac MRI, and RT3DE and 64 slices CT were then performed on a subsequent day. The study population was then divided into 5 clinical groups depending on the underlying heart disease. RT3DE volumes correlated well with MRI values (R (2) values: 0.90 for EDV and 0.94 for ESV). RT3DE measurements of EF correlated well with MRI values (R (2) = 0.86). RT3DE measurements resulted in slightly underestimated values of both EDV and ESV, as reflected by biases of -9.18 and -4.50 mL, respectively. Comparison of RT3DE and MRI in various types of cardiomyopathies showed no statistical difference between different LV geometrical patterns. These results confirm that RT3DE has good accuracy in everyday clinical practice and can be of clinical utility in all types of cardiomyopathy independently of LV geometric pattern, LV diameter or wall thickness, taking into account a slight underestimation of LV volumes and EF compared to MRI.

  1. The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome

    PubMed Central

    Brown, I W; Peebles, C R; Harden, S P; Shambrook, J S

    2014-01-01

    The term “acute aortic syndrome” (AAS) encompasses several non-traumatic life-threatening pathologies of the thoracic aorta presenting in patients with a similar clinical profile. These include aortic dissection, intramural haematoma and penetrating atherosclerotic ulcers. These different pathological entities can be indistinguishable on clinical grounds alone and may be confused with other causes of chest pain, including myocardial infarction. Multidetector-row CT (MDCT) is the current modality of choice for imaging AAS with a sensitivity and specificity approaching 100%. Early diagnosis and accurate radiological classification is associated with improved clinical outcomes in AAS. We review the characteristic radiological features of the different pathologies that encompass AAS and highlight the vital role of MDCT in determining the management of these life-threatening conditions. PMID:25083552

  2. High Resolution Multi-Detector CT Aided Tissue Analysis and Quantification of Lung Fibrosis

    PubMed Central

    Zavaletta, Vanessa A.; Bartholmai, Brian J.; Robb, Richard A

    2009-01-01

    Rational and Objectives Volumetric high-resolution scans can be acquired of the lungs with multi-detector CT (MDCT). Such scans have potential to facilitate useful visualization, characterization, and quantification of the extent of diffuse lung diseases, such as Usual Interstitial Pneumonitis or Idiopathic Pulmonary Fibrosis (UIP/IPF). There is a need to objectify, standardize and improve the accuracy and repeatability of pulmonary disease characterization and quantification from such scans. This paper presents a novel texture analysis approach toward classification and quantification of various pathologies present in lungs with UIP/IPF. The approach integrates a texture matching method with histogram feature analysis. Materials and Methods Patients with moderate UIP/IPF were scanned on a Lightspeed 8-detector GE CT scanner (140kVp, 250mAs). Images were reconstructed with 1.25mm slice thickness in a high-frequency sparing algorithm (BONE) with 50% overlap and a 512 × 512 axial matrix, (0.625 mm3 voxels). Eighteen scans were used in this study. Each dataset is pre-processed which includes segmentation of the lungs and the broncho-vascular trees. Two types of analysis were performed, first an analysis of independent volume of interests (VOIs) and second an analysis of whole lung datasets. 1.) Fourteen of the eighteen scans were used to create a database of independent 15×15×15 cubic voxel VOIs. The VOIs were selected by experts as having greater than 70% of the defined class. The database was composed of the following: Honeycombing (# of VOIs 337), Reticular (130), Ground glass (148), Normal (240), and Emphysema (54). This database was used to develop our algorithm. Three progressively challenging classification experiments were designed to test our algorithm. All three experiments were performed using a 10-fold cross validation method for error estimation. Experiment 1 consisted of a two class discrimination: Normal and Abnormal. Experiment 2 consisted of a four

  3. Three-dimensional contrast-enhanced magnetic resonance venography for detection of renal vein thrombosis: comparison with multidetector CT venography.

    PubMed

    Zhang, Long Jiang; Wu, Xinsheng; Yang, Gui Fen; Tang, Chun Xiang; Luo, Song; Zhou, Chang Sheng; Ji, Xue Man; Lu, Guang Ming

    2013-12-01

    Renal vein thrombosis is not uncommon, however, there have been few reports on the diagnostic accuracy of three-dimensional contrast-enhanced magnetic resonance venography (3D-CE-MRV) in the detection of renal vein thrombosis (RVT). To evaluate the value of 3D-CE-MRV for detecting RVT with multidetector computed tomography (CT) venography as reference standard. Thirty-two patients with nephrotic syndrome underwent renal CT venography and gradient echo pulse sequence (FLASH 3D) 3D-CE-MRV in a clinical 3-T whole-body MR scanner for suspected RVT with time interval of 0-5 days. RVT was recorded on a per-patient and per-vessel (left renal vein, right renal vein, and inferior vena cava) basis. The diagnostic accuracy of 3D-CE-MRV for detection of RVT was calculated with CT venography as reference standard. Inter-reader agreement for RVT detection was evaluated using Kappa statistics. Of 32 patients, CT venography detected 22 vessels with thrombosis in 17 patients, including five in right renal veins, 14 in left renal veins, and three in inferior vena cava, while 15 patients had no RVT. 3D-CE-MRV detected 21 vessels (21/96, 21.9%) with thrombosis in 16 patients (6/32, 50%), including five in right renal veins, 13 in left renal veins, and three in inferior vena cava, while 16 patients (16/32, 50%) had no RVT. With CT venography as reference standard, the sensitivities and specificities of 3D-CE-MRV for RVT detection were 94.1%, 100%; 95.5%, 100% on a per-patient and a per-vessel basis, respectively. Excellent inter-reader agreement (Kappa value = 0.969, P < 0.001) was observed for RVT detection. 3D-CE-MRV has a high diagnostic accuracy in the detection of RVT, which is optimal alternative imaging modality in the detection of RVT.

  4. 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

  5. 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.

  6. Renal stone assessment with dual-energy multidetector CT and advanced postprocessing techniques: improved characterization of renal stone composition--pilot study.

    PubMed

    Boll, Daniel T; Patil, Neil A; Paulson, Erik K; Merkle, Elmar M; Simmons, W Neal; Pierre, Sean A; Preminger, Glenn M

    2009-03-01

    To prospectively evaluate the capability of noninvasive, simultaneous dual-energy (DE) multidetector computed tomography (CT) to improve characterization of human renal calculi in an anthropomorphic DE renal phantom by introducing advanced postprocessing techniques, with ex vivo renal stone spectroscopy as the reference standard. Fifty renal calculi were assessed: Thirty stones were of pure crystalline composition (uric acid, cystine, struvite, calcium oxalate, calcium phosphate, brushite), and 20 were of polycrystalline composition. DE CT was performed with a 64-detector CT unit. A postprocessing algorithm (DECT(Slope)) was proposed as a pixel-by-pixel approach to generate Digital Imaging and Communications in Medicine dataset gray-scale-encoding ratios of relative differences in attenuation values of low- and high-energy DE CT. Graphic analysis, in which clusters of equal composition were identified, was performed by sorting attenuation values of color composition-encoded calculi in an ascending sequence. Multivariate general linear model analysis was used to determine level of significance to differentiate composition on native and postprocessed DE CT images. Graphic analysis of native DE CT images was used to identify clusters for uric acid (453-629 HU for low-energy CT, 443-615 HU for high-energy CT), cystine (725-832 HU for low-energy CT, 513-747 HU for high-energy CT), and struvite (1337-1530 HU for low-energy CT, 1007-1100 HU for high-energy CT) stones; high-energy clusters showed attenuation value overlap. Polycrystalline calcium oxalate and calcium phosphate calculi were found throughout the entire spectrum, and dense brushite had attenuation values of more than 1500 HU for low-energy CT and more than 1100 HU for high-energy CT. The DE CT algorithm was used to generate specific identifiers for uric acid (77-80 U(Slope), one outlier), cystine (70-71 U(Slope)), struvite (56-60 U(Slope)), calcium oxalate and calcium phosphate (17-59 U(Slope)), and brushite

  7. Diagnostic capability of gadoxetate disodium-enhanced liver MRI for diagnosis of hepatocellular carcinoma: comparison with multi-detector CT.

    PubMed

    Toyota, Naoyuki; Nakamura, Yuko; Hieda, Masashi; Akiyama, Naoko; Terada, Hiroaki; Matsuura, Noriaki; Nishiki, Masayo; Kono, Hirotaka; Kohno, Hiroshi; Irei, Toshimitsu; Yoshikawa, Yukinobu; Kuraoka, Kazuya; Taniyama, Kiyomi; Awai, Kazuo

    2013-09-01

    The purpose of this study was to evaluate the diagnostic capability of gadoxetate disodium (Gd-EOB)-MRI for the detection of hepatocellular carcinoma (HCC) compared with multidetector CT (MDCT). Fifty patients with 57 surgically proven HCCs who underwent Gd-EOB-MRI and MDCT from March 2008 to June 2011 were evaluated. Two observers evaluated MR and CT on a lesion-by-lesion basis. We analyzed sensitivity by grading on a 5-point scale, the degree of arterial enhancement and the differences in histological grades in the diffusion-weighted images (DWI). The results showed that the sensitivity of Gd-EOB-MRI was higher than that of MDCT especially for HCCs that were 1 cm in diameter or smaller. The hepatobiliary phase was useful for the detecting of small HCC. We had few cases in which it was difficult to judge HCC in the arterial enhancement between MRI and MDCT. In the diffusion-weighted image, well differentiated HCC tended to show a low signal intensity, and poorly differentiated HCC tended to show a high signal intensity. In moderately differentiated HCC's, the mean diameter of the high signal intensity group was larger than that of the low signal intensity group (24.5 mm vs. 15.8 mm). In conclusion, Gd-EOB-MRI tended to show higher sensitivity compared to MDCT in the detection of HCC.

  8. 64-slice computed tomographic angiography for the diagnosis of intermediate risk coronary artery disease: an evidence-based analysis.

    PubMed

    2010-01-01

    In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities.After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html The objective of this report is to determine the accuracy of computed tomographic angiography (CTA) compared to the more invasive option of coronary angiography (CA) in the detection of coronary artery disease (CAD) in stable (non-emergent) symptomatic patients. CT ANGIOGRAPHY: CTA is a cardiac imaging test that assesses the presence or absence, as well as the extent, of coronary artery stenosis for the diagnosis of CAD. As such, it is a test of cardiac structure and

  9. Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: a meta-analysis.

    PubMed

    Carrabba, Nazario; Schuijf, Joanne D; de Graaf, Fleur R; Parodi, Guido; Maffei, Erica; Valenti, Renato; Palumbo, Alessandro; Weustink, Annick C; Mollet, Nico R; Accetta, Gabriele; Cademartiri, Filippo; Antoniucci, David; Bax, Jeroen J

    2010-06-01

    We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection. MEDLINE, Cochrane library, and BioMed Central database searches were performed until April 2009 for original articles. Inclusion criteria were (1) 64-MDCT was used as a diagnostic test for ISR, with >50% diameter stenosis selected as the cut-off criterion for significant ISR, using invasive coronary angiography and quantitative coronary angiography as the standard of reference; (2) absolute numbers of true positive, false positive, true negative, and false negative results could be derived. Standard meta-analytic methods were applied. Nine studies with a total of 598 patients with 978 stents included were considered eligible. On average, 9% of stents were unassessable (range 0-42%). Accuracy tests with 95% confidence intervals (CIs) comparing 64-MDCT vs invasive coronary angiography showed that pooled sensitivity, specificity, positive and negative likelihood ratio (random effect model) values were: 86% (95% CI 80-91%), 93% (95% CI 91-95%), 12.32 (95% CI 7.26-20.92), 0.18 (95% CI 0.12-0.28) for binary ISR detection. The symmetric area under the curve value was 0.94, indicating good agreement between 64-MDCT and invasive coronary angiography. 64-MDCT has a good diagnostic accuracy for ISR detection with a particularly high negative predictive value. However, still a relatively large proportion of stents remains uninterpretable. Accordingly, only in selected patients, 64-MDCT may serve as a potential alternative noninvasive method to rule out ISR.

  10. Use of an automatic exposure control mechanism for dose optimization in multi-detector row CT examinations: clinical evaluation.

    PubMed

    Mulkens, Tom H; Bellinck, Patrick; Baeyaert, Michel; Ghysen, Dirk; Van Dijck, Xavier; Mussen, Elvier; Venstermans, Caroline; Termote, Jean-Luc

    2005-10-01

    To prospectively compare dose reduction and image quality achieved with an automatic exposure control system that is based on both angular (x-y axis) and z-axis tube current modulation with dose reduction and image quality achieved with an angular modulation system for multi-detector row computed tomography (CT). The study protocol was approved by the institutional review board, and oral informed consent was obtained. In two groups of 200 patients, five anatomic regions (ie, the thorax, abdomen-pelvis, abdomen-liver, lumbar spine, and cervical spine) were examined with this modulation system and a six-section multi-detector row CT scanner. Data from these patients were compared with data from 200 patients who were examined with an angular modulation system. Dose reduction by means of reduction of the mean effective tube current in 600 examinations, image noise in 200 examinations performed with each modulation system, and subjective image quality scores in 100 examinations per-formed with each modulation system were compared with Wilcoxon signed rank tests. Mean dose reduction for the angular and z-axis tube current modulation system and for the angular modulation system was as follows: thorax, 20% and 14%, respectively; abdomen-liver, 38% and 18%, respectively; abdomen-pelvis, 32% and 26%, respectively; lumbar spine, 37% and 10%, respectively; and cervical spine, 68% and 16%, respectively. These differences were statistically significant (P < .05). There was no significant difference in image noise and mean image quality scores between modulation systems, with the exception of cervical spinal examinations (P < .001 for both), where the examinations with angular modulation resulted in better scores. There is good correlation between the mean effective tube current level and the body mass index of patients with the new modulation system. Correlation was as follows: thorax, 0.77; abdomen-pelvis, 0.83; abdomen-liver, 0.84; lumbar spine, 0.8; and cervical spine, 0

  11. Reduced image noise at low-dose multidetector CT of the abdomen with prior image constrained compressed sensing algorithm.

    PubMed

    Lubner, Meghan G; Pickhardt, Perry J; Tang, Jie; Chen, Guang-Hong

    2011-07-01

    standard FBP low-dose multidetector CT abdominal images results in substantial noise reduction and improved image quality.

  12. The radiological diagnosis of fenestral otosclerosis: the utility of histogram analysis using multidetector row CT.

    PubMed

    Yamashita, Koji; Yoshiura, Takashi; Hiwatashi, Akio; Togao, Osamu; Kikuchi, Kazufumi; Inoguchi, Takashi; Kumazawa, Seiji; Honda, Hiroshi

    2014-12-01

    Bone density measurements using high-resolution CT have been reported to be useful to diagnose fenestral otosclerosis. However, small region of interest (ROI) chosen by less-experienced radiologists may result in false-negative findings. Semi-automatic analysis such as CT histogram analysis may offer improved assessment. The aim of this study was to evaluate the utility of CT histogram analysis in diagnosing fenestral otosclerosis. Temporal bone CT of consecutive patients with otosclerosis and normal controls was retrospectively analyzed. The control group consisted of the normal-hearing contralateral ears of patients with otitis media, cholesteatoma, trauma, facial nerve palsy, or tinnitus. All CT images were obtained using a 64-detector-row CT scanner with 0.5-mm collimation. AROI encompassing 10 × 10 pixels was placed in the bony labyrinth located anterior to the oval window. The mean CT value, variance and entropy were compared between otosclerosis patients and normal controls using Student's t test. The number of pixels below mean minus SD in the control (%Lowcont) and total subjects (%Lowtotal) were also compared. In addition, the area under the receiver operating characteristic curves (AUC) value for the discrimination between otosclerosis patients and normal controls was calculated. 51 temporal bones of 38 patients with otosclerosis and 30 temporal bones of 30 control subjects were included. The mean CT value was significantly lower in otosclerosis cases than in normal controls (p < 0.01). In addition, variance, entropy, %Lowcont and %Lowtotal were significantly higher in otosclerosis cases than in normal controls (p < 0.01, respectively). The AUC values for the mean CT value, %Lowcont and %Lowtotal were 0.751, 0.760 and 0.765, respectively. In conclusion, our results demonstrated that histogram analysis of CT image may be of clinical value in diagnosing otosclerosis.

  13. Variants of the popliteal artery terminal branches as detected by multidetector ct angiography

    PubMed Central

    Oztekin, Pelin Seher; Ergun, Elif; Cıvgın, Esra; Yigit, Hasan; Kosar, Pınar Nercis

    2015-01-01

    Objective To evaluate variants of the popliteal artery (PA) terminal branches with 64-multidetector computed tomographic angiography (64-MD CTA). Materials and Methods A total of 495 extremities (251 right, 244 left) of 253 patients undergoing a 64-MD CTA examination were included in the study. Of these, 242 extremities were evaluated bilaterally, whereas 11 were evaluated unilaterally. The terminal branching pattern of the PA was classified according to the classification scheme proposed by Kim; the distance between the medial tibial plateau and the origin of the anterior tibial artery (A) and the length of the tibioperoneal trunk (B) have been measured and recorded. Results In 459 cases (92.7%) branching of PA occurred distal to the knee joint (Type I); in 18 cases (2.8%) PA branching was superior to the knee joint (Type II); and hypoplasia of the PA branches was found in 27 cases (5.5%) (Type III). Among these types the most frequent branching patterns were Type IA (87.5%), Type IIIA (3.9%), and Type IB (3.8%). The ranges of A and B mean distances were 47.6 mm and 29.6 mm, respectively Conclusion Variations in popliteal artery terminal branching pattern occurred in 7.4% to 17.6% of patients. Pre-surgical detection of these variations with MD CTA may help to reduce the risk of iatrogenic arterial injury by enabling a better surgical treatment plan. PMID:28352741

  14. 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.

  15. Ruling out coronary artery disease with noninvasive coronary multidetector CT angiography before noncoronary cardiovascular surgery.

    PubMed

    Catalán, Paz; Leta, Rubén; Hidalgo, Alberto; Montiel, José; Alomar, Xavier; Viladés, David; Barros, Antonio; Pujadas, Sandra; Carreras, Francesc; Padró, Josep M; Cinca, Juan; Pons-Lladó, Guillem

    2011-02-01

    To assess the usefulness of preoperative coronary computed tomographic (CT) angiography in the detection of coronary artery disease (CAD) in nonselected patients scheduled to undergo noncoronary cardiovascular surgery to avoid unnecessary invasive coronary angiography (ICA). The institutional review board approved the study protocol; informed consent was given. This prospective study involved 161 consecutive patients who underwent coronary calcium scoring and coronary CT angiography before undergoing noncoronary cardiovascular surgery. Seven patients were excluded because of contraindications to CT angiography. The major indication of noncoronary cardiovascular surgery was valvular heart disease (121 patients). Follow-up was performed at a median of 20 months to define ischemic events described as acute coronary syndrome or death secondary to acute coronary syndrome, arrhythmias, or cardiac failure. Multivariate analysis was performed to determine predictors of nondiagnostic coronary CT angiography. Kaplan-Meier analysis was performed to evaluate outcome at follow-up. Twenty-one patients did not undergo surgery, which left 133 patients as the study group. Atrial fibrillation was present in 45 of 133 patients. The interquartile range of the Agatston coronary calcium score was 0-471. Coronary CT angiography was diagnostic in 108 of 133 patients. Of these, 93 of 108 had no significant CAD (≤ 50% stenosis), and noncoronary cardiovascular surgery was performed in them without preoperative ICA. No patients in this group had postoperative ischemic events at follow-up. Coronary CT angiography was nondiagnostic in 25 of 133 patients who were referred for preoperative ICA. Multivariate analysis showed Agatston score to be the only independent predictor of nondiagnostic coronary CT angiography (odds ratio = 1.002; 95% confidence interval: 1.001, 1.003; P = .001). The best Agatston score cutoff for diagnostic coronary CT angiography was 579. In nonselected patients scheduled

  16. 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

  17. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels.

    PubMed

    Gao, Feng; Li, Ming; Ge, Xiaojun; Zheng, Xiangpeng; Ren, Qingguo; Chen, Yan; Lv, Fangzhen; Hua, Yanqing

    2013-12-01

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant.

  18. Volume Changes of Experimental Carotid Sidewall Aneurysms Due to Embolization with Liquid Embolic Agents: A Multidetector CT Angiography Study

    SciTech Connect

    Dudeck, O. Okuducu, A. F.; Jordan, O.; Tesmer, K.; Pech, M.; Weigang, E.; Ruefenacht, D. A.; Doelker, E.; Felix, R.

    2006-12-15

    Iodine-containing polyvinyl alcohol polymer (I-PVAL) is a novel precipitating liquid embolic that allows for artifact-free evaluation of CT angiography (CTA). As accurate aneurysm volumetry can be performed with multidetector CTA, we determined volumes of experimental aneurysms before, immediately after, and 4 weeks after embolization of 14 porcine experimental carotid sidewall aneurysms with this liquid embolic. An automated three-dimensional software measurement tool was used for volumetric analysis of volume-rendering CTA data. Furthermore, intra-aneurysmal pressure changes during liquid embolization were measured in four silicone aneurysms and potential polymer volume changes within 4 weeks were assessed in vitro. Liquid embolic injection was performed during temporary balloon occlusion of the aneurysm neck, resulting in a mean occlusion rate of 98.3%. Aneurysms enlarged significantly during embolization by 61.1 {+-} 28.9%, whereas a significant shrinkage of 5.6 {+-} 2.7% was observed within the follow-up period. Histologic analysis revealed an inflammatory foreign body reaction with partial polymer degradation. In silicone aneurysm models, intra-aneurysmal pressure remained unchanged during liquid embolic injection, whereas balloon inflation resulted in a mean pressure increase of 31.2 {+-} 0.7%. No polymer shrinkage was observed in vitro. The aneurysm enlargement noted was presumably due to pressure elevation after balloon inflation, which resulted in dilatation of the weak venous wall of the newly constructed aneurysm-another shortcoming of this experimental aneurysm model. The volume decrease after 4 weeks expressed partial polymer degradation.

  19. Can multidetector CT detect the site of gastrointestinal tract injury in trauma? – A retrospective study

    PubMed Central

    Panda, Ananya; Kumar, Atin; Gamanagatti, Shivanand; Das, Ranjita; Paliwal, Swati; Gupta, Amit; Kumar, Subodh

    2017-01-01

    PURPOSE We aimed to assess the performance of computed tomography (CT) in localizing site of traumatic gastrointestinal tract (GIT) injury and determine the diagnostic value of CT signs in site localization. METHODS CT scans of 97 patients with surgically proven GIT or mesenteric injuries were retrospectively reviewed by radiologists blinded to surgical findings. Diagnosis of either GIT or mesenteric injuries was made. In patients with GIT injuries, site of injury and presence of CT signs such as focal bowel wall hyperenhancement, hypoenhancement, wall discontinuity, wall thickening, extramural air, intramural air, perivisceral infiltration, and active vascular contrast leak were evaluated. RESULTS Out of 97 patients, 90 had GIT injuries (70 single site injuries and 20 multiple site injuries) and seven had isolated mesenteric injury. The overall concordance between CT and operative findings for exact site localization was 67.8% (61/90), partial concordance rate was 11.1% (10/90), and discordance rate was 21.1% (19/90). For single site localization, concordance rate was 77.1% (54/70), discordance rate was 21.4% (15/70), and partial concordance rate was 1.4% (1/70). In multiple site injury, concordance rate for all sites of injury was 35% (7/20), partial concordance rate was 45% (9/20), and discordance rate was 20% (4/20). For upper GIT injuries, wall discontinuity was the most accurate sign for localization. For small bowel injury, intramural air and hyperenhancement were the most specific signs for site localization, while for large bowel injury, wall discontinuity and hypoenhancement were the most specific signs. CONCLUSION CT performs better in diagnosing small bowel injury compared with large bowel injury. CT can well predict the presence of multiple site injury but has limited performance in exact localization of all injury sites. PMID:27924777

  20. Clinical applications of the superior epigastric artery perforator (SEAP) flap: anatomical studies and preoperative perforator mapping with multidetector CT.

    PubMed

    Hamdi, Moustapha; Van Landuyt, Koenraad; Ulens, Sara; Van Hedent, Eddy; Roche, Nathalie; Monstrey, Stan

    2009-09-01

    Pedicled superior epigastric artery perforator (SEAP) flaps can be raised to cover challenging thoracic defects. We present an anatomical study based on multidetector computerized tomography (MDCT) scan findings of the SEA perforators in addition to the first reported clinical series of SEAP flaps in anterior chest wall reconstruction. (a) In the CT scan study, images of a group of 20 patients who underwent MDCT scan analysis were used to visualise bilaterally the location of musculocutaneous SEAP. X- and Y-axes were used as landmarks to localise the perforators. The X-axis is a horizontal line at the junction of sternum and xyphoid (JCX) and the Y-axis is at the midline. (b) In the clinical study, seven pedicled SEAP flaps were performed in another group of patients. MDCT images revealed totally 157 perforators with a mean of 7.85 perforators per patient. The dominant perforators (137 perforators) were mainly localised in an area between 1.5 and 6.5 cm from the X-axis on both sides and between 3 and 16 cm below the Y-axis. The calibre of these dominant perforators was judged as 'good' to 'very good' in 82.5% of the cases. The average dimension of the flap was 21.7x6.7 cm. All flaps were based on one perforator. Mean harvesting time was 110 min. There were no flap losses. Minor tip necrosis occurred in two flaps. One of them was treated with excision and primary closure. Our clinical experience indicates that the SEAP flap provides a novel and useful approach for reconstruction of anterior chest wall defects. CT-based imaging allows for anatomical assessment of the perforators of the superior epigastric artery (SEA).

  1. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan

    PubMed Central

    Lin, Chung-Jung; Mok, Greta S. P.; Tsai, Mang-Fen; Tsai, Wei-Ta; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin

    2015-01-01

    Introduction The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database. Materials and Methods Taiwan’s Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A); multi-detector CT (MDCT) with 2-64 slices (Group B); and MDCT with more than 64 slices (Group C). Correlations between computed tomography dose index (CTDI) and signal-to-noise ratio (SNR) with cumulated tube rotation number (CTW(n)) and cumulated tube rotation time (CTW(s)), and sub group analyses of CTDI and SNR across the three groups were performed. Results CTDI values demonstrated a weak correlation (r = 0.33) with CTW(n) in Group A. SNR values demonstrated a weak negative correlation (r = -0.46) with CTW(n) in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C. Conclusion CTW(n) and CTW(s) did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices. PMID:26125549

  2. Multidetector and three-dimensional CT evaluation of the patient with maxillofacial injury.

    PubMed

    Avery, Laura L; Susarla, Srinivas M; Novelline, Robert A

    2011-01-01

    Interpretation of images associated with the traumatically injured face is challenging. The complexity of facial anatomy, coupled with the superimposition of numerous bony structures on plain radiographs, poses specific obstacles to accurate interpretation of facial injury. Although plain radiographs can be helpful in cases of isolated injuries, CT is the most useful modality for evaluating facial injury. This article reviews facial anatomy as it pertains to traumatic injury, emphasizes the clinical findings associated with various types of facial injury, and simplifies the diagnosis of facial injury on CT. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. A retrospective comparison of smart prep and test bolus multi-detector CT pulmonary angiography protocols

    SciTech Connect

    Suckling, Tara; Smith, Tony; Reed, Warren

    2013-06-15

    Optimal arterial opacification is crucial in imaging the pulmonary arteries using computed tomography (CT). This poses the challenge of precisely timing data acquisition to coincide with the transit of the contrast bolus through the pulmonary vasculature. The aim of this quality assurance exercise was to investigate if a change in CT pulmonary angiography (CTPA) scanning protocol resulted in improved opacification of the pulmonary arteries. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. A total of 160 CTPA examinations (80 using each protocol) performed between January 2010 and February 2011 were assessed retrospectively. CT attenuation coefficients were measured in Hounsfield Units (HU) using regions of interest at the level of the pulmonary trunk. The average pixel value, standard deviation (SD), maximum, and minimum were recorded. For each of these variables a mean value was then calculated and compared for these two CTPA protocols. Minimum opacification of 200 HU was achieved in 98% of the TBP sample but only 90% of the SPP sample. The average CT attenuation over the pulmonary trunk for the SPP was 329 (SD = ±21) HU, whereas for the TBP it was 396 (SD = ±22) HU (P = 0.0017). The TBP also recorded higher maximum (P = 0.0024) and minimum (P = 0.0039) levels of opacification. This study has found that a TBP resulted in significantly better opacification of the pulmonary trunk than the SPP.

  4. Update on multidetector coronary CT angiography of coronary stents: in vitro evaluation of 29 different stent types with dual-source CT.

    PubMed

    Maintz, David; Burg, Matthias C; Seifarth, Harald; Bunck, Alexander C; Ozgün, Murat; Fischbach, Roman; Jürgens, Kai Uwe; Heindel, Walter

    2009-01-01

    The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70 HU). Stents were imaged in axial orientation with standard parameters: 32 x 0.6 collimation, pitch 0.24, 400 mAs, 120 kV, rotation time 0.33 s. Image reconstructions were obtained with four different convolution kernels (soft, medium-soft, standard high-resolution, stent-dedicated). To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density, and noise were measured. The stent-dedicated kernel offered best average lumen visualization (54 +/- 8.3%) and most realistic lumen attenuation (222 +/- 44 HU) at the expense of increased noise (23.9 +/- 1.9 HU) compared with standard CTA protocols (p < 0.001 for all). The magnesium stent showed the least artifacts with a lumen visibility of 90%. The majority of stents (79%) exhibited a lumen visibility of 50-59%. Less than half of the stent lumen was visible in only six stents. Stent lumen visibility largely varies depending on the stent type. Magnesium is by far more favorable a stent material with regard to CT imaging when compared with the more common materials steel, cobalt-chromium, or tantalum. The magnesium stent exhibits a lumen visibility of 90%, whereas the majority of the other stents exhibit a lumen visibility of 50-59%.

  5. Characterization of Pulmonary Vein Dimensions Using High-Definition 64-Slice Computed Tomography prior to Radiofrequency Catheter Ablation for Atrial Fibrillation.

    PubMed

    Gebhard, Catherine; Krasniqi, Nazmi; Stähli, Barbara E; Klaeser, Bernd; Fuchs, Tobias A; Ghadri, Jelena R; Haegeli, Laurent; Lüscher, Thomas F; Kaufmann, Philipp A; Duru, Firat

    2014-01-01

    Background. Contrast-enhanced computed tomography is commonly acquired before radiofrequency catheter ablation (RFCA) for atrial fibrillation (AFib) to guide the procedure. We analyzed pulmonary vein (PV) ostial diameter and volumes on a high-definition 64-slice CT (HDCT) scanner in patients with AFib prior to RFCA. Methods and Results. This retrospective study included 50 patients (mean age 60.2 ± 11.4 years, 30 males) undergoing cardiac HDCT scanning before RFCA for drug refractory AFib and 50 age-, BMI-, and sex-matched controls with normal sinus rhythm undergoing HDCT. PV ostial diameter and volume were measured and calculated using a semiautomatic calliper tool. Total ostial PV volume was significantly increased in patients with AFib as compared to controls (P < 0.005). Similarly, total ostial PV diameter was significantly increased in AFib compared to controls (P < 0.001). In AFib, the largest PV volume and diameters were measured in right superior PV (P < 0.05 versus controls). The difference in PV volume between patients and controls was most pronounced in right superior PVs (P = 0.015). Right middle PVs were found more often in patients with AFib (16/50; 32%) than in normal subjects (7/50; 14%). Conclusion. Enlargement of PV ostial area and enlargement of volume are frequent findings in patients with drug refractory AFib. These parameters may add to the risk stratification for AFib recurrence following RFCA.

  6. Automated characterization of normal and pathologic lung tissue by topological texture analysis of multidetector CT

    NASA Astrophysics Data System (ADS)

    Boehm, H. F.; Fink, C.; Becker, C.; Reiser, M.

    2007-03-01

    Reliable and accurate methods for objective quantitative assessment of parenchymal alterations in the lung are necessary for diagnosis, treatment and follow-up of pulmonary diseases. Two major types of alterations are pulmonary emphysema and fibrosis, emphysema being characterized by abnormal enlargement of the air spaces distal to the terminal, nonrespiratory bronchiole, accompanied by destructive changes of the alveolar walls. The main characteristic of fibrosis is coursening of the interstitial fibers and compaction of the pulmonary tissue. With the ability to display anatomy free from superimposing structures and greater visual clarity, Multi-Detector-CT has shown to be more sensitive than the chest radiograph in identifying alterations of lung parenchyma. In automated evaluation of pulmonary CT-scans, quantitative image processing techniques are applied for objective evaluation of the data. A number of methods have been proposed in the past, most of which utilize simple densitometric tissue features based on the mean X-ray attenuation coefficients expressed in terms of Hounsfield Units [HU]. Due to partial volume effects, most of the density-based methodologies tend to fail, namely in cases, where emphysema and fibrosis occur within narrow spatial limits. In this study, we propose a methodology based upon the topological assessment of graylevel distribution in the 3D image data of lung tissue which provides a way of improving quantitative CT evaluation. Results are compared to the more established density-based methods.

  7. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution: a cardiac phantom study.

    PubMed

    Greuter, M J W; Groen, J M; Nicolai, L J; Dijkstra, H; Oudkerk, M

    2009-11-01

    The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative method which corrects for the influences of these parameters using a linear moving cardiac phantom. On a robotic arm with artificial arteries with four calcifications of increasing density, a linear movement was applied between 0 and 120 mm/s (step of 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT, and EBT using a standard acquisition protocol. The average Agatston, volume, and mass scores were determined for each velocity, calcification, and scanner. Susceptibility to motion was quantified using a cardiac motion susceptibility (CMS) index. Resemblance to EBT and physical volume and mass was quantified using a Delta index. Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The calcium score showed a linear dependency on motion from which a correction factor could be derived. This correction factor showed a linear dependency on the mean calcification density with a good fit for all three scoring methods and all three scanners (0.73 < or = R2 < or = 0.95). The slope and offset of this correction factor showed a linear dependency on temporal resolution with a good fit for all three scoring methods and all three scanners (0.83 < or = R2 < or = 0.98). CMS was minimal for EBT and increasing values were observed for DSCT and highest values for 64-slice MDCT. CMS was minimal for mass score and increasing values were observed for volume score and highest values for Agatston score. For all densities and scoring methods DSCT showed on average the closest resemblance to EBT calcium scores. When using the correction factor, CMS index decreased on average by 15% and Delta index

  8. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution: A cardiac phantom study

    SciTech Connect

    Greuter, M. J. W.; Groen, J. M.; Nicolai, L. J.; Dijkstra, H.; Oudkerk, M.

    2009-11-15

    Purpose: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative method which corrects for the influences of these parameters using a linear moving cardiac phantom. Methods: On a robotic arm with artificial arteries with four calcifications of increasing density, a linear movement was applied between 0 and 120 mm/s (step of 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT, and EBT using a standard acquisition protocol. The average Agatston, volume, and mass scores were determined for each velocity, calcification, and scanner. Susceptibility to motion was quantified using a cardiac motion susceptibility (CMS) index. Resemblance to EBT and physical volume and mass was quantified using a {Delta} index. Results: Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The calcium score showed a linear dependency on motion from which a correction factor could be derived. This correction factor showed a linear dependency on the mean calcification density with a good fit for all three scoring methods and all three scanners (0.73{<=}R{sup 2}{<=}0.95). The slope and offset of this correction factor showed a linear dependency on temporal resolution with a good fit for all three scoring methods and all three scanners (0.83{<=}R{sup 2}{<=}0.98). CMS was minimal for EBT and increasing values were observed for DSCT and highest values for 64-slice MDCT. CMS was minimal for mass score and increasing values were observed for volume score and highest values for Agatston score. For all densities and scoring methods DSCT showed on average the closest resemblance to EBT calcium scores. When using the correction factor, CMS index decreased on average by

  9. [Comparison of a dental cone beam CT with a multi-detector row CT on effective doses and physical image quality].

    PubMed

    Yoshida, Yutaka; Tokumori, Kenji; Okamura, Kazutoshi; Yoshiura, Kazunori

    2011-01-01

    The purpose of this study was to compare a dental cone beam computed tomography (dental CBCT) and a multi-detector row CT (MDCT) using effective doses and physical image quality. A dental mode (D-mode) and an implant mode (I-mode) were employed for calculating effective doses. Field of view (FOV) size of the MDCT was 150 mm. Three types of images were obtained using 3 different reconstruction functions: FC1 (for abdomen images), FC30 (for internal ear and bone images) and FC81 (for high resolution images). Effective doses obtained with the D-mode and with the I-mode were about 20% and 50% of those obtained with the MDCT, respectively. Resolution properties obtained with the D-mode and I-mode were superior to that of the MDCT in a high frequency range. Noise properties of the D-mode and the I-mode were better than those with FC81. It was found that the dental CBCT has better potential as compared with MDCT in both dental and implant modes.

  10. A comparison of the use of contrast media with different iodine concentrations for multidetector CT of the kidney.

    PubMed

    Jung, Seung Chai; Kim, Seung Hyup; Cho, Jeong Yeon

    2011-01-01

    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. 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. 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). 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.

  11. 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

  12. Split-Bolus Single-Pass Multidetector-Row CT Protocol for Diagnosis of Acute Pulmonary Embolism

    PubMed Central

    Scialpi, Michele; Rebonato, Alberto; Cagini, Lucio; Brunese, Luca; Piscioli, Irene; Pierotti, Luisa; Bellantonio, Lucio; D’Andrea, Alfredo; Rotondo, Antonio

    2016-01-01

    Background: Currently computed tomography pulmonary angiography (CTPA) has become a widely accepted clinical tool in the diagnosis of acute pulmonary embolism (PE). Objectives: To report split-bolus single-pass 64-multidetector-row CT (MDCT) protocol for diagnosis of PE. Patients and Methods: MDCT split-bolus results in 40 patients suspicious of PE were analyzed in terms of image quality of target pulmonary vessels (TPVs) and occurrence and severity of flow-related artifact, flow-related artifact, false filling defect of the pulmonary veins and beam hardening streak artifacts. Dose radiation to patients was calculated. Results: MDCT split-bolus protocol allowed diagnostic images of high quality in all cases. Diagnosis of PE was obtained in 22 of 40 patients. Mean attenuation for target vessels was higher than 250 HU all cases: 361 ± 98 HU in pulmonary artery trunk (PAT); 339 ± 93 HU in right pulmonary artery (RPA); 334 ± 100 HU in left pulmonary artery (LPA). Adequate enhancement was obtained in the right atrium (RA):292 ± 83 HU; right pulmonary vein (RPV): 302 ± 91 HU, and left pulmonary vein (LPV): 291 ± 83 HU. The flow related artifacts and the beam hardening streak artifacts have been detected respectively in 4 and 25 patients. No false filling defect of the pulmonary veins was revealed. Conclusion: MDCT split-bolus technique by simultaneous opacification of pulmonary arteries and veins represents an accurate technique for diagnosis of acute PE, removes the false filling defects of the pulmonary veins, and reduces flow related artifacts. PMID:27110334

  13. Voxel-Based Sensitivity of Flat-Panel CT for the Detection of Intracranial Hemorrhage: Comparison to Multi-Detector CT

    PubMed Central

    Frölich, Andreas M.; Buhk, Jan-Hendrik; Fiehler, Jens; Kemmling, Andre

    2016-01-01

    Objectives Flat-panel CT (FPCT) allows cross-sectional parenchymal, vascular and perfusion imaging within the angiography suite, which could greatly facilitate acute stroke management. We hypothesized that FPCT offers equal diagnostic accuracy compared to multi-detector CT (MDCT) as a primary tool to exclude intracranial hemorrhage. Methods 22 patients with intracranial hematomas who had both MDCT and FPCT performed within 24 hours were retrospectively identified. Patients with visible change in hematoma size or configuration were excluded. Two raters independently segmented hemorrhagic lesions. Data sets and corresponding binary lesion maps were co-registered to compare hematoma volume. Diagnostic accuracy of FPCT to detect hemorrhage was calculated from voxel-wise analysis of lesion overlap compared to reference MDCT. Results Mean hematoma size was similar between MDCT (16.2±8.9 ml) and FPCT (16.1±8.6 ml), with near perfect correlation of hematoma sizes between modalities (ρ = 0.95, p<0.001). Sensitivity and specificity of FPCT to detect hemorrhagic voxels was 61.6% and 99.8% for intraventricular hematomas and 67.7% and 99.5% for all other intracranial hematomas. Conclusions In this small sample containing predominantly cases with subarachnoid hemorrhage, FPCT based assessment of hemorrhagic volume in brain yields acceptable accuracy compared to reference MDCT, albeit with a limited sensitivity on a voxel level. Further assessment and improvement of FPCT is necessary before it can be applied as a primary imaging modality to exclude intracranial hemorrhage in acute stroke patients. PMID:27806106

  14. Crossed Fused Renal Ectopia: Presentations on 99mTc-MAG3 Scan, 99mTc-DMSA SPECT, and Multidetector CT.

    PubMed

    Moon, Eun Ha; Kim, Min-Woo; Kim, Young Jun; Sun, In O

    2015-10-01

    Crossed renal ectopia is an uncommon developmental anomaly in which both kidneys are located on the same side of the body. The present case describes a 20-year-old man who underwent the military entrance physical examination. The ultrasound showed the right kidney in normal site with slightly increased size, but the left kidney was not identified. Tc-MAG3 scan showed a single kidney with 2 ureters, and the orifices of the ureters were connected at both sides of bladder. Tc-DMSA SPECT and contrast-enhanced multidetector CT were performed and revealed crossed fused renal ectopia.

  15. Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

    PubMed

    Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

    2016-04-01

    To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the

  16. Computerized assessment of motion-contaminated calcified plaques in cardiac multidetector CT

    SciTech Connect

    King, Martin; Giger, Maryellen L.; Suzuki, Kenji; Bardo, Dianna M. E.; Greenberg, Brent; Lan Li; Pan Xiaochuan

    2007-12-15

    An automated method for evaluating the image quality of calcified plaques with respect to motion artifacts in noncontrast-enhanced cardiac computed tomography (CT) images is introduced. This method involves using linear regression (LR) and artificial neural network (ANN) regression models for predicting two patient-specific, region-of-interest-specific, reconstruction-specific and temporal phase-specific image quality indices. The first is a plaque motion index, which is derived from the actual trajectory of the calcified plaque and is represented on a continuous scale. The second is an assessability index, which reflects the degree to which a calcified plaque is affected by motion artifacts, and is represented on an ordinal five-point scale. Two sets of assessability indices were provided independently by two radiologists experienced in evaluating cardiac CT images. Inputs for the regression models were selected from 12 features characterizing the dynamic, morphological, and intensity-based properties of the calcified plaques. Whereas LR-velocity (LR-V) used only a single feature (three-dimensional velocity), the LR-multiple (LR-M) and ANN regression models used the same subset of these 12 features selected through stepwise regression. The regression models were parameterized and evaluated using a database of simulated calcified plaque images from the dynamic NCAT phantom involving nine heart rate/multi-sector gating combinations and 40 cardiac phases covering two cardiac cycles. Six calcified plaques were used for the plaque motion indices and three calcified plaques were used for both sets of assessability indices. In one configuration, images from the second cardiac cycle were used for feature selection and regression model parameterization, whereas images from the first cardiac cycle were used for testing. With this configuration, repeated measures concordance correlation coefficients (CCCs) and associated 95% confidence intervals for the LR-V, LR-M, and ANN

  17. Comparison of multidetector CT and endoscopic ultrasonography in malignant pancreatic mass lesions.

    PubMed

    Arabul, Mahmut; Karakus, Funda; Alper, Emrah; Kandemir, Altay; Celik, Mustafa; Karakus, Volkan; Yucel, Kamil; Unsal, Belkis

    2012-01-01

    Endoscopic ultrasonography (EUS) has been shown to be superior to conventional CT in detecting and staging pancreatic cancer. We conducted a prospective trial to compare EUS and MDCT, in discriminating benign/malignant, in determining local and vascular invasion of a suspected pancreatic cancer and deciding its resectability. The study was performed at the Gastroenterology Department of Izmir Ataturk Training and Research Hospital, from June 2009 to June 2010, all patients with suspected pancreatic and periampullary tumors referred to our department were enrolled. A total of 56 patients were evaluated at the beginning. Five patients having distal CBD tumor (n=2), gallbladder tumor (n=1) and papillary tumor (n=2) were excluded from the study. Analysis was done for the remaining 51 patients. For the diagnosis of resectability/unresectability, EUS alone demonstrated a definite role in 4 (9%) of the 43 patients in confirming surgical and pathologic results and MDCT alone demonstrated a definite role in 6 (14%) of the 43 patients in confirming their results. An accurate diagnostic decision regarding resectability/unresectability was accomplished in 27 (63%) patients with EUS and MDCT. While MDCT is clinically quite effective, in terms of a correct resectability/unresectability decision, EUS should also be used.

  18. Improving Image Quality of On-Board Cone-Beam CT in Radiation Therapy Using Image Information Provided by Planning Multi-Detector CT: A Phantom Study

    PubMed Central

    Yang, Ching-Ching; Chen, Fong-Lin; Lo, Yeh-Chi

    2016-01-01

    Purpose The aim of this study was to improve the image quality of cone-beam computed tomography (CBCT) mounted on the gantry of a linear accelerator used in radiation therapy based on the image information provided by planning multi-detector CT (MDCT). Methods MDCT-based shading correction for CBCT and virtual monochromatic CT (VMCT) synthesized using the dual-energy method were performed. In VMCT, the high-energy data were obtained from CBCT, while the low-energy data were obtained from MDCT. An electron density phantom was used to investigate the efficacy of shading correction and VMCT on improving the target detectability, Hounsfield unit (HU) accuracy and variation, which were quantified by calculating the contrast-to-noise ratio (CNR), the percent difference (%Diff) and the standard deviation of the CT numbers for tissue equivalent background material, respectively. Treatment plan studies for a chest phantom were conducted to investigate the effects of image quality improvement on dose planning. Results For the electron density phantom, the mean value of CNR was 17.84, 26.78 and 34.31 in CBCT, shading-corrected CBCT and VMCT, respectively. The mean value of %Diff was 152.67%, 11.93% and 7.66% in CBCT, shading-corrected CBCT and VMCT, respectively. The standard deviation within a uniform background of CBCT, shading-corrected CBCT and VMCT was 85, 23 and 15 HU, respectively. With regards to the chest phantom, the monitor unit (MU) difference between the treatment plan calculated using MDCT and those based on CBCT, shading corrected CBCT and VMCT was 6.32%, 1.05% and 0.94%, respectively. Conclusions Enhancement of image quality in on-board CBCT can contribute to daily patient setup and adaptive dose delivery, thus enabling higher confidence in patient treatment accuracy in radiation therapy. Based on our results, VMCT has the highest image quality, followed by the shading corrected CBCT and the original CBCT. The research results presented in this study should be

  19. Multi-detector row CT of the left atrium and pulmonary veins before radio-frequency catheter ablation for atrial fibrillation.

    PubMed

    Lacomis, Joan M; Wigginton, William; Fuhrman, Carl; Schwartzman, David; Armfield, Derek R; Pealer, Karen M

    2003-10-01

    Radio-frequency catheter ablation (RFCA) of the distal pulmonary veins and posterior left atrium is increasingly being used to treat recurrent or refractory atrial fibrillation that resists pharmacologic therapy or cardioversion. Successful RFCA of atrial fibrillation requires resolution of abnormal rhythms while minimizing complications and can be achieved with precise, preprocedural, three-dimensional (3D) anatomic delineation of the target, the atriopulmonary venous junction. Three-dimensional multi-detector row computed tomography (CT) of the pulmonary veins and left atrium provides the necessary anatomic information for successful RFCA, including (a) the number, location, and angulation of pulmonary veins and their ostial branches unobscured by adjacent cardiac and vascular anatomy, and (b) left atrial volume. The 3D multi-detector row CT scanning and postprocessing techniques used for pre-RFCA planning are straightforward. Radiologists must not only understand these techniques but must also be familiar with atrial fibrillation and the technical considerations and complications associated with RFCA of this condition. In addition, radiologists must be familiar with anatomic variants of the left atrium and distal pulmonary veins and understand the importance of these variants to the referring cardiac interventional electrophysiologist. Copyright RSNA, 2003

  20. Automatic exposure control in pediatric and adult multidetector CT examinations: A phantom study on dose reduction and image quality

    SciTech Connect

    Papadakis, Antonios E.; Perisinakis, Kostas; Damilakis, John

    2008-10-15

    The aim of this study was to assess the potential of a modern x,y,z modulation-based automatic exposure control system (AEC) for dose reduction in pediatric and adult multidetector CT (MDCT) imaging and evaluate the quality of the images obtained. Five physical anthropomorphic phantoms that simulate the average individual as neonate, 1-, 5-, 10-year old child, and adult were scanned with a MDCT scanner, equipped with a modern AEC system. Dose reduction (%DR) was calculated as the percentage difference of the mean modulated and the preset tube current-time product that is prescribed for standard head and body scan protocols. The effect of the tube potential and the orientation of the topogram acquisition on dose reduction were assessed. Image quality was evaluated on the basis of image noise and signal to noise ratio (SNR). The dose reduction values achieved in pediatric phantoms were remarkably lower than those achieved for the adult. The efficiency of the AEC is decreased at 80 kVp compared to higher tube potentials and for helical scans following an anterior posterior (AP-AEC) compared to a lateral (LAT-AEC) topogram acquisition. In AP-AEC scans, the dose reduction ranged between 4.7 and 34.7% for neonate, 15.4 and 30.9% for 1 year old, 3.1 and 26.7% for 5 years old, 1.2 and 58.7% for 10 years old, and 15.5 and 57.4% for adult. In LAT-AEC scans, the corresponding dose reduction ranged between 11.0 and 36.5%, 27.2 and 35.7%, 11.3 and 35.6%, 0.3 and 67.0%, and 15.0 and 61.7%, respectively. AP-AEC scans resulted in a 17.1% and 19.7% dose increase in the thorax of neonate and the pelvis of the 10-year old phantom, respectively. The variation in the measured noise among images obtained along the scanning z axis was lower in AEC activated compared to fixed milliamperes scans. However, image noise was significantly increased (P<.001) and SNR significantly decreased (P<.001) in most AEC activated compared to fixed milliamperes scans. In conclusion, AEC resulted in a (i

  1. 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.

  2. Safe cervical spine clearance in adult obtunded blunt trauma patients on the basis of a normal multidetector CT scan--a meta-analysis and cohort study.

    PubMed

    Raza, Mushahid; Elkhodair, Samer; Zaheer, Asif; Yousaf, Sohail

    2013-11-01

    A true gold standard to rule out a significant cervical spine injury in subset of blunt trauma patients with altered sensorium is still to be agreed upon. The objective of this study is to determine whether in obtunded adult patients with blunt trauma, a clinically significant injury to the cervical spine be ruled out on the basis of a normal multidetector cervical spine computed tomography. Comprehensive database search was conducted to include all the prospective and retrospective studies on blunt trauma patients with altered sensorium undergoing cervical spine multidetector CT scan as core imaging modality to "clear" the cervical spine. The studies used two main gold standards, magnetic resonance imaging of the cervical spine and/or prolonged clinical follow-up. The data was extracted to report true positive, true negatives, false positives and false negatives. Meta-analysis of sensitivity, specificity, negative and positive predictive values was performed using Meta Analyst Beta 3.13 software. We also performed a retrospective investigation comparing a robust clinical follow-up and/or cervical spine MR findings in 53 obtunded blunt trauma patients, who previously had undergone a normal multidetector CT scan of the cervical spine reported by a radiologist. A total of 10 studies involving 1850 obtunded blunt trauma patients with initial cervical spine CT scan reported as normal were included in the final meta-analysis. The cumulative negative predictive value and specificity of cervical spine CT of the ten studies was 99.7% (99.4-99.9%, 95% confidence interval). The positive predictive value and sensitivity was 93.7% (84.0-97.7%, 95% confidence interval). In the retrospective review of our obtunded blunt trauma patients, none was later diagnosed to have significant cervical spine injury that required a change in clinical management. In a blunt trauma patient with altered sensorium, a normal cervical spine CT scan is conclusive to safely rule out a clinically

  3. The role of 64-slice CT following perfusion with iohexol via the hepatopancreatic ampulla in assessing pancreaticobiliary junctions.

    PubMed

    Guo, Wan-Liang; Bai, Xue-Jie; Huang, Shun-Gen; Fang, Lin; Wang, Jian

    2015-07-01

    The aim of this study was to delineate the structure of the pancreatic and biliary ducts in premature infants using a novel imaging method. The duodenal papillae of 30 premature infant cadavers were dissected. The pancreatic and biliary ducts were visualized using 64-detector multislice spiral computed tomography (MSCT). Contrast agent was injected into the duodenal papilla via the hepatopancreatic ampulla of Vater. MSCT scanning revealed both the pancreatic and biliary ducts as well as the common channel in 18 cases. The bile duct was visualized in the remaining 12 cases. Four patterns of the pancreaticobiliary ductal junction were noted: Y-type (73.3%), U-type (13.3%), V-type (6.7%), and II-type (6.7%). The results showed that MSCT and three-dimensional reconstruction can be used to visualize the junction pattern and common channel of the pancreatic and biliary ducts, and the structure of the surrounding tissue, in premature infants.

  4. 64 slice-coronary computed tomography sensitivity and specificity in the evaluation of coronary artery bypass graft stenosis: A meta-analysis.

    PubMed

    Barbero, Umberto; Iannaccone, Mario; d'Ascenzo, Fabrizio; Barbero, Cristina; Mohamed, Abdirashid; Annone, Umberto; Benedetto, Sara; Celentani, Dario; Gagliardi, Marco; Moretti, Claudio; Gaita, Fiorenzo

    2016-08-01

    A non-invasive approach to define grafts patency and stenosis in the follow-up of coronary artery bypass graft (CABG) patients may be an interesting alternative to coronary angiography. 64-slice-coronary computed tomography is nowadays a diffused non-invasive method that permits an accurate evaluation of coronary stenosis, due to a high temporal and spatial resolution. However, its sensitivity and specificity in CABG evaluation has to be clearly defined, since published studies used different protocols and scanners. We collected all studies investigating patients with stable symptoms and previous CABG and reporting the comparison between diagnostic performances of invasive coronary angiography and 64-slice-coronary computed tomography. As a result, sensitivity and specificity of 64-slice-coronary computed tomography for CABG occlusion were 0.99 (95% CI 0.97-1.00) and 0.99 (95% CI: 0.99-1.00) with an area under the curve (AUC) of 0.99. 64-slice-coronary computed tomography sensitivity and specificity for the presence of any CABG stenosis >50% were 0.98 (95% CI: 0.97-0.99) and 0.98 (95% CI: 0.96-0.98), while AUC was 0.99. At meta-regression, neither the age nor the time from graft implantation had effect on sensitivity and specificity of 64-slice-coronary computed tomography detection of significant CABG stenosis or occlusion. In conclusion 64-slice-coronary computed tomography confirmed its high sensitivity and specificity in CABG stenosis or occlusion evaluation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Impact of image noise levels, scout scan dose and lens shield on image quality and radiation exposure in z-axis dose-modulated neck MSCT on 16- and 64-slice Toshiba Aquilion scanners.

    PubMed

    Bauknecht, Hans-Christian; Jach, Cornelia; Bohner, Georg; Meyer, Henning; Scheurig, Christian; Siebert, Eberhard; Klingebiel, Randolf

    2010-02-01

    Assessing the impact of image noise (IN) levels, scout scan dose and lens shield use on image quality and radiation exposure in neck multislice CT (MSCT) when using z-axis dose modulation (DM). Neck MSCT phantom studies with/without z-axis DM were performed by using different IN levels (S.D. 7.5-30HU) and scout scan tube currents (7.5-50mA) on Toshiba Aquilion scanners (16-/64-slice). Image quality indices were evaluated by two radiologists and radiation exposure parameters calculated. Cadaveric phantom measurements elucidated lens shield interactions with DM efficacy. The lowest dose scan protocol with diagnostic image quality was introduced into the clinical imaging routine and retrospectively evaluated in 20 age-matched patients undergoing neck MSCT with/without DM. The highest image noise level in DM neck studies with comparable image quality to standard neck CT amounted to 20HU, resulting in a mean tube current of 50mAs (CTDI(w) 6.3mGy). DM reduced effective dose by 35% and organ dose figures (lens, thyroid) by 33%. Scout scan dose lowering to 20mA resulted in an effective dose (ED) decrease of 0.06mSv (5%). Avoiding lens shield placement during scout scan effected an organ dose decrease of 20%. Overall contour sharpness and image contrast did not differ significantly (DM/without DM) whereas image noise was rated higher in DM neck CT studies (p<0.05). z-Axis dose modulation, as assessed on 16- and 64-slice Toshiba Aquilion scanners, is effective and mandatory in neck MSCT. DM efficacy can be enhanced by optimising scout scan doses and lens shield use. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

  6. Dynamic multidetector CT and non-contrast-enhanced MR for right adrenal vein imaging: comparison with catheter venography in adrenal venous sampling.

    PubMed

    Ota, Hideki; Seiji, Kazumasa; Kawabata, Masahiro; Satani, Nozomi; Omata, Kei; Ono, Yoshikiyo; Iwakura, Yoshitsugu; Morimoto, Ryo; Matsuura, Tomonori; Kudo, Masataka; Tominaga, Junya; Satoh, Fumitoshi; Ito, Sadayoshi; Takase, Kei

    2016-03-01

    To evaluate visualization of the right adrenal vein (RAV) with multidetector CT and non-contrast-enhanced MR imaging in patients with primary aldosteronism. A total of 125 patients (67 men) scheduled for adrenal venous sampling (AVS) were included. Dynamic 64-detector-row CT and balanced steady-state free precession-based non-contrast-enhanced 3-T MR imaging were performed. RAV visualization based on a four-point score was documented. Both anatomical location and variation on cross-sectional imaging were evaluated, and the findings were compared with catheter venography as the gold standard. The RAV was visualized in 93.2% by CT and 84.8% by MR imaging (p = 0.02). Positive predictive values of RAV visualization were 100% for CT and 95.2% for MR imaging. Imaging score was significantly higher in CT than MR imaging (p < 0.01). The RAV formed a common trunk with an accessory hepatic vein in 16% of patients. The RAV orifice level on cross-sectional imaging was concordant with catheter venography within the range of 1/3 vertebral height in >70% of subjects. Success rate of AVS was 99.2%. Dynamic CT is a reliable way to map the RAV prior to AVS. Non-contrast-enhanced MR imaging is an alternative when there is a risk of complication from contrast media or radiation exposure. Dynamic CT and non-contrast-enhanced MR imaging detect the right adrenal vein (RAV). Dynamic CT can visualize the RAV more than non-contrast-enhanced MR imaging. Mapping the RAV helps to achieve successful adrenal venous sampling. Sixteen per cent of RAVs share the common trunk with accessory hepatic veins.

  7. Pulmonary adenocarcinomas presenting as ground-glass opacities on multidetector CT: three-dimensional computer-assisted analysis of growth pattern and doubling time

    PubMed Central

    Borghesi, Andrea; Farina, Davide; Michelini, Silvia; Ferrari, Matteo; Benetti, Diego; Fisogni, Simona; Tironi, Andrea; Maroldi, Roberto

    2016-01-01

    PURPOSE We aimed to evaluate the growth pattern and doubling time (DT) of pulmonary adenocarcinomas exhibiting ground-glass opacities (GGOs) on multidetector computed tomography (CT). METHODS The growth pattern and DT of 22 pulmonary adenocarcinomas exhibiting GGOs were retrospectively analyzed using three-dimensional semiautomatic software. Analysis of each lesion was based on calculations of volume and mass changes and their respective DTs throughout CT follow-up. Three-dimensional segmentation was performed by a single radiologist on each CT scan. The same observer and another radiologist independently repeated the segmentation at the baseline and the last CT scan to determine the variability of the measurements. The relationships among DTs, histopathology, and initial CT features of the lesions were also analyzed. RESULTS Pulmonary adenocarcinomas presenting as GGOs exhibited different growth patterns: some lesions grew rapidly and some grew slowly, whereas others alternated between periods of growth, stability, or shrinkage. A significant increase in volume and mass that exceeded the coefficient of repeatability of interobserver variability was observed in 72.7% and 84.2% of GGOs, respectively. The volume-DTs and mass-DTs were heterogeneous throughout the follow-up CT scan (range, −4293 to 21928 and −3113 to 17020 days, respectively), and their intra- and interobserver variabilities were moderately high. The volume-DTs and mass-DTs were not correlated with the initial CT features of GGOs; however, they were significantly shorter in invasive adenocarcinomas (P = 0.002 and P = 0.001, respectively). CONCLUSION Pulmonary adenocarcinomas exhibiting GGOs show heterogeneous growth patterns with a trend toward a progressive increase in size. DTs may be useful for predicting tumor aggressiveness. PMID:27682741

  8. Quantitative analysis of orthopedic metal artefact reduction in 64-slice computed tomography scans in large head metal-on-metal total hip replacement, a phantom study.

    PubMed

    Boomsma, Martijn F; Warringa, Niek; Edens, Mireille A; Mueller, Dirk; Ettema, Harmen B; Verheyen, Cees C P M; Maas, Mario

    2016-01-01

    artefacts by significantly reducing metal artefacts subsequently and increasing CNR on a 64 slice CT system in light and medium disturbance of the image.

  9. Relationship between the Self-Rating Anxiety Scale score and the success rate of 64-slice computed tomography coronary angiography.

    PubMed

    Li, Hui; Jin, Dan; Qiao, Fang; Chen, Jianchang; Gong, Jianping

    Computed tomography coronary angiography, a key method for obtaining coronary artery images, is widely used to screen for coronary artery diseases due to its noninvasive nature. In China, 64-slice computed tomography systems are now the most common models. As factors that directly affect computed tomography performance, heart rate and rhythm control are regulated by the autonomic nervous system and are highly related to the emotional state of the patient. The aim of this prospective study is to use a pre-computed tomography scan Self-Rating Anxiety Scale assessment to analyze the effects of tension and anxiety on computed tomography coronary angiography success. Subjects aged 18-85 years who were planned to undergo computed tomography coronary angiography were enrolled; 1 to 2 h before the computed tomography scan, basic patient data (gender, age, heart rate at rest, and family history) and Self-Rating Anxiety Scale score were obtained. The same group of imaging department doctors, technicians, and nurses performed computed tomography coronary angiography for all the enrolled subjects and observed whether those subjects could finish the computed tomography coronary angiography scan and provide clear, diagnostically valuable images. Participants were divided into successful (obtained diagnostically useful coronary images) and unsuccessful groups. Basic data and Self-Rating Anxiety Scale scores were compared between the groups. The Self-Rating Anxiety Scale standard score of the successful group was lower than that of the unsuccessful group (P = 0.001). As the Self-Rating Anxiety Scale standard score rose, the success rate of computed tomography coronary angiography decreased. The Self-Rating Anxiety Scale score has a negative relationship with computed tomography coronary angiography success. Anxiety can be a disadvantage in computed tomography coronary angiography examination. The pre-computed tomography coronary angiography scan Self-Rating Anxiety Scale

  10. Dosimetric characterization and image quality evaluation of the AIRO mobile CT scanner.

    PubMed

    Weir, Victor J; Zhang, Jie; Bruner, Angela P

    2015-01-01

    Radiation dose and image quality from a recently introduced mobile CT imaging system are presented. Radiation dose was measured using a conventional 100 mm pencil ionization chamber and CT polymethylmetacrylate (PMMA) body and head phantoms. Image quality was evaluated with a CATPHAN 500 phantom. Spatial resolution, low contrast resolution, Modulation Transfer Function (MTF), and Normalized Noise Power Spectrum (NNPS) were analyzed. Radiation dose and image quality were compared to those from a multi-detector CT scanner (Siemens Sensation 64). Under identical technique factors radiation dose (mGy/mAs) from the AIRO mobile CT system (AIRO) is higher than that from a 64 slice CT scanner. Based on MTF analysis, both Soft and Standard filters of the AIRO system lost resolution quickly compared to the Sensation 64 slice CT. The Siemens scanner had up to 7 lp/cm for the head FOV and H40 kernel and up to 5 lp/cm at body FOV for the B40f kernel. The Standard kernel in the AIRO system was evaluated to have 3 lp/cm and 4 lp/cm for the body and head FOVs respectively. NNPS of the AIRO shows low frequency noise due to ring-like artifacts which may be caused by detector calibration or lack of artifact reducing image post-processing. Due to a higher dose in terms of mGy/mAs at both head and body FOV, the contrast to noise ratio is higher in the AIRO system than in the Siemens scanner. However detectability of the low contrast objects is poorer in the AIRO due to the presence of ring artifacts in the location of the targets.

  11. Radiation dose is reduced with a single-pass whole-body multi-detector row CT trauma protocol compared with a conventional segmented method: initial experience.

    PubMed

    Ptak, Thomas; Rhea, James T; Novelline, Robert A

    2003-12-01

    Radiation dose data were collected from a calibrated multi-detector row computed tomographic (CT) scanner during trauma CT. One protocol (used with 10 case subjects) involved a single-pass continuous whole-body acquisition from cranial vertex to symphysis pubis, while the other, conventional protocol (used with 10 control subjects) involved scouting and scanning body segments (head, cervical spine, chest, abdomen, and pelvis) individually. Technical factors were kept constant within each body segment for the single-pass and the segmented protocols. Statistics included univariate analysis, two-tailed t testing to evaluate statistical significance of the summary statistic, and power and subject population contingency tables. The mean dose length product (DLP) with the single-pass protocol was 17% lower than the sum of the DLPs of each of the individual body segment scans (P <.001). Analysis of power and subject population by using a difference in mean of 500 mGy. cm and an alpha of.05 revealed a (1-beta) of higher than 0.90 for a sample of 10 patients. Thus, a whole-body single-pass trauma protocol, compared with a typical segmented acquisition protocol matched for imaging technique, resulted in reduced total radiation dose. The reduction in radiation dose is thought to represent a reduction in redundant imaging at overlap zones between body segments scanned in the segmental protocol but not in the continuous acquisition.

  12. Coronary artery calcium measurement with multi-detector row CT: in vitro assessment of effect of radiation dose.

    PubMed

    Hong, Cheng; Bae, Kyongtae T; Pilgram, Thomas K; Suh, Jongdae; Bradley, David

    2002-12-01

    The authors assessed in vitro the effect of radiation dose on coronary artery calcium quantification with multi-detector row computed tomography. A cardiac phantom with calcified cylinders was scanned at various milliampere second settings (20-160 mAs). A clear tendency was found for image noise to decrease as tube current increased (P <.001). No tendency was found for the Agatson score or calcium volume and mass errors to vary with tube current. Calcium measurements were not significantly affected by the choice of tube current. Calcium mass error was strongly correlated with calcium volume error (P <.001). The calcium mass measurement was more accurate and less variable than the calcium volume measurement.

  13. Evaluation of the relationship between extremity soft tissue sarcomas and adjacent major vessels using contrast-enhanced multidetector CT and three-dimensional volume-rendered CT angiography: a preliminary study.

    PubMed

    Li, YangKang; Zheng, Yu; Lin, JianBang; Cai, AiQun; Zhou, XiuGuo; Wei, XiaoLong; Cheng, Ying; Liu, GuoRui

    2013-10-01

    Accurate description of the relationship between extremity soft tissue sarcoma and the adjacent major vessels is crucial for successful surgery. In addition to magnetic resonance imaging (MRI) or in patients who cannot undergo MRI, two-dimensional (2D) postcontrast computed tomography (CT) images and three-dimensional (3D) volume-rendered CT angiography may be valuable alternative imaging techniques for preoperative evaluation of extremity sarcomas. To preoperatively assess extremity sarcomas using multidetector CT (MDCT), with emphasis on postcontrast MDCT images and 3D volume-rendered MDCT angiography in evaluating the relationship between tumors and adjacent major vessels. MDCT examinations were performed on 13 patients with non-metastatic extremity sarcomas. Conventional CT images and 3D volume-rendered CT angiography were evaluated, with focus on the relationship between tumors and adjacent major vessels. Kappa consistency statistics were performed with surgery serving as the reference standard. The relationship between sarcomas and adjacent vessels was described as one of three patterns: proximity, adhesion, and encasement. Proximity was seen in five cases on postcontrast CT images or in eight cases on volume-rendered images. Adhesion was seen in three cases on both postcontrast CT images and volume-rendered images. Encasement was seen in five cases on postcontrast CT images or in two cases on volume-rendered images. Compared to surgical results, postcontrast CT images had 100% sensitivity, 83.3% specificity, 87.5% positive predictive value, 100% negative predictive value, and 92.3% accuracy in the detection of vascular invasion (κ = 0.843, P = 0.002). 3D volume-rendered CT angiography had 71.4% sensitivity, 100% specificity, 100% positive predictive value, 75% negative predictive value, and 84.6% accuracy in the detection of vascular invasion (κ = 0.698, P = 0.008). On volume-rendered images, all cases with adhesion or encasement had arterial stenosis and

  14. Validity of blood flow measurement using 320 multi-detectors CT and first-pass distribution theory: a phantom study

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Yu, Xuefang; Xu, Shaopeng; Zhou, Kenneth J.

    2015-03-01

    To evaluate the feasibility of measuring the myocardial blood flow using 320 row detector CT by first-pass technique. Heart was simulated with a container that was filled with pipeline of 3mm diameter; coronary artery was simulated with a pipeline of 2 cm diameter and connected with the simulated heart. The simulated coronary artery was connected with a big container with 1500 ml saline and 150ml contrast agent. One pump linking with simulated heart will withdraw with a speed of 10 ml/min, 15 ml/min, 20 ml/min, 25 ml/min and 30 ml/min. First CT scan starts after 30 s of pumpback with certain speed. The second CT scan starts 5 s after first CT scans. CT images processed as follows: The second CT scan images subtract first CT scan images, calculate the increase of CT value of simulated heart and the CT value of the unit volume of simulated coronary artery and then to calculate the total inflow of myocardial blood flow. CT myocardial blood flows were calculated as: 0.94 ml/s, 2.09 ml/s, 2.74 ml/s, 4.18 ml/s, 4.86 ml/s. The correlation coefficient is 0.994 and r2 = 0.97. The method of measuring the myocardial blood flow using 320 row detector CT by 2 scans is feasible. It is possible to develop a new method for quantitatively and functional assessment of myocardial perfusion blood flow with less radiation does.

  15. Morphometric evaluation of subaxial cervical spine using multi-detector computerized tomography (MD-CT) scan: the consideration for cervical pedicle screws fixation.

    PubMed

    Chanplakorn, Pongsthorn; Kraiwattanapong, Chaiwat; Aroonjarattham, Kitti; Leelapattana, Pittavat; Keorochana, Gun; Jaovisidha, Suphaneewan; Wajanavisit, Wiwat

    2014-04-11

    Cervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify cortical thickness of the cervical isthmus by using Multi-detector Computerized Tomography (MD-CT) scan. The cervical CT scans were performed in 74 patients (37 males and 37 females) with 1-mm slice thickness and then retro-reconstructed into sagittal and coronal planes to measure various cervical parameters as follows: outer pedicle width (OPW), inner pedicle width (IPW), outer pedicle height (OPH), inner pedicle height (IPH), pedicle cortical thickness, pedicle sagittal angle (PSA), and pedicle transverse angle (PTA). Total numbers of 740 pedicles were measured in this present study. The mean OPW and IPW significantly increased from C3 to C7 while the mean OPH and IPH of those showed non-significant difference between any measured levels. The medial-lateral cortical thickness was significantly smaller than the superior-inferior one. PTA in the upper cervical spine was significantly wider than the lower ones. The PSA changed from upward inclination at upper cervical spine to the downward inclination at lower cervical spine. This study has demonstrated that cervical vertebra has relatively small and narrow inner pedicle canal with thick outer pedicle cortex and also shows a variable in pedicle width and inconsistent transverse angle. To enhance the safety of CPS insertion, the entry point and trajectories should be determined individually by using preoperative MD-CT scan and the inner pedicle width should be a key parameter to determine the screw dimensions.

  16. Utility of virtual unenhanced images and split-bolus injection using spectral multidetector CT for the assessment of renal cell carcinoma conspicuity and radiation dose.

    PubMed

    Wang, Wei; Liu, Lin; Zeng, Hong; Sun, Changjiang; Huang, Ning; Zhang, Mengchao

    2016-09-01

    The aim of this study was to evaluate the radiation dose and renal cell carcinoma conspicuity with virtual unenhanced images and split-bolus injection from spectral multidetector CT (MDCT). This prospective study was approved by the Ethics Committee, and informed consent was obtained. Ninety suspected patients of renal cell carcinoma diagnosed by abdominal ultrasonography and CEUS were randomly divided into two groups by a radiographer. Patients of the first group underwent spectral MDCT with virtual unenhanced imaging and split-bolus injection, while patients in the second group underwent conventional unenhanced as well as tri-phasic enhanced CT. Group A (split-bolus spectral MDCT group): The contrast material was administered at a dose of 1.5 mL/kg body weight at a flow rate of 4 mL/s, with a ratio of 7 to 5 before the CT scan with an interval of 60 seconds. Virtual unenhanced images were generated using a standard three-material decomposition algorithm, and the best mono-energy (keV) was calculated to show the tumour, renal artery and renal vein. Group B (conventional tri-phasic enhanced CT group): the contrast agent was injected with a dose of 1.5 mL/kg body weight at a flow rate of 4 mL/s. The corticomedullary phase scanning was performed once the arterial CT value reached 100 HU; the nephrographic phase was scanned 60 seconds later. And the excretory phase was scanned 5 min after onset of contrast injection. The LKR (lesion kidney ratio), CNR, and CT value of the corticomedullary and nephrographic phase were measured. The opacification of the renal collection system (including calices, infundibula and renal pelvis) was scored. The radiation dose was recorded. Statistical analysis was performed using Student's t-test, Fisher's exact test, the Mann-Whitney U-test, and k statistics. There were no statistically significant differences between the two groups in age, sex and body mass index (BMI), but there was significant difference in treatment methods

  17. Reduced Z-axis coverage multidetector CT angiography for suspected acute pulmonary embolism could decrease dose and maintain diagnostic accuracy.

    PubMed

    Kallen, Joshua A; Coughlin, Bret F; O'Loughlin, Michael T; Stein, Barry

    2010-01-01

    Multidetector computed tomographic angiography (MDCTA) is the method of choice for evaluation of suspected acute pulmonary embolism (PE) in most patients because it is accurate and widely available. The use of computed tomography, including MDCTA for PE, has risen dramatically over the last several years with an attendant rise in radiation exposure. Many methods currently employed to reduce radiation dose may affect image quality and potentially affect diagnostic accuracy. Reducing Z-axis coverage would decrease radiation dose without any effect on image quality. This study was performed to assess the effect on the accuracy of MDCTA for suspected acute PE if the Z-axis coverage was reduced to the anatomic range from the top of the aortic arch through the heart. Two hundred ninety-five examinations were performed on a 64-detector-row MDCT and interpreted as positive for PE from July 2005 to February 2008. When the anatomic range of these data sets were retrospectively reduced and reinterpreted for PE, no case was interpreted as negative for PE. The Z-axis coverage was reduced by 37%. In the interest of keeping radiation doses as low as reasonably achievable, further research in this area is warranted.

  18. The Role of Three-Dimensional Multidetector CT Gastrography in the Preoperative Imaging of Stomach Cancer: Emphasis on Detection and Localization of the Tumor

    PubMed Central

    Kim, Jin Woong; Heo, Suk Hee; Lim, Hyo Soon; Lim, Nam Yeol; Park, Young Kyu; Jeong, Yong Yeon; Kang, Heoung Keun

    2015-01-01

    Multidetector CT (MDCT) gastrography has been regarded as a promising technique for the preoperative imaging of gastric cancer. It has the ability to produce various three-dimensional (3D) images. Because 3D reconstruction images are more effective and intuitive for recognizing abnormal changes in the gastric folds and subtle mucosal nodularity than two-dimensional images, 3D MDCT gastrography can enhance the detection rate of early gastric cancer, which, in turn, contributes to the improvement of the accuracy of preoperative tumor (T) staging. In addition, shaded surface display and tissue transition projection images provide a global view of the stomach, with the exact location of gastric cancer, which may replace the need for barium studies. In this article, we discuss technical factors in producing high-quality MDCT gastrographic images and present cases demonstrating the usefulness of MDCT gastrography for the detection and T staging of gastric cancer while emphasizing the significance of preoperative localization of gastric cancer in terms of surgical margin. PMID:25598676

  19. The "cluster of black pearls" sign of sarcoid lymphadenopathy: a new sign on thin-section contrast-enhanced multidetector CT.

    PubMed

    Venkata Ramanan, R; Pudhiavan, A; Venkataramanan, A

    2017-09-01

    To identify a specific diagnostic sign for sarcoid adenopathy on contrast-enhanced multidetector computed tomography (MDCT) based on nodal morphology. A prospective study was performed on 105 patients with 1654 nodes. Of this, 18 patients with sarcoidosis formed the study group. The control group consisted of the remaining 87 patients with other proven disease entities of metastatic adenocarcinoma, lymphoma, tuberculosis, and reactive adenopathy for comparison. CT examinations were undertaken using a 64-section helical mode in the arterial and venous phases with a 0.5-mm section thickness. The lymph nodes were evaluated for various morphological criteria and the presence of the "cluster of black pearls" (CBP) sign. The CBP sign was considered present when tiny round nodules each measuring 1-2 mm were seen distributed uniformly within the whole or part of the lymph node. The CBP sign had a significance of p<0.001, 83% sensitivity, 98% specificity, 91% positive predictive value, and 96% negative predictive value on a per node basis and a sensitivity of 100% on a per patient basis. The CBP sign is an accurate morphological sign differentiating sarcoid from other adenopathy. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  20. Comparison between blinded and partially blinded detection of gastric cancer with multidetector CT using surgery and endoscopic submucosal dissection as reference standards.

    PubMed

    Kim, H J; Lee, D H; Ko, Y T

    2010-08-01

    The aim of this study is to compare blinded with partially blinded detection of gastric cancer with multidetector (MD) CT by using surgery and endoscopic submucosal dissection (ESD) as reference standards. 44 patients with gastric cancer underwent MDCT with air as an oral contrast agent. Surgery was performed on 37 patients, ESD on six and surgery after ESD on one. To provide comparison cases of blinded evaluation, 38 MDCT examinations were added for cases where no focal gastric lesion was seen on endoscopy. Two radiologists, blinded to the presence, number and location of the tumours, evaluated axial and axial plus multiplanar reformation (MPR) images of 82 MDCT examinations with or without gastric cancer. For partially blinded evaluation, the same radiologists, blinded to the location and number of tumours, evaluated axial and axial plus MPR images of 44 MDCT examinations of gastric cancer. Differences in assessment were resolved by consensus. 45 gastric cancers were found in surgical and ESD specimens. Detection rates of gastric cancer from axial and axial plus MPR images during blinded evaluation and from axial and axial plus MPR images during partially blinded evaluation were 62% (28/45), 64% (29/45), 64% (29/45) and 71% (32/45), respectively. There was no statistical significance for the comparison between blinded and partially blinded detection rates of gastric cancer. The detection rate of gastric cancer with MDCT during blinded evaluation showed no specific difference compared with the detection rate of gastric cancer with MDCT during partially blinded evaluation.

  1. Multidetector CT coronary angiography for patient triage to invasive coronary angiography: Performance and cost in ambulatory patients with equivocal or suspected inaccurate noninvasive stress tests.

    PubMed

    Menon, Madhav; Lesser, John R; Hara, Hidehiko; Birkett, Richard; Knickelbine, Thomas; Longe, Terry; Flygenring, Bjorn; Henry, Jason; Schwartz, Robert

    2009-03-01

    Multidetector-CT angiography (MDCTA) differs from noninvasive stress tests by directly imaging coronary anatomy. The utility of MDCTA for invasive triage is undefined however. We evaluated MDCTA triage to invasive coronary angiography in outpatients with indeterminate or suspected inaccurate stress tests, and estimated cost savings by MDCTA in this role. Consecutive MDCTA patients were retrospectively compared with noninvasive stress tests if performed within 6 months of MDCTA. Twelve-month clinical follow up was obtained for patients not undergoing invasive angiography, and cost using MDCTA for triage to invasive coronary angiography was calculated. MDCTA was performed in 385 patients who had noninvasive stress testing. Stress tests include included treadmill (n = 37), stress echo (n = 178), and nuclear perfusion imaging (n = 170). Invasive angiography was performed in 57 (14.8%). MDCTA compared to CA showed positive and negative predictive values of 94%/100% respectively for lesions found by invasive QCA. Stress testing compared to MDCTA showed positive/negative predictive values of 100%/67% for treadmill exercise, 60%/54% for stress echo, and 59%/55% of nuclear perfusion examinations respectively. One year clinical follow up in 314 patients showed no coronary events in 98% (309) of patients. Triage to invasive angiography by MDCTA showed a 4-fold cost reduction. MDCTA shows excellent performance as a triage for invasive angiography in patients with stress tests that are equivocal or thought inaccurate. A negative CTA confers good 12-month prognosis. Substantial cost savings may accrue using MDCTA in this triage role.

  2. Optimization of Z-axis automatic exposure control for multidetector row CT evaluation of neck and comparison with fixed tube current technique for image quality and radiation dose.

    PubMed

    Namasivayam, S; Kalra, M K; Pottala, K M; Waldrop, S M; Hudgins, P A

    2006-01-01

    Z-axis automatic exposure control (AEC) technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare diagnostic acceptability, noise, and radiation exposure of multidetector row CT (MDCT) of neck performed with z-axis AEC and with fixed current. Two study groups of 26 patients each underwent MDCT of neck using z-axis AEC with 8 noise index (NI), 150-440 mA, and 10 NI, 75-440 mA, respectively. A control group consisting of another 26 patients underwent MDCT of neck with fixed-current technique (300 mA). Objective noise and mean tube current-time products (mA . s) were recorded. Two radiologists evaluated images for diagnostic acceptability and subjective noise on a 5-point scale. All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with z-axis AEC (shoulder: NI 8, 20.6 +/- 6.2 HU; NI 10, 22.2 +/- 4.6 HU) than with fixed current (16.2 +/- 6 HU) (P = .01). There was no significant difference between AEC and fixed current in diagnostic acceptability and subjective noise (P = .22-.42). AEC resulted in significant radiation dose reduction (NI 8, 186.3 +/- 20.5 mA . s; NI 10, 158.1 +/- 21.2 mA x s), compared with fixed current (235 +/- 21.8 mA x s). Z-axis AEC resulted in similar subjective noise and diagnostic acceptability, with radiation dose reduction of 21% for NI of 8 and 33% for NI of 10, respectively, for MDCT evaluation of neck, compared with those of fixed current technique.

  3. Assessment of organ absorbed doses and estimation of effective doses from pediatric anthropomorphic phantom measurements for multi-detector row CT with and without automatic exposure control.

    PubMed

    Brisse, Hervé J; Robilliard, Magalie; Savignoni, Alexia; Pierrat, Noelle; Gaboriaud, Geneviève; De Rycke, Yann; Neuenschwander, Sylvia; Aubert, Bernard; Rosenwald, Jean-Claude

    2009-10-01

    This study was designed to measure organ absorbed doses from multi-detector row computed tomography (MDCT) on pediatric anthropomorphic phantoms, calculate the corresponding effective doses, and assess the influence of automatic exposure control (AEC) in terms of organ dose variations. Four anthropomorphic phantoms (phantoms represent the equivalent of a newborn, 1-, 5-, and 10-y-old child) were scanned with a four-channel MDCT coupled with a z-axis-based AEC system. Two CT torso protocols were compared: a first protocol without AEC and constant tube current-time product and a second protocol with AEC using age-adjusted noise indices. Organ absorbed doses were monitored by thermoluminescent dosimeters (LiF: Mg, Cu, P). Effective doses were calculated according to the tissue weighting factors of the International Commission on Radiological Protection (). For fixed mA acquisitions, organ doses normalized to the volume CT dose index in a 16-cm head phantom (CTDIvol16) ranged from 0.6 to 1.5 and effective doses ranged from 8.4 to 13.5 mSv. For the newborn-equivalent phantom, the AEC-modulated scan showed almost no significant dose variation compared to the fixed mA scan. For the 1-, 5- and 10-y equivalent phantoms, the use of AEC induced a significant dose decrease on chest organs (ranging from 61 to 31% for thyroid, 37 to 21% for lung, 34 to 17% for esophagus, and 39 to 10% for breast). However, AEC also induced a significant dose increase (ranging from 28 to 48% for salivary glands, 22 to 51% for bladder, and 24 to 70% for ovaries) related to the high density of skull base and pelvic bones. These dose increases should be considered before using AEC as a dose optimization tool in children.

  4. 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.

  5. Frequency and importance of small amount of isolated pelvic free fluid detected with multidetector CT in male patients with blunt trauma.

    PubMed

    Yu, Jinxing; Fulcher, Ann S; Wang, Deng-Bin; Turner, Mary A; Ha, Jonathan D; McCulloch, Madison; Kennedy, Robert M; Malhotra, Ajai K; Halvorsen, Robert A

    2010-09-01

    To retrospectively determine the frequency and importance of a small amount of isolated pelvic free fluid seen at multidetector computed tomography (CT) in male patients who have blunt trauma without an identifiable cause. Institutional review board approval was obtained, and the requirement for informed consent was waived for this HIPAA-compliant study. One thousand male patients with blunt trauma who underwent abdominopelvic CT at a level 1 trauma center between January 2004 and June 2006 were entered into this study. The CT images of the 1000 patients were reviewed independently by two abdominal radiologists. CT scan assessment included evaluation for presence or absence of pelvic free fluid, any traumatic or nontraumatic cause of the free fluid, pelvic free fluid attenuation and volume measurements, and determination of the location of pelvic free fluid. Interobserver agreement was determined with kappa statistics, and the Student t test was used to assess differences in the mean volume and mean attenuation of the pelvic free fluid in the patients with and those without injury. Pelvic free fluid was identified in 10.2% (102 of 1000) of patients. A small amount of isolated pelvic free fluid without any identifiable cause was identified in 4.8% (48 of 1000) of patients by reader 1 and in 5.0% (50 of 1000) of patients by reader 2 (kappa value, 0.76) and was located at or below the level of the third sacral vertebral body in all 49 patients with isolated pelvic free fluid. The mean volume and mean attenuation of the small amount of isolated pelvic free fluid were 2.3 mL +/- 1.5 (standard deviation) and 8.1 HU +/- 3.9, respectively. None of the patients in this group had an undiagnosed bowel and/or mesenteric injury. In male patients with blunt trauma, a small amount of isolated pelvic free fluid with attenuation equal to that of simple fluid and located in the deep region of the pelvis likely is not a sign of bowel and/or mesenteric injury. (c) RSNA, 2010.

  6. Estimating radiation doses from multidetector CT using Monte Carlo simulations: effects of different size voxelized patient models on magnitudes of organ and effective dose.

    PubMed

    DeMarco, J J; Cagnon, C H; Cody, D D; Stevens, D M; McCollough, C H; Zankl, M; Angel, E; McNitt-Gray, M F

    2007-05-07

    The purpose of this work is to examine the effects of patient size on radiation dose from CT scans. To perform these investigations, we used Monte Carlo simulation methods with detailed models of both patients and multidetector computed tomography (MDCT) scanners. A family of three-dimensional, voxelized patient models previously developed and validated by the GSF was implemented as input files using the Monte Carlo code MCNPX. These patient models represent a range of patient sizes and ages (8 weeks to 48 years) and have all radiosensitive organs previously identified and segmented, allowing the estimation of dose to any individual organ and calculation of patient effective dose. To estimate radiation dose, every voxel in each patient model was assigned both a specific organ index number and an elemental composition and mass density. Simulated CT scans of each voxelized patient model were performed using a previously developed MDCT source model that includes scanner specific spectra, including bowtie filter, scanner geometry and helical source path. The scan simulations in this work include a whole-body scan protocol and a thoracic CT scan protocol, each performed with fixed tube current. The whole-body scan simulation yielded a predictable decrease in effective dose as a function of increasing patient weight. Results from analysis of individual organs demonstrated similar trends, but with some individual variations. A comparison with a conventional dose estimation method using the ImPACT spreadsheet yielded an effective dose of 0.14 mSv mAs(-1) for the whole-body scan. This result is lower than the simulations on the voxelized model designated 'Irene' (0.15 mSv mAs(-1)) and higher than the models 'Donna' and 'Golem' (0.12 mSv mAs(-1)). For the thoracic scan protocol, the ImPACT spreadsheet estimates an effective dose of 0.037 mSv mAs(-1), which falls between the calculated values for Irene (0.042 mSv mAs(-1)) and Donna (0.031 mSv mAs(-1)) and is higher relative

  7. Automated multidetector row CT dataset segmentation with an interactive watershed transform (IWT) algorithm: Part 1. Understanding the IWT technique.

    PubMed

    Heath, David G; Hahn, Horst K; Johnson, Pamela T; Fishman, Elliot K

    2008-12-01

    Segmentation of volumetric computed tomography (CT) datasets facilitates evaluation of 3D CT angiography renderings, particularly with maximum intensity projection displays. This manuscript describes a novel automated bone editing program that uses an interactive watershed transform (IWT) technique to rapidly extract the skeletal structures from the volume. Advantages of this tool include efficient segmentation of large datasets with minimal need for correction. In the first of this two-part series, the principles of the IWT technique are reviewed, followed by a discussion of clinical utility based on our experience.

  8. Investigation of sinonasal anatomy via low-dose multidetector CT examination in chronic rhinosinusitis patients with higher risk for perioperative complications.

    PubMed

    Fraczek, Marcin; Guzinski, Maciej; Morawska-Kochman, Monika; Krecicki, Tomasz

    2017-02-01

    The aim of the study was to compare visualisation of the surgically relevant anatomical structures via low- and standard-dose multidetector CT protocol in patients with chronic rhinosinusitis (CRS) and higher risk for perioperative complications (i.e. presence of bronchial asthma, history of sinus surgery and advanced nasal polyposis). 135 adult CRS patients were divided randomly into standard-dose (120 kVp, 100 mAs) or low-dose CT groups (120 kVp, 45 mAs). The detectability of the vital anatomical structures (anterior ethmoid artery, optic nerve, cribriform plate and lamina papyracea) was scored using a five-point scale (from excellent to unacceptable) by a radiologist and sinus surgeon. Polyp sizes were quantified endoscopically according to the Lildholdt's scale (LS). Olfactory function was tested with the "Sniffin' Sticks" test. On the low-dose CT images, detectability ranged from 2.42 (better than poor) for cribriform plate among anosmic cases to 4.11 (better than good) for lamina papyracea in cases without nasal polyps. Identification of lamina papyracea on low-dose scans was significantly worse in each group and the same was the case with cribriform plates in patients with advanced polyposis and anosmia. Cribriform plates were the most poorly identified (between poor and average) among all the structures on low-dose images. Identification of anterior ethmoid artery (AEA) with reduced dose was insignificantly worse than with standard-dose examination. The AEA was scored as an average-defined structure and was the second weakest visualised. In conclusion, preoperatively, low-dose protocols may not sufficiently visualise the surgically relevant anatomical structures in patients with CRS and bronchial asthma, advanced nasal polyps (LS > 2) and history of sinus surgery. Low mAs value enables comparable detectability of sinonasal landmarks with standard-dose protocols in patients without analysed risk factors. In the context of planned surgery, the current

  9. Impact of iterative reconstruction on image quality and radiation dose in multidetector CT of large body size adults.

    PubMed

    Desai, Gaurav S; Uppot, Raul N; Yu, Elaine W; Kambadakone, Avinash R; Sahani, Dushyant V

    2012-08-01

    To compare image quality and radiation dose using Adaptive Statistical Iterative Reconstruction (ASiR) and Filtered Back Projection (FBP) in patients weighing ≥ 91 kg. In this Institution Review Board-approved retrospective study, single-phase contrast-enhanced abdominopelvic CT examinations of 100 adults weighing ≥ 91 kg (mean body weight: 107.6 ± 17.4 kg range: 91-181.9 kg) with (1) ASiR and (2) FBP were reviewed by two readers in a blinded fashion for subjective measures of image quality (using a subjective standardized numerical scale and objective noise) and for radiation exposure. Imaging parameters and radiation dose results of the two techniques were compared within weight and BMI sub-categories. All examinations were found to be of adequate quality. Both subjective (mean = 1.4 ± 0.5 vs. 1.6 ± 0.6, P < 0.05) and objective noise (13.0 ± 3.2 vs.19.5 ± 5.7, P < 0.0001) were lower with ASiR. Average radiation dose reduction of 31.5 % was achieved using ASiR (mean CTDIvol. ASiR: 13.5 ± 7.3 mGy; FBP: 19.7 ± 9.0 mGy, P < 0.0001). Other measures of image quality were comparable between the two techniques. Trends for all parameters were similar in patients across weight and BMI sub-categories. In obese individuals, abdominal CT images reconstructed using ASiR provide diagnostic images with reduced image noise at lower radiation dose. • CT images in obese adults are noisy, even with high radiation dose. • Newer iterative reconstruction techniques have theoretical advantages in obese patients. • Adaptive statistical iterative reconstruction should reduce image noise and radiation dose. • This has been proven in abdominopelvic CT images of obese patients.

  10. How reliable are 40 MHz IVUS and 64-slice MDCT in characterizing coronary plaque composition? An ex vivo study with histopathological comparison.

    PubMed

    Chopard, Romain; Boussel, Loic; Motreff, Pascal; Rioufol, Gilles; Tabib, Alain; Douek, Philippe; Meyronet, David; Revel, Didier; Finet, Gérard

    2010-04-01

    The present study investigated whether IVUS could serve as a reliable reference in validating MDCT characterization of coronary plaque against a histological gold standard. Twenty-one specimens were postmortem human coronary arteries. Coronary cross-sections were imaged by 40 MHz IVUS and by 64-slice MDCT and characterized histologically as presenting calcified, fibrous or lipid-rich plaques. Plaque composition was analyzed visually and intra-plaque MDCT attenuation was measured in Hounsfield Units (HU). 83 atherosclerotic plaques were identified. IVUS failed to characterize calcified plaque accurately, with a positive predictive value (ppv) of 75% versus 100% for MDCT. Lipid-rich plaque was even less accurately characterized, with ppv of 60 and 68% for IVUS and MDCT respectively. Mean MDCT attenuation was 966 +/- 473 HU for calcified plaque, 83 +/- 35 HU for fibrous plaque and 70.92 HU +/- 41 HU for lipid-rich plaque. No significant difference in mean MDCT attenuation was found between fibrous and lipid-rich plaques (P = 0.276). In vivo validation of MDCT against an IVUS reference thus appears to be an unsuitable and unreliable approach: 40 MHz IVUS suffers from acoustic ambiguities in plaque characterization, and 64-slice MDCT fails to analyze plaque morphology and components accurately.

  11. Development of adaptive noise reduction filter algorithm for pediatric body images in a multi-detector CT

    NASA Astrophysics Data System (ADS)

    Nishimaru, Eiji; Ichikawa, Katsuhiro; Okita, Izumi; Ninomiya, Yuuji; Tomoshige, Yukihiro; Kurokawa, Takehiro; Ono, Yutaka; Nakamura, Yuko; Suzuki, Masayuki

    2008-03-01

    Recently, several kinds of post-processing image filters which reduce the noise of computed tomography (CT) images have been proposed. However, these image filters are mostly for adults. Because these are not very effective in small (< 20 cm) display fields of view (FOV), we cannot use them for pediatric body images (e.g., premature babies and infant children). We have developed a new noise reduction filter algorithm for pediatric body CT images. This algorithm is based on a 3D post-processing in which the output pixel values are calculated by nonlinear interpolation in z-directions on original volumetric-data-sets. This algorithm does not need the in-plane (axial plane) processing, so the spatial resolution does not change. From the phantom studies, our algorithm could reduce SD up to 40% without affecting the spatial resolution of x-y plane and z-axis, and improved the CNR up to 30%. This newly developed filter algorithm will be useful for the diagnosis and radiation dose reduction of the pediatric body CT images.

  12. The vascularized groin lymph node flap (VGLN): Anatomical study and flap planning using multi-detector CT scanner. The golden triangle for flap harvesting.

    PubMed

    Zeltzer, Assaf A; Anzarut, Alexander; Braeckmans, Delphine; Seidenstuecker, Katrin; Hendrickx, Benoit; Van Hedent, Eddy; Hamdi, Moustapha

    2017-09-01

    A growing number of surgeons perform lymph node transfers for the treatment of lymphedema. When harvesting a vascularized lymph node groin flap (VGLNF) one of the major concerns is the potential risk of iatrogenic lymphedema of the donor-site. This article helps understanding of the lymph node distribution of the groin in order to minimize this risk. Fifty consecutive patients undergoing abdominal mapping by multi-detector CT scanner were included and 100 groins analyzed. The groin was divided in three zones (of which zone II is the safe zone) and lymph nodes were counted and mapped with their distances to anatomic landmarks. Further node units were plotted and counted. The average age was 48 years. A mean number of nodes of 6.5/groin was found. In zone II, which is our zone of interest a mean of 3.1 nodes were counted with a mean size of 7.8 mm. In three patients no nodes were found in zone II. In five patients nodes were seen in zone II but were not sufficient in size or number to be considered a lymph node unit. On average the lymph node unit in zone II was found to be 48.3 mm from the pubic tubercle when projected on a line from the pubic tubercle to the anterior superior iliac spine, 16.0 mm caudal to this line, and 20.4 mm above the groin crease. On average the lymph node unit was a mean of 41.7 mm lateral to the SCIV-SIEV confluence. This study provides increased understanding of the lymphatic anatomy in zone II of the groin flap and suggests a refined technique for designing the VGLNF. As with any flap there is a degree of individual patient variability. However, having information on the most common anatomy and flap design is of great value. © 2017 Wiley Periodicals, Inc.

  13. Perihilar branching patterns of renal artery and extrarenal length of arterial branches and tumour-feeding arteries on multidetector CT angiography.

    PubMed

    Kang, W Y; Sung, D J; Park, B J; Kim, M J; Han, N Y; Cho, S B; Kang, C H; Kang, S H

    2013-03-01

    The purpose of our study was to assess the extrarenal length of renal arterial branches and tumour-feeding arteries on multidetector CT (MDCT) angiography, in addition to the perihilar branching patterns, with relevance to segmental artery clamping. MDCT angiograms of 64 patients with renal masses <4 cm were retrospectively reviewed by 2 radiologists. The perihilar branching patterns of the single main renal artery were assessed according to the number of pre-segmental and segmental arteries. The extrarenal lengths of segmental plus pre-segmental arteries and the tumour-feeding arteries, measured on volume-rendered images, were compared according to the vascular segmentation and the tumour location, respectively. In the 116 kidneys, 1 pre-segmental plus 5 segmental arteries (n=48) was the most common branching pattern. The mean extrarenal length of the inferior segmental plus pre-segmental arteries (33.05 mm) and the posterior segmental plus pre-segmental arteries (32.30 mm) was longer than any of the other segmental plus pre-segmental arteries (apical, 23.87 mm; superior, 26.80 mm; middle, 29.23 mm) (p<0.05). The mean extrarenal length of the lower pole tumour-feeding arteries (35.94 mm) was longer than those of the upper and mid-pole tumour-feeding arteries (24.95 mm, 29.62 mm), with significant difference between the lower and the upper pole tumour-feeding arteries (p<0.05). Tumours in the lower pole, supplied by the inferior or posterior segmental artery, may be more amenable to segmental artery clamping. MDCT angiography with volume rendering can demonstrate the extrarenal length of tumour-feeding arteries and may help in determining the accessibility for segmental artery clamping.

  14. Is aortic atherothrombotic disease detected using multidetector-row CT associated with an increased risk of early ischemic lesion recurrence after acute ischemic stroke?

    PubMed

    Ko, Youngchai; Kim, Wook-Joo; Jang, Myung Suk; Yang, Mi Hwa; Park, Jung Hyun; Choi, Sang Il; Chun, Eun Ju; Lee, Soo Joo; Han, Moon-Ku; Bae, Hee-Joon

    2012-03-01

    Multidetector-row CT (MDCT) is emerging as a new tool for diagnosing aortic atherothrombotic disease (AAD). We elucidated whether MDCT-detected AAD is associated with an increased risk of early ischemic lesion recurrence on diffusion-weighted MRI after ischemic stroke. A consecutive series of patients with acute ischemic stroke confirmed using diffusion-weighted MRI who were hospitalized within 48 hours after symptom onset and underwent MDCT were identified in a prospective stroke registry database. AAD on MDCT was defined as the presence of plaque formation that was noncalcified and ≥4 mm thick, ulcerative, or soft and thrombosed (vulnerable) in the proximal aortic arch. Ischemic lesion recurrence on diffusion-weighted MRI was defined as the occurrence of any new lesion separate from the index lesion on follow-up diffusion-weighted MRI performed within 14 days after symptom onset. A total of 138 patients was selected. MDCT detected AAD in 24 of 138 (17.4%); ≥4 mm thickness in 17 of 138 (12.3%); ulcerated plaque in 20 of 138 (14.5%); and vulnerable plaque in 16 of 138 (11.6%). With respect to diffusion-weighted MRI lesion recurrence, the crude ORs (95% CIs) were as follows: AAD, 3.56 (1.43-8.89); vulnerable plaque, 3.21 (1.11-9.30); ulcerated plaque, 3.37 (1.27-8.95); and ≥4 mm thickness of the noncalcified plaque, 4.23 (1.11-16.19). These results remained significant after adjustments for potential confounders were made. This study shows that AAD detected by MDCT increases the risk of early ischemic lesion recurrence after acute ischemic stroke, thus supporting the role of MDCT in diagnosing AAD and assessing its contribution to recurrence.

  15. Impaired left ventricular function has a detrimental effect on image quality in multi-detector row CT coronary angiography.

    PubMed

    Manghat, N E; Morgan-Hughes, G J; Shaw, S R; Marshall, A J; Roobottom, C A

    2008-04-01

    To determine whether there is a relationship between left ventricular (LV) haemodynamic parameters, circulation times, and arterial contrast opacification that might affect the image quality of computed tomography (CT) coronary angiography. Thirty-six patients were included in the study: 18 with cardiomyopathy (CM) and LV dilatation of suspected ischaemic aetiology [age 57.9+/-13.7 years, range 30-77 years; 14 male, four female; body mass index (BMI)=27.7+/-4.5, range 25.5-31.8] and 18 controls (age 62.3+/-9.4 years, range 47-89 years; 10 male, eight female; BMI 27.8+/-6.6; range 19.2-33.6). Coronary artery image quality was assessed using a three-point visual scale; contrast medium circulation times, aortic root contrast attenuation, and LV functional parameters were studied. Visually reduced contrast opacification impaired image quality more often in the CM group than the control group (27.4 versus 5.1%). A total of 55.6% CM patients had a contrast transit time ranging from 30-75 s; the number of "unassessable" segments increased with increasing transit time conforming to a fitted quadratic model (R2=0.74). The relationship between LV ejection fraction and contrast attenuation may also conform to a quadratic model (R2=0.71). LV haemodynamics influence coronary artery opacification using cardiac CT, and users imaging this subgroup must do so with the knowledge of this potential pitfall. The results indicate the need for further studies examining CT protocols in this clinical subgroup.

  16. Comparison of dynamic contrast-enhanced 3T MR and 64-row multidetector CT angiography for the localization of spinal dural arteriovenous fistulas.

    PubMed

    Oda, S; Utsunomiya, D; Hirai, T; Kai, Y; Ohmori, Y; Shigematsu, Y; Iryo, Y; Uetani, H; Azuma, M; Yamashita, Y

    2014-02-01

    For the localization of spinal dural arteriovenous fistulas, it is not determined whether dynamic contrast-enhanced MRA is more reliable than multidetector CTA. The aim of this study was to compare the agreement between intra-arterial DSA, dynamic contrast-enhanced MRA at 3T, and 64-row multidetector CTA for the localization of spinal dural arteriovenous fistulas. We enrolled 12 consecutive patients (11 men, 1 woman; age range, 46-83 years; mean, 65 years) who underwent preoperative dynamic contrast-enhanced MRA at 3T and 64-row multidetector CTA. The spinal dural arteriovenous fistula location was confirmed by intra-arterial DSA as the reference standard. Two reviewers independently evaluated the level of the artery feeding the spinal dural arteriovenous fistula on the basis of continuity between the feeder and abnormal spinal vessels on 3T dynamic contrast-enhanced MRA and 64-row multidetector CTA images. Interobserver and intermodality agreement was determined by calculation of the κ coefficient. On DSA, the vessel feeding the spinal dural arteriovenous fistula was the intercostal artery (7 cases), the lumbar artery (3 cases), and the internal iliac artery or the ascending pharyngeal artery (1 case each). For the fistula level, interobserver agreement was excellent for 3T dynamic contrast-enhanced MRA (κ = 0.97; 95% CI, 0.92-1.00) and very good for 64-row multidetector CTA (κ = 0.84; 95% CI, 0.72-0.96). Intermodality agreement with DSA was good for 3T dynamic contrast-enhanced MRA (κ = 0.78; 95% CI, 0.49-1.00) and moderate for 64-row multidetector CTA (κ = 0.41; 95% CI, 0.020-0.84). For the localization of spinal dural arteriovenous fistulas, 3T dynamic contrast-enhanced MRA may be more reliable than 64-row multidetector CTA.

  17. Exposure (mAs) optimisation of a multi-detector CT protocol for hepatic lesion detection: Are thinner slices better?

    PubMed

    Dobeli, Karen Leigh; Lewis, Sarah Jane; Meikle, Steven Richard; Thiele, David Lewis; Brennan, Patrick Christopher

    2014-04-01

    The purpose of this work was to determine the exposure-optimised slice thickness for hepatic lesion detection with CT. A phantom containing spheres (diameter 9.5, 4.8 and 2.4 mm) with CT density 10 HU below the background (50 HU) was scanned at 125, 100, 75 and 50 mAs. Data were reconstructed at 5-, 3- and 1-mm slice thicknesses. Noise, contrast-to-noise ratio (CNR), area under the curve (AUC) as calculated using receiver operating characteristic analysis and sensitivity representing lesion detection were calculated and compared. Compared with the 125 mAs/5 mm slice thickness setting, significant reductions in AUC were found for 75 mAs (P < 0.01) and 50 mAs (P < 0.05) at 1- and 3-mm thicknesses, respectively; sensitivity for the 9.5-mm sphere was significantly reduced for 75 (P < 0.05) and 50 mAs (P < 0.01) at 1-mm thickness; sensitivity for the 4.8-mm sphere was significantly lower for 100, 75 and 50 mAs at all three slice thicknesses (P < 0.05). The 2.4-mm sphere was rarely detected. At each slice thickness, noise at 100, 75 and 50 mAs exposures was approximately 10, 30 and 50% higher, respectively, than that at 125 mAs exposure. CNRs decreased in an irregular manner with reductions in exposure and slice thickness. This study demonstrated no advantage to using slices below 5 mm thickness, and consequently thinner slices are not necessarily better. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  18. The added diagnostic value of 64-row multidetector CT combined with contrast-enhanced US in the evaluation of hepatocellular nodule vascularity: implications in the diagnosis of malignancy in patients with liver cirrhosis.

    PubMed

    Quaia, Emilio; Alaimo, Valerio; Baratella, Elisa; Medeot, Alessandro; Midiri, Massimo; Cova, Maria Assunta

    2009-03-01

    The aim of this study was to assess the added diagnostic value of contrast-enhanced US (CEUS) combined with 64-row multidetector CT (CT) in the assessment of hepatocellular nodule vascularity in patients with liver cirrhosis. One hundred and six cirrhotic patients (68 male, 38 female; mean age +/- SD, 70 +/- 7 years) with 121 biopsy-proven hepatocellular nodules (72 hepatocellular carcinomas, 10 dysplastic and 15 regenerative nodules, 12 hemangiomas, and 12 other benignancies) detected during US surveillance were prospectively recruited. Each nodule was scanned by CEUS during the arterial (10-40 s), portal venous (45-90 s), and delayed sinusoidal phase (from 100 s after microbubble injection to microbubble disappearance). Nodule vascularity at CEUS, CT, and combined CEUS/CT was evaluated side-by-side by two independent blinded readers who classified nodules as benign or malignant according to reference diagnostic criteria. The combined assessment of CEUS/CT provided higher sensitivity (97%, both readers) than did separate assessment of CEUS (88% reader 1; 87% reader 2) and CT (74% reader 1; 71% reader 2; P < 0.05), while no change in specificity was provided by combined analysis. The combined assessment of hepatocellular nodule vascularity at CT and CEUS improved sensitivity in the diagnosis of malignancy in patients with liver cirrhosis.

  19. Role of multidetector CT in the recognition of hyperdense middle cerebral artery sign (HMCAS) in patients with acute cerebral ischaemia: correlation with DWI-MRI sequences and clinical data.

    PubMed

    Romano, Andrea; Biraschi, Francesco; Tavanti, Francesca; Beccia, Mario; Dilisi, Filomena; Castrignanò, Antonella; Giuliani, Giorgia; Pierallini, Alberto; Fantozzi, Luigi Maria; Rasura, Maurizia; Bozzao, Alessandro

    2015-02-01

    The aim of this study was to verify the sensitivity and specificity of the hyperdense middle cerebral artery sign (HMCAS) obtained by multidetector computed tomography (CT) in predicting acute stroke, using diffusion-weighted (DW) magnetic resonance imaging (MRI) as a reference. The location of the HMCAS, the extension of the ischaemic lesion and its prognostic value were also assessed. The CT examinations of 654 patients with symptoms related to acute cerebral stroke were retrospectively reviewed. DW-MRI confirmed recent stroke in 175 patients. Two expert neuroradiologists analysed the CT examinations of these patients in four phases. Sensitivity, specificity and interobserver reliability was evaluated. Patients were divided into three groups according to the HMCAS site (M1-M2-M3) and the Alberta Stroke Program Early CT Score (ASPECTS) on DW-MRI was calculated. The ASPECTS average score was correlated with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) at 3 months. In 41 patients, the presence of HMCAS was confirmed (71 % sensitivity; 100 % specificity; Interobserver reliability k, 84 %). An inverse correlation was found by comparing the ASPECTS and NIHSS scores (Rsq = -0.206). After logistic regression analysis, HMCAS was found to be independently associated with a poor outcome (mRS >2) at 3 months after adjusting for age, NIHSS on admission, risk factors and aetiology of stroke. Our study demonstrated that HMCAS obtained with multidetector CT can be detected in more than 70 % of patients with large acute ischaemic lesion and it is an unfavourable prognostic sign.

  20. Diagnostic accuracy of three-dimensional contrast-enhanced MR angiography at 3-T for acute pulmonary embolism detection: comparison with multidetector CT angiography.

    PubMed

    Zhang, Long Jiang; Luo, Song; Yeh, Benjamin M; Zhou, Chang Sheng; Tang, Chun Xiang; Zhao, Yan'e; Li, Lin; Zheng, Ling; Huang, Wei; Lu, Guang Ming

    2013-10-12

    Three-dimensional contrast-enhanced MR pulmonary angiography (MRPA) is a suitable option for pulmonary embolism (PE) detection. However, there have been few reports on the diagnostic accuracy of MRPA for PE detection in a 3-T MR system. The purpose of this study was to evaluate the accuracy of MRPA in a 3-T MR system to detect acute PE with multidetector CT pulmonary angiography (CTPA) as reference standard. Twenty-seven patients (18 males and 9 females, mean age 38.9±14.4 years) underwent both MRPA and CTPA within 3 days (range, 0-3 days) for evaluating PE. Pulmonary emboli in MRPA were independently analyzed on a per-patient and per-lobe basis by two radiologists. CTPA was regarded as reference standard, which was evaluated by another two radiologists in consensus. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for PE detection were calculated. Weighted κ values were calculated to evaluate agreement between readers. Twenty-four patients had PE in 55 lung lobes in CTPA, while 3 patients had no PE detected. Readers 1 and 2 correctly detected 47 and 46 lung lobes having clots in 24 and 23 patients, corresponding to sensitivities, specificities, PPV, NPV, and accuracies of 100%, 100%, 100%, 100%, 100%; 100%, 66.7%, 96.0%, 100%, 96.4% on a per-patient basis and 85.5%, 100%, 100%, 90.9%, 94.1%; 83.6%, 93.7%, 90.2%, 89.2%, 89.6% on a per-lobe basis; respectively. Excellent inter-reader agreement (κ values=1.00 and 0.934; both P<0.001) were found for detecting PE on a per-patient and per-lobe analysis. Three-dimensional contrast-enhanced MRPA with a 3-T MR system is a suitable alternative modality to CTPA to detect PE on a per-patient basis based on this small cohort study. © 2013.

  1. Angular on-line tube current modulation in multidetector CT examinations of children and adults: The influence of different scanning parameters on dose reduction

    SciTech Connect

    Papadakis, Antonios E.; Perisinakis, Kostas; Damilakis, John

    2007-07-15

    The purpose of this study was to assess the potential of angular on-line tube current modulation on dose reduction in pediatric and adult patients undergoing multidetector computed tomography (MDCT) examinations. Five physical anthropomorphic phantoms that simulate the average individual as neonate, 1-year-old, 5-year-old, 10-year-old, and adult were employed in the current study. Phantoms were scanned with the use of on-line tube current modulation (TCM). Percent dose reduction (%DR) factors achieved by applying TCM, were determined for standard protocols used for head and neck, shoulder, thorax, thorax and abdomen, abdomen, abdomen and pelvis, pelvis, and whole body examinations. A preliminary study on the application of TCM in MDCT examinations of adult patients was performed to validate the results obtained in anthropomorphic phantoms. Dose reduction was estimated as the percentage difference of the modulated milliamperes for each scan and the preset milliamperes prescribed by the scan protocol. The dose reduction in children was found to be much lower than the corresponding reduction achieved for adults. For helical scans the %DR factors, ranged between 1.6% and 7.4% for the neonate, 2.9% and 8.7% for the 1-year old, 2% and 6% for the 5-year-old, 5% and 10.9% for the 10-year-old, and 10.4% and 20.7% for the adult individual. For sequential scans the corresponding %DR factors ranged between 1.3% and 6.7%, 4.5% and 11%, 4.2% and 6.6%, 6.4% and 12.3%, and 8.9% and 23.3%, respectively. Broader beam collimations are associated with decreased %DR factors, when other scanning parameters are held constant. TCM did not impair image noise. In adult patients, the %DR values were found to be in good agreement with the corresponding results obtained in the anthropomorphic adult phantom. In conclusion, on-line TCM may be considered as a valuable tool for reducing dose in routine CT examinations of pediatric and adult patients. However, the dose reduction achieved with TCM

  2. Role of multidetector-row CT in assessing the source of arterial haemorrhage in patients with pelvic vascular trauma. Comparison with angiography.

    PubMed

    Pinto, A; Niola, R; Tortora, G; Ponticiello, G; Russo, G; Di Nuzzo, L; Gagliardi, N; Scaglione, M; Merola, S; Stavolo, C; Maglione, F; Romano, L

    2010-06-01

    We investigated the role of multidetector-row computed tomography (MDCT) in identifying active bleeding and its source in polytrauma patients with pelvic vascular injuries with or without associated fractures of the pelvis. From January 2003 to December 2007, 28 patients (19 men and nine women, age range 16-80 years) with acute symptoms from blunt pelvic trauma and a drop in haematocrit underwent MDCT and angiography. Conventional radiography of the pelvis was performed in all patients at the time of admission to the emergency department. MDCT was performed with a four-row unit in 15 patients and a 16-row unit in the remaining 13 patients. The study included whole-body CT to identify craniocerebral, vertebral, thoracic, abdominal and pelvic injuries. CT was performed before and after rapid infusion (4-5 ml/s) of intravenous contrast material (120 ml) using a power injector. A triphasic contrast-enhanced study was performed in all patients. MDCT images were transferred to a workstation to assess pelvic fracture, site of haematoma and active extravasation of contrast material, visibility of possible vascular injuries and associated traumatic lesions. At angiography, an abdominal and pelvic aortogram was obtained in all cases before selective catheterisation of the internal iliac arteries and superselective catheterisation of their branches for embolisation purposes. Results related to identifying the source of bleeding at MDCT were compared with sites of bleeding or vascular injury identified by selective pelvic angiography. The sensitivity and positive predictive value (PPV) of MDCT were determined. MDCT allowed us to identify pelvic bleeding in 21/28 patients (75%), with most cases being detected in the delayed contrast-enhanced phase (13/21 cases, 61.9%). Injured arteries were identified on MDCT in 12/21 cases (57%): the obturator artery (n=9), internal iliac artery (n=6), internal pudendal artery (n=6) and superior gluteal artery (n=5) were most frequently

  3. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

    PubMed Central

    Vavere, Andrea L.; Rochitte, Carlos E.; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A.; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E.; Lima, João A. C.

    2012-01-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its noninvasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective “CORE-64” trial (“Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors”). This multi-centre trialwas unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. PMID:18998142

  4. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64.

    PubMed

    Miller, Julie M; Dewey, Marc; Vavere, Andrea L; Rochitte, Carlos E; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A; Bush, David E; Lardo, Albert C; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E; Lima, João A C

    2009-04-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective "CORE-64" trial ("Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors"). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows.

  5. Prevalence of incidental pulmonary findings and early follow-up results in patients undergoing dual-source 64-slice computed tomography coronary angiography.

    PubMed

    Yorgun, Hikmet; Kaya, Ergün Barş; Hazirolan, Tuncay; Ateş, Ahmet Hakan; Canpolat, Uğur; Sunman, Hamza; Aytemr, Kudret; Kabakçi, Giray; Tokgözoğlu, Lale; Karçaaltincaba, Muşturay; Akata, Deniz; Oto, Ali

    2010-01-01

    In this study, we aimed to evaluate the incidence of pulmonary abnormalities and document early follow-up results in subjects undergoing multislice computed tomography coronary angiography for the assessment of coronary artery disease. In this retrospective analysis, 1206 patients including 701 men (58.1%) with a mean age of 58.75 (SD, 11.4) years were involved in the study who underwent coronary multislice computed tomography imaging with a 64-slice dual-source scanner. Pulmonary abnormalities were reported as nodules, pulmonary mass, emphysema, bullae, atelectasia, bronchiectasia, pleural effusion, pulmonary fibrosis, and other findings. In total, 186 pulmonary abnormalities were detected in 171 patients (14.1%). Of those, 90 (48.4%) were pulmonary nodules, and 30 (16.1%) were emphysema. Also, we report 3 cases of lung cancer, and 1 case of breast cancer. Early follow-up results revealed stable pulmonary findings. Multislice computed tomography can give important clues including diseases regarding the pulmonary system. It is essential for the reporting practitioner to review the entire scan for pulmonary pathological findings.

  6. Heart rate recovery after exercise and coronary atheroma in asymptomatic individuals with type 2 diabetes mellitus: a study using 64-slice coronary CT angiography.

    PubMed

    Halon, David A; Dobrecky-Mery, Idit; Gaspar, Tamar; Azencot, Mali; Yaniv, Nisan; Peled, Nathan; Lewis, Basil S

    2010-11-05

    Impaired heart rate recovery after exercise (HRR) is a marker of autonomic dysfunction and a predictor of long-term mortality either directly or due to associated cardiovascular disease. In a cohort of 552 asymptomatic type 2 diabetics (age 63.2 ± 5.4 yr, 54.9% women) participating in a long-term prospective outcomes study, we examined the hypothesis that cardiac autonomic dysfunction, as demonstrated by HRR in the first minute after exercise, is an independent correlate of multivessel coronary artery atheroma. HRR1 was reduced in patients with any coronary plaque (p = 0.012), multivessel coronary plaque (p = 0.006), and coronary stenosis (p = 0.027). However, the association was not independent of the United Kingdom Prospective Diabetes Study risk score thus it appears to be related to the adverse risk profile of these patients.

  7. Planning deep inferior epigastric perforator flaps for breast reconstruction: a comparison between multidetector computed tomography and magnetic resonance angiography.

    PubMed

    Cina, A; Barone-Adesi, L; Rinaldi, P; Cipriani, A; Salgarello, M; Masetti, R; Bonomo, L

    2013-08-01

    Deep inferior epigastric perforator (DIEP) flaps have become the state of the art in breast reconstruction. We compared the diagnostic performance of multidetector computed tomography (CTA) and magnetic resonance angiography (MRA) in DIEP flap planning. Twenty-three women (mean age 48.0 years, range 26-72 years) underwent preoperative blinded evaluation using 64-slice CTA and 1.5-T MRA. Perforator identification, measurement of their calibre, intramuscular course (IMC), assessment of direct venous connections (DVC) with main superficial veins, superficial venous communications (SVC) between the right and left hemi-abdomen and deep inferior epigastric artery (DIEA) branching type were performed. Surgery was carried out by the same team. Intraoperative findings were the standard of reference. Accuracy in identifying dominant perforators was 91.3 % for both techniques and mean error in calibre measurement 1.18 ± 0.35 mm for CTA and 1.63 ± 0.39 mm for MRA. Accuracy in assessing perforator IMCs was 97.1 % for CTA and 88.4 % for MRA, DVC 94.4 % for both techniques, SVC 91.3 % as well, and DIEA branching type 100 % for CTA and 91.3 % for MRA. Image acquisition and interpretation time was 21 ± 3 min for CTA (35 ± 5 min for MRA). In a strategy to optimise DIEP flap planning avoiding radiation exposure, MRA can be proposed alternatively to CTA. • Identification of deep inferior epigastric perforators (DIEP) is important before breast reconstruction. • Both CT and MR angiography are accurate in identifying DIEA perforator branches. • CTA and MRA are equivalent in demonstrating perforator-venous connections. • MRA can be proposed as an alternative to CTA in DIEP planning.

  8. [Valvular heart disease: multidetector computed tomography evaluation].

    PubMed

    Franco, A; Fernández-Pérez, G C; Tomás-Mallebrera, M; Badillo-Portugal, S; Orejas, M

    2014-01-01

    Heart valve disease is a clinical problem that has been studied with classical imaging techniques like echocardiography and MRI. Technological advances in CT make it possible to obtain static and dynamic images that enable not only a morphological but also a functional analysis in many cases. Although it is currently indicated only in patients with inconclusive findings at echocardiography and MRI or those in whom these techniques are contraindicated, multidetector CT makes it possible to diagnose stenosis or regurgitation through planimetry, to evaluate and quantify valvular calcium, and to show the functional repercussions of these phenomena on the rest of the structures of the heart. Given that multidetector CT is being increasingly used in the diagnosis of ischemic heart disease, we think it is interesting for radiologists to know its potential for the study of valvular disease. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  9. Common carotid artery pseudoaneurysm after neck dissection: colour Doppler ultrasound and multidetector computed tomography findings.

    PubMed

    Flor, N; Sardanelli, F; Ghilardi, G; Tentori, A; Franceschelli, G; Felisati, G; Cornalba, G P

    2007-05-01

    Common carotid artery pseudoaneurysm is a rare disease, which has been previously unreported in association with neck dissection. We describe the Doppler ultrasound and multidetector computed tomography (CT) findings of a case of carotid pseudoaneurysm, one month after pharyngolaryngectomy with bilateral neck dissection. Multidetector CT confirmed the diagnosis made on the basis of Doppler ultrasound; the high image quality of axial and three-dimensional reconstructions avoided the need for pre-operative conventional angiography. In the presence of a pulsatile cervical mass after neck surgery, pseudoaneurysm of the carotid artery should be included in the differential diagnosis, and multidetector CT can be the sole pre-operative diagnostic imaging modality.

  10. Diagnostic accuracy of 16-slice multidetector-row CT for detection of in-stent restenosis vs detection of stenosis in nonstented coronary arteries.

    PubMed

    Kefer, Joelle M; Coche, Emmanuel; Vanoverschelde, Jean-Louis J; Gerber, Bernhard L

    2007-01-01

    The purpose of this study was to assess the diagnostic accuracy of 16-slice multidetector-row computed tomography (MDCT) for detecting in-stent restenosis. Fifty patients with 69 previously implanted coronary stents underwent 16-slice MDCT before quantitative coronary angiography (QCA). Diagnostic accuracy of MDCT for detection of in-stent restenosis defined as >50% lumen diameter stenosis (DS) in stented and nonstented coronary segments >1.5-mm diameter was computed using QCA as reference. According to QCA, 18/69 (25%) stented segments had restenosis. In addition, 33/518 (6.4%) nonstented segments had >50% DS. In-stent restenosis was correctly identified on MDCT images in 12/18 stents, and absence of restenosis was correctly identified in 50/51 stents. Stenosis in native coronary arteries was correctly identified in 22/33 segments and correctly excluded in 482/485 segments. Thus, sensitivity (67% vs 67% p=1.0), specificity (98% vs 99%, p=0.96) and overall diagnostic accuracy (90% vs 97%, p=0.68) was similarly high for detecting in-stent restenosis as for detecting stenosis in nonstented coronary segments. MDCT has similarly high diagnostic accuracy for detecting in-stent restenosis as for detecting coronary artery disease in nonstented segments. This suggests that MDCT could be clinically useful for identification of restenosis in patients after coronary stenting.

  11. Three-dimensional volume-rendered multidetector CT imaging of the posterior inferior pancreaticoduodenal artery: its anatomy and role in diagnosing extrapancreatic perineural invasion

    PubMed Central

    Giacomini, Craig; Brooke Jeffrey, R.; Willmann, Juergen K.; Olcott, Eric

    2013-01-01

    Abstract Extrapancreatic perineural spread in pancreatic adenocarcinoma contributes to poor outcomes, as it is known to be a major contributor to positive surgical margins and disease recurrence. However, current staging classifications have not yet taken extrapancreatic perineural spread into account. Four pathways of extrapancreatic perineural spread have been described that conveniently follow small defined arterial pathways. Small field of view three-dimensional (3D) volume-rendered multidetector computed tomography (MDCT) images allow visualization of small peripancreatic vessels and thus perineural invasion that may be associated with them. One such vessel, the posterior inferior pancreaticoduodenal artery (PIPDA), serves as a surrogate for extrapancreatic perineural spread by pancreatic adenocarcinoma arising in the uncinate process. This pictorial review presents the normal and variant anatomy of the PIPDA with 3D volume-rendered MDCT imaging, and emphasizes its role as a vascular landmark for the diagnosis of extrapancreatic perineural invasion from uncinate adenocarcinomas. Familiarity with the anatomy of PIPDA will allow accurate detection of extrapancreatic perineural spread by pancreatic adenocarcinoma involving the uncinate process, and may potentially have important staging implications as neoadjuvant therapy improves. PMID:24434918

  12. 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

  13. 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.

    PubMed

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

    2009-05-07

    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

  14. Consideration of the Pathological Features of Pediatric Congenital Heart Diseases Which Are Ideally Suitable for Diagnosing With Multidetector-row CT

    PubMed Central

    Hayabuchi, Yasunobu; Inoue, Miki; Watanabe, Noriko; Sakata, Miho; Ohnishi, Tatsuya; Kagami, Shoji

    2011-01-01

    Background A lots of articles published regarding the usefulness of multidetector-row computed tomography (MDCT) in children with congenital heart disease (CHD) mostly describe that it can be an alternative to the invasive catheterization and angiography. The unique diagnostic features of this imaging modality have been largely ignored or disregarded. We described the pathological conditions that cannot be diagnosed by conventional angiography with cardiac catheterization but can be accurately diagnosed by MDCT. Methods We retrospectively reviewed non-ECG-gated MDCT images acquired from 452 children and young adults with CHD between 2005 and 2010 in our institute. In this article, we focused on the diagnostic advantages of MDCT, and indicated five pathological conditions. (1) When Blalock-Taussig shunt total occlusion prevents catheter insertion into the artificial vessel and angiography is ruled out, the peripheral pulmonary artery during the peripheral pulmonary artery can be imaged and diagnosed using MDCT based on blood flow supplied from many small collateral vessels originating from the aorta. (2) The location and protrusion of the device in the vessel after coil embolization to treat patent ductus arteriosus can be accurately visualized by virtual endoscopy using MDCT. (3) Calcification of patches, synthetic blood vessels, and other prostheses that is indistinct on conventional angiograms is clear on MDCT. (4) Simultaneous MDCT observations of the anatomical relationships between arterial and venous systems on the same image can clarify the detail diagnosis for surgical treatment. (5) Compression of the airways by the great vessels and pulmonary segmental emphysematous change can be diagnosed by MDCT. Results and Conclusions Among patients with CHD, MDCT is useful not only as a non-invasive alternative to conventional angiography, but also as a tool for specific morphological diagnoses. In the future, it will be necessary to accumulate experience in the

  15. The incidence of pulmonary embolism and deep vein thrombosis and their predictive risk factors after lower extremity arthroplasty: a retrospective analysis based on diagnosis using multidetector CT.

    PubMed

    Fujita, Yoshihisa; Nakatsuka, Hideki; Namba, Yoshifumi; Mitani, Shigeru; Yoshitake, Nami; Sugimoto, Etsuko; Hazama, Keita

    2015-04-01

    The true incidence of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) events, and the predictive risk factors are not well-defined in patients who undergo major lower extremity arthroplasty such as total hip arthroplasty (THA) or total or partial knee arthroplasty (TPKA). Using multidetector computed tomography (MDCT), pulmonary angiography (CTA), and MDCT venography (CTV), we investigated the prevalence of VTE and its predictive risk factors in patients for whom the guideline recommends prophylaxis. The electronic records of patients who underwent elective THA or TPKA at our institution from April 2010 through July 2013 were surveyed. We examined a total of 1,163 patient records for 986 patients who had undergone MDCT seven days after THA or TPKA. No PE-related deaths occurred in this study, though arterial embolization was needed for major bleeding in two cases. CTA-CTV revealed VTE in 51 (4.4 %) patients, PE in 20 (1.7 %), and DVT in 43 (3.3 %). Five of 51 patients had symptoms suggestive of DVT. In the logistic regression model, the type of surgery (TPKA > THA), patient age, and body mass index (BMI) were identified as predictive risk factors for VTE. This observational study showed that the overall incidence of VTE after THA and TPKA is 4.4 % in patients receiving recommended antithrombotic prophylaxis. TPKA is associated with a higher incidence of VTE than of THA, and greater BMI and older patient age are also independent risk factors.

  16. Multi-detector thoracic CT findings in cerebro-costo-mandibular syndrome: rib gaps and failure of costo-vertebral separation.

    PubMed

    Watson, Tom Anthony; Arthurs, Owen John; Muthialu, Nagarajan; Calder, Alistair Duncan

    2014-02-01

    Cerebro-costo-mandibular syndrome (CCMS) describes a triad of mandibular hypoplasia, brain dysfunction and posterior rib defects ("rib gaps"). We present the CT imaging for a 2-year-old girl with CCMS that highlights the rib gap defects and shows absent transverse processes with abnormal fusion of the ribs directly to the vertebral bodies. We argue that this is likely to relate to abnormal lateral sclerotome development in embryology, with the failure of normal costo-vertebral junctions compounding impaired thoracic function. The case also highlights the use of CT for specific indications in skeletal dysplasia.

  17. A new low-dose multi-phase trauma CT protocol and its impact on diagnostic assessment and radiation dose in multi-trauma patients.

    PubMed

    Alagic, Zlatan; Eriksson, Andreas; Drageryd, Erika; Motamed, Sara Rezaei; Wick, Marius C

    2017-04-05

    Computed tomography (CT) examinations, often using high-radiation dosages, are increasingly used in the acute management of polytrauma patients. This study compares a low-dose polytrauma multi-phase whole-body CT (WBCT) protocol on a latest generation of 16-cm detector 258-slice multi-detector CT (MDCT) scanner with advanced dose reduction techniques to a single-phase polytrauma WBCT protocol on a 64-slice MDCT scanner. Between March and September 2015, 109 polytrauma patients (group A) underwent acute WBCT with a low-dose multi-phase WBCT protocol on a 258-slice MDCT whereas 110 polytrauma patients (group B) underwent single-phase trauma CT on a 64-slice MDCT. The diagnostic accuracy to trauma-related injuries, radiation dose, quantitative and semiquantitative image quality parameters, subjective image quality scorings, and workflow time parameters were compared. In group A, statistically significantly more arterial injuries (p = 0.04) and arterial dissections (p = 0.002) were detected. In group A, the mean (±SD) dose length product value was 1681 ± 183 mGy*cm and markedly lower when compared to group B (p < 0.001). The SDs of the mean Houndsfield unit values of the brain, liver, and abdominal aorta were lower in group A (p < 0.001). Mean signal-to-noise ratios (SNRs) for the brain, liver, and abdominal aorta were significantly higher in group A (p < 0.001). Group A had significantly higher image quality scores for all analyzed anatomical locations (p < 0.02). However, the mean time from patient registration until completion of examination was significantly longer for group A (p < 0.001). The low-dose multi-phase CT protocol improves diagnostic accuracy and image quality at markedly reduced radiation. However, due to technical complexities and surplus electronic data provided by the newer low-dose technique, examination time increases, which reduces workflow in acute emergency situations.

  18. Multidetector computed tomography for acute pulmonary embolism.

    PubMed

    Stein, Paul D; Fowler, Sarah E; Goodman, Lawrence R; Gottschalk, Alexander; Hales, Charles A; Hull, Russell D; Leeper, Kenneth V; Popovich, John; Quinn, Deborah A; Sos, Thomas A; Sostman, H Dirk; Tapson, Victor F; Wakefield, Thomas W; Weg, John G; Woodard, Pamela K

    2006-06-01

    The accuracy of multidetector computed tomographic angiography (CTA) for the diagnosis of acute pulmonary embolism has not been determined conclusively. The Prospective Investigation of Pulmonary Embolism Diagnosis II trial was a prospective, multicenter investigation of the accuracy of multidetector CTA alone and combined with venous-phase imaging (CTA-CTV) for the diagnosis of acute pulmonary embolism. We used a composite reference test to confirm or rule out the diagnosis of pulmonary embolism. Among 824 patients with a reference diagnosis and a completed CT study, CTA was inconclusive in 51 because of poor image quality. Excluding such inconclusive studies, the sensitivity of CTA was 83 percent and the specificity was 96 percent. Positive predictive values were 96 percent with a concordantly high or low probability on clinical assessment, 92 percent with an intermediate probability on clinical assessment, and nondiagnostic if clinical probability was discordant. CTA-CTV was inconclusive in 87 of 824 patients because the image quality of either CTA or CTV was poor. The sensitivity of CTA-CTV for pulmonary embolism was 90 percent, and specificity was 95 percent. CTA-CTV was also nondiagnostic with a discordant clinical probability. In patients with suspected pulmonary embolism, multidetector CTA-CTV has a higher diagnostic sensitivity than does CTA alone, with similar specificity. The predictive value of either CTA or CTA-CTV is high with a concordant clinical assessment, but additional testing is necessary when the clinical probability is inconsistent with the imaging results. Copyright 2006 Massachusetts Medical Society.

  19. Multidetector computed tomography angiography of the abdomen.

    PubMed

    Güven, Koray; Acunaş, Bülent

    2004-10-01

    Multidetector computed tomography (MDCT) angiography has provided excellent opportunities for advancement of computed tomography (CT) technology and clinical applications. It has a wide range of applications in the abdomen including vascular pathologies either occlusive or aneurysmal; enables the radiologist to produce vascular mapping that clearly show tumor invasion of vasculature and the relationship of vessels to mass lesions. MDCTA can be used in preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation. MDCTA can also provide extremely valuable information in the evaluation of ischemic bowel disease, active Crohn disease, the extent and location of collateral vessels in cirrhosis.

  20. Effect of Low Tube Voltage on Image Quality, Radiation Dose, and Low-Contrast Detectability at Abdominal Multidetector CT: Phantom Study

    PubMed Central

    Tang, Kun; Wang, Ling; Li, Rui; Lin, Jie; Zheng, Xiangwu; Cao, Guoquan

    2012-01-01

    Purpose. To investigate the effect of low tube voltage (80 kV) on image quality, radiation dose, and low-contrast detectability (LCD) at abdominal computed tomography (CT). Materials and Methods. A phantom containing low-contrast objects was scanned with a CT scanner at 80 and 120 kV, with tube current-time product settings at 150–650 mAs. The differences between image noise, contrast-to-noise ratio (CNR), and scores of LCD obtained with 80 kV at 150–650 mAs and those obtained with 120 kV at 300 mAs were compared respectively. Results. The image noise substantially increased with low tube voltage. However, with identical dose, use of 80 kV resulted in higher CNR compared with CNR at 120 kV. There were no statistically significant difference in CNR and scores of LCD between 120 kV at 300 mAs and 80 kV at 550–650 mAs (P > 0.05). The relative dose delivered at 80 kV ranged from 58% at 550 mAs to 68% at 650 mAs. Conclusion. With a reduction of the tube voltage from 120 kV to 80 kV at abdominal CT, the radiation dose can be reduced by 32% to 42% without degradation of CNR and LCD. PMID:22619490

  1. [Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps].

    PubMed

    Fansa, H; Schirmer, S; Frerichs, O; Gehl, H B

    2011-04-01

    Muscle sparing TRAM flaps and DIEA perforator flaps are standard procedures for breast reconstruction. Recently CT-angiography has been established to evaluate perforator vessels pre-operatively. CT-angiography was introduced to our department in July 2009. In a retrospective analysis data of the last 20 patients (altogether 22 flaps) before CT-angiography introduction and the following 20 (also 22 flaps) patients after introduction of CT-angiography were analysed with regard to the ratio of TRAM to DIEP flaps, and the time required to raise the flaps. The same surgeon raised all flaps. As different surgeons performed dissection of the recipient site, anastomoses, and insertion of flaps, and patients received primary (with sentinel or complete lymphadenctomy) or secondary reconstructions, only the time required harvesting the flap was compared. Thus other influences on raising the flap were eliminated. DIEP flaps were harvested with one single perforator. If perfusion or was considered not to be safe via one single perforator a muscle sparing TRAM flap (ms2) was raised. Angiography was performed using a 64-slice multi-detector CT scanner. CT-angiography did not lead to an increased rate of DIEP flaps in relation to ms2-TRAM flaps. Harvesting time of all flap types with CT-angiography on average was 121 min, without CT-angiography 135 min. This was not significantly different. However, separate analysis of DIEP flaps and ms2-TRAM flaps revealed a significant advantage of CT-angiography based harvesting of DIEP flaps of 26 min: with CT-angiography 101 min vs. 127 min without CT-angiography (p<0.028). There were no significant differences for ms2-TRAM flaps. All scans showed course and branching, diameter and size of the inferior epigastric artery. If evident the superficial inferior epigastric artery (SIEA) was marked. Dosage was 292 mGy-606 mGy×cm dependent on body weight. CTDI was 6.8-14.7 mGy. CT-angiography is a reproducible and observer independent procedure

  2. Dual-energy multidetector CT: how does it work, what can it tell us, and when can we use it in abdominopelvic imaging?

    PubMed

    Coursey, Courtney A; Nelson, Rendon C; Boll, Daniel T; Paulson, Erik K; Ho, Lisa M; Neville, Amy M; Marin, Daniele; Gupta, Rajan T; Schindera, Sebastian T

    2010-01-01

    Dual-energy CT provides information about how substances behave at different energies, the ability to generate virtual unenhanced datasets, and improved detection of iodine-containing substances on low-energy images. Knowing how a substance behaves at two different energies can provide information about tissue composition beyond that obtainable with single-energy techniques. The term K edge refers to the spike in attenuation that occurs at energy levels just greater than that of the K-shell binding because of the increased photoelectric absorption at these energy levels. K-edge values vary for each element, and they increase as the atomic number increases. The energy dependence of the photoelectric effect and the variability of K edges form the basis of dual-energy techniques, which may be used to detect substances such as iodine, calcium, and uric acid crystals. The closer the energy level used in imaging is to the K edge of a substance such as iodine, the more the substance attenuates. In the abdomen and pelvis, dual-energy CT may be used in the liver to increase conspicuity of hypervascular lesions; in the kidneys, to distinguish hyperattenuating cysts from enhancing renal masses and to characterize renal stone composition; in the adrenal glands, to characterize adrenal nodules; and in the pancreas, to differentiate between normal and abnormal parenchyma.

  3. The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms.

    PubMed

    Brisse, H J; Brenot, J; Pierrat, N; Gaboriaud, G; Savignoni, A; De Rycke, Y; Neuenschwander, S; Aubert, B; Rosenwald, J-C

    2009-04-07

    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 LCD(1%) assessed in a Catphan phantom and a constant central absorbed dose. The required variations of CTDIvol(16) 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 CNR(2.8%)), 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 rLCD(1%) for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol(16) values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

  4. 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).

  5. The effect of z overscanning on radiation burden of pediatric patients undergoing head CT with multidetector scanners: A Monte Carlo study

    SciTech Connect

    Tzedakis, Antonis; Perisinakis, Kostas; Raissaki, Maria; Damilakis, John

    2006-07-15

    The purpose of this study was to investigate the effect of z overscanning on eye lens dose and effective dose received by pediatric patients undergoing head CT examinations. A pediatric patient study was carried out to obtain the exposure parameters and data regarding the eye lens position with respect to imaged volume boundaries. This information was used to simulate CT exposures by Monte Carlo code. The Monte Carlo N-Particle (MCNP, version 4C2) radiation transport code and five mathematical anthropomorphic phantoms representing newborn, 1-, 5-, 10-, and 15-year-old patient, were employed in the current study. To estimate effective dose, the weighted computed tomography dose index was calculated by cylindrical polymethyl-methacrylate phantoms of 9.7, 13.1, 15.4, 16.1, and 16.9 cm in diameter representing the pediatric head of newborn, 1-, 5-, 10-, and 15-year-old individuals, respectively. The validity of the Monte Carlo calculated approach was verified by comparison with dose data obtained using physical pediatric anthropomorphic phantoms and thermoluminescence dosimetry. For all patients studied, the eye lenses were located in the region -1 to 3 cm from the first slice of the imaged volume. Doses from axial scans were always lower than those from corresponding helical examinations. The percentage differences in normalized eye lens absorbed dose between contiguous axial and helical examinations with pitch=1 were found to be up to 10.9%, when the eye lenses were located inside the region to be imaged. When the eye lenses were positioned 0-3 cm far from the first slice of region to be imaged, the normalized dose to the lens from contiguous axial examinations was up to 11 times lower than the corresponding values from helical mode with pitch=1. The effective dose from axial examinations was up to 24% lower than corresponding values from helical examinations with pitch=1. In conclusion, it is more dose efficient to use axial mode acquisition rather than helical scan

  6. Transcatheter Arterial Embolization Therapy for a Hypoplastic Pelvic Kidney with a Single Vaginal Ectopic Ureter to Control Incontinence: The Usefulness of Three-Dimensional CT Angiography Using Multidetector-Row Helical CT

    SciTech Connect

    Kudoh, Kouichi Kadota, Masataka; Nakayama, Yoshiharu; Imuta, Masanori; Yasuda, Tsuyoshi; Yamashita, Yasuyuki; Inadome, Akito; Yoshida, Masaki; Ueda, Shouichi

    2003-09-15

    A girl with continuous urinary incontinence was successfully treated by angiographic embolization of a hypoplastic pelvic kidney with a single unilateral vaginal ectopic opening of the ureter. For this intervention, CT angiography was useful for detecting the corresponding renal artery of the hypoplastic kidney.

  7. Patient-specific dose estimation for pediatric chest CT

    SciTech Connect

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P.

    2008-12-15

    Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ dose for

  8. Radiation dose reduction with application of non-linear adaptive filters for abdominal CT

    PubMed Central

    Singh, Sarabjeet; Kalra, Mannudeep K; Sung, Mi Kim; Back, Anni; Blake, Michael A

    2012-01-01

    AIM: To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different radiation dose levels. METHODS: Nineteen patients (mean age 61.6 ± 7.9 years, M:F = 8:11) gave informed consent for an Institutional Review Board approved prospective study involving acquisition of 4 additional image series (200, 150, 100, 50 mAs and 120 kVp) on a 64 slice multidetector row CT scanner over an identical 10 cm length in the abdomen. The CT images acquired at 150, 100 and 50 mAs were processed with the NLAF. Two radiologists reviewed unprocessed and processed images for image quality in a blinded randomized manner. CT dose index volume, dose length product, patient weight, transverse diameters, objective noise and CT numbers were recorded. Data were analyzed using Analysis of Variance and Wilcoxon signed rank test. RESULTS: Of the 31 lesions detected in abdominal CT images, 28 lesions were less than 1 cm in size. Subjective image noise was graded as unacceptable in unprocessed images at 50 and 100 mAs, and in NLAF processed images at 50 mAs only. In NLAF processed images, objective image noise was decreased by 21% (14.4 ± 4/18.2 ± 4.9) at 150 mAs, 28.3% (15.7 ± 5.6/21.9 ± 4) at 100 mAs and by 39.4% (18.8 ± 9/30.4 ± 9.2) at 50 mAs compared to unprocessed images acquired at respective radiation dose levels. At 100 mAs the visibility of smaller structures improved from suboptimal in unprocessed images to excellent in NLAF processed images, whereas diagnostic confidence was respectively improved from probably confident to fully confident. CONCLUSION: NLAF lowers image noise, improves the visibility of small structures and maintains lesion conspicuity at down to 100 mAs for abdominal CT. PMID:22328968

  9. Multidetector CT of hepatic artery pathologies.

    PubMed

    Karaosmanoglu, D; Erol, B; Karcaaltincaba, M

    2012-01-01

    The hepatic artery can be involved by a variety of pathology and diseases.Today MDCT enables high quality imaging of the hepatic artery using axial, MIP and volume rendered images. We illustrate MDCT findings of anatomical variations, aneurysm, dilatation, dissection, arteriovenous fistula, thrombosis and stenosis. Aneurysms can be saccular, fusiform and multiple and may develop due to atherosclerosis, vasculitis, trauma and biopsy. Dilatation of hepatic artery can be seen in portal hypertension, Osler-Weber-Rendu disease and hemangiomatosis. Hepatic artery can be occluded after trauma and transplantation. Dissection develops due to atherosclerosis, Marfan and Ehler Danlos syndromes and during pregnancy. Arteriovenous fistula can be congenital and acquired. We conclude that various hepatic artery pathologies can be confidently diagnosed by MDCT.

  10. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    MedlinePlus

    ... a Heart Attack Treatment of a Heart Attack Life After a Heart Attack Heart Failure About Heart Failure ... Non-invasive - Invasive • Treatment of a Heart Attack • Life After a Heart Attack • Heart Attack Tools & Resources • Support ...

  11. Usefulness of multidetector spiral computed tomography according to age and gender for diagnosis of acute pulmonary embolism.

    PubMed

    Stein, Paul D; Beemath, Afzal; Quinn, Deborah A; Olson, Ronald E; Goodman, Lawrence R; Gottschalk, Alexander; Hales, Charles A; Hull, Russell D; Leeper, Kenneth V; Sostman, H Dirk; Weg, John G; Woodard, Pamela K

    2007-05-01

    Data from the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) were evaluated to test the hypothesis that the performance of multidetector computed tomographic (CT) pulmonary angiography and CT venography is independent of a patient's age and gender. In 773 patients with adequate CT pulmonary angiography and 737 patients with adequate CT pulmonary angiography and CT venography, the sensitivity and specificity for pulmonary embolism for groups of patients aged 18 to 59, 60 to 79, and 80 to 99 years did not differ to a statistically significant extent, nor were there significant differences according to gender. Overall, however, the specificity of CT pulmonary angiography was somewhat greater in women, but in men and women, it was > or =93%. In conclusion, the results indicate that multidetector CT pulmonary angiography and CT pulmonary angiography and CT venography may be used with various diagnostic strategies in adults of all ages and both genders.

  12. Coronary CT angiography with low radiation dose.

    PubMed

    Xu, Lei; Zhang, Zhaoqi

    2010-02-01

    With the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography(CCTA) has emerged as a useful diagnostic imaging modality for the noninvasive assessment of coronary heart disease. Recently, the risks associated with ionizing radiation on CT have raised serious concerns.The main concern of exposure to ionizing radiation is the potential risk of cancer. CCTA involves much higher radiation dose with the advances in the spatial and temporal resolution of cardiac CT. Currently,various dose-saving algorithms, such as ECG (electrocardiography)-based dose modulation, reduced tube voltage, and prospective ECG gating, high-pitch helical scanning are available to lower radiation exposure during cardiac CT. Therefore, careful selection of CT scanning protocols is needed to keep the radiation exposure 'as low as reasonably achievable (ALARA)'. In this review we will discuss the radiation dose safety issues, the measurement of radiation dose and current use of dose-saving techniques in CCTA.

  13. The role of multidetector CT in the evaluation of the left atrium and pulmonary veins anatomy before and after radio-frequency catheter ablation for atrial fibrillation. Preliminary results and work in progress. Technical note.

    PubMed

    Centonze, Maurizio; Del Greco, Maurizio; Nollo, Giandomenico; Ravelli, Flavia; Marini, Massimiliano; Della Sala, Sabino Walter; Dalla Palma, Francesco

    2005-01-01

    Radio-frequency catheter ablation (RFCA) of the distal pulmonary veins is increasingly being used to treat recurrent or refractory atrial fibrillation that doesn't respond to pharmacologic therapy or cardioversion. Successful RFCA of atrial fibrillation depends on the pre-procedural understanding of the complex anatomy of the distal pulmonary veins and the left atrium. Aim of this paper is to describe the technical main features that characterise the multidetector helical computed tomography in the evaluation of this anatomic region before and after RFCA procedure. The 3D post-processing techniques useful for pre-RFCA planning are straightforward.

  14. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography

    PubMed Central

    Soukup, Jason W.; Drees, Randi; Koenig, Lisa J.; Snyder, Christopher J.; Hetzel, Scott; Miles, Chanda R.; Schwarz, Tobias

    2016-01-01

    Summary The objective of this blinded study was to validate the use of cone beam computed tomography (CT) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT. Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methyl methacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxilla segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored. In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting, cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT. PMID:26415384

  15. Impact of Calcium Score on Agreement Between Multidetector Computed Tomography and Invasive Coronary Angiography.

    PubMed

    de Agustín, José Alberto; Gómez de Diego, José Juan; Marcos-Alberca, Pedro; Mahía, Patricia; Rodrigo, José Luis; Luaces, María; Núñez-Gil, Iván Javier; Ferreiros, Joaquín; Bustos, Ana; Cabeza, Beatriz; García-Fernández, Miguel Ángel; Macaya, Carlos; Pérez de Isla, Leopoldo

    2017-05-18

    Multidetector computed tomography (MDCT) has been demonstrated as a feasible alternative to invasive coronary angiography (ICA). However, contradictory results have been reported regarding the effect of coronary artery calcium score (CS) on the diagnostic accuracy of MDCT. Our aim was to assess the agreement of MDCT and ICA and to evaluate the influence of CS on this agreement. We enrolled 266 consecutive patients who underwent evaluation with 64-slice MDCT and ICA. Standard CS software tools were used to calculate the Agatston score. Stenosis was qualitatively classified as mild, moderate, or severe by 1 blinded observer and the results were compared with those of ICA, which was used as the gold standard. The mean age of the patients was 65.4 ± 11.2 years, and 188 patients (70.3%) were men. A total of 484 segments with coronary stenosis ≥ mild were qualitatively evaluated and quantified with MDCT. Noninvasive measurements were concordant with ICA in 402 stenoses (83.05%; Kappa, 0.684), with no significant differences between vessels and with no statistically significant influence of CS on this agreement (OR, 0.93; 95%CI, 0.76-1.09; P = .21). Multidetector computed tomography had high sensitivity, specificity, positive predictive value, and negative predictive value on a per-segment, per-vessel, and per-patient basis. Non-ICA using MDCT showed good agreement with ICA in the qualitative quantification coronary stenosis and CS had no significant impact on this agreement. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Associations Between Cardio-Ankle Vascular Index and Aortic Structure and Sclerosis Using Multidetector Computed Tomography.

    PubMed

    Horinaka, Shigeo; Yagi, Hiroshi; Fukushima, Hiromichi; Shibata, Yoshimasa; Takeshima, Hiroshi; Ishimitsu, Toshihiko

    2017-04-01

    Aortic pulse wave velocity (PWV) has been accepted as the gold standard for arterial stiffness measurement. However, PWV depends on blood pressure (BP). To eliminate the BP dependency of PWV, the cardio-ankle vascular index (CAVI) was developed. This study aimed to define the relationship between CAVI and aortic atherosclerosis or structure on multidetector computed tomography (MDCT). Patients with (n = 49) or without (n = 49) coronary artery disease were studied. The lumen and vessel diameters and wall thickness were calculated from the cross-sectional area at the pulmonary bifurcation level by 64-slice MDCT. The CAVI was measured within 3 days before MDCT. Multivariate analysis showed that the vessel diameter of the ascending and descending aorta on MDCT depends on age, body surface area, and diastolic BP. The CAVI significantly correlated with the vessel diameter ( r = .453) and wall thickness ( r = .387) of the thoracic descending aorta ( P < .001, respectively). The CAVI was an independent predictor of the descending aortic wall thickness on multiple stepwise regression analysis. These data suggest that CAVI, a simple index, is useful for evaluating thoracic aortic atherosclerosis.

  17. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography.

    PubMed

    Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias

    2015-01-01

    The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.

  18. Is weight-based adjustment of automatic exposure control necessary for the reduction of chest CT radiation dose?

    PubMed

    Prakash, Priyanka; Kalra, Mannudeep K; Gilman, Matthew D; Shepard, Jo-Anne O; Digumarthy, Subba R

    2010-01-01

    To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and non-weight-adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; < 60 kg (n = 17), 60-90 kg (n = 52), and > 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p < 0.0001). With weight-adjusted AEC, the CTDIvol decreased to 15.8, 15.9, and 27.3 mGy for the < 60, 60-90 and > 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight-adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 +/- 3.1) and weight-adjusted (16.1 +/- 5.6) AEC techniques (p > 0.05). The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT.

  19. A novel method of estimating effective dose from the point dose method: a case study—parathyroid CT scans

    NASA Astrophysics Data System (ADS)

    Januzis, Natalie; Nguyen, Giao; Hoang, Jenny K.; Lowry, Carolyn; Yoshizumi, Terry T.

    2015-02-01

    The purpose of this study was to validate a novel approach of applying a partial volume correction factor (PVCF) using a limited number of MOSFET detectors in the effective dose (E) calculation. The results of the proposed PVCF method were compared to the results from both the point dose (PD) method and a commercial CT dose estimation software (CT-Expo). To measure organ doses, an adult female anthropomorphic phantom was loaded with 20 MOSFET detectors and was scanned using the non-contrast and 2 phase contrast-enhanced parathyroid imaging protocols on a 64-slice multi-detector computed tomography scanner. E was computed by three methods: the PD method, the PVCF method, and the CT-Expo method. The E (in mSv) for the PD method, the PVCF method, and CT-Expo method was 2.6  ±  0.2, 1.3  ±  0.1, and 1.1 for the non-contrast scan, 21.9  ±  0.4, 13.9  ±  0.2, and 14.6 for the 1st phase of the contrast-enhanced scan, and 15.5  ±  0.3, 9.8  ±  0.1, and 10.4 for the 2nd phase of the contrast-enhanced scan, respectively. The E with the PD method differed from the PVCF method by 66.7% for the non-contrast scan, by 44.9% and by 45.5% respectively for the 1st and 2nd phases of the contrast-enhanced scan. The E with PVCF was comparable to the results from the CT-Expo method with percent differences of 15.8%, 5.0%, and 6.3% for the non-contrast scan and the 1st and 2nd phases of the contrast-enhanced scan, respectively. To conclude, the PVCF method estimated E within 16% difference as compared to 50-70% in the PD method. In addition, the results demonstrate that E can be estimated accurately from a limited number of detectors.

  20. Hepatocellular carcinoma: prediction of blood supply from an intercostal artery with multidetector row computed tomography.

    PubMed

    Kim, Min-Uk; Kim, Hyo-Cheol; Chung, Jin Wook; An, Sangbu; Seong, Nak Jong; Jae, Hwan Jun; Park, Jae Hyung

    2011-10-01

    To evaluate the ability of multidetector row computed tomography (CT) to detect blood supply from the intercostal artery in patients with hepatocellular carcinoma (HCC). Between January 2003 and December 2007, angiography of the intercostal artery was performed in 93 patients (76 men and 17 women, mean age 58 years) with HCC who had also undergone multidetector row CT. CT scans and digital subtraction angiograms of these patients were retrospectively reviewed by two investigators in consensus to evaluate tumor feeding vessels. Multiple logistic regression analysis was used to identify factors that predict the presence of an HCC blood supply from an intercostal artery. Tumor staining fed by an intercostal artery was noted in 65 patients (70%; 112 tumor feeding vessels) by intercostal angiography. Readers interpreted that tumor feeding vessels were evident by CT in 35 (54%) of these 65 patients with tumor staining supplied by an intercostal artery by angiography. Multiple logistic regression analysis showed that a visible tumor feeding vessel by CT (P = .003) and hepatic artery attenuation by angiography (P = .014) were significantly related to the presence of a blood supply from an intercostal artery. Visualization of a tumor feeding vessel from the intercostal artery by multidetector row CT is an important sign of parasitic supply to an HCC. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  1. 64-section multiphase CT enterography as a diagnostic tool in the evaluation of obscure gastrointestinal bleeding.

    PubMed

    Sodhi, Jaswinder Singh; Zargar, Showkat Ali; Rashid, Wasim; Shaheen, Feroz; Singh, Manjeet; Javid, Gul; Ali, Sadaf; Khan, Bashir Ahmad; Yattoo, Ghulam Nabi; Shah, Altaf; Gulzar, Ghulam Mohamad; Khan, Mushtaq Ahmed; Ahmad, Zeeshan

    2012-04-01

    Small bowel follow through (SBFT) and enteroclysis have low sensitivity in picking up lesions in obscure gastrointestinal bleed (OGIB). Computed tomographic enterography (CT-EG), performed with 64-slice multiphase CT system by using large volumes of ingested neutral enteric contrast material, has high spatial and temporal resolution in visualization of the small bowel wall and lumen. The role of 64-slice multiphase CT-EG in the evaluation of OGIB is still evolving, and data on this role are scarce. We evaluated the efficacy of 64-slice multiphase CT-EG using polyethylene glycol (PEG) electrolyte solution as neutral contrast in patients of OGIB. CT-EG was performed with 64-slice multiphase CT system using large volume (2,000 mL) of PEG electrolyte solution as oral contrast in patients of OGIB. Thirty-five patients (21 men, age 41.4 [13.5] y, range 19-70 year) with OGIB underwent CT-EG; 20 patients had overt OGIB whereas 15 patients had occult OGIB. Among 15 patients with occult OGIB, 10 patients had iron deficiency anemia (IDA) with fecal occult blood test (FOBT) positive and 5 had IDA with FOBT negative. Thirty-two patients (92 %) completed the procedure successfully. The total time taken for the ingestion of 2,000 mL of PEG electrolyte solution was median 64 (range 60-78) minutes. Adequate luminal distension of small bowel was seen in 29 (90.6 %) patients for successful interpretation of radiological images. Fifteen of 32 (46.9 %) patients had positive findings on CT-EG; 12 of them underwent exploratory laparotomy. The surgical findings were in conformity with CT-EG findings in all patients, which included gastrointestinal stromal tumors (GIST; n = 6), carcinoid (1), Meckel's diverticulum (1), small bowel adenocarcinoma (2) and jejunal vascular malformation (2). 64-slice multiphase CT-EG is a useful investigation in the evaluation of both occult and overt OGIB.

  2. CT enterography.

    PubMed

    Zamboni, Giulia A; Raptopoulos, Vassilios

    2010-04-01

    Conventional radiologic and endoscopic evaluations of the small bowel are often limited by the length, caliber, and motility of the small bowel loops. The development of new multidetector-row CT scanners, with faster scan times and isotropic spatial resolution, allows high-resolution multiphasic and multiplanar assessment of the bowel, bowel wall, and lumen. CT Enterography (CTE) is a variant of routine abdominal scanning, geared toward more sustained bowel filling with oral contrast material, and the use of multiplanar images, that can enhance gastrointestinal (GI) tract imaging. This article examines the techniques and clinical applications of CTE in comparison with CT enteroclysis, focusing on Crohn disease, obscure GI bleeding, GI tumors, acute abdominal pain, and bowel obstruction. Copyright 2010 Elsevier Inc. All rights reserved.

  3. The feasibility of patient size-corrected, scanner-independent organ dose estimates for abdominal CT exams.

    PubMed

    Turner, Adam C; Zhang, Di; Khatonabadi, Maryam; Zankl, Maria; DeMarco, John J; Cagnon, Chris H; Cody, Dianna D; Stevens, Donna M; McCollough, Cynthia H; McNitt-Gray, Michael F

    2011-02-01

    A recent work has demonstrated the feasibility of estimating the dose to individual organs from multidetector CT exams using patient-specific, scanner-independent CTDIvol-to-organ-dose conversion coefficients. However, the previous study only investigated organ dose to a single patient model from a full-body helical CT scan. The purpose of this work was to extend the validity of this dose estimation technique to patients of any size undergoing a common clinical exam. This was done by determining the influence of patient size on organ dose conversion coefficients generated for typical abdominal CT exams. Monte Carlo simulations of abdominal exams were performed using models of 64-slice MDCT scanners from each of the four major manufacturers to obtain dose to radiosensitive organs for eight patient models of varying size, age, and gender. The scanner-specific organ doses were normalized by corresponding CTDIvol values and averaged across scanners to obtain scanner-independent CTDIvol-to-organ-dose conversion coefficients for each patient model. In order to obtain a metric for patient size, the outer perimeter of each patient was measured at the central slice of the abdominal scan region. Then, the relationship between CTDIvol-to-organ-dose conversion coefficients and patient perimeter was investigated for organs that were directly irradiated by the abdominal scan. These included organs that were either completely ("fully irradiated") or partly ("partially irradiated") contained within the abdominal exam region. Finally, dose to organs that were not at all contained within the scan region ("nonirradiated") were compared to the doses delivered to fully irradiated organs. CTDIvol-to-organ-dose conversion coefficients for fully irradiated abdominal organs had a strong exponential correlation with patient perimeter. Conversely, partially irradiated organs did not have a strong dependence on patient perimeter. In almost all cases, the doses delivered to nonirradiated

  4. Determining contrast medium dose and rate on basis of lean body weight: does this strategy improve patient-to-patient uniformity of hepatic enhancement during multi-detector row CT?

    PubMed

    Ho, Lisa M; Nelson, Rendon C; Delong, David M

    2007-05-01

    To prospectively evaluate the use of lean body weight (LBW) as the main determinant of the volume and rate of contrast material administration during multi-detector row computed tomography of the liver. This HIPAA-compliant study had institutional review board approval. All patients gave written informed consent. Four protocols were compared. Standard protocol involved 125 mL of iopamidol injected at 4 mL/sec. Total body weight (TBW) protocol involved 0.7 g iodine per kilogram of TBW. Calculated LBW and measured LBW protocols involved 0.86 g of iodine per kilogram and 0.92 g of iodine per kilogram calculated or measured LBW for men and women, respectively. Injection rate used for the three experimental protocols was determined proportionally on the basis of the calculated volume of contrast material. Postcontrast attenuation measurements during portal venous phase were obtained in liver, portal vein, and aorta for each group and were summed for each patient. Patient-to-patient enhancement variability in same group was measured with Levene test. Two-tailed t test was used to compare the three experimental protocols with the standard protocol. Data analysis was performed in 101 patients (25 or 26 patients per group), including 56 men and 45 women (mean age, 53 years). Average summed attenuation values for standard, TBW, calculated LBW, and measured LBW protocols were 419 HU +/- 50 (standard deviation), 443 HU +/- 51, 433 HU +/- 50, and 426 HU +/- 33, respectively (P = not significant for all). Levene test results for summed attenuation data for standard, TBW, calculated LBW, and measured LBW protocols were 40 +/- 29, 38 +/- 33 (P = .83), 35 +/- 35 (P = .56), and 26 +/- 19 (P = .05), respectively. By excluding highly variable but poorly perfused adipose tissue from calculation of contrast medium dose, the measured LBW protocol may lessen patient-to-patient enhancement variability while maintaining satisfactory hepatic and vascular enhancement.

  5. Analysis of the topological properties of the proximal femur on a regional scale: evaluation of multi-detector CT-scans for the assessment of biomechanical strength using local Minkowski functionals in 3D

    NASA Astrophysics Data System (ADS)

    Boehm, H. F.; Link, T. M.; Monetti, R. A.; Kuhn, V.; Eckstein, F.; Raeth, C. W.; Reiser, M.

    2006-03-01

    In our recent studies on the analysis of bone texture in the context of Osteoporosis, we could already demonstrate the great potential of the topological evaluation of bone architecture based on the Minkowski Functionals (MF) in 2D and 3D for the prediction of the mechanical strength of cubic bone specimens depicted by high resolution MRI. Other than before, we now assess the mechanical characteristics of whole hip bone specimens imaged by multi-detector computed tomography. Due to the specific properties of the imaging modality and the bone tissue in the proximal femur, this requires to introduce a new analysis method. The internal architecture of the hip is functionally highly specialized to withstand the complex pattern of external and internal forces associated with human gait. Since the direction, connectivity and distribution of the trabeculae changes considerably within narrow spatial limits it seems most reasonable to evaluate the femoral bone structure on a local scale. The Minkowski functionals are a set of morphological descriptors for the topological characterization of binarized, multi-dimensional, convex objects with respect to shape, structure, and the connectivity of their components. The MF are usually used as global descriptors and may react very sensitively to minor structural variations which presents a major limitation in a number of applications. The objective of this work is to assess the mechanical competence of whole hip bone specimens using parameters based on the MF. We introduce an algorithm that considers the local topological aspects of the bone architecture of the proximal femur allowing to identify regions within the bone that contribute more to the overall mechanical strength than others.

  6. Advances and perspectives in lung cancer imaging using multidetector row computed tomography.

    PubMed

    Coche, Emmanuel

    2012-10-01

    The introduction of multidetector row computed tomography (CT) into clinical practice has revolutionized many aspects of the clinical work-up. Lung cancer imaging has benefited from various breakthroughs in computing technology, with advances in the field of lung cancer detection, tissue characterization, lung cancer staging and response to therapy. Our paper discusses the problems of radiation, image visualization and CT examination comparison. It also reviews the most significant advances in lung cancer imaging and highlights the emerging clinical applications that use state of the art CT technology in the field of lung cancer diagnosis and follow-up.

  7. Semi-automated scoring of pulmonary emphysema from X-ray CT: trainee reproducibility and accuracy.

    PubMed

    Owrangi, Amir M; Entwistle, Brandon; Lu, Andrew; Chiu, Jack; Hussain, Nabil; Etemad-Rezai, Roya; Parraga, Grace

    2013-11-01

    We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies. Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0=no abnormalities, 1=1-25%, 2=26-50%, 3=51-75% and 4=76-100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU 15), relative area at -950 HU (RA(950)), low attenuation clusters at -950 HU (LAC(950)), -856 HU (LAC(856)) and the diffusing capacity for carbon monoxide (DL(CO%pred)). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations. Trainee-expert correlations were significant (r=0.85-0.97, p<0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA(950) (r=0.88, p<0.0001), HU 15 (r=-0.77, p<0.0001), LAC(950) (r=0.76, p<0.0001), LAC(856) (r=0.74, p=0.0001) and DLCO%pred (r=-0.71, p<0.0001). Intra-observer reproducibility (COV=4-27%; ICC=0.75-0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score. We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Photon intensity interferometry with multidetectors

    NASA Astrophysics Data System (ADS)

    Badalà, A.; Barbera, R.; Palmeri, A.; Pappalardo, G. S.; Riggi, F.; Russo, A. C.; Russo, G.; Turrisi, R.

    1994-12-01

    The technique of two-photon interferometry in heavy ion collisions at the intermediate energies is discussed and the importance of a new methodology, used in the treatment of the experimental data, is evidenced. For the first time, both the relative momentum, qrel, and the relative energy, q0, of the two correlated photons have been simultaneously used to extract the source size and lifetime of the emitting source. As an application, the performances of the BaF 2 ball of the MEDEA multidetector as a photon intensity interferometer have been evaluated. The response of such a detector to correlated pairs of photons has been studied through full GEANT3 simulations. The effects of the experimental filter on the photon correlation function have been investigated, and the noise, induced in the correlation signal by cosmic radiation, neutral pion decay, and γ-conversion, has also been estimated.

  9. Effect of Radiation Dose Reduction and Reconstruction Algorithm on Image Noise, Contrast, Resolution, and Detectability of Subtle Hypoattenuating Liver Lesions at Multidetector CT: Filtered Back Projection versus a Commercial Model-based Iterative Reconstruction Algorithm.

    PubMed

    Solomon, Justin; Marin, Daniele; Roy Choudhury, Kingshuk; Patel, Bhavik; Samei, Ehsan

    2017-02-07

    Purpose To determine the effect of radiation dose and iterative reconstruction (IR) on noise, contrast, resolution, and observer-based detectability of subtle hypoattenuating liver lesions and to estimate the dose reduction potential of the IR algorithm in question. Materials and Methods This prospective, single-center, HIPAA-compliant study was approved by the institutional review board. A dual-source computed tomography (CT) system was used to reconstruct CT projection data from 21 patients into six radiation dose levels (12.5%, 25%, 37.5%, 50%, 75%, and 100%) on the basis of two CT acquisitions. A series of virtual liver lesions (five per patient, 105 total, lesion-to-liver prereconstruction contrast of -15 HU, 12-mm diameter) were inserted into the raw CT projection data and images were reconstructed with filtered back projection (FBP) (B31f kernel) and sinogram-affirmed IR (SAFIRE) (I31f-5 kernel). Image noise (pixel standard deviation), lesion contrast (after reconstruction), lesion boundary sharpness (average normalized gradient at lesion boundary), and contrast-to-noise ratio (CNR) were compared. Next, a two-alternative forced choice perception experiment was performed (16 readers [six radiologists, 10 medical physicists]). A linear mixed-effects statistical model was used to compare detection accuracy between FBP and SAFIRE and to estimate the radiation dose reduction potential of SAFIRE. Results Compared with FBP, SAFIRE reduced noise by a mean of 53% ± 5, lesion contrast by 12% ± 4, and lesion sharpness by 13% ± 10 but increased CNR by 89% ± 19. Detection accuracy was 2% higher on average with SAFIRE than with FBP (P = .03), which translated into an estimated radiation dose reduction potential (±95% confidence interval) of 16% ± 13. Conclusion SAFIRE increases detectability at a given radiation dose (approximately 2% increase in detection accuracy) and allows for imaging at reduced radiation dose (16% ± 13), while maintaining low

  10. Patient-specific dose estimation for pediatric chest CT

    PubMed Central

    Li, Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P.

    2008-01-01

    Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9–18.2kg) were created based on the patients’ actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120kVp, 70 or 75mA, 0.4s gantry rotation period, pitch of 1.375, 20mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7–5.3mSv∕100mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4–12.6mGy∕100mAs and 11.2–13.3mGy∕100mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%–18%) and for partially or indirectly exposed organs (11%–77%). Normalized effective dose correlated weakly with body weight (correlation coefficient:r=−0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=−0.99, heart: r=−0.93); these strong correlation relationships can be used to estimate patient

  11. Rare bilateral C6 spondylolysis and spondylolisthesis in an adolescent athlete: evaluation with magnetic resonance imaging and multidetector computerized tomography.

    PubMed

    Amin, Mohammed F; Mollano, Anthony V; Weinstein, Stuart L; El-Khoury, George Y

    2006-10-01

    Case report. To show a rare case of cervical spondylolysis and spondylolisthesis secondary to bilateral stress fractures at the pedicle laminar junction of C6 in a 16-year-old athlete playing high school baseball. The patient presented with 3 months of neck pain and intermittent right arm radicular symptoms. Plain radiographs and multidetector computerized tomography (CT) of the cervical spines. Plain radiographs revealed loss of lower cervical lordosis. Multidetector CT indicated bilateral C6 spondylolysis. Magnetic resonance imaging showed bilateral marrow edema at the pedicle laminar junction of C6. Treatment included placing his neck in a Philadelphia collar for 6 weeks. Follow-up CT revealed progression of healing. Early diagnosis and appropriate management of these cases are important to promote healing.

  12. Role of cardiac multidetector computed tomography beyond coronary angiography.

    PubMed

    Sato, Akira; Aonuma, Kazutaka

    2015-01-01

    Cardiac multidetector computed tomography (MDCT) has become a useful noninvasive modality for anatomical imaging of coronary artery disease (CAD). Currently, the main clinical advantage of coronary computed tomography angiography (CCTA) appears to be related to its high negative predictive value at low or intermediate pretest probability for CAD. With the development of technical aspects of MDCT, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology, myocardial perfusion, and patient outcomes. The presence of positive vessel remodeling, low-attenuation plaques, napkin-ring sign, or spotty calcification on CCTA could be useful information on high-risk vulnerable plaques. The napkin-ring sign, especially, showed higher accuracy for the detection of thin-cap fibroatheroma. Recently, it was reported that cardiac 3D single-photon emission tomography/CT fusion imaging, noninvasive fractional flow reserve computed from CT, and integrated CCTA and CT myocardial perfusion were associated with improved diagnostic accuracy for the detection of hemodynamically significant CAD. Furthermore, several randomized, large clinical trials have evaluated the clinical value of CCTA for chest pain triage in the emergency department or long-term reduction in death, myocardial infarction, or hospitalization for unstable angina. In this review we discuss the role of cardiac MDCT beyond coronary angiography, including a comparison with other currently available imaging modalities used to examine atherosclerotic plaque and myocardial perfusion.

  13. Multidetector calibration for mass spectrometers

    SciTech Connect

    Bayne, C.K.; Donohue, D.L.; Fiedler, R.

    1994-06-01

    The International Atomic Energy Agency`s Safeguards Analytical Laboratory has performed calibration experiments to measure the different efficiencies among multi-Faraday detectors for a Finnigan-MAT 261 mass spectrometer. Two types of calibration experiments were performed: (1) peak-shift experiments and (2) peak-jump experiments. For peak-shift experiments, the ion intensities were measured for all isotopes of an element in different Faraday detectors. Repeated measurements were made by shifting the isotopes to various Faraday detectors. Two different peak-shifting schemes were used to measure plutonium (UK Pu5/92138) samples. For peak-jump experiments, ion intensities were measured in a reference Faraday detector for a single isotope and compared with those measured in the other Faraday detectors. Repeated measurements were made by switching back-and-forth between the reference Faraday detector and a selected Faraday detector. This switching procedure is repeated for all Faraday detectors. Peak-jump experiments were performed with replicate measurements of {sup 239}Pu, {sup 187}Re, and {sup 238}U. Detector efficiency factors were estimated for both peak-jump and peak-shift experiments using a flexible calibration model to statistically analyze both types of multidetector calibration experiments. Calculated detector efficiency factors were shown to depend on both the material analyzed and the experimental conditions. A single detector efficiency factor is not recommended for each detector that would be used to correct routine sample analyses. An alternative three-run peak-shift sample analysis should be considered. A statistical analysis of the data from this peak-shift experiment can adjust the isotopic ratio estimates for detector differences due to each sample analysis.

  14. Prospective study evaluating the relative sensitivity of 18F-NaF PET/CT for detecting skeletal metastases from renal cell carcinoma in comparison to multidetector CT and 99mTc-MDP bone scintigraphy, using an adaptive trial design

    PubMed Central

    Gerety, E. L.; Lawrence, E. M.; Wason, J.; Yan, H.; Hilborne, S.; Buscombe, J.; Cheow, H. K.; Shaw, A. S.; Bird, N.; Fife, K.; Heard, S.; Lomas, D. J.; Matakidou, A.; Soloviev, D.; Eisen, T.; Gallagher, F. A.

    2015-01-01

    Background The detection of occult bone metastases is a key factor in determining the management of patients with renal cell carcinoma (RCC), especially when curative surgery is considered. This prospective study assessed the sensitivity of 18F-labelled sodium fluoride in conjunction with positron emission tomography/computed tomography (18F-NaF PET/CT) for detecting RCC bone metastases, compared with conventional imaging by bone scintigraphy or CT. Patients and methods An adaptive two-stage trial design was utilized, which was stopped after the first stage due to statistical efficacy. Ten patients with stage IV RCC and bone metastases were imaged with 18F-NaF PET/CT and 99mTc-labelled methylene diphosphonate (99mTc-MDP) bone scintigraphy including pelvic single photon emission computed tomography (SPECT). Images were reported independently by experienced radiologists and nuclear medicine physicians using a 5-point scoring system. Results Seventy-seven lesions were diagnosed as malignant: 100% were identified by 18F-NaF PET/CT, 46% by CT and 29% by bone scintigraphy/SPECT. Standard-of-care imaging with CT and bone scintigraphy identified 65% of the metastases reported by 18F-NaF PET/CT. On an individual patient basis, 18F-NaF PET/CT detected more RCC metastases than 99mTc-MDP bone scintigraphy/SPECT or CT alone (P = 0.007). The metabolic volumes, mean and maximum standardized uptake values (SUVmean and SUVmax) of the malignant lesions were significantly greater than those of the benign lesions (P < 0.001). Conclusions 18F-NaF PET/CT is significantly more sensitive at detecting RCC skeletal metastases than conventional bone scintigraphy or CT. The detection of occult bone metastases could greatly alter patient management, particularly in the context when standard-of-care imaging is negative for skeletal metastases. PMID:26202597

  15. CHIMERA Multidetector at Laboratori Nazionali del Sud

    SciTech Connect

    Aiello, S.; Anzalone, A.; Baldo, M.; Barna, R.; Campisi, M.g.; Cardella, G.; Cavallaro, Sl., Amico, V.D.; De Filippo, E.; DePasquale, D.; Femino, S.; Geraci, E.; Giustolisi, F.; Guazzoni, P.; Iacono-Manno, C.M.; Italiano, A.; Lanzalone, G.; Lanzano, G.; LoNigro, S.; Lombardo, U.; Manfredi, G.; Pagano, A.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Sambataro, S.; Sperduto, M.L.; Sutera, C.M.; Zetta, L.

    2000-12-31

    The installation of CHIMERA multidetector, designed in order to study central collisions in heavy ion reactions at intermediate energy, is going on at LNS and the first experiment with the forward part (688 telescopes) is running since May 1999. The aim of this contribution is to present the status of the project.

  16. Bladder trauma: multidetector computed tomography cystography.

    PubMed

    Ishak, Charbel; Kanth, Nalini

    2011-08-01

    Multidetector computed tomography (MDCT) cystography is rapidly becoming the most recommended study for evaluation of the bladder for suspected trauma. This article reviews the bladder trauma with emphasis on the application of MDCT cystography to traumatic bladder injuries using a pictorial essay based on images collected in our level I trauma center.

  17. Pericardial fat amount is an independent risk factor of coronary artery stenosis assessed by multidetector-row computed tomography: the Korean Atherosclerosis Study 2.

    PubMed

    Kim, Tae Hyuk; Yu, Sung Hoon; Choi, Sung Hee; Yoon, Ji Won; Kang, Seon Mee; Chun, Eun Ju; Choi, Sang Il; Shin, Hayley; Lee, Hong Kyu; Park, Kyong Soo; Jang, Hak Chul; Lim, Soo

    2011-05-01

    Pericardial fat surrounding the heart and coronary arteries might aggravate vessel wall inflammation and stimulate the progression of coronary atherosclerosis. However, there has been little comprehensive evaluation of the effects of pericardial fat on coronary artery disease (CAD). We investigated the relationship between pericardial fat volume and the severity of coronary artery stenosis assessed by computed tomography and angiography among patients with suspected CAD. Participants from the cohort of the Korean Atherosclerosis Study 2 (n = 402, mean age of 54 years, 57.0% men) underwent 64-slice multidetector-row computed tomography (MDCT) to assess pericardial fat amount, coronary artery calcium score (CACS), severity of coronary artery stenosis, and plaque characteristics. Patients with atherosclerotic lesion had significantly larger volume of pericardial fat than patients without atherosclerosis (308 ± 96 cm(3) vs. 251 ± 93 cm(3); P < 0.01). In a multivariate regression analysis adjusting for age, gender and BMI, subjects with more pericardial fat had a higher risk for significant (>50%) stenosed coronary vessels (odds ratio (OR) = 1.012; 95% confidence interval (CI) 1.001-1.030; P = 0.017). This association remained after adjusting for hypertension, diabetes, smoking status, and lipid profiles (OR = 1.007; 95% CI 1.001-1.014; P = 0.042). In conclusion, an increased pericardial fat volume was an independent risk factor for stenotic CAD and could be helpful in assessing subclinical CADs.

  18. Multidetector computed tomographic pulmonary angiography in patients with a high clinical probability of pulmonary embolism.

    PubMed

    Moores, L; Kline, J; Portillo, A K; Resano, S; Vicente, A; Arrieta, P; Corres, J; Tapson, V; Yusen, R D; Jiménez, D

    2016-01-01

    ESSENTIALS: When high probability of pulmonary embolism (PE), sensitivity of computed tomography (CT) is unclear. We investigated the sensitivity of multidetector CT among 134 patients with a high probability of PE. A normal CT alone may not safely exclude PE in patients with a high clinical pretest probability. In patients with no clear alternative diagnosis after CTPA, further testing should be strongly considered. Whether patients with a negative multidetector computed tomographic pulmonary angiography (CTPA) result and a high clinical pretest probability of pulmonary embolism (PE) should be further investigated is controversial. This was a prospective investigation of the sensitivity of multidetector CTPA among patients with a priori clinical assessment of a high probability of PE according to the Wells criteria. Among patients with a negative CTPA result, the diagnosis of PE required at least one of the following conditions: ventilation/perfusion lung scan showing a high probability of PE in a patient with no history of PE, abnormal findings on venous ultrasonography in a patient without previous deep vein thrombosis at that site, or the occurrence of venous thromboembolism (VTE) in a 3-month follow-up period after anticoagulation was withheld because of a negative multidetector CTPA result. We identified 498 patients with a priori clinical assessment of a high probability of PE and a completed CTPA study. CTPA excluded PE in 134 patients; in these patients, the pooled incidence of VTE was 5.2% (seven of 134 patients; 95% confidence interval [CI] 1.5-9.0). Five patients had VTEs that were confirmed by an additional imaging test despite a negative CTPA result (five of 48 patients; 10.4%; 95% CI 1.8-19.1), and two patients had objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months (two of 86 patients; 2.3%; 95% CI 0-5.5). None of the patients had a fatal PE during follow-up. A normal multidetector CTPA result alone may not safely

  19. The measurement of opening angle and orifice area of a bileaflet mechanical valve using multidetector computed tomography.

    PubMed

    Lee, Dong-Hyeon; Youn, Ho-Joong; Shim, Sung-Bo; Lee, Sun-Hee; Jung, Jung-Im; Jung, Seung-Eun; Choi, Yun-Seok; Park, Chul-Soo; Oh, Yong-Seog; Chung, Wook-Sung; Kim, Jae-Hyung

    2009-04-01

    The aim of this study was to assess mechanical valve function using 64-slice multidetector computed tomography (MDCT). In 20 patients (mean age, 50+/-12 years; male-to-female ratio, 10:10), 30 St. Jude bileaflet mechanical valves (15 aortic and 15 mitral valves) were evaluated using MDCT. We selected images vertical and parallel to the mechanical valve. The valve orifice area (OA) and valve length were determined by manual tracing and the opening and closing angles were measured using a protractor. The OA and length of the mechanical valves were compared with the manufacturer's values. The geometric orifice areas (GOAs) based on the manufacturer's values and the OAs determined by MDCT were 3.4+/-0.2 cm(2) and 3.4+/-0.3 cm(2) for the mitral valves and 2.1+/-0.3 cm(2) and 2.1+/-0.4 cm(2) for the aortic valves, respectively. The correlation coefficients between the OA measures were 0.433 for the mitral valves and 0.874 for the aortic valves (both p<0.001). The lengths based on the manufacturer's values and determined by MDCT were 29.3+/-1.99 mm and 29.6+/-1.65 mm for the mitral valves and 21.5+/-2.1 mm and 20.7+/-2.3 mm for the aortic valves, respectively. The correlation coefficients between the measures were 0.651 for the mitral valve and 0.846 for the aortic valve (both p<0.001). The opening and closing angles determined by MDCT were 10.9+/-0.6 degrees and 131.1+/-3.2 degrees for the mitral valves and 11.1+/-0.9 degrees and 120.6+/-1.7 degrees for the aortic valves, respectively. MDCT is an accurate modality with which to assess the function and morphology of bileaflet mechanical valves.

  20. Magnetic resonance imaging of pulmonary infection in immunocompromised children: comparison with multidetector computed tomography.

    PubMed

    Ozcan, H Nursun; Gormez, Ayşegul; Ozsurekci, Yasemin; Karakaya, Jale; Oguz, Berna; Unal, Sule; Cetin, Mualla; Ceyhan, Mehmet; Haliloglu, Mithat

    2017-02-01

    Computed tomography (CT) is commonly used to detect pulmonary infection in immunocompromised children. To compare MRI and multidetector CT findings of pulmonary abnormalities in immunocompromised children. Seventeen neutropaenic children (6 girls; ages 2-18 years) were included. Non-contrast-enhanced CT was performed with a 64-detector CT scanner. Axial and coronal non-enhanced thoracic MRI was performed using a 1.5-T scanner within 24 h of the CT examination (true fast imaging with steady-state free precession, fat-saturated T2-weighted turbo spin echo with motion correction, T2-weighted half-Fourier single-shot turbo spin echo [HASTE], fat-saturated T1-weighted spoiled gradient echo). Pulmonary abnormalities (nodules, consolidations, ground glass opacities, atelectasis, pleural effusion and lymph nodes) were evaluated and compared among MRI sequences and between MRI and CT. The relationship between MRI sequences and nodule sizes was examined by chi- square test. Of 256 CT lesions, 207 (81%, 95% confidence interval [CI] 76-85%) were detected at MRI. Of 202 CT-detected nodules, 157 (78%, 95% CI 71-83%) were seen at motion-corrected MRI. Of the 1-5-mm nodules, 69% were detected by motion-corrected T2-weighted MRI and 38% by HASTE MRI. Sensitivity of MRI (both axial fat-saturated T2-weighted turbo spin echo with variable phase encoding directions (BLADE) images and HASTE sequences) to detect pulmonary abnormalities is promising.

  1. Validation of a paediatric thyroid phantom using different multidetector computed tomography models

    NASA Astrophysics Data System (ADS)

    Alsabbagh, M.; Ng, L. Y.; Tajuddin, A. A.; Manap, M. A.; Zainon, R.

    2016-03-01

    The aim of this study was to compare the attenuation values of a fabricated paediatric thyroid phantom material using different MDCT models. A paediatric thyroid phantom was designed to mimic the shape and size of a paediatric patient with an age of 9 years using high- density Polyethylene as the phantom material. The fabricated phantom was scanned using two different multidetector CT scanners (16- and 128-row detectors). The CT numbers were evaluated and the mass attenuation coefficients (μ/ρ) of the phantom material were obtained at each applied energy from each scanner. The results were compared with the tables of the National Institute of Standards and Technology (NIST). The CTs of 16- and 128-row detectors showed that the obtained attenuation values are very similar to the NIST's values. However, the CT of the 128-row detectors showed a slightly much closer match to the NIST's values. This refers to the type and quality of the electronic connections between the detectors. Furthermore, the type and number of detectors (16- and 128-detectors) could affect the details and quality of the output images. The results show that different multidetector CTs can be used to validate the phantom and determine the mass attenuation coefficients of its material.

  2. Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity

    PubMed Central

    Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

    2016-01-01

    Abstract Purpose: To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. Methods: A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA. As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Results: Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP. Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. Conclusion: MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP. PMID:27399123

  3. Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity.

    PubMed

    Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

    2016-07-01

    To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA.As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP.Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP.

  4. State-of-the-art in CT hardware and scan modes for cardiovascular CT

    PubMed Central

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J.; Gentry, Ralph; George, Richard T.; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm. Guy

    2013-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and the coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography (SCCT) Basic and Emerging Sciences and Technology (BEST) Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging. PMID:22551595

  5. State-of-the-art in CT hardware and scan modes for cardiovascular CT.

    PubMed

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J; Gentry, Ralph; George, Richard T; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm Guy

    2012-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography Basic and Emerging Sciences and Technology Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging.

  6. Visibility of sutures of the orbit and periorbital region using multidetector computed tomography.

    PubMed

    Gufler, Hubert; Preiß, Markus; Koesling, Sabrina

    2014-01-01

    Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from "not visible" to "well visible". The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans.

  7. Visibility of Sutures of the Orbit and Periorbital Region Using Multidetector Computed Tomography

    PubMed Central

    Preiß, Markus; Koesling, Sabrina

    2014-01-01

    Objective Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Materials and Methods Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from "not visible" to "well visible". The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Results Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Conclusion Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans. PMID:25469093

  8. Estimating patient dose from CT exams that use automatic exposure control: Development and validation of methods to accurately estimate tube current values.

    PubMed

    McMillan, Kyle; Bostani, Maryam; Cagnon, Christopher H; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia H; McNitt-Gray, Michael F

    2017-08-01

    The vast majority of body CT exams are performed with automatic exposure control (AEC), which adapts the mean tube current to the patient size and modulates the tube current either angularly, longitudinally or both. However, most radiation dose estimation tools are based on fixed tube current scans. Accurate estimates of patient dose from AEC scans require knowledge of the tube current values, which is usually unavailable. The purpose of this work was to develop and validate methods to accurately estimate the tube current values prescribed by one manufacturer's AEC system to enable accurate estimates of patient dose. Methods were developed that took into account available patient attenuation information, user selected image quality reference parameters and x-ray system limits to estimate tube current values for patient scans. Methods consistent with AAPM Report 220 were developed that used patient attenuation data that were: (a) supplied by the manufacturer in the CT localizer radiograph and (b) based on a simulated CT localizer radiograph derived from image data. For comparison, actual tube current values were extracted from the projection data of each patient. Validation of each approach was based on data collected from 40 pediatric and adult patients who received clinically indicated chest (n = 20) and abdomen/pelvis (n = 20) scans on a 64 slice multidetector row CT (Sensation 64, Siemens Healthcare, Forchheim, Germany). For each patient dataset, the following were collected with Institutional Review Board (IRB) approval: (a) projection data containing actual tube current values at each projection view, (b) CT localizer radiograph (topogram) and (c) reconstructed image data. Tube current values were estimated based on the actual topogram (actual-topo) as well as the simulated topogram based on image data (sim-topo). Each of these was compared to the actual tube current values from the patient scan. In addition, to assess the accuracy of each method in estimating

  9. [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.

  10. Diagnostic Yield of Multidetector Computed Tomography in Patients with Acute Spondylodiscitis.

    PubMed

    Rausch, Vanessa Hanna; Bannas, Peter; Schoen, Gerhard; Froelich, Andreas; Well, Lennart; Regier, Marc; Adam, Gerhard; Henes, Frank Oliver Gerhard

    2017-03-01

    Purpose To determine the value of multidetector computed tomography (MDCT) in patients with acute spondylodiscitis. Methods and Materials For data acquisition, we searched our radiological database for all patients who had undergone magnetic resonance imaging (MRI) for suspected spondylodiscitis between 2007 and 2015 (n = 325). For further analyses, we included all patients (n = 67) who initially underwent MDCT prior to MRI. Overall accuracy, sensitivity, specificity and positive and negative predictive values were calculated for MDCT and, separately, for contrast-enhanced CT (CECT, n = 36) and for non-enhanced CT (NECT, n = 31). MRI together with clinical evaluation served as the standard of reference.

  11. Dose performance of a 64-channel dual-source CT scanner.

    PubMed

    McCollough, Cynthia H; Primak, Andrew N; Saba, Osama; Bruder, Herbert; Stierstorfer, Karl; Raupach, Rainer; Suess, Christoph; Schmidt, Bernhard; Ohnesorge, Bernd M; Flohr, Thomas G

    2007-06-01

    To prospectively compare the dose performance of a 64-channel multi-detector row computed tomographic (CT) scanner and a 64-channel dual-source CT scanner from the same manufacturer. To minimize dose in the cardiac (dual-source) mode, the evaluated dual-source CT system uses a cardiac beam-shaping filter, three-dimensional adaptive noise reduction, heart rate-dependent pitch, and electrocardiographically based modulation of the tube current. Weighted CT dose index per 100 mAs was measured for the head, body, and cardiac beam-shaping filters. Kerma-length product was measured in the spiral cardiac mode at four pitch values and three electrocardiographic modulation temporal windows. Noise was measured in an anthropomorphic phantom. Data were compared with data from a 64-channel multi-detector row CT scanner. For the multi-detector row and dual-source CT systems, respectively, weighted CT dose index per 100 mAs was 14.2 and 12.2 mGy (head CT), 6.8 and 6.4 mGy (body CT), and 6.8 and 5.3 mGy (cardiac CT). In the spiral cardiac mode (no electrocardiographically based tube current modulation, 0.2 pitch), equivalent noise occurred at volume CT dose index values of 23.7 and 35.0 mGy (coronary artery calcium CT) and 58.9 and 61.2 mGy (coronary CT angiography) for multi-detector row CT and dual-source CT, respectively. The use of heart rate-dependent pitch values reduced volume CT dose index to 46.2 mGy (0.265 pitch), 34.0 mGy (0.36 pitch), and 26.6 mGy (0.46 pitch) compared with 61.2 mGy for 0.2 pitch. The use of electrocardiographically based tube current-modulation and temporal windows of 110, 210, and 310 msec further reduced volume CT dose index to 9.1-25.1 mGy, dependent on the heart rate. For electrocardiographically gated coronary CT angiography, image noise equivalent to that of multi-detector row CT can be achieved with dual-source CT at doses comparable to or up to a factor of two lower than the doses at multi-detector row CT, depending on heart rate of the patient

  12. Association of Neutrophil-to-Lymphocyte Ratio with the Severity and Morphology of Coronary Atherosclerotic Plaques Detected by Multidetector Computerized Tomography

    PubMed Central

    Ateş, Ahmet Hakan; Aytemir, Kudret; Koçyiğit, Duygu; Yalcin, Muhammed Ulvi; Gürses, Kadri Murat; Yorgun, Hikmet; Canpolat, Uğur; Hazırolan, Tuncay; Özer, Necla

    2016-01-01

    Background Studies have demonstrated a consistent relationship between white blood cell (WBC) counts and coronary artery disease (CAD). The neutrophil/lymphocyte ratio (NLR) has been considered as a potential marker for identifying individuals under risk of CAD and associated events. In this study, we aimed to evaluate whether NLR was associated with the severity and morphology of coronary atherosclerotic plaques shown by multidetector computed tomography (MDCT). Methods Our study population consisted of 684 patients who underwent dual-source 64 slice MDCT for the assessment of CAD. Coronary arteries were evaluated on a 16-segment basis and critical coronary plaque was described as luminal narrowing > 50%, whereas plaque morphology was assessed on a per segment basis. Total WBC, neutrophil and lymphocyte counts were determined using commercially available assay kits. Results WBC count [7700 (6400-8800) vs. 6800 (5700-7900), p < 0.05] and NLR [2.40 (1.98-3.07) vs. 1.86 (1.50-2.38), p < 0.001] were found to be higher in patients with critical stenosis than in those without. In the binary logistic regression analysis, NLR was a predictor of critical stenosis (odds ratio, 1.68; 95% confidence interval, 1.39-2.03, p < 0.001). NLR levels differed among plaque morphology subtypes (p < 0.05) and was significantly higher in non-calcified plaque (NCP) compared to mixed plaque (MP) and calcified plaque (CP) (p < 0.05). In the multinomial logistic regression analysis, NLR was found to be an independent predictor of NCP, MP and CP (p < 0.001). Conclusions These data show that NLR is associated with both the severity and morphology of coronary atherosclerotic disease. PMID:27899854

  13. SU-E-I-21: Dosimetric Characterization and Image Quality Evaluation of the AIRO Mobile CT Scanner

    SciTech Connect

    Weir, V; Zhang, J; Bruner, A

    2015-06-15

    Purpose: The AIRO Mobile CT system was recently introduced which overcomes the limitations from existing CT, CT fluoroscopy, and intraoperative O-arm. With an integrated table and a large diameter bore, the system is suitable for cranial, spine and trauma procedures, making it a highly versatile intraoperative imaging system. This study is to investigate radiation dose and image quality of the AIRO and compared with those from a routine CT scanner. Methods: Radiation dose was measured using a conventional 100mm pencil ionization chamber and CT polymethylmetacrylate (PMMA) body and head phantoms. Image quality was evaluated with a CATPHAN 500 phantom. Spatial resolution, low contrast resolution (CNR), Modulation Transfer Function (MTF), and Normalized Noise Power Spectrum (NNPS) were analyzed. Results: Under identical technique conditions, radiation dose (mGy/mAs) from the AIRO mobile CT system (AIRO) is higher than that from a 64 slice CT scanner. MTFs show that both Soft and Standard filters of the AIRO system lost resolution quickly compared to the Sensation 64 slice CT. With the Standard kernel, the spatial resolutions of the AIRO system are 3lp/cm and 4lp/cm for the body and head FOVs, respectively. NNPSs show low frequency noise due to ring-like artifacts. Due to a higher dose in terms of mGy/mAs at both head and body FOV, CNR of the AIRO system is higher than that of the Siemens scanner. However detectability of the low contrast objects is poorer in the AIRO due to the presence of ring artifacts in the location of the targets. Conclusion: For image guided surgery applications, the AIRO has some advantages over a routine CT scanner due to its versatility, large bore size, and acceptable image quality. Our evaluation of the physical performance helps its future improvements.

  14. [CT - diagnosis and differential diagnosis of inflammatory acute intestinal conditions].

    PubMed

    Wiesner, W

    2011-08-24

    Multidetector-row CT has shown over the past years that it is able to provide reliable diagnoses in various acute intestinal conditions. The presented article provides an overview of primary and secondary inflammatory acute intestinal pathologies and their differential diagnoses.

  15. Multislice CT angiography in coronary artery disease: Technical developments, radiation dose and diagnostic value

    PubMed Central

    Sun, Zhonghua

    2010-01-01

    Multislice computed tomography (CT) angiography has been increasingly used in the detection and diagnosis of coronary artery disease because of its rapid technical evolution from the early generation of 4-slice CT scanners to the latest models such as 64-slice, 256-slice and 320-slice CT scanners. Technical developments of multislice CT imaging enable improved diagnostic value in the detection of coronary artery disease, and this indicates that multislice CT can be used as a reliable less-invasive alternative to invasive coronary angiography in selected patients. In addition, multislice CT angiography has played a significant role in the prediction of disease progression and cardiac events. Despite promising results reported in the literature, multislice CT has the disadvantage of having a high radiation dose which could contribute to the radiation-induced malignancy. A variety of strategies have been currently undertaken to reduce the radiation dose associated with multislice CT coronary angiography while in the meantime acquiring diagnostic images. In this article, the author will review the technical developments, radiation dose associated with multislice CT coronary angiography, and strategies to reduce radiation dose. The diagnostic and prognostic value of multislice CT angiography in coronary artery disease is briefly discussed, and future directions of multislice CT angiography in the diagnosis of coronary artery disease will also be highlighted. PMID:21160611

  16. Research on radiation exposure from CT part of hybrid camera and diagnostic CT

    NASA Astrophysics Data System (ADS)

    Solný, Pavel; Zimák, Jaroslav

    2014-11-01

    Research on radiation exposure from CT part of hybrid camera in seven different Departments of Nuclear Medicine (DNM) was conducted. Processed data and effective dose (E) estimations led to the idea of phantom verification and comparison of absorbed doses and software estimation. Anonymous data from about 100 examinations from each DNM was gathered. Acquired data was processed and utilized by dose estimation programs (ExPACT, ImPACT, ImpactDose) with respect to the type of examination and examination procedures. Individual effective doses were calculated using enlisted programs. Preserving the same procedure in dose estimation process allows us to compare the resulting E. Some differences and disproportions during dose estimation led to the idea of estimated E verification. Consequently, two different sets of about 100 of TLD 100H detectors were calibrated for measurement inside the Aldersnon RANDO Anthropomorphic Phantom. Standard examination protocols were examined using a 2 Slice CT- part of hybrid SPECT/CT. Moreover, phantom exposure from body examining protocol for 32 Slice and 64 Slice diagnostic CT scanner was also verified. Absorbed dose (DT,R) measured using TLD detectors was compared with software estimation of equivalent dose HT values, computed by E estimation software. Though, only limited number of cavities for detectors enabled measurement within the regions of lung, liver, thyroid and spleen-pancreas region, some basic comparison is possible.

  17. Dynamic multidetector computed tomography findings of hepatocellular carcinoma of hepatitis B virus-positive and -negative patients

    PubMed Central

    2014-01-01

    Background The objective of this study was to retrospectively investigate and compare multidetector computed tomography findings of hepatocellular carcinoma (HCC) in hepatitis B virus (HBV)-positive and -negative patients. Methods Triphasic (arterial, portal venous, and delayed phases) dynamic multidetector computed tomography (CT) was performed in 83 patients with HCC, 48 of whom were HBV-positive. The diagnosis of HCC was established with typical CT imaging findings (68 patients) or histopathological evaluation (15 patients). Distribution of solitary, multiple, and diffuse HCC, portal/hepatic vein thrombosis, metastasis, and patients with high alpha-fetoprotein levels in the HBV-positive and -negative groups were compared using the Kolmogorov–Smirnov test. Lesion size, alpha-fetoprotein levels, arterial, portal, delayed enhancement, and washout of lesions were compared using the Student’s t-test. Results Hypervascular tumors were observed in 72 (87%) patients, and hypovascular tumors were found in 11 (13%) patients. The mean alpha-fetoprotein value of HBV-positive patients with HCC was significantly higher than the mean alpha-fetoprotein value of HBV-negative patients (P < 0.05). Portal/hepatic vein thrombosis and metastasis were more frequently observed in HBV-positive patients (P < 0.05). The frequencies of solitary, multiple, and diffuse lesions in HBV-positive and -negative patients were not significantly different (P > 0.05). The mean diameters, arterial, portal, and delayed phase attenuations, and washout of HCC were not significantly different (P > 0.05). Conclusions Multidetector CT imaging findings of HCC in HBV-positive and -negative patients are alike. Portal/hepatic vein thrombosis and metastasis are more frequently observed in HBV-positive patients. Alpha-fetoprotein levels are higher in HBV-positive patients. PMID:25608603

  18. [Visualization of pulmonary vein stenosis after radio frequency ablation for treatment of atrial fibrillation using multidetector computed tomography with retrospective gating].

    PubMed

    Trabold, T; Küttner, A; Heuschmid, M; Burgstahler, C; Mewis, C; Kopp, A F; Schröder, S; Kühlkamp, V; Claussen, C D

    2003-01-01

    With the number of radio frequency ablations (RFA) for treatment of chronic atrial fibrillation increasing, the diagnostic evaluation for RFA associated pulmonary vein stenosis is getting more important. This study investigates the feasibility of the visualization of pulmonary vein stenosis using non-invasive multidetector computed tomography. Twenty-eight patients were examined following RFA-treatment. A 4-slice (20 patients) and a 16-slice (8 patients) multidetector CT scanner (SOMATOM Volume Zoom and Sensation 16, Siemens, Forchheim, Germany) with retrospective gating was used to assess the pulmonary veins. Lesion severity was determined on a semi-quantitative scale (< 30 %, 30 - 50 %, > 50 %). CT was performed without any complications in all patients. Diagnostic image quality could be obtained in all examinations. The pulmonary veins showed lesions < 30 % in four patients, lesions of 30 -, 50 % in five patients and a stenosis > 50 % in one patient. Eighteen patients showed no lesions. Multidetector CT of the pulmonary veins seems to be able to visualize high-grade and low-grade lesions, but larger catheter-controlled studies are needed for further assessment of the diagnostic accuracy and clinical reliability of this noninvasive method.

  19. Visualisation of the Bonebridge by means of CT and CBCT

    PubMed Central

    2013-01-01

    Background With the Bonebridge, a new bone-anchored hearing aid has been available since March 2012. The objective of the study was to analyse the visualisation of the implant itself as well as its impact on the representation of the bony structures of the petrosal bone in CT, MRI and cone beam CT (CBCT). Methods The Bonebridge was implanted unilaterally in two completely prepared human heads. The radiological imaging by means of CBCT, 64-slice CT, 1.5-T and 3.0-T MRI was conducted both preoperatively and postoperatively. The images were subsequently evaluated from both the ENT medical and nd radiological perspectives. Results As anticipated, no visualisation of the implant or of the petrosal bones could be realised on MRI because of the interactive technology and the magnet artefact. In contrast, an excellent evaluability of the implant itself as well as of the surrounding neurovascular structures (sinus sigmoideus, skull base, middle ear, inner ear, inner auditory canal) was exhibited in both the CT and in the CBCT. Conclusion The Bonebridge can be excellently imaged with the radiological imaging technologies of CT and CBCT. In the process, CBCT shows discrete advantages in comparison with CT. No relevant restrictions in image quality in the evaluation of the bony structures of the petrosal bones could be seen. PMID:24004903

  20. 64-Slice CT angiography of the abdominal aorta and abdominal arteries: comparison of the diagnostic efficacy of iobitridol 350 mgI/ml versus iomeprol 400 mgI/ml in a prospective, randomised, double-blind multi-centre trial.

    PubMed

    Loewe, Christian; Becker, Christoph R; Berletti, Riccardo; Cametti, Carlo Alberto; Caudron, Jerome; Coudyzer, Walter; De Mey, Johan; Favat, Massimo; Heautot, Jean-François; Heye, Sam; Hittinger, Markus; Larralde, Antoine; Lestrat, Jean-Pierre; Marangoni, Roberto; Nieboer, Koenraad; Reimer, Peter; Schwarz, Martin; Schernthaner, Melanie; Lammer, Johannes

    2010-03-01

    The purpose of this study was to assess the influence of iodine concentration on diagnostic efficacy in multi-detector-row computed tomography (MDCT) angiography of the abdominal aorta and abdominal arteries. IRB approval and informed consent were obtained. In this double-blind trial, patients were randomised to undergo MDCT angiography of the abdominal arteries during administration of iobitridol (350 mgI/ml) or iomeprol (400 mgI/ml). Each centre applied its own technique for delivery of contrast medium, regardless of iodine concentration. Diagnostic efficacy, image quality, visualisation of the arterial wall and arterial enhancement were evaluated. A total of 153 patients received iobitridol and 154 received iomeprol. The ability to reach a diagnosis was "satisfactory" to "totally satisfactory" in 152 (99.3%) and 153 (99.4%) patients respectively. Image quality was rated as being "good" to "excellent" in 94.7 and 94.8% segments respectively. Similar results were observed for image quality of arterial walls (84.3 vs. 83.2%). The mean relative changes in arterial enhancement between baseline and arterial phase images showed no statistically significant differences. This study demonstrated the non-inferiority of the 350 versus 400 mgI/ml iodine concentration, in terms of diagnostic efficacy, in abdominal MDCT angiography. It also confirmed the high robustness and reliability of this technique across multi-national practices.

  1. Morphometric analysis of sex differences in contemporary Japanese pelves using multidetector computed tomography.

    PubMed

    Torimitsu, Suguru; Makino, Yohsuke; Saitoh, Hisako; Sakuma, Ayaka; Ishii, Namiko; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Yamaguchi, Rutsuko; Hashimoto, Mari; Hoshioka, Yumi; Iwase, Hirotaro

    2015-12-01

    Sex estimation of decomposed or skeletal remains is clearly important in forensic contexts. Recently, contemporary population-specific data has been obtained using multidetector computed tomography (MDCT) scanning. The main purpose of this study was to investigate skeletal pelvic dimorphism in a contemporary Japanese forensic sample and to quantify the accuracy of sex estimation using various pelvic measurements obtained from three-dimensional (3D) CT images. This study used a total of 208 cadavers (104 males, 104 females) of which postmortem CT scanning and subsequent forensic autopsy were conducted between December 2011 and August 2014. Eleven measurements of each pelvis were obtained from 3D CT reconstructed images that extracted only bone data. The measurements were analyzed using descriptive statistics and discriminant function analyses. All except one measurement were dimorphic in terms of sex differences. Univariate discriminant function analyses using these measurements provided sex classification accuracy rates of 62.0-98.1%. The subpubic angle was found to contribute most significantly to accurate sex estimation. Multivariate discriminant functions yielded sex prediction accuracy rates of 63.9-98.1%. In conclusion, the pelvic measurements obtained from 3D CT images of a contemporary Japanese population successfully demonstrated sexual dimorphism and may be useful for the estimation of skeletal sex in the field of forensic anthropology.

  2. Diagnostic accuracy of intra-abdominal fluid collection characterization in the era of multidetector computed tomography.

    PubMed

    Allen, Brian C; Barnhart, Huiman; Bashir, Mustafa; Nieman, Christopher; Breault, Steven; Jaffe, Tracy A

    2012-02-01

    The purpose of this study was to test the hypothesis that with improved technology, the presence of abscess in a postoperative fluid collection may be prospectively made. This is an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective review of computed tomography (CT)-guided intra-abdominal fluid collection drainages. The diagnostic CT scans of 95 consecutive patients performed on 16- and 64-multidetector CT (MDCT) were reviewed by four readers with varying abdominal imaging expertise. Readers were asked to determine fluid content, to document whether infection was present, and to rate reader confidence for infection. A fifth radiologist reviewed the collections for imaging characteristics. The gold standard for presence of infection was microbiological Gram stain and culture. The logistic regression model showed that both fluid collections containing gas or high attenuation fluid (average CT density 20 or greater Hounsfield units) are significant predictors of infection (P = 0.001). The average sensitivity over the four readers for determining presence of infection was 83.4 per cent and specificity was 39.3 per cent. Even in the era of MDCT, the ability to predict whether or not a fluid collection is infected or not, based on imaging findings alone, is limited. Presence of gas is a strong indicator of infection, but no imaging finding is characteristic of a sterile fluid collection.

  3. Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements.

    PubMed

    Wyler, Annabelle; Bousson, Valérie; Bergot, Catherine; Polivka, Marc; Leveque, Eric; Vicaut, Eric; Laredo, Jean-Denis

    2007-02-01

    To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard. Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined. At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P < .001) compared with the anatomic reference standard. Ninety-five percent of the differences between CT arthrography and anatomic values ranged from -1.34 to 0.74 mm. The difference between mean cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P < .001). Changes in cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement. Spiral

  4. Intramural gastric abscess--preoperative diagnosis with CT.

    PubMed

    Asrani, Ashwin; Novelline, Robert; Abujudeh, Hani; Lawrason, James; Kaewlai, Rathachai

    2007-09-01

    Intramural gastric abscess is a rare condition representing a localized form of suppurative gastritis, which was described in the time of Galen. Cases are usually diagnosed either with a combination of imaging modalities such as upper gastrointestinal series, ultrasound, computed tomography (CT), and endoscopic ultrasound or in conjunction with endoscopy and laparotomy. The authors describe a case of intramural gastric abscess in which the diagnosis was made preoperatively using axial, coronal, and sagittal reformations obtained with multidetector CT.

  5. Coronary CT angiography: current status and continuing challenges

    PubMed Central

    Sun, Z; Choo, G H; Ng, K H

    2012-01-01

    Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease owing to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with multislice CT scanners (64 slice and higher), and in selected patients coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. With high-quality coronary CT imaging increasingly being performed, patients can benefit from an imaging modality that provides a rapid and accurate diagnosis while avoiding an invasive procedure. Despite the tremendous contributions of coronary CT angiography to cardiac imaging, study results reported in the literature should be interpreted with caution as there are some limitations existing within the study design or related to patient risk factors. In addition, some attention must be given to the potential health risks associated with the ionising radiation received during cardiac CT examinations. Radiation dose associated with coronary CT angiography has raised serious concerns in the literature, as the risk of developing malignancy is not negligible. Various dose-saving strategies have been implemented, with some of the strategies resulting in significant dose reduction. The aim of this review is to present an overview of the role of coronary CT angiography on cardiac imaging, with focus on coronary artery disease in terms of the diagnostic and prognostic value of coronary CT angiography. Various approaches for dose reduction commonly recommended in the literature are discussed. Limitations of coronary CT angiography are identified. Finally, future directions and challenges with the use of coronary CT angiography are highlighted. PMID:22253353

  6. CT angiography in the abdomen: a pictorial review and update.

    PubMed

    Liu, Peter S; Platt, Joel F

    2014-02-01

    The development of multidetector CT technology and helical scanning techniques has revolutionized the use of CT for primary diagnostic evaluation of the abdominal vasculature, particularly the arterial system. CT angiography has numerous benefits relative to conventional catheter angiography, and has largely replaced catheter-based techniques in many clinical algorithms. This pictorial review and update will cover important technical principles related to modern CT angiography (including contrast delivery and dose considerations), discuss relevant anatomy and variants, and illustrate numerous arterial conditions related to the abdominal aorta and branch vessels.

  7. Strategies for reduction of radiation dose in cardiac multislice CT.

    PubMed

    Paul, Jean-François; Abada, Hicham T

    2007-08-01

    Because cardiac computed tomography (CT) (mainly coronary CT angiography) is a very promising technique, used more and more for coronary artery evaluation, the benefits and risks of this new low-invasive technique must be balanced. Radiation dose is a major concern for coronary CT angiography, especially in case of repeated examinations or in particular subgroups of patients (for example young female patients). Radiation dose to patient tends to increase from 16- to 64-slice CT. Radiation exposure in ECG-gated acquisitions may reach up to 40 mSv; considerable differences are attributable to the performance of CT machines, to technical dose-sparing tools, but also to radiological habits. Setting radiation dose at the lowest level possible should be a constant goal for the radiologist. Current technological tools are detailed in regard to their efficiency. Optimisation is necessary, by a judicious use of technological tools and also by individual adaptation of kV or mAs. This paper reviews the different current strategies for radiation dose reduction, keeping image quality constant. Data from the literature are discussed, and future technological developments are considered in regards to radiation dose reduction. The particular case of paediatric patients with congenital heart disease is also addressed.

  8. Myocardial perfusion 320-row multidetector computed tomography-guided treatment strategy for the clinical management of patients with recent acute-onset chest pain: Design of the CArdiac cT in the treatment of acute CHest pain (CATCH)-2 randomized controlled trial.

    PubMed

    Sørgaard, Mathias; Linde, Jesper J; Hove, Jens D; Petersen, Jan R; Jørgensen, Tem B S; Abdulla, Jawdat; Heitmann, Merete; Kragelund, Charlotte; Hansen, Thomas Fritz; Udholm, Patricia M; Pihl, Christian; Kühl, J Tobias; Engstrøm, Thomas; Jensen, Jan Skov; Høfsten, Dan E; Kelbæk, Henning; Kofoed, Klaus F

    2016-09-01

    Patients admitted with chest pain are a diagnostic challenge because the majority does not have coronary artery disease (CAD). Assessment of CAD with coronary computed tomography angiography (CCTA) is safe, cost-effective, and accurate, albeit with a modest specificity. Stress myocardial computed tomography perfusion (CTP) has been shown to increase the specificity when added to CCTA, without lowering the sensitivity. This article describes the design of a randomized controlled trial, CATCH-2, comparing a clinical diagnostic management strategy of CCTA alone against CCTA in combination with CTP. Patients with acute-onset chest pain older than 50 years and with at least one cardiovascular risk factor for CAD are being prospectively enrolled to this study from 6 different clinical sites since October 2013. A total of 600 patients will be included. Patients are randomized 1:1 to clinical management based on CCTA or on CCTA in combination with CTP, determining the need for further testing with invasive coronary angiography including measurement of the fractional flow reserve in vessels with coronary artery lesions. Patients are scanned with a 320-row multidetector computed tomography scanner. Decisions to revascularize the patients are taken by the invasive cardiologist independently of the study allocation. The primary end point is the frequency of revascularization. Secondary end points of clinical outcome are also recorded. The CATCH-2 will determine whether CCTA in combination with CTP is diagnostically superior to CCTA alone in the management of patients with acute-onset chest pain. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Dynamic volume CT: the next revolution in clinical CT

    NASA Astrophysics Data System (ADS)

    Boedeker, Kirsten; Mather, Rich

    2008-08-01

    The need for table motion in multi-detector CT causes image volumes acquired for whole organ motion and perfusion studies to lack temporal uniformity. The next revolution in clinical CT, dynamic volume CT, mitigates this limitation by providing the ability to acquire an entire organ with isotropic resolution in a single gantry rotation with no table movement. The first dynamic volume CT scanner has recently been introduced and comprises 320 detector rows of 0.5mm channel thickness, covering 16cm of anatomy in one rotation of 0.35sec. This scanner offers many advancements in terms of temporal uniformity, reconstruction, and radiation dose. This system significantly reduces motion artifact and eliminates contrast phase differences within the volume. Because this scanner does not require helical acquisition for volumetric imaging, it delivers significantly less dose for applications such as CT coronary angiography exams as well as reduced dose in most other applications. Furthermore, by eliminating table motion, the need for complex interpolation methods that can distort cardiac images is removed. Image quality is not sacrificed compared with standard 64-row CT scanners, as demonstrated via low contrast, resolution, and accuracy measurements presented in this work. By capturing the entire brain in one rotation, brain perfusion, bone subtraction, and quantitative perfusion analysis are now possible with a single low dose exam. Dynamic volume CT offers to change the way medicine approaches stroke patients, myocardial perfusion studies, and imaging of other moving body parts such as the lung and joints.

  10. Hyperdense middle cerebral artery sign in multidetector computed tomography: definition, occurrence, and reliability analysis.

    PubMed

    Abul-Kasim, Kasim; Selariu, Eufrozina; Brizzi, Marco; Petersson, Jesper

    2009-01-01

    The hyperdense middle cerebral artery sign (HMCAS) is one of the early changes seen on the computed tomography in acute ischemic stroke of MCA territory. To evaluate the reliability of subjective evaluation of HMCAS on CT performed at multidetector CT (MDCT) and evaluated in the Picture Archiving Communication Systems, to define objective criteria for HMCAS and to find out if there are any predictors for the occurrence of HMCAS. CTs of 121 consecutive patients (mean age of 70 years) treated with thrombolytic therapy were retrospectively evaluated by two neuroradiologists both subjectively and objectively with respect to HMCAS. HMCAS was subjectively found in 32% of study population. The interobserver and intraobserver agreement were substantial (K value of 0.69 and 0.80, respectively) and increased to almost perfect (K value of 0.86) when the reader provided with clinical information. The HMCAS was found twice as often in male patients. Patients with HMCAS were three years younger than those whose baseline CT did not show HMCAS. A 100% sensitivity achieved when objective criteria were defined as combination of MCA attenuation >or= 46 HU and MCA ratio > 1.2 (using oval ROIs) and MCA attenuation >or= 50 HU and MCA ratio of > 1.4 (using pixel sized ROIs). Performing CT examinations on MDCT and assessment of the images in PACS might have contributed to improvement of the reliability of evaluating HMCAS on CT by enabling an objective evaluation of this sign with measurements of attenuation value in the course of MCA using oval or pixel sized ROIs as well as estimation of MCA ratio.

  11. Managing patient dose in multi-detector computed tomography(MDCT). ICRP Publication 102.

    PubMed

    Valentin, J

    2007-01-01

    Computed tomography (CT) technology has changed considerably in recent years with the introduction of increasing numbers of multiple detector arrays. There are several parameters specific to multi-detector computed tomography (MDCT) scanners that increase or decrease patient dose systematically compared to older single detector computed tomography (SDCT) scanners. This document briefly reviews the MDCT technology, radiation dose in MDCT, including differences from SDCT and factors that affect dose, radiation risks, and the responsibilities for patient dose management. The document recommends that users need to understand the relationship between patient dose and image quality and be aware that image quality in CT is often higher than that necessary for diagnostic confidence. Automatic exposure control (AEC) does not totally free the operator from selection of scan parameters, and awareness of individual systems is important. Scanning protocols cannot simply be transferred between scanners from different manufacturers and should be determined for each MDCT. If the image quality is appropriately specified by the user, and suited to the clinical task, there will be a reduction in patient dose for most patients. Understanding of some parameters is not intuitive and the selection of image quality parameter values in AEC systems is not straightforward. Examples of some clinical situation shave been included to demonstrate dose management, e.g. CT examinations of the chest, the heart for coronary calcium quantification and non-invasive coronary angiography, colonography, the urinary tract, children, pregnant patients, trauma cases, and CT guided interventions. CT is increasingly being used to replace conventional x-ray studies and it is important that patient dose is given careful consideration, particularly with repeated or multiple examinations.

  12. Is multidetector computed tomography comparable to magnetic resonance imaging for assessment of lumbar foraminal stenosis?

    PubMed

    Kang, Woo Young; Ahn, Joong Mo; Lee, Joon Woo; Lee, Eugene; Bae, Yun Jung; Seo, Jiwoon; Kim, Junghoon; Kang, Heung Sik

    2017-02-01

    Background Both multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are used for assessment of lumbar foraminal stenosis (LFS). Therefore, it is relevant to assess agreement between these imaging modalities. Purpose To determine intermodality, inter-, and intra-observer agreement for assessment of LFS on MDCT and MRI. Material and Methods A total of 120 foramina in 20 patients who visited our institution in January and February 2014 were evaluated by six radiologists with different levels of experience. Radiologists evaluated presence and severity of LFS on sagittal CT and MR images according to a previously published LFS grading system. Intermodality agreement was analyzed by using weighted kappa statistics, while inter- and intra-observer agreement were analyzed by using intraclass correlation coefficients (ICCs) and kappa statistics. Results Overall intermodality agreement was moderate to good (kappa, 0.478-0.765). In particular, two professors and one fellow tended to overestimate the degree of LFS on CT compared with MRI. For inter-observer agreement of all six observers, ICCs indicated excellent agreement for both CT (0.774) and MRI (0.771), while Fleiss' kappa values showed moderate agreement for CT (0.482) and MRI (0.575). There was better agreement between professors and fellows compared with residents. For intra-observer agreement, ICCs indicated excellent agreement, while kappa values showed good to excellent agreement for both CT and MRI. Conclusion MDCT was comparable to MRI for diagnosis and assessment of LFS, especially for experienced observers. However, there was a tendency to overestimate the degree of LFS on MDCT compared with MRI.

  13. Adrenal lesions: spectrum of imaging findings with emphasis on multi-detector computed tomography and magnetic resonance imaging.

    PubMed

    Guerrisi, Antonino; Marin, Daniele; Baski, Mahbubeh; Guerrisi, Pietro; Capozza, Federica; Catalano, Carlo

    2013-01-01

    The adrenal gland is a common site of a large spectrum of abnormalities like primary tumors, hemorrhage, metastases, and enlargement of the gland from external hormonal stimulation. Most of these lesions represent nonfunctioning adrenal adenomas and thus warrant a conservative management. Multi-detector computed tomography (CT) and magnetic resonance (MR) imaging are still considered highly specific and complementary techniques for the detection and characterization of adrenal abnormalities. Radiologist can establish a definitive diagnosis for most adrenal masses (i.e., carcinoma, hemorrhage) based on imaging alone. Imaging therefore can differentiate malignant lesions from those benign and avoid unnecessary aggressive management of benign lesions. The article gives an overview of the adrenal lesions and their imaging characteristics seen on CT and MR imaging.

  14. A Modular and Compact Multidetector System Based on Monolithic Telescopes

    SciTech Connect

    Figuera, P.; Cardella, G.; Di Pietro, A.; Papa, M.; Tian, W.; Amorini, F.; Musumarra, A.; Pappalardo, G.; Rizzo, F.; Tudisco, S.; Fallica, G.; Valvo, G.

    2004-02-27

    The characteristics of a new multidetector based on the use of Monolithic Silicon Telescopes are presented. Using suitable ion implantation techniques, the {delta}E and residual energy stages of the telescopes have been integrated on a single Si chip, obtaining a typical thickness for the {delta}E stage of the order of 2{mu}m.

  15. Anomalous origin of the left coronary artery from the pulmonary artery in children: diagnostic use of multidetector computed tomography.

    PubMed

    Shen, Quanli; Yao, Qiong; Hu, Xihong

    2016-09-01

    Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital anomaly. It is important to demonstrate the anomalous origin of the left coronary artery and its course before surgery. To explore the clinical diagnostic use of multidetector CT coronary angiography in detecting anomalous origin of the left coronary artery from the pulmonary artery in children. Nine children (2 boys, 7 girls) ages 2 months to 9 years with surgically confirmed anomalous origin of the left coronary artery from the pulmonary artery were studied. Clinical data, transthoracic echocardiography and CT coronary angiography images were retrospectively analyzed. Transthoracic echocardiography correctly diagnosed anomalous origin of the left coronary artery from the pulmonary artery in 7 of 9 patients (95% CI: 40-97%). CT coronary angiography revealed the anomalous origin of the left coronary artery in all children (95% CI: 66-100%). In a 4-year-old girl and a 9-year-old girl, CT coronary angiography showed dilation of the right coronary artery and collateral circulation between the right and the left coronary arteries. CT coronary angiography is a useful method to show the anomalous origin of the coronary artery in children with anomalous origin of the left coronary artery from the pulmonary artery, especially for patients in whom origin of the left coronary artery cannot be detected by transthoracic echocardiography.

  16. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT.

    PubMed

    Simon-Yarza, Isabel; Viteri-Ramírez, Guillermo; Saiz-Mendiguren, Ramón; Slon-Roblero, Pedro J; Paramo, María; Bastarrika, Gorka

    2012-06-01

    Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

  17. Radiation dose-reduction strategies for neuroradiology CT protocols.

    PubMed

    Smith, A B; Dillon, W P; Gould, R; Wintermark, M

    2007-10-01

    Within the past 2 decades, the number of CT examinations performed has increased almost 10-fold. This is in large part due to advances in multidetector-row CT technology, which now allows faster image acquisition and improved isotropic imaging. The increased use, along with multidetector technique, has led to a significantly increased radiation dose to the patient from CT studies. This places increased responsibility on the radiologist to ensure that CT examinations are indicated and that the "as low as reasonably achievable" concept is adhered to. Neuroradiologists are familiar with factors that affect patient dose such as pitch, milliamperes, kilovolt peak (kVp), collimation, but with increasing attention being given to dose reduction, they are looking for additional ways to further reduce the radiation associated with their CT protocols. In response to increasing concern, CT manufacturers have developed dose-reduction tools, such as dose modulation, in which the tube current is adjusted along with the CT acquisition, according to patient's attenuation. This review will describe the available techniques for reducing dose associated with neuroradiologic CT imaging protocols.

  18. 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

  19. Multidetector row computed tomography evaluation of potential living laparoscopic renal donors: the story so far.

    PubMed

    Namasivayam, Saravanan; Kalra, Mannudeep K; Small, William C; Torres, William E; Mittal, Pardeep K

    2006-01-01

    Renal transplantation is the treatment of choice for end-stage renal disease. Living related kidney donation is the major source of renal grafts due to limited availability of cadaveric kidneys. Open nephrectomy was used to harvest donor kidneys. However, the laparoscopic approach is associated with less postoperative pain and quick recovery. So, most centers now prefer a laparoscopic approach to explant donor kidneys. Laparoscopic approach is technically challenging due to limited operative visibility. Hence, accurate preoperative detection of renal arterial and venous anomalies is imperative to avoid inadvertent vascular injury and bleeding. The preoperative workup of renal donors includes clinical evaluation, laboratory tests, and imaging. Traditionally, the renal donors were evaluated with conventional imaging techniques, which included renal catheter angiography and intravenous urography. However, conventional imaging is invasive, expensive, and less accurate for evaluation of complex renal venous anomalies, small calculi, and diffuse or focal renal parenchymal lesions. The introduction of multidetector row computed tomography (MDCT) revolutionized the CT technology by enabling isotropic resolution with faster scan coverage in a single, short breath-hold. Consequently, MDCT has now replaced conventional imaging for comprehensive imaging of potential living renal donors. MDCT is a minimally invasive technique that can accurately detect urolithiasis, renal arterial and venous anomalies, renal parenchymal lesions, and urinary tract anomalies. Renal vascular anomalies detected by MDCT can help the surgeon in planning donor nephrectomy. MDCT with three-dimensional CT angiography enables accurate preoperative renal vascular mapping. This article reviews the role of MDCT in preoperative evaluation of potential laparoscopic renal donors.

  20. Role of Multidetector Computed Tomography for Evaluation of Living Kidney Donors

    PubMed Central

    Asghari, Baratali; Babaei, Mansour; Pakroshan, Bijan; Vaziriniya, Alireza; Babamahmoodi, Abdolreza

    2013-01-01

    Background Kidney transplantation from living donors has been increased recently. Preoperative evaluation of living donor is important to select the appropriate kidney for transplantation and to decrease donor surgical complications. Objectives The aim of this study was to compare the accuracy of the use of multidetector computed tomography (MDCT) to evaluate vascular anatomy in living kidney donors with traditional angiography. Patients and Methods A total number of 60 living kidney donors who underwent open surgical approach for transplantation were selected: Kidney anatomy of donors evaluated by CT angiography (group 1) or traditional angiographic examination (group 2). Renal vessels anatomy was compared with surgical findings in both groups. Results The accuracy for detecting number of main renal arteries were not different in both groups which were 96.7% in CT angiography group and 90% in traditional angiography group (P = 0.15). The accuracy for detection of main renal veins were 100% in group 1 and 96.7% in group 2 (P = 0.31). Conclusions MDCT has the same accuracy as traditional angiography to detect renal abnormalities in living kidney donors. PMID:24350084

  1. Assessment of acute thoracolumbar fractures: challenges in multidetector computed tomography and added value of emergency MRI.

    PubMed

    Pizones, Javier; Castillo, Ernesto

    2013-09-01

    Acute thoracolumbar fractures are commonly diagnosed by clinical symptoms and X-ray plain films. Computed tomography (CT) is used to assess vertebral body damage, posterior wall canal intrusion, and posterior column injury. Both of these imaging tools have helped to develop classifications systems that aid the clinician in differentiating stable versus unstable spinal injuries. Multidetector CT has become the standard of care in polytrauma patients. It provides superior evaluation of bony anatomy and has been reported to be more cost effective than X-ray plain films, particularly in the cervicothoracic junction and in thoracolumbar unstable burst fractures. One disadvantage might be the increase in radiation exposure. Another important limitation remains the inability to provide adequate assessment for ligamentous injury and spinal cord lesions. Disc and ligaments play an important role in fracture stability because the failure of the posterior tension band may lead to progressive kyphosis. The integrity of the posterior ligamentous complex has been included in recent fracture classification systems and treatment algorithms. MR imaging becomes essential for soft tissue injury assessment, especially when including T2-weighted sequences with fat suppression. MRI can now be considered key to accurate fracture classification, detection of occult and distant injuries, and as the basis for therapeutic decision making. It is therefore strongly recommended in the early assessment of spine trauma patients. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. Evaluation of diagnostic utility of multidetector computed tomography and magnetic resonance imaging in blunt pancreatic trauma: a prospective study.

    PubMed

    Panda, Ananya; Kumar, Atin; Gamanagatti, Shivanand; Bhalla, Ashu Seith; Sharma, Raju; Kumar, Subodh; Mishra, Biplab

    2015-04-01

    Blunt pancreatic trauma is an uncommon injury with high morbidity and mortality. Retrospective analyses of computed tomography (CT) performance report CT to have variable sensitivity in diagnosing pancreatic injury. Both a prospective analysis of multidetector CT (MDCT) performance and diagnostic utility of magnetic resonance imaging (MRI) in acute blunt pancreatic injury remain unexplored. To prospectively evaluate the utility of MDCT with MRI correlation in patients with blunt pancreatic trauma using intraoperative findings as the gold standard for analysis. The contrast-enhanced CT (CECT) scans of patients admitted with blunt abdominal trauma were prospectively evaluated for CT signs of pancreatic injury. Patients detected to have pancreatic injury on CT were assigned a CT grade of injury according to American Association for Surgery of Trauma classification. MRI was performed in patients not undergoing immediate laparotomy and MRI grade independent of CT grade was assigned. Surgical grade was taken as gold standard and accuracy of CT and MRI for grading pancreatic injury and pancreatic ductal injury (PDI) was calculated. A quantitative and qualitative comparison of MRI was also done with CT to determine the performance of MRI in acute pancreatic injury. Thirty out of 1198 patients with blunt trauma abdomen were detected to have pancreatic injury on CT, which was surgically confirmed in 24 patients. Seventeen underwent MRI and surgical correlation was available in 14 patients. CT and MRI correctly identified the grade of pancreatic injury in 91.7% (22/24) and 92.86% (13/14) patients, respectively. Both CT and MRI correctly identified PDI in 18/19 and 11/12 patients, respectively, with good inter-modality agreement of 88.9% (kappa value of 0.78). MRI also qualitatively added to the information provided by CT and increased diagnostic confidence in 58.8% of patients. MDCT performs well in grading pancreatic injury and evaluating pancreatic ductal injury. MRI is

  3. Flat-panel volume CT: fundamental principles, technology, and applications.

    PubMed

    Gupta, Rajiv; Cheung, Arnold C; Bartling, Soenke H; Lisauskas, Jennifer; Grasruck, Michael; Leidecker, Christianne; Schmidt, Bernhard; Flohr, Thomas; Brady, Thomas J

    2008-01-01

    Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition. Its fluoroscopic and angiographic capabilities are useful for intraoperative and vascular applications. Furthermore, the high-volume coverage and continuous rotation of the detector may enable depiction of dynamic processes such as coronary blood flow and whole-brain perfusion. Other applications in which flat-panel volume CT may play a role include small-animal imaging, nondestructive testing in animal survival surgeries, and tissue-engineering experiments. Such versatility has led some to predict that flat-panel volume CT will gain importance in interventional and intraoperative applications, especially in specialties such as cardiac imaging, interventional neuroradiology, orthopedics, and otolaryngology. However, the contrast resolution of flat-panel volume CT is slightly inferior to that of multidetector CT, a higher radiation dose is needed to achieve a comparable signal-to-noise ratio, and a slower scintillator results in a longer scanning time.

  4. Congenital abnormalities of the ribs: evaluation with multidetector computed tomography.

    PubMed

    Davran, Ramazan; Bayarogullari, Hanifi; Atci, Nesrin; Kayali, Alperen; Ozturk, Fatma; Burakgazi, Gulen

    2017-02-01

    To evaluate congenital abnormalities of ribs using multidetector computed tomography. The retrospective study was conducted at Mustafa Kemal University Research Hospital, Hatay, Turkey and comprised data of patients aged 1-45 years who attended the Radiology Department for computed tomography of the thorax between January 2010 and July 2013. Multiplanar reconstructions, maximum intensity projections, and 3-dimensional images were acquired to investigate numerical and structural abnormalities of the ribs of the patients who underwent multidetector computed tomography for a variety of indications. The study comprised 650 patients. Of them, 231(35.5%) were female and 419(64.5%) male. The overall mean age was 20.9± 5.1years. However, data of 90(13.8%) patients was excluded from cervical rib evaluation and of 120(18.5%) from lumbar rib evaluation as these regions were out of the section because of the positioning. Finally, 560(86.5%) patients were included in the cervical rib evaluations, and 530(81.5%) in the lumbar rib evaluations. All the 650(100%) patients were included in the thoracic rib evaluations. Numerical abnormalities were observed in cervical ribs in 19(3.6%), in thoracic ribs in 1(0.15%) and in lumbar ribs in 7(1.3%) cases. The structural abnormalities were bifid rib in 44(6.7%) and fused type in 17(2.6%) cases. Multidetector computed tomography enabled evaluation of the thoracic cage as a whole.

  5. The clinical outcome of occult pulmonary contusion on multidetector-row computed tomography in blunt trauma patients.

    PubMed

    Deunk, Jaap; Poels, Tielke C; Brink, Monique; Dekker, Helena M; Kool, Digna R; Blickman, Johan G; van Vugt, Arie B; Edwards, Michael John Richard

    2010-02-01

    Multidetector-row computed tomography (MDCT) is a more sensitive modality as compared with conventional radiography (CR) in detecting pulmonary injuries. MDCT often detects pulmonary contusion that is not visualized by CR, defined as occult pulmonary contusion (OPC). The aim of this study was to investigate whether OPC on MDCT has implications for the outcome in blunt trauma patients. We used prospectively collected data from 1,040 adult high-energy blunt trauma patients who were primarily presented at our emergency department and who underwent CR and MDCT of the chest. All patients with pulmonary contusion were identified and divided into two groups: The "CR/computed tomography (CT) group" consisted of patients with pulmonary contusion visible on both CR and MDCT. The "CT-only" group consisted of patients with OPC, visible exclusively on MDCT. The control group consisted of blunt trauma patients without pulmonary contusion. These groups were compared with respect to difference in mortality and other outcome measures. In addition, a multivariate analysis was performed. Two hundred fifty-five patients suffered pulmonary contusion: The CT-only group consisted of 157 and the CR/CT group of 98 patients. The CT-only group did not differ from the control group with respect to mortality rate and other outcome measures. However, compared with the CR/CT group, mortality rate was significantly lower (8% versus 16%, p = 0.039) and most other outcome measures were significantly better in the CT-only group. OPC on MDCT is not associated with a worse outcome as compared with patients without pulmonary contusion. OPC has a better outcome as compared with pulmonary contusion visible on both CR and MDCT.

  6. Precision of dosimetry-related measurements obtained on current multidetector computed tomography scanners

    SciTech Connect

    Mathieu, Kelsey B.; McNitt-Gray, Michael F.; Zhang, Di; Kim, Hyun J.; Cody, Dianna D.

    2010-08-15

    Purpose: Computed tomography (CT) intrascanner and interscanner variability has not been well characterized. Thus, the purpose of this study was to examine the within-run, between-run, and between-scanner precision of physical dosimetry-related measurements collected over the course of 1 yr on three different makes and models of multidetector row CT (MDCT) scanners. Methods: Physical measurements were collected using nine CT scanners (three scanners each of GE VCT, GE LightSpeed 16, and Siemens Sensation 64 CT). Measurements were made using various combinations of technical factors, including kVp, type of bowtie filter, and x-ray beam collimation, for several dosimetry-related quantities, including (a) free-in-air CT dose index (CTDI{sub 100,air}); (b) calculated half-value layers and quarter-value layers; and (c) weighted CT dose index (CTDI{sub w}) calculated from exposure measurements collected in both a 16 and 32 cm diameter CTDI phantom. Data collection was repeated at several different time intervals, ranging from seconds (for CTDI{sub 100,air} values) to weekly for 3 weeks and then quarterly or triannually for 1 yr. Precision of the data was quantified by the percent coefficient of variation (%CV). Results: The maximum relative precision error (maximum %CV value) across all dosimetry metrics, time periods, and scanners included in this study was 4.33%. The median observed %CV values for CTDI{sub 100,air} ranged from 0.05% to 0.19% over several seconds, 0.12%-0.52% over 1 week, and 0.58%-2.31% over 3-4 months. For CTDI{sub w} for a 16 and 32 cm CTDI phantom, respectively, the range of median %CVs was 0.38%-1.14% and 0.62%-1.23% in data gathered weekly for 3 weeks and 1.32%-2.79% and 0.84%-2.47% in data gathered quarterly or triannually for 1 yr. Conclusions: From a dosimetry perspective, the MDCT scanners tested in this study demonstrated a high degree of within-run, between-run, and between-scanner precision (with relative precision errors typically well

  7. SU-E-I-19: Optimization of Low Contrast Detectability Across Two CT Manufacturers

    SciTech Connect

    Mahmood, U; Dauer, L; Erdi, Y

    2015-06-15

    Purpose: Our goal was to evaluate low contrast detectability (LCD) for abdominal CT protocols across two CT scanner manufacturers, while producing a similar noise texture and CTDIvol for acquired images. Methods: A CIRS tissue equivalent LCD phantom containing three columns of 7 spherical targets, ranging from 10 mm to 2.4 mm, that are 5, 10, and 20 HU below the background matrix (HUBB) was scanned using two a GE HD750 64 slice scanner and a Siemens Somatom Definition AS 64 slice scanner. Protocols were designed to deliver a CTDIvol of 12.26 mGy and images were reconstructed with FBP, ASIR and Sapphire. Comparisons were made with those algorithms that had matching noise power spectrum peaks (NPS). NPS information was extracted from a previously published article that matched NPS peak frequencies across manufacturers by calculating the NPS from uniform phantom images reconstructed with several IR algorithms. Results: The minimum detectable lesion size in the 20 HUBB and 10 HUBB column was 6.3 mm, and 10 mm in the 5 HUBB column for the GE HD 750 scanner. The minimum detectable lesion size in the 20 HUBB column was 4.8 mm, in the 10 HUBB column, 9.5 mm, and the 5 HUBB column, 10 mm for the Siemens Somatom Definition AS. Conclusion: Reducing radiation dose while improving or maintaining LCD is possible with application of IR. However, there are several different IR algorithms, with each generating a different resolution and noise texture. In multi-manufacturer settings, matching only the CTDIvol between manufacturers may Result in a loss of clinically relevant information.

  8. Organ doses to adult patients for chest CT

    SciTech Connect

    Huda, Walter; Sterzik, Alexander; Tipnis, Sameer; Schoepf, U. Joseph

    2010-02-15

    Purpose: The goal of this study was to estimate organ doses for chest CT examinations using volume computed tomography dose index (CTDI{sub vol}) data as well as accounting for patient weight. Methods: A CT dosimetry spreadsheet (ImPACT CT patient dosimetry calculator) was used to compute organ doses for a 70 kg patient undergoing chest CT examinations, as well as volume computed tomography dose index (CTDI{sub vol}) in a body CT dosimetry phantom at the same CT technique factors. Ratios of organ dose to CTDI{sub vol} (f{sub organ}) were generated as a function of anatomical location in the chest for the breasts, lungs, stomach, red bone marrow, liver, thyroid, liver, and thymus. Values of f{sub organ} were obtained for x-ray tube voltages ranging from 80 to 140 kV for 1, 4, 16, and 64 slice CT scanners from two vendors. For constant CT techniques, we computed ratios of dose in water phantoms of differing diameter. By modeling patients of different weights as equivalent water cylinders of different diameters, we generated factors that permit the estimation of the organ doses in patients weighing between 50 and 100 kg who undergo chest CT examinations relative to the corresponding organ doses received by a 70 kg adult. Results: For a 32 cm long CT scan encompassing the complete lungs, values of f{sub organ} ranged from 1.7 (thymus) to 0.3 (stomach). Organs that are directly in the x-ray beam, and are completely irradiated, generally had f{sub organ} values well above 1 (i.e., breast, lung, heart, and thymus). Organs that are not completely irradiated in a total chest CT scan generally had f{sub organ} values that are less than 1 (e.g., red bone marrow, liver, and stomach). Increasing the x-ray tube voltage from 80 to 140 kV resulted in modest increases in f{sub organ} for the heart (9%) and thymus (8%), but resulted in larger increases for the breast (19%) and red bone marrow (21%). Adult patient chests have been modeled by water cylinders with diameters between

  9. CT enterography with polyethylene glycol solution vs CT enteroclysis in small bowel disease

    PubMed Central

    Minordi, L M; Vecchioli, A; Mirk, P; Bonomo, L

    2011-01-01

    Objective The aim of the study is to compare CT enterography with polyethylene glycol solution (PEG-CT) with CT enteroclysis (CT-E) in patients with suspected small bowel disease. Methods 145 patients underwent abdominal contrast-enhanced 16-row multidetector CT after administration of 2000 ml of PEG by mouth (n = 75) or after administration of 2000 ml of methylcellulose by nasojejunal tube (n = 70). Small bowel distension, luminal and extraluminal findings were evaluated and compared with small bowel follow-through examination in 60 patients, double contrast enema in 50, surgery in 25 and endoscopy in 35. Statistical evaluation was carried out by χ2 testing. For both techniques we have also calculated the effective dose and the equivalent dose in a standard patient. Results Crohn's disease was diagnosed in 64 patients, neoplasms in 16, adhesions in 6. Distension of the jejunum was better with CT-E than PEG-CT (p<0.05: statistically significant difference). No significant difference was present for others sites (p>0.05). Evaluation of pathological ileal loops was good with both techniques. The values of sensitivity, specificity and diagnostic accuracy were respectively 94%, 100% and 96% with CT-E, and 93%, 94% and 93% with PEG-CT. The effective dose for PEG-CT was less than the dose for the CT-E (34.7 mSv vs 39.91 mSv). Conclusion PEG-CT shows findings of Crohn's disease as well as CT-E does, although CT-E gives better bowel distension, especially in the jejunum, and has higher specificity than PEG-CT. PMID:20959377

  10. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    SciTech Connect

    Liao, S; Wang, Y; Weng, H

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

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

    PubMed

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

    2016-05-28

    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. 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. 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

  12. [Weighted-averaging multi-planar reconstruction method for multi-detector row computed tomography].

    PubMed

    Aizawa, Mitsuhiro; Nishikawa, Keiichi; Sasaki, Keita; Kobayashi, Norio; Yama, Mitsuru; Sano, Tsukasa; Murakami, Shin-ichi

    2012-01-01

    Development of multi-detector row computed tomography (MDCT) has enabled three-dimensions (3D) scanning with minute voxels. Minute voxels improve spatial resolution of CT images. At the same time, however, they increase image noise. Multi-planar reconstruction (MPR) is one of effective 3D-image processing techniques. The conventional MPR technique can adjust slice thickness of MPR images. When a thick slice is used, the image noise is decreased. In this case, however, spatial resolution is deteriorated. In order to deal with this trade-off problem, we have developed the weighted-averaging multi-planar reconstruction (W-MPR) technique to control the balance between the spatial resolution and noise. The weighted-average is determined by the Gaussian-type weighting function. In this study, we compared the performance of W-MPR with that of conventional simple-addition-averaging MPR. As a result, we could confirm that W-MPR can decrease the image noise without significant deterioration of spatial resolution. W-MPR can adjust freely the weight for each slice by changing the shape of the weighting function. Therefore, W-MPR can allow us to select a proper balance of spatial resolution and noise and at the same time produce suitable MPR images for observation of targeted anatomical structures.

  13. Multidetector computed tomography analysis of benign and malignant nodules in patients with chronic lymphocytic thyroiditis.

    PubMed

    Zhu, Caisong; Liu, Wei; Yang, Jun; Yang, Jing; Shao, Kangwei; Yuan, Lixin; Chen, Hairong; Lu, Wei; Zhu, Ying

    2016-07-01

    The aim of the present study was to compare the multidetector computed tomography (MDCT) features of benign and malignant nodules in patients with chronic lymphocytic thyroiditis (CLT). MDCT findings, including the size, solid percentage, calcification, margin, capsule, anteroposterior-transverse diameter ratio as well as the mode and the degree of enhancement of 137 thyroid nodules in 127 CLT cases were retrospectively analyzed. Furthermore, the correlation between MDCT findings and pathological results combined with the CT perfusion imaging was analyzed for the differences between benign and malignant nodules. A total of 77.5% (31/40) of malignant nodules were completely solid, and 33% (32/97) of benign nodules were predominantly cystic. Compared with the benign nodules, micro-calcification and internal calcification were more frequently observed in the malignant nodules (P<0.05). MDCT features such as ill-defined margin, absence of capsule or incomplete capsule or homogeneous enhancement were more likely to be present in the malignant nodules (P<0.05). Nevertheless, no significant difference was observed in the enhancement degree at arterial or venous phase between benign and malignant nodules (P>0.05). MDCT features are useful in differentiating the benign and malignant nodules in CLT patients, and it may be essential for a radiologist to review the MDCT characteristics of nodules in the clinical practice.

  14. Fitz-Hugh-Curtis syndrome: CT findings of three cases.

    PubMed

    Cho, Hyeon Je; Kim, Ho Kyun; Suh, Jung Ho; Lee, Ghi Jai; Shim, Jae-Chan; Kim, Young Hwa

    2008-01-01

    Clinical manifestations and computed tomography (CT) findings of Fitz-Hugh-Curtis syndrome (FHCS) are relatively well stabilized as right upper quadrant abdominal pain and hepatic capsular enhancement because of perihepatitis associated with pelvic inflammatory disease caused by N. gonorrhoeae and C. trachomatis. We encountered three patients with serial FHCS associated with pelvic inflammatory disease, who visited the emergency room with right upper quadrant abdominal pain. Abdominal CT revealed hepatic capsular or pericapsular enhancement along the anterior surface of the liver on the arterial phase. Recently, multi-detector CT has evolved as the first-line imaging modality of acute abdomen at the emergency room; we reemphasized the importance of the CT findings of this syndrome for differential diagnosis of right upper quadrant abdominal pain in sexually active young women. Physicians at the emergency room acknowledge the syndrome and should perform dynamic abdominopelvic CT including the arterial phase.

  15. Sixty-four-slice CT angiography to determine the three dimensional relationships of vascular and soft tissue wounds in lower extremity war time injuries.

    PubMed

    Smith, Jennifer M; Fox, Charles J; Brazaitis, Michael P; Via, Kathy; Garcia, Roman; Feuerstein, Irwin M

    2010-01-01

    This article analyzes the use and benefits of the 64-slice CT scanner in determining the 3D relationships of vascular and soft tissue wounds in lower extremity war time injuries. A brief overview of CT scanning is given as well as the techniques used to produce the images needed for diagnosis. The series follows two similar cases of war time injury patients at the Walter Reed Army Medical Center. The first case is a 30-year-old active duty male, who presented with multiple trauma from a motor vehicle accident because of an improvised explosive device (IED) blast, sustaining substantial lower extremity injuries. The second case is a 34-year-old active duty male, who presented with multiple trauma blast injuries. Both cases were of interest because the vasculature was found to be very close to the surface of the wound, which put the arteries at risk for rupture and for iatrogenic injury during repeated debridements.

  16. Cardiac MDCT in children: CT technology overview and interpretation.

    PubMed

    Goo, Hyun Woo

    2011-09-01

    Cardiac multidetector computed tomography (MDCT) for congenital heart disease is a useful, rapid, and noninvasive imaging technique bridging the gaps between echocardiography, cardiac catheterization, and cardiac MRI. Fast scan speed and greater anatomic coverage, combined with flexible ECG-synchronized scans and a low radiation dose, are critical for improving the image quality of cardiac MDCT and minimizing patient risk. Current MDCT techniques can accurately evaluate extracardiac great vessels, lungs, and airways, as well as coronary arteries and intracardiac structures. Radiologists who perform cardiac MDCT in children should be familiarized with optimal cardiac computed tomography (CT) scan techniques and characteristic cardiac CT scan imaging findings. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. New insights on COPD imaging via CT and MRI

    PubMed Central

    Sverzellati, N; Molinari, F; Pirronti, T; Bonomo, L; Spagnolo, P; Zompatori, M

    2007-01-01

    Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD. PMID:18229568

  18. Hybrid imaging: integration of nuclear imaging and cardiac CT.

    PubMed

    Di Carli, Marcelo F

    2009-05-01

    The integration of nuclear medicine cameras with multidetector CT scanners provides a unique opportunity to delineate cardiac and vascular anatomic abnormalities and their physiologic consequences in a single setting. By revealing the burden of anatomic coronary artery disease and its physiologic significance, hybrid imaging can provide unique information that may improve noninvasive diagnosis, risk assessment, and management of coronary artery disease. By integrating the detailed anatomic information from CT with the high sensitivity of radionuclide imaging to evaluate targeted molecular and cellular abnormalities, hybrid imaging may play a key role in shaping the future of molecular diagnostics and therapeutics. This article reviews potential clinical applications of hybrid imaging in cardiovascular disease.

  19. Thoracic wall trauma—misdiagnosed lesions on radiographs and usefulness of ultrasound, multidetector computed tomography and magnetic resonance imaging

    PubMed Central

    Facenda, Catherine; Vaz, Nuno; Castañeda, Edgar Augusto; del Amo, Montserrat; Garcia-Diez, Ana Isabel; Pomes, Jaime

    2017-01-01

    Blunt injuries to the chest wall are an important chapter on emergency room (ER) departments, being the third most common injuries in trauma patients which ominous complications could appear. This article describes different types of traumatic events affecting the chest wall, which maybe misdiagnosed with conventional X-ray. Special emphasis has been done in computed tomography (CT) and multidetector CT (MDCT) imaging. This technique is considered the “gold-standard” for those traumatic patients, due to its fast acquisition covering the whole area of interest in axial plane, reconstructing multiplanar (2D, 3D) volume-rendered images with a superb quality and angiographic CT capabilities for evaluating vascular damage. Complementary techniques such as ultrasonography (US) and magnetic resonance imaging (MRI) may improve the diagnostic accuracy due to its great capacity in visualising soft-tissue trauma (muscle-tendinous tears) and subtle fractures. All these imaging methods have an important role in quantifying the severity of chest wall trauma. The findings of this study have been exposed with cases of our archives in a didactic way. PMID:28932697

  20. Multidetector Computed Tomographic Angiography (MDCTA) for Penetrating Neck Injuries.

    PubMed

    Pasley, Jason; Berg, Regan J; Inaba, Kenji

    2012-07-01

    Evaluation of patients after penetrating neck injury has evolved over time. Previously, location of injury and symptoms were used to determine management. The contemporary management of penetrating neck injuries relies on physical examination. Patients with hard signs of vascular or aerodigestive tract injury require immediate operation, regardless of location of injury. Those with no signs can be observed. For the remainder with soft signs, multidetector computed tomographic angiography (MDCTA) is a highly sensitive and specific screening modality for evaluating the vasculature and aerodigestive structures in the neck. Utilizing MDCTA, the patient can be safely directed towards operative intervention, observation, or further investigation.

  1. Multidetector Computed Tomographic Angiography (MDCTA) for Penetrating Neck Injuries

    PubMed Central

    Pasley, Jason; Berg, Regan J.; Inaba, Kenji

    2012-01-01

    Evaluation of patients after penetrating neck injury has evolved over time. Previously, location of injury and symptoms were used to determine management. The contemporary management of penetrating neck injuries relies on physical examination. Patients with hard signs of vascular or aerodigestive tract injury require immediate operation, regardless of location of injury. Those with no signs can be observed. For the remainder with soft signs, multidetector computed tomographic angiography (MDCTA) is a highly sensitive and specific screening modality for evaluating the vasculature and aerodigestive structures in the neck. Utilizing MDCTA, the patient can be safely directed towards operative intervention, observation, or further investigation. PMID:23908840

  2. 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.

  3. 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

  4. Limitations of multidetector computed tomography angiography for the diagnosis of blunt cerebrovascular injury.

    PubMed

    Grandhi, Ramesh; Weiner, Gregory M; Agarwal, Nitin; Panczykowski, David M; Ares, William J; Rodriguez, Jesse S; Gelfond, Jonathan A; Myers, John G; Alarcon, Louis H; Okonkwo, David O; Jankowitz, Brian T

    2017-08-11

    OBJECTIVE Blunt cerebrovascular injuries (BCVIs) following trauma carry risk for morbidity and mortality. Since patients with BCVI are often asymptomatic at presentation and neurological sequelae often occur within 72 hours, timely diagnosis is essential. Multidetector CT angiography (CTA) has been shown to be a noninvasive, cost-effective, reliable means of screening; however, the false-positive rate of CTA in diagnosing patients with BCVI represents a key drawback. Therefore, the authors assessed the role of DSA in the screening of BCVI when utilizing CTA as the initial screening modality. METHODS The authors performed a retrospective analysis of patients who experienced BCVI between 2013 and 2015 at 2 Level I trauma centers. All patients underwent CTA screening for BCVI according to the updated Denver Screening Criteria. Patients who were diagnosed with BCVI on CTA underwent confirmatory digital subtraction angiography (DSA). Patient demographics, screening indication, BCVI grade on CTA and DSA, and laboratory values were collected. Comparison of false-positive rates stratified by BCVI grade on CTA was performed using the chi-square test. RESULTS A total of 140 patients (64% males, mean age 50 years) with 156 cerebrovascular blunt injuries to the carotid and/or vertebral arteries were identified. After comparison with DSA findings, CTA findings were incorrect in 61.5% of vessels studied, and the overall CTA false-positive rates were 47.4% of vessels studied and 47.9% of patients screened. The positive predictive value (PPV) for CTA was higher among worse BCVI subtypes on initial imaging (PPV 76% and 97%, for BCVI Grades II and IV, respectively) compared with Grade I injuries (PPV 30%, p < 0.001). CONCLUSIONS In the current series, multidetector CTA as a screening test for blunt cerebrovascular injury had a high-false positive rate, especially in patients with Grade I BCVI. Given a false-positive rate of 47.9% with an estimated average of 132 patients per year

  5. Blunt cerebrovascular injury screening with 64-channel multidetector computed tomography: more slices finally cut it.

    PubMed

    Paulus, Elena M; Fabian, Timothy C; Savage, Stephanie A; Zarzaur, Ben L; Botta, Vandana; Dutton, Wesley; Croce, Martin A

    2014-02-01

    Aggressive screening to diagnose blunt cerebrovascular injury (BCVI) results in early treatment, leading to improved outcomes and reduced stroke rates. While computed tomographic angiography (CTA) has been widely adopted for BCVI screening, evidence of its diagnostic sensitivity is marginal. Previous work from our institution using 32-channel multidetector CTA in 684 patients demonstrated an inadequate sensitivity of 51% (Ann Surg. 2011,253: 444-450). Digital subtraction angiography (DSA) continues to be the reference standard of diagnosis but has significant drawbacks of invasiveness and resource demands. There have been continued advances in CT technology, and this is the first report of an extensive experience with 64-channel multidetector CTA. Patients screened for BCVI using CTA and DSA (reference) at a Level 1 trauma center during the 12-month period ending in May 2012 were identified. Results of CTA and DSA, complications, and strokes were retrospectively reviewed and compared. A total of 594 patients met criteria for BCVI screening and underwent both CTA and DSA. One hundred twenty-eight patients (22% of those screened) had 163 injured vessels: 99 (61%) carotid artery injuries and 64 (39%) vertebral artery injuries. Sixty-four-channel CTA demonstrated an overall sensitivity per vessel of 68% and specificity of 92%. The 52 false-negative findings on CTA were composed of 34 carotid artery injuries and 18 vertebral artery injuries; 32 (62%) were Grade I injuries. Overall, positive predictive value was 36.2%, and negative predictive value was 97.5%. Six procedure-related complications (1%) occurred with DSA, including two iatrogenic dissections and one stroke. Sixty-four-channel CTA demonstrated a significantly improved sensitivity of 68% versus the 51% previously reported for the 32-channel CTA (p = 0.0075). Sixty-two percent of the false-negative findings occurred with low-grade injuries. Considering complications, cost, and resource demand associated with

  6. Visualisation of passive middle ear implants by cone beam and multi-detector computed tomography: a comparative in vitro study.

    PubMed

    Nguyen, T D; Kösling, S; Mlynski, R; Plontke, S K

    2016-12-01

    Modern passive middle ear titanium prostheses are filigree structures, resulting in poorer depiction on CT compared to prostheses used in the past. We compared the visibility of newer prostheses on cone beam CT (CBCT) to multi-detector CT (MDCT) with standard and lower dose in vitro, and analysed image noise and metal artefacts. Six different titanium middle ear prostheses (three partial and one total ossicular replacement prostheses, two stapes prostheses) were implanted twice in formalin-fixed head specimens-first correctly and then with displacement. Imaging was performed using standard CBCT and MDCT as well as MDCT with lower dose (36 single imaging investigations). Images were analysed with knowledge of the used types of middle ear prostheses, but blinded with respect to the positioning in the specific case. On all images the type of prostheses and their positions could be clearly recognized. Their identifiability including their details was rated as statistically significantly higher for all CBCT investigations than for MDCT. MDCT with lower dose showed the worst results. No statistical differences were found in image noise and metal artefacts. If available, CBCT should be preferred over MDCT in diagnostic evaluation of passive middle ear prostheses. • Middle ear prostheses became more filigree, leading to poorer visibility on CT. • High spatial resolution and paraxial reconstructions are necessary requirements for imaging evaluation. • CBCT and MDCT can identify type and positioning of titanium prostheses. • Metal artefacts play a minor part in filigree titanium prostheses. • Regarding visualisation of prostheses details, cone beam CT aids the evaluation.

  7. From the RSNA refresher courses: CT angiography: clinical applications in the abdomen.

    PubMed

    Fishman, E K

    2001-10-01

    The development of spiral computed tomography (CT) and subsequently multidetector CT has provided unparalleled opportunities for advancement of CT technology and clinical applications. One of the most influential developments has been CT angiography, which is the use of thin-section CT combined with postprocessing of imaging data by using a variety of three-dimensional reconstruction techniques to produce vascular maps that equal or exceed those provided by classic angiography in many applications. In the evaluation of pancreatic disease, the use of multidetector CT angiography enables the radiologist to produce vascular maps that clearly show tumor invasion of vasculature and the relationship of vessels to pancreatic masses. Anatomic areas for which the three-dimensional display is especially helpful include the confluence of the portal vein and the superior mesenteric vein and the more distal portions of the portal vein. Preliminary studies indicate that CT angiography may prove beneficial in the evaluation of ischemic bowel and active Crohn disease. CT angiography has proved extremely valuable for applications such as preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation, pretreatment planning for patients considered for hepatic arterial infusion chemotherapy, and pretreatment evaluation of portal vein patency for a variety of reasons. CT angiography can also provide supplemental information in patients with cirrhosis, upper gastrointestinal tract bleeding due to varices, or primary extrahepatic neoplasms.

  8. Spontaneous left main coronary artery dissection complicated by pseudoaneurysm formation in pregnancy: role of CT coronary angiography.

    PubMed

    Rahman, Shahid; Abdul-Waheed, Mohammed; Helmy, Tarek; Huffman, Lynn C; Koshal, Vipin; Guitron, Julian; Merrill, Walter H; Lewis, David F; Dunlap, Stephanie; Shizukuda, Yukitaka; Weintraub, Neal L; Meyer, Christopher; Cilingiroglu, Mehmet

    2009-04-01

    We report a case of a 26-year-old female, who presented at 34 weeks of an uncomplicated pregnancy with an acute ST elevation anterior wall myocardial infarction. Cardiac catheterization suggested a left main coronary artery dissection with pseudoaneurysm formation. The patient's course was complicated by congestive heart failure. She was initially managed conservatively by a multidisciplinary team including heart failure specialists, obstetricians, and cardiovascular surgeons. 4 days after admission, her LMC was imaged by dual-source 64 slice Cardiac computed tomography, coronary dissection was identified extending to the lumen, and the presence of pseudoaneurysm was confirmed. She underwent subsequently a staged procedure, which included placement of an intra-aortic balloon pump, cesarean section, and coronary artery bypass grafting. This case illustrates the utility of coronary artery CT imaging to assess the complexity and stability of coronary artery dissections, thereby helping to determine the need for, and timing of revascularization procedures.

  9. Multidetector Computed Tomography for Congenital Anomalies of the Aortic Arch: Vascular Rings.

    PubMed

    García-Guereta, Luis; García-Cerro, Estefanía; Bret-Zurita, Montserrat

    2016-07-01

    The development of multidetector computed tomography has triggered a revolution in the study of the aorta and other large vessels and has replaced angiography in the diagnosis of congenital anomalies of the aortic arch, particularly vascular rings. The major advantage of multidetector computed tomography is that it permits clear 3-dimensional assessment of not only vascular structures, but also airway and esophageal compression. The current update aims to summarize the embryonic development of the aortic arch and the developmental anomalies leading to vascular ring formation and to discuss the current diagnostic and therapeutic role of multidetector computed tomography in this field.

  10. SU-E-I-23: A General KV Constrained Optimization of CNR for CT Abdominal Imaging

    SciTech Connect

    Weir, V; Zhang, J

    2015-06-15

    Purpose: While Tube current modulation has been well accepted for CT dose reduction, kV adjusting in clinical settings is still at its early stage. This is mainly due to the limited kV options of most current CT scanners. kV adjusting can potentially reduce radiation dose and optimize image quality. This study is to optimize CT abdomen imaging acquisition based on the assumption of a continuous kV, with the goal to provide the best contrast to noise ratio (CNR). Methods: For a given dose (CTDIvol) level, the CNRs at different kV and pitches were measured with an ACR GAMMEX phantom. The phantom was scanned in a Siemens Sensation 64 scanner and a GE VCT 64 scanner. A constrained mathematical optimization was used to find the kV which led to the highest CNR for the anatomy and pitch setting. Parametric equations were obtained from polynomial fitting of plots of kVs vs CNRs. A suitable constraint region for optimization was chosen. Subsequent optimization yielded a peak CNR at a particular kV for different collimations and pitch setting. Results: The constrained mathematical optimization approach yields kV of 114.83 and 113.46, with CNRs of 1.27 and 1.11 at the pitch of 1.2 and 1.4, respectively, for the Siemens Sensation 64 scanner with the collimation of 32 x 0.625mm. An optimized kV of 134.25 and 1.51 CNR is obtained for a GE VCT 64 slice scanner with a collimation of 32 x 0.625mm and a pitch of 0.969. At 0.516 pitch and 32 x 0.625 mm an optimized kV of 133.75 and a CNR of 1.14 was found for the GE VCT 64 slice scanner. Conclusion: CNR in CT image acquisition can be further optimized with a continuous kV option instead of current discrete or fixed kV settings. A continuous kV option is a key for individualized CT protocols.

  11. Effect of contrast material on image noise and radiation dose in adult chest computed tomography using automatic exposure control: a comparative study between 16-, 64- and 128-slice CT.

    PubMed

    Paul, Jijo; Schell, Boris; Kerl, J Matthias; Maentele, Werner; Vogl, Thomas J; Bauer, Ralf W

    2011-08-01

    To determine the difference in radiation dose between non-enhanced (NECT) and contrast-enhanced (CECT) chest CT examinations contributed by contrast material with different scanner generations with automatic exposure control (AEC). Each 42 adult patients received a NECT and CECT of the chest in one session on a 16-, 64- or 128-slice CT scanner with the same scan protocol settings. However, AEC technology (Care Dose 4D, Siemens) underwent upgrades in each of the three scanner generations. DLP, CTDIvol and image noise were compared. Although absolute differences in image noise were very small and ranged between 10 and 13 HU for NECT and CECT in median, the differences in image noise and dose (DLP: 16-slice:+2.8%; 64-slice:+3.9%; 128-slice:+5.6%) between NECT and CECT were statistically significant in all groups. Image noise and dose parameters were significantly lower in the most recent 128-slice CT generation for both NECT and CECT (DLP: 16-slice:+35.5-39.2%; 64-slice:+6.8-8.5%). The presence of contrast material lead to an increase in dose for chest examinations in three CT generations with AEC. Although image noise values were significantly higher for CECT, the absolute differences were in a range of 3 HU. This can be regarded as negligible, thus indicating that AEC is able to fulfill its purpose of maintaining image quality. However, technological developments lead to a significant reduction of dose and image noise with the latest CT generation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Dynamic CT perfusion imaging of the myocardium using a wide-detector scanner: a semiquantitative analysis in an animal model.

    PubMed

    Muenzel, Daniela; Noël, Peter B; Gramer, Bettina M; Leber, Vivian; Schneider, Armin; Leber, Alexander; Vembar, Mani; Fingerle, Alexander A; Rummeny, Ernst J; Huber, Armin

    2014-01-01

    Functional assessment of myocardial perfusion in computed tomography (CT) is a challenge. To evaluate CT dynamic myocardial perfusion imaging (MPI) using a wide-detector scanner. Time to peak (TTP), peak enhancement (PE), upslope (US), and the area under the curve (AUC) were calculated in 12 pigs (256-slice multidetector CT scanner). The entire myocardium was covered by the scan volume. TTP was increased, and PE, US, and AUC were decreased in poststenotic myocardium. CT MPI with complete coverage of the myocardium is feasible, providing evaluation of the physiological significance of coronary artery stenosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Petamenophis (Padiamenemipet), an Egyptian Child Mummy Protected for Eternity: Revelation by Multidetector Computed Tomography.

    PubMed

    Martina, Maria Cristina; Cesarani, Federico; Boano, Rosa; Fiore Marochetti, Elisa; Gandini, Giovanni

    2017-08-03

    The objective of our work was to report the most recent findings obtained with multidetector computed tomography of a child mummy from the Roman period (119-123 CE) housed at the Egyptian Museum in Turin, Italy. Multidetector computed tomography and postprocessing were applied to understand the embalming techniques, the nature of a foreign object, and anthropometrical values. The information was compared with that from other mummies that were buried in the same tomb, but today housed in different museums. New information regarding the embalming technique was revealed. Multidetector computed tomography allowed the identification of a knife-like metallic object, probably an amulet for the child's protection in the afterlife. Multidetector computed tomography and image postprocessing confirm their valuable role in noninvasive studies in ancient mummies and provided evidence of a unique cultural practice in the late history of Ancient Egypt such as placing a knife possibly as an amulet.

  14. [Study of renal veins by multidetector-row computed tomography scans].

    PubMed

    Bouali, O; Mouttalib, S; Labarre, D; Munzer, C; Lopez, R; Lauwers, F; Moscovici, J

    2014-12-01

    To determine the prevalence of renal vein variants. To investigate the distribution of renal veins. We retrospectively reviewed spiral computed tomography (CT) scans of the abdomen performed during a two-month period. The same protocol was used for all CT scans: same multidetector-row CT scanner (Siemens(®)), 1 to 2-mm section thickness, injection of intravenous iomeprol. The study group included 121 patients, aged 21.7 to 93.4 years (mean age 60.9 ± 15.4 years). The sex ratio was 2/1, with 80 men and 41 women. Seventy-three percent of the study group (88 patients) had no variants of the renal veins. Indeed almost 40% (48 patients) had one artery and one vein on each side, with typical course, and 33% (40 patients) had course and/or number variants of the renal arteries. Variants of the right renal vein consisted in multiple veins in 20.6% (25 cases). We detected no case of multiple left renal veins, but we described variations of its course in 9.1% (11 cases): 5 cases of retroaortic left renal vein (4.1%) and 6 cases of circumaortic left renal vein (5%). Three of these 11 patients had an associated double right renal vein. The probability to have a right renal vein variant was significantly higher than a left one (OR = 2.6, P = 0.01). And we found a significantly higher risk of having a venous variant in women (OR = 2.4, P = 0.04). We detected no case of inferior vena cava variant. In our study, prevalence of a circum- or retroaortic left renal vein appeared higher than previously reported in the literature (9.1%). Knowledge of anatomical variants of renal vasculature is crucial and this study puts the emphasis on variations of course and number of renal vessels. Those variations are not so uncommon and should be known by radiologists and also by surgeons. Their knowledge has major clinical implications in practice and it contributes to the safety of renal and retroperitoneal surgery. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  15. Does the Degree of Perihepatitis Have Any Relevance to the Severity of the Manifestations of Pelvic Inflammatory Disease on Multidetector Computed Tomography?

    PubMed

    Kim, Ji Su; Kim, Hyun Cheol; Kim, Sang Won; Yang, Dal Mo; Rhee, Sun Jung; Shin, Jong Soo

    2015-01-01

    This study aimed to evaluate the relationship between the degree of perihepatitis and the severity of pelvic inflammatory disease (PID) on multidetector computed tomography (MDCT). A total of 177 women with PID who underwent biphasic abdominal computed tomography (CT) scans were enrolled. Two reviewers retrospectively reviewed the CT scans with consensus and subjectively categorized the severity of PID into 4 grades (normal, mild, moderate, and severe). Another reviewer independently assigned the extent (grades 0 to 4) and the depth (grades 0 to 4) of hepatic surface enhancement in terms of the degree of perihepatitis. Relationships between the degree of perihepatitis and the CT severity as well as each CT manifestation of PID were evaluated using the χ test or a cumulative logistic regression analysis. Of the 177 patients, 99 (55.9%) showed hepatic surface enhancement. The severity of PID on MDCT was significantly related with the degree of perihepatitis (all P < 0.001). Salpingitis, oophoritis, pelvic fat haziness, complicated ascites, and omental/mesenteric fat infiltration were significantly related with the degree of perihepatitis (all P < 0.05). Among these variables, omental/mesenteric fat infiltration (odds ratio = 10.9) and salpingitis (odds ratio = 6.0) were the CT manifestations that were most associated with the presence of perihepatitis in PID. The degree of perihepatitis seems to show a relationship with the severity of PID on MDCT. Omental/mesenteric fat infiltration and salpingitis can be strongly related with perihepatitis in PID.

  16. The value of CT cardiac angiography and CT calcium score testing in a modern cardiology service in New Zealand: a report of a single centre eight-year experience from 5,237 outpatient procedures.

    PubMed

    Ellis, Chris; Gamble, Greg; Edwards, Colin; van Pelt, Niels; Gabriel, Ruvin; Lowe, Boris; Christiansen, Jonathan; To, Andrew; Winch, Helen; Osborne, Mark; Ormiston, John; Legget, Malcolm

    2016-12-02

    Computed tomographic (CT) cardiac angiography is of increasing value in several areas of patient management in cardiology. We assessed the ability of CT cardiac angiography to effectively 'rule out' severe coronary stenoses in patients presenting with 'atypical' symptoms and/or an equivocal stress test, which offers a new approach to the management of coronary artery disease. We also examined the use of the CT calcium score test in cardiovascular (CVS) risk assessment. From a large single centre (Mercy Hospital) in Auckland, using a prospectively acquired, comprehensive database, we audited the entire eight-year experience of 5,169 patients (7/8/06 to 31/1/14) who underwent 5,237 64-slice computed tomographic (CT) cardiac angiogram or CT calcium score tests (GE Lightspeed scanner). From 5,169 patients there were 5,237 CT procedures. The mean patient age was 57 (SD 10) years; 42% patients were female. Of the 3,603 (69%) full CT cardiac angiogram scans, 3,509 (67%) included a calcium score test. One thousand four hundred and eighty-three (28%) of scans were a calcium score test only. Of the 3,603 (69%) full CT cardiac angiogram scans, it was possible to 'rule out' significant coronary atheroma (stenosis ≥50%) in 2,947 (82%) of these procedures. Of the 4,903 (94%) patients who had a CT calcium score test, in whom we could calculate the NZ Framingham-based CVS risk, it was possible to reassign 532 (22%) of these patients who were previously thought to be at 'low risk' to be at a higher CVS risk. CT cardiac angiography has become established in the modern management of cardiology patients. It has particular value as a tool to 'rule out' severe coronary stenoses, and as a tool to give a more accurate assessment of CVS risk. It adds significant value to the care of many patients within an established cardiology practice.

  17. [The different manifestations of pulmonary aspergillosis: multidetector computed tomography findings].

    PubMed

    Koren Fernández, L; Alonso Charterina, S; Alcalá-Galiano Rubio, A; Sánchez Nistal, M A

    2014-01-01

    Pulmonary aspergillosis is a fungal infection usually caused by inhaling Aspergillus fumigatus spores. However, when we talk about aspergillosis, we normally refer to the spectrum of clinical and radiological findings that depend directly on the patient's immune status, on the prior existence of lung disease, and on the virulence of the infective organism. There are four types of pulmonary aspergillosis (aspergilloma, allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, and invasive aspergillosis), and each type has its own distinct radiologic findings. We review the signs of pulmonary aspergillosis on multidetector computed tomography and we correlate them with patients' symptoms and immune responses. Likewise, we discuss the differential diagnoses. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

  18. Multidetector computed tomography findings in deaths with severe burns.

    PubMed

    Levy, Angela D; Harcke, Howard T; Getz, John M; Mallak, Craig T

    2009-06-01

    This study compared autopsy with postmortem multidetector computed tomography (MDCT) findings in charred remains. Seventeen consecutive male subjects (mean age, 29.4 years) who perished in a fire-related event resulting in charred remains underwent total body MDCT immediately prior to routine autopsy that included serum carboxyhemoglobin measurement. MDCT showed all thermal tissue changes (skin and subcutaneous fat loss, skeletal muscle retraction, pugilistic attitude, cortical fractures, bone and organ destruction, thermal epidural hematoma, and thermal amputation) and established all fracture patterns that were lethal, but autopsy added the fire as a contributory cause of death when there was carboxyhemoglobin elevation. MDCT had limited value in determination of lethal vascular and visceral injuries. MDCT is an effective complement to autopsy in the setting of charred remains and may serve to augment a limited autopsy. This may be particularly useful in mass casualty scenarios.

  19. Multidetector computed tomography of temporomandibular joint: A road less travelled.

    PubMed

    Pahwa, Shivani; Bhalla, Ashu Seith; Roychaudhary, Ajoy; Bhutia, Ongkila

    2015-05-16

    This article reviews the imaging anatomy of temporomandibular joint (TMJ), describes the technique of multi-detector computed tomography (MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures.

  20. Toroid cavity/coil NMR multi-detector

    DOEpatents

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  1. Enhanced security for multi-detector quantum random number generators

    NASA Astrophysics Data System (ADS)

    Marangon, Davide G.; Vallone, Giuseppe; Zanforlin, Ugo; Villoresi, Paolo

    2016-11-01

    Quantum random number generators (QRNG) represent an advanced solution for randomness generation, which is essential in every cryptographic application. In this context, integrated arrays of single-photon detectors have promising applications as QRNGs based on the spatial detection of photons. For the employment of QRNGs in cryptography, it is necessary to have efficient methods to evaluate the so-called quantum min-entropy that corresponds to the amount of the true extractable quantum randomness from the QRNG. Here, we present an efficient method that allows the estimation of the quantum min-entropy for a multi-detector QRNG. In particular, we consider a scenario in which an attacker can control the efficiency of the detectors and knows the emitted number of photons. Eventually, we apply the method to a QRNG with 103 detectors.

  2. CT Scans

    MedlinePlus

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  3. Clinical significance of multidetector-row computed tomography in breast surgery.

    PubMed

    Doihara, Hiroyoshi; Fujita, Takeo; Takabatake, Daisuke; Takahashi, Hirotoshi; Ogasawara, Yutaka; Shimizu, Nobuyoshi

    2006-01-01

    Several reports support the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of tumor extension and adequate surgical margin are important factors affecting tumor recurrence after breast-conserving surgery (BCS). Many studies have reported the utility of magnetic resonance imaging (MRI) for diagnosing the tumor extension of breast cancer, but few have evaluated the utility of multidetector-row computed tomography (MDCT). The results of this study show the clinical significance of MDCT for detecting cancer extension and demonstrate the clinical role of MDCT in BCS. Subjects comprised 136 patients grouped into two categories based on whether or not tumor extension was evaluated with MDCT preoperatively. The positive surgical margin rate and breast conservation rate were analyzed in each group and the clinical role of MDCT in BCS was evaluated. Moreover, evaluation of intraductal extension was done both with MDCT and histologically, and computed tomography (CT)-pathologic correlations were examined retrospectively. Finally, the margin-positive cases were analyzed in relation to their clinical characteristics. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of the intraductal component were 71.8%, 85.7%, 82.1%, and 76.9%, respectively. The positive surgical margin rate and conservation rate are 7.46% and 81.9%, respectively, for those who were diagnosed with MDCT preoperatively; their corresponding rates without MDCT were 16.67% and 67.9%. Most margin-positive patients have remarkable lymphatic space invasion. Positive surgical margins were often recognized toward the nipple. For diagnosing the intraductal extension, MDCT shows sufficient diagnosability. Moreover, MDCT can provide appropriate information for the determination of adequate surgical margins and contribute to increases in breast conservation

  4. Automated 3-dimensional aortic annular assessment by multidetector computed tomography in transcatheter aortic valve implantation.

    PubMed

    Watanabe, Yusuke; Morice, Marie-Claude; Bouvier, Erik; Leong, Tora; Hayashida, Kentaro; Lefèvre, Thierry; Hovasse, Thomas; Romano, Mauro; Chevalier, Bernard; Donzeau-Gouge, Patrick; Farge, Arnaud; Cormier, Bertrand; Garot, Philippe

    2013-09-01

    This study sought to evaluate the accuracy, reproducibility, and predictive value for post-procedural aortic regurgitation (AR) of an automated multidetector computed tomography (MDCT) post-processing imaging software, 3mensio Valves (version 5.1.sp1, 3mensio Medical Imaging BV, the Netherlands), in the assessment of patients undergoing transcatheter aortic valve implantation (TAVI). Accurate pre-operative aortic annulus measurements are crucial for patients undergoing TAVI. One hundred five patients undergoing MDCT screening before TAVI were evaluated. Aortic annular measurement was compared between automated 3mensio Valves software and manual data post-processing software on a dedicated workstation; we analyzed the discrimination value of annulus measurement for post-procedural AR in 44 recipients of a self-expanding valve. The automated 3mensio Valves software showed good concordance with manual MDCT measurements as demonstrated by Bland-Altman analysis. The automated software provided equally good reproducibility as manual measurement, especially for measurement of aortic annulus area (intraobserver intraclass correlation coefficients 0.98 vs. 0.97, interobserver 0.98 vs. 0.95). In 44 patients after implantation of a self-expanding valve, the valve diameter/CT-measured geometric mean annulus diameter ratio by automated 3mensio Valves software showed moderate and better discrimination ability in predicting post-procedural AR compared with manual measurement (p = 0.12, area under the curve 0.77, 95% confidence interval: 0.63 to 0.91, area under the curve 0.68, 95% confidence interval: 0.50 to 0.86, respectively). The automated 3mensio Valves software demonstrated reliable, reproducible aortic annulus measurement and better predictive value for post-procedural AR, suggesting important clinical implications for pre-operative assessment of patients undergoing TAVI. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights

  5. Computed tomography automatic exposure control techniques in 18F-FDG oncology PET-CT scanning.

    PubMed

    Iball, Gareth R; Tout, Deborah

    2014-04-01

    Computed tomography (CT) automatic exposure control (AEC) systems are now used in all modern PET-CT scanners. A collaborative study was undertaken to compare AEC techniques of the three major PET-CT manufacturers for fluorine-18 fluorodeoxyglucose half-body oncology imaging. An audit of 70 patients was performed for half-body CT scans taken on a GE Discovery 690, Philips Gemini TF and Siemens Biograph mCT (all 64-slice CT). Patient demographic and dose information was recorded and image noise was calculated as the SD of Hounsfield units in the liver. A direct comparison of the AEC systems was made by scanning a Rando phantom on all three systems for a range of AEC settings. The variation in dose and image quality with patient weight was significantly different for all three systems, with the GE system showing the largest variation in dose with weight and Philips the least. Image noise varied with patient weight in Philips and Siemens systems but was constant for all weights in GE. The z-axis mA profiles from the Rando phantom demonstrate that these differences are caused by the nature of the tube current modulation techniques applied. The mA profiles varied considerably according to the AEC settings used. CT AEC techniques from the three manufacturers yield significantly different tube current modulation patterns and hence deliver different doses and levels of image quality across a range of patient weights. Users should be aware of how their system works and of steps that could be taken to optimize imaging protocols.

  6. Mechanical thrombectomy using a combined CT/C-arm X-ray system

    PubMed Central

    Herweh, Christian; Pham, Mirko; Schönenberger, Silvia; Bösel, Julian; Ringleb, Peter A; Heiland, Sabine; Bendszus, Martin; Möhlenbruch, Markus

    2016-01-01

    Background Mechanical thrombectomy (MT) using stent-retrievers has been proven to be a safe and effective treatment in acute ischemic stroke (AIS), particularly in large vessel occlusion. Other than patient characteristics, time to recanalization is the most important factor linked to outcome. MT is usually performed in a dedicated angiography suite using a floor- and/or ceiling-mounted biplane angiographic system. Here we report our first experience of MT with a new combined CT and mobile C-arm X-ray device setup. Methods Patients with AIS underwent stroke imaging (non-contrast enhanced CT, CT perfusion, and CT angiography) using a commercially available 64-slice CT scanner which was modified for combined use with a C-arm system. In patients with large vessel occlusion, MT was conducted without further patient transfer within the CT imaging suite using a mobile C-arm X-ray device equipped with a 30×30 cm (12×12 inch), 1.5×1.5 k full-view flat detector which was positioned between the gantry and patient table. The safety and feasibility of this new system was assessed in preliminary patients. Results Angiographic imaging quality of the mobile C-arm was feasible and satisfactory for diagnostic angiography and MT. Using this setup, time between stroke imaging and groin puncture (picture-to-puncture time) was reduced by up to 35 min (including time for preparation of the patient such as intubation). Conclusions MT using a combined CT/C-arm system is safe and feasible. The potential advantages, particularly time saving and ensuing improvement in patient outcome, need to be assessed in a larger study. PMID:25935925

  7. Relevance of MTF and NPS in quantitative CT: towards developing a predictable model of quantitative performance

    NASA Astrophysics Data System (ADS)

    Chen, Baiyu; Richard, Samuel; Samei, Ehsan

    2012-03-01

    The quantification of lung nodule volume based on CT images provides valuable information for disease diagnosis and staging. However, the precision of the quantification is protocol, system, and technique dependent and needs to be evaluated for each specific case. To efficiently investigate the quantitative precision and find an optimal operating point, it is important to develop a predictive model based on basic system parameters. In this study, a Fourier-based metric, the estimability index (e') was proposed as such a predictor, and validated across a variety of imaging conditions. To first obtain the ground truth of quantitative precision, an anthropomorphic chest phantom with synthetic spherical nodules were imaged on a 64 slice CT scanner across a range of protocols (five exposure levels and two reconstruction algorithms). The volumes of nodules were quantified from the images using clinical software, with the precision of the quantification calculated for each protocol. To predict the precision, e' was calculated for each protocol based on several Fourier-based figures of merit, which modeled the characteristic of the quantitation task and the imaging condition (resolution, noise, etc.) of a particular protocol. Results showed a strong correlation (R2=0.92) between the measured and predicted precision across all protocols, indicating e' as an effective predictor of the quantitative precision. This study provides a useful framework for quantification-oriented optimization of CT protocols.

  8. Multidetector CT and histological features of benign mesenchymoma of the infratemporal space: a rare case report

    PubMed Central

    Kelkar, CA; Desai, RS; Kambadakone, A; Shetty, SJ

    2013-01-01

    Benign mesenchymoma is a soft tissue neoplasm composed of an admixture of two or more benign mesenchymal components in addition to fibrous tissue. A rare case of benign mesenchymoma of the infratemporal space in a 14-year-old boy is presented. In this case report we discuss the salient imaging and histopathological features of this rare entity. PMID:22282510

  9. The jet ski open-book pelvic fracture: diagnosis with multidetector CT.

    PubMed

    Tsai, Andy; Rhea, James T; Novelline, Robert A

    2003-10-01

    A 10-year-old girl sustained a traumatic open-book pelvic fracture from a straddle injury in a jet ski accident. Plain films and computed tomography both demonstrated diastasis of the symphysis pubis and bilateral widening of the sacroiliac joints. The open-book fracture resulted from the patient's striking the steering column of the watercraft during a deceleration accident. The unusual cause of this injury is of clinical interest because with increasing popularity of personal watercraft and changes in the design of these vehicles, the incidence and prevalence of this type of injury may increase in the future.

  10. Multi-detector CT assessment in pulmonary hypertension: techniques, systematic approach to interpretation and key findings.

    PubMed

    Lewis, Gareth; Hoey, Edward T D; Reynolds, John H; Ganeshan, Arul; Ment, Jerome

    2015-06-01

    Pulmonary arterial hypertension (PAH) may be suspected based on the clinical history, physical examination and electrocardiogram findings but imaging is usually central to confirming the diagnosis, establishing a cause and guiding therapy. The diagnostic pathway of PAH involves a variety of complimentary investigations of which computed tomography pulmonary angiography (CTPA) has established a central role both in helping identify an underlying cause for PAH and assessing resulting functional compromise. In particular CTPA is considered as the gold standard technique for the diagnosis of thromboembolic disease. This article reviews the CTPA evaluation in PAH, describing CTPA techniques, a systematic approach to interpretation and spectrum of key imaging findings.

  11. Neurologic applications of whole-brain volumetric multidetector computed tomography.

    PubMed

    Snyder, Kenneth V; Mokin, Maxim; Bates, Vernice E

    2014-02-01

    The introduction of computed tomography (CT) scanning in the 1970s revolutionized the way clinicians could diagnose and treat stroke. Subsequent advances in CT technology significantly reduced radiation dose, reduced metallic artifact, and achieved speeds that enable dynamic functional studies. The recent addition of whole-brain volumetric CT perfusion technology has given clinicians a powerful tool to assess parenchymal perfusion parameters as well as visualize dynamic changes in blood vessel flow throughout the brain during a single cardiac cycle. This article reviews clinical applications of volumetric multimodal CT that helped to guide and manage care.

  12. CT of Normal Developmental and Variant Anatomy of the Pediatric Skull: Distinguishing Trauma from Normality.

    PubMed

    Idriz, Sanjin; Patel, Jaymin H; Ameli Renani, Seyed; Allan, Rosemary; Vlahos, Ioannis

    2015-01-01

    The use of computed tomography (CT) in clinical practice has been increasing rapidly, with the number of CT examinations performed in adults and children rising by 10% per year in England. Because the radiology community strives to reduce the radiation dose associated with pediatric examinations, external factors, including guidelines for pediatric head injury, are raising expectations for use of cranial CT in the pediatric population. Thus, radiologists are increasingly likely to encounter pediatric head CT examinations in daily practice. The variable appearance of cranial sutures at different ages can be confusing for inexperienced readers of radiologic images. The evolution of multidetector CT with thin-section acquisition increases the clarity of some of these sutures, which may be misinterpreted as fractures. Familiarity with the normal anatomy of the pediatric skull, how it changes with age, and normal variants can assist in translating the increased resolution of multidetector CT into more accurate detection of fractures and confident determination of normality, thereby reducing prolonged hospitalization of children with normal developmental structures that have been misinterpreted as fractures. More important, the potential morbidity and mortality related to false-negative interpretation of fractures as normal sutures may be avoided. The authors describe the normal anatomy of all standard pediatric sutures, common variants, and sutural mimics, thereby providing an accurate and safe framework for CT evaluation of skull trauma in pediatric patients.

  13. Clinical contributions of 64-slice computed tomography in the evaluation of cardiomyopathy of unknown origin.

    PubMed

    Boulmier, Dominique; Audinet, Caroline; Heautot, Jean-François; Larralde, Antoine; Veillard, David; Hamonic, Stéphanie; Bedossa, Marc; Leurent, Guillaume; Garreau, Mireille; Le Breton, Hervé

    2009-10-01

    Meta-analyses have confirmed the high performance of multislice computed tomography (MSCT) in coronary stenosis detection. Recent reports have described the study of left ventricular anatomy and function and coronary venous anatomy with MSCT. We sought to compare, in patients with cardiomyopathy of unknown origin, the performance of MSCT versus angiography for significant coronary artery disease detection and versus transthoracic echocardiography (TTE) for left ventricular anatomy and function evaluation, and to assess its ability to characterize coronary venous anatomy. Fifty-nine patients with cardiomyopathy (left ventricular ejection fraction [LVEF] less than or equal to 40%) of unknown origin, in sinus rhythm, underwent MSCT, TTE and coronary angiography. Twenty-four (3%) of 724 analysable coronary segments (97%) and 12 (20%) patients had significant coronary artery disease. MSCT sensitivity, specificity, and positive and negative predictive values for coronary artery disease detection were 87.5%, 98.5%, 67.7% and 99.6% in the per-segment assessment and 100%, 91%, 75% and 100% in the per-patient evaluation, respectively. Statistical analyses showed good agreement between MSCT and TTE in LVEF measurement (33+/-10% vs 32+/-11%, p=0.4, mean difference=0.7%, limits of agreement+/-13.6%) and a small LVED diameter overestimation (65.0+/-9.3mm vs 63.6+/-9.4mm, p=0.03). MSCT allowed detection of the posterolateral vein in 86% of cases. In selected patients presenting with idiopathic cardiomyopathy, MSCT is accurate for coronary artery disease detection and is a useful coronary venous imaging tool. MSCT studies of left ventricular function and morphology were mostly concordant with TTE measurements.

  14. ESTIMATION OF CARDIAC CT ANGIOGRAPHY RADIATION DOSE TOWARD THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVEL FOR CCTA IN IRAN.

    PubMed

    Hosseini Nasab, Seyed Mohammad Bagher; Shabestani-Monfared, Ali; Deevband, Mohammad Reza; Paydar, Reza; Nabahati, Mehrdad

    2016-08-29

    In recent years, with the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography (CCTA) has emerged as a useful diagnostic imaging modality as a non-invasive assessment of coronary heart disease. CT produces a larger radiation dose than other imaging tests and cardiac CT involves higher radiation dose with the advances in the spatial and temporal resolution. The aims of this study are patient dose assessment and establishment of national diagnostic reference level for CCTA in Iran. A questionnaire was sent to CCTA centers. Data for patient and CT protocols were obtained. The volumetric CT dose index (CTDIvol), dose length product (DLP) and total DLP were considered in the 32 cm standard body phantom. Calculation of estimated effective dose (ED) was obtained by multiplying the DLP by a conversion factor [k = 0.014 mSv (mGy·cm)(-1)]. Mean value of CTDIvol and DLP for CCTA was 50 mGy and 825 mGy·cm. The third quartile (75th) of the distribution of mean CTDIvol (66.54 mGy) and DLP (1073 mGy·cm) values was expressed as the diagnostic reference level (DRL) for CCTA in Iran. The median of ED was 10.26 mSv and interquartile range of ED was 7.08-15.03 mSv. A large variety in CTDIvol and DLP among CT scanner and different sites due to variability in CT parameter is noted. It seems that training could help to reduce patient's dose.

  15. Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis and management of pancreatic cancer; comparison with multidetector row computed tomography, magnetic resonance imaging and endoscopic ultrasonography.

    PubMed

    Ergul, N; Gundogan, C; Tozlu, M; Toprak, H; Kadıoglu, H; Aydin, M; Cermik, T F

    2014-01-01

    We aimed to analyze the contribution of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging to the diagnosis and management of pancreatic cancer compared with multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS). We retrospectively scanned the data of 52 patients who were referred for FDG PET/CT imaging for evaluation of pancreatic lesions greater than 10mm. The diagnostic performances of 4 imaging methods and the impact of PET/CT on the management of pancreatic cancer were defined. Pancreatic adenocarcinoma was diagnosed in 33 of 52 patients (63%), 15 patients had benign diseases of pancreas (29%), and 4 patients were normal (8%). Sensitivity and NPV of EUS and PET/CT were equal (100%) and higher than MDCT and MRI. Specificity, PPV and NPV of PET/CT were significantly higher than MDCT. However, sensitivities of two imaging methods were not significantly different. There was no significant difference between PET/CT and MRI and EUS for these values. When the cut-off value of SUVmax was 3.2, the most effective sensitivity and specificity values were obtained. PET/CT contributed to the management of pancreatic cancer in 30% of patients. FDG PET/CT is a valuable imaging method for the diagnosis and management of pancreatic cancer, especially when applied along with EUS as first line diagnostic tools. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  16. Low-dose CT for quantitative analysis in acute respiratory distress syndrome

    DTIC Science & Technology

    2013-08-31

    few studies on pulmonary emphysema [22-24], that showed that quantification of hyperinflated tissue is not affected by a reduction of tube current...Pulmonary emphysema : radiation dose and section thickness at multidetector CT quantification--comparison with macroscopic and microscopic...pulmonary emphysema using a low-dose technique. Radiol Med 2002, 104:13-24. 24. Nishio M, Matsumoto S, Ohno Y, Sugihara N, Inokawa H, Yoshikawa T

  17. Quantitative assessment of lipiodol deposition after Chemoembolization: Comparison between cone-beam CT and multi-detector CT

    PubMed Central

    Chen, Rongxin; Geschwind, Jean-François; Wang, Zhijun; Tacher, Vania; Lin, MingDe

    2013-01-01

    Purpose To evaluate the ability of cone-beam computed tomography (CBCT) acquired directly after TACE to assess lipiodol deposition in hepatocellular carcinoma (HCC) and compare it to unenhanced MDCT. Materials and methods Fifteen HCC patients were treated with conventional TACE, and CBCT was used to assess the lipiodol deposition directly after TACE. Unenhanced MDCT was performed 24 hours after TACE. Four patients were excluded because the margin of tumor or area of lipiodol deposition was not clear. The image enhancement density of the entire tumor (T) and liver parenchyma (L) was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and lipiodol was performed by semiautomatic 3D volume segmentation and compared using linear regression to evaluate consistency between two imaging modalities. Results The mean value of TLC on CBCT was not significantly different from that on MDCT (337.7±233.5 HU versus 283.0±152.1 HU, P=0.103). The average volume of the whole tumor and of only the lipiodol deposited regions, and the calculated average percentage of lipiodol retention on CBCT were not significantly different when compared to MDCT (tumor volume: 9.6±11.8 cm3 versus 10.8±14.2 cm3, P=0.142; lipiodol volume: 6.3±7.7 cm3 versus 7.0±8.1 cm3, P=0.214; percentage of lipiodol retention: 68.9%±24.0% versus 72.2%±23.1%, P=0.578). Additionally, there was a high correlation in the volume of tumor and lipiodol between CBCT and MDCT (R2=0.919 and 0.903, respectively). Conclusions The quantitative image enhancement and volume analyses demonstrate that CBCT is similar to MDCT in assessing the lipiodol deposition in HCC after TACE. PMID:24094672

  18. 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.

  19. Accuracy of water-enema multidetector computed tomography (WE-MDCT) in colon cancer staging: a prospective study.

    PubMed

    Sibileau, E; Ridereau-Zins, Catherine; Vanel, D; Pavageau, A H; Bertrais, S; Metivier-Cesbron, E; Venara, A; Aubé, C

    2014-10-01

    To assess the accuracy of water-enema multidetector computed tomography (WE-MDCT) in extra-rectal colon cancer staging. Fifty-three patients (mean age 70 years) with extra-rectal colon cancer proven by colonoscopy and biopsy were prospectively evaluated by preoperative WE-MDCT. CT scans were both intraluminal (water enema or WE) and intravenous (iodinated) contrast enhanced (CE). All patients underwent surgery. Tumors were classified with the TNM staging system. Noted CT features were: tumor size and location; tumor form and edges; spread to the pericolic fat or neighboring organs; thickening of retroperitoneal fascia; number, size, and enhancement of the peritumoral lymph nodes. Tumors were classified on CT into 3 T-stage groups: T1/T2, T3, and T4. Lymph nodes were classified by their density after injection [positive over 100 Hounsfield units (HU)]. Tumor localization to the specific colon segment was correct in all the cases. The agreement between WE-MDCT staging and histopathology staging was good (k = 0.64). An irregular and bowl-shaped aspect of the external edges of tumor provided excellent sensitivity for T3/T4 inclusion (Se 97.7%, NPV 85.7%). Thickening of a fascia or the abdominal wall provided good specificity for T4 stage (Sp 88.1%, NPV 94.9%). Enhancement over 100 HU of at least one peritumoral lymph node was the best criterion of N+ staging (Sp 67.7%, NPV 87.5%). WE-MDCT permits good staging of colon cancer based on objective features.

  20. Inter-scan variability of coronary artery calcium scoring assessed on 64-multidetector computed tomography vs. dual-source computed tomography: a head-to-head comparison.

    PubMed

    Ghadri, Jelena R; Goetti, Robert; Fiechter, Michael; Pazhenkottil, Aju P; Küest, Silke M; Nkoulou, Rene N; Windler, Christina; Buechel, Ronny R; Herzog, Bernhard A; Gaemperli, Oliver; Templin, Christian; Kaufmann, Philipp A

    2011-08-01

    Coronary artery calcium (CAC) scoring has emerged as a tool for risk stratification and potentially for monitoring response to risk factor modification. Therefore, repeat measurements should provide robust results and low inter-scanner variability for allowing meaningful comparison. The purpose of this study was to investigate inter-scanner variability of CAC for Agatston, volume, and mass scores by head-to-head comparison using two different cardiac computed tomography scanners: 64-detector multislice CT (MSCT) and 64-slice dual-source CT (DSCT). Thirty patients underwent CAC measurements on both 64-MSCT (GE LightSpeed XT scanner: 120 kV, 70 mAs, 2.5 mm slices) and 64-DSCT (Siemens Somatom Definition: 120 kV, 80 mAs, 3 mm slices) within <100 days (0-97). Retrospective intra-scan comparison revealed an excellent correlation. The excellent intra-scan (inter-observer) agreement was documented by narrow limits of agreement and a correlation coefficient of variation (COV) of r ≥ 0.99 (P < 0.001) for all CAC scores with a low COV for both scanners (64-MSCT/64-DSCT), i.e. Agatston (2.0/2.1%), mass (3.0/2.0%), and volume (4.7/3.9%). Inter-scanner comparison revealed larger Bland-Altman (BA) limits of agreement, despite high correlation (r ≥ 0.97) for all scores, with COV at 15.1, 21.6, and 44.9% for Agatston, mass, and volume scores. The largest BA limits were observed for volume scores (-1552.8 to 574.2), which was massively improved (-241.0 to 300.4, COV 11.5%) after reanalysing the 64-DSCT scans (Siemens) with GE software/workstation (while Siemens software/workstation does not allow cross-vendor analysis). Phantom measurements confirmed overestimation of volume scores by 'syngo Ca-Scoring' (Siemens) software which should therefore be reviewed (vendor has been notified). Intra- and inter-scan agreement of CAC measurement in a given data set is excellent. Inter-scanner variability is reasonable, particularly for Agatston units in the clinically most relevant range

  1. Development of a method to estimate organ doses for pediatric CT examinations

    SciTech Connect

    Papadakis, Antonios E. Perisinakis, Kostas; Damilakis, John

    2016-05-15

    Purpose: To develop a method for estimating doses to primarily exposed organs in pediatric CT by taking into account patient size and automatic tube current modulation (ATCM). Methods: A Monte Carlo CT dosimetry software package, which creates patient-specific voxelized phantoms, accurately simulates CT exposures, and generates dose images depicting the energy imparted on the exposed volume, was used. Routine head, thorax, and abdomen/pelvis CT examinations in 92 pediatric patients, ranging from 1-month to 14-yr-old (49 boys and 43 girls), were simulated on a 64-slice CT scanner. Two sets of simulations were performed in each patient using (i) a fixed tube current (FTC) value over the entire examination length and (ii) the ATCM profile extracted from the DICOM header of the reconstructed images. Normalized to CTDI{sub vol} organ dose was derived for all primary irradiated radiosensitive organs. Normalized dose data were correlated to patient’s water equivalent diameter using log-transformed linear regression analysis. Results: The maximum percent difference in normalized organ dose between FTC and ATCM acquisitions was 10% for eyes in head, 26% for thymus in thorax, and 76% for kidneys in abdomen/pelvis. In most of the organs, the correlation between dose and water equivalent diameter was significantly improved in ATCM compared to FTC acquisitions (P < 0.001). Conclusions: The proposed method employs size specific CTDI{sub vol}-normalized organ dose coefficients for ATCM-activated and FTC acquisitions in pediatric CT. These coefficients are substantially different between ATCM and FTC modes of operation and enable a more accurate assessment of patient-specific organ dose in the clinical setting.

  2. Development of a method to estimate organ doses for pediatric CT examinations.

    PubMed

    Papadakis, Antonios E; Perisinakis, Kostas; Damilakis, John

    2016-05-01

    To develop a method for estimating doses to primarily exposed organs in pediatric CT by taking into account patient size and automatic tube current modulation (ATCM). A Monte Carlo CT dosimetry software package, which creates patient-specific voxelized phantoms, accurately simulates CT exposures, and generates dose images depicting the energy imparted on the exposed volume, was used. Routine head, thorax, and abdomen/pelvis CT examinations in 92 pediatric patients, ranging from 1-month to 14-yr-old (49 boys and 43 girls), were simulated on a 64-slice CT scanner. Two sets of simulations were performed in each patient using (i) a fixed tube current (FTC) value over the entire examination length and (ii) the ATCM profile extracted from the DICOM header of the reconstructed images. Normalized to CTDIvol organ dose was derived for all primary irradiated radiosensitive organs. Normalized dose data were correlated to patient's water equivalent diameter using log-transformed linear regression analysis. The maximum percent difference in normalized organ dose between FTC and ATCM acquisitions was 10% for eyes in head, 26% for thymus in thorax, and 76% for kidneys in abdomen/pelvis. In most of the organs, the correlation between dose and water equivalent diameter was significantly improved in ATCM compared to FTC acquisitions (P < 0.001). The proposed method employs size specific CTDIvol-normalized organ dose coefficients for ATCM-activated and FTC acquisitions in pediatric CT. These coefficients are substantially different between ATCM and FTC modes of operation and enable a more accurate assessment of patient-specific organ dose in the clinical setting.

  3. Aborted sudden cardiac death associated with an anomalous right coronary artery

    PubMed Central

    Diaz, Rienzi A; Valdés, Julio

    2015-01-01

    Coronary artery anomalies arising from the opposite sinus of Valsalva and having an interarterial course between the aorta (AO) and pulmonary artery (PA) are the second most common cause of sudden cardiac death among young athletes, after hypertrophic cardiomyopathy. The right coronary artery (RCA) originating from the AO above the left sinus of Valsalva (LSV) is an extremely rare anomaly. We report the first case of a RCA arising from the AO above the LSV that subsequently runs between the AO and the PA, discovered by a 64-slice multidetector coronary CT, in a patient who was successfully resuscitated from ventricular fibrillation (VF) cardiac arrest while running in a marathon race. PMID:26153291

  4. SU-E-T-541: Measurement of CT Density Model Variations and the Impact On the Accuracy of Monte Carlo (MC) Dose Calculation in Stereotactic Body Radiation Therapy for Lung Cancer

    SciTech Connect

    Xiang, H; Li, B; Behrman, R; Russo, G; Kachnic, L; Lu, H; Fernando, H

    2015-06-15

    Purpose: To measure the CT density model variations between different CT scanners used for treatment planning and impact on the accuracy of MC dose calculation in lung SBRT. Methods: A Gammex electron density phantom (RMI 465) was scanned on two 64-slice CT scanners (GE LightSpeed VCT64) and a 16-slice CT (Philips Brilliance Big Bore CT). All three scanners had been used to acquire CT for CyberKnife lung SBRT treatment planning. To minimize the influences of beam hardening and scatter for improving reproducibility, three scans were acquired with the phantom rotated 120° between scans. The mean CT HU of each density insert, averaged over the three scans, was used to build the CT density models. For 14 patient plans, repeat MC dose calculations were performed by using the scanner-specific CT density models and compared to a baseline CT density model in the base plans. All dose re-calculations were done using the same plan beam configurations and MUs. Comparisons of dosimetric parameters included PTV volume covered by prescription dose, mean PTV dose, V5 and V20 for lungs, and the maximum dose to the closest critical organ. Results: Up to 50.7 HU variations in CT density models were observed over the baseline CT density model. For 14 patient plans examined, maximum differences in MC dose re-calculations were less than 2% in 71.4% of the cases, less than 5% in 85.7% of the cases, and 5–10% for 14.3% of the cases. As all the base plans well exceeded the clinical objectives of target coverage and OAR sparing, none of the observed differences led to clinically significant concerns. Conclusion: Marked variations of CT density models were observed for three different CT scanners. Though the differences can cause up to 5–10% differences in MC dose calculations, it was found that they caused no clinically significant concerns.

  5. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... conditions: Birth (congenital) defect of the head or brain Brain infection Brain tumor Buildup of fluid inside ...

  6. 64-MULTIDETECTOR COMPUTED TOMOGRAPHIC ANGIOGRAPHY OF THE CANINE CORONARY ARTERIES

    PubMed Central

    Drees, Randi; Frydrychowicz, Alex; Reeder, Scott B.; Pinkerton, Marie E.; Johnson, Rebecca

    2012-01-01

    Canine coronary artery angiography (CTA) was performed in four anesthetized healthy dogs using 64-multi-detector computed tomography. Esmolol, a β-1 adrenergic receptor antagonist, and sodium nitroprusside, an arteriolar and venous dilator, were administered to enhance visualization of the coronary arteries by reducing heart rate and creating vasodilation. The left main coronary artery with its three main branches and the right coronary artery were visualized and subdivided in 13 segments for evaluation. Optimal reconstruction interval, expressed as percentage of the R-to-R interval, was determined at 5% in 2.9%, 35% in 1%, 75% in 21.2%, 85% in 43.3%, and 95% in 31.7% of the segments. Overall image quality was good in 41.3% of the segments and excellent in 14.4%. There was blur in 98.1%, motion in 17.3%, and stair step in 6.7% of the evaluated segments, but these artifacts did not interfere with anatomic depiction of the arteries. Cross-sectional anatomy of the coronary arteries as evaluated from the coronary CTA agreed well with gross anatomic evaluation and published information. The use of esmolol did not lead to the target heart rate of 60–65 beats/min. Nitroprusside had no significant effect on visualized length or diameter of the coronary artery branches. Coronary CTA is useful for the anatomic depiction of coronary artery branches in the dog. PMID:21521398

  7. [Assessment of neoplastic pancreatic focal injury by multidetector computed tomography].

    PubMed

    Ramírez Gaspar, Alberto Motta; Morató López Alberto, Emilio; Valenzuela Tamaris, Jorge; Castillo González, Federico Armando

    2012-01-01

    pancreatic focal neoplastic lesions (PFNL) should be characterized through image methods to differentiate from no neoplastic lesions, suggesting one or more probable diagnosis, and staging of malignant lesions, in order to help define the estrategy of medial or surgical management. The multidetector computed tomography (MDCT) offers multiple properties and advantages that enable adequate characterization of the PFNL. The objective of this study is to evaluate de usefulness of MDCT in characterizing PFNL. a descriptive, retrospective caseseries study has been conducted. It consisted of reviewing MDCT studies in which PFNL were found, over a period of 4 years 11 months from January 2006 to November 2010. we obtained 54 cases of PFNL which were characterized by MDCT; 75.9% for a specific diagnosis, and were categorized as indeterminate 24.1%, considering more than one possible diagnosis. The most frequent PFNL type was pancreatic ductal adenocarcinoma in 51.9%. Pancreatic cystic neoplasms accounted for 16.7%. MDCT is useful for identifying and characterizing LFNP, this means the possibility of establishing one or more diagnostic possibilities and guide medical management.

  8. Dual-energy perfusion-CT of pancreatic adenocarcinoma.

    PubMed

    Klauss, M; Stiller, W; Pahn, G; Fritz, F; Kieser, M; Werner, J; Kauczor, H U; Grenacher, L

    2013-02-01

    To evaluate the feasibility of dual-energy CT (DECT)-perfusion of pancreatic carcinomas for assessing the differences in perfusion, permeability and blood volume of healthy pancreatic tissue and histopathologically confirmed solid pancreatic carcinoma. 24 patients with histologically proven pancreatic carcinoma were examined prospectively with a 64-slice dual source CT using a dynamic sequence of 34 dual-energy (DE) acquisitions every 1.5s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). 80 kV(p), 140 kV(p), and weighted average (linearly blended M0.3) 120 kV(p)-equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool (Body-PCT, Siemens Medical Solutions, Erlangen, Germany) for estimating perfusion, permeability, and blood volume values. Color-coded parameter maps were generated. In all 24 patients dual-energy CT-perfusion was. All carcinomas could be identified in the color-coded perfusion maps. Calculated perfusion, permeability and blood volume values were significantly lower in pancreatic carcinomas compared to healthy pancreatic tissue. Weighted average 120 kV(p)-equivalent perfusion-, permeability- and blood volume-values determined from DE image data were 0.27 ± 0.04 min(-1) vs. 0.91 ± 0.04 min(-1) (p<0.0001), 0.5 ± 0.07 *0.5 min(-1) vs. 0.67 ± 0.05 *0.5 min(-1) (p=0.06) and 0.49 ± 0.07 min(-1) vs. 1.28 ± 0.11 min(-1) (p<0.0001). Compared with 80 and 140 kV(p) the standard deviations of the kV(p)120 kV(p)-equivalent values were manifestly smaller. Dual-energy CT-perfusion of the pancreas is feasible. The use of DECT improves the accuracy of CT-perfusion of the pancreas by fully exploiting the advantages of enhanced iodine contrast at 80 kV(p) in combination with the noise reduction at 140 kV(p). Therefore using dual-energy perfusion data could improve the delineation of pancreatic carcinomas. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. CT-automatic exposure control devices: What are their performances?

    NASA Astrophysics Data System (ADS)

    Gutierrez, Daniel; Schmidt, Sabine; Denys, Alban; Schnyder, Pierre; Bochud, François O.; Verdun, Francis R.

    2007-10-01

    PurposeTo avoid unnecessary exposure to the patients, constructors have developed tube current modulation algorithms. The purpose of this work is to assess the performance of computed tomography (CT) tube current modulation concerning patient dose and image noise in MSCT scanners. Material and methodsA conical PMMA phantom with elliptical cross-section, to vary the thickness of the irradiated object in a monotonous way, and an anthropomorphic chest phantom were scanned under similar conditions on a general electrics (GE) LightSpeed VCT (64 slices) scanner. Noise measurements were made by calculating the standard deviation of the CT-number on a homogeneous ROI in both phantoms. The dose was estimated with the parameters read in the DICOM header of each studied image. ResultsThe study has shown that most of the time, constant noise levels (noise index) can be obtained by a variation of the mA. Nevertheless, this adaptation can be not fast enough when the variation of the attenuation changes is rapid. Thus, an adaptation length up to 5 cm was obtained. A 18% dose reduction can be achieved (mean of 9.9%) by switching from z-axis modulation algorithm to xyz-axis modulation option. However, exposure in the chest area can be higher with current modulation than without, when trying to keep an image noise level constant in thoraco-abdominal investigations. ConclusionCurrent modulation algorithms can produce inadequate quality images due to problems with tube current stabilization when a sudden attenuation variation takes place as at the start of a scanning sequence. As expected, rotational ( xyz-axis) modulation performs better than only z-axis modulation algorithm. The use of automatic exposure control (AEC) can lead to an increase of the dose if the maximum allowed current is not properly set in thoraco-abdominal acquisitions.

  10. Coronary artery imaging with multidetector computed tomography: a call for an evidence-based, multidisciplinary approach.

    PubMed

    Schoenhagen, Paul; Stillman, Arthur E; Garcia, Mario J; Halliburton, Sandra S; Tuzcu, E Murat; Nissen, Steven E; Modic, Michael T; Lytle, Bruce W; Topol, Eric J; White, Richard D

    2006-05-01

    Modern multidetector computed tomography systems are capable of a comprehensive assessment of the cardiovascular system, including noninvasive assessment of coronary anatomy. Multidetector computed tomography is expected to advance the role of noninvasive imaging for coronary artery disease, but clinical experience is still limited. Clinical guidelines are necessary to standardize scanner technology and appropriate clinical applications for coronary computed tomographic angiography. Further evaluation of this evolving technology will benefit from cooperation between different medical specialties, imaging scientists, and manufacturers of multidetector computed tomography systems, supporting multidisciplinary teams focused on the diagnosis and treatment of early and advanced stages of coronary artery disease. This cooperation will provide the necessary education, training, and guidelines for physicians and technologists assuring standard of care for their patients.

  11. Usefulness of 40-slice multidetector row computed tomography to detect coronary disease in patients prior to cardiac valve surgery.

    PubMed

    Pouleur, Anne-Catherine; le Polain de Waroux, Jean-Benoît; Kefer, Joëlle; Pasquet, Agnès; Coche, Emmanuel; Vanoverschelde, Jean-Louis; Gerber, Bernhard L

    2007-12-01

    Preoperative identification of significant coronary artery disease (CAD) in patients prior to valve surgery requires systematic invasive coronary angiography. The purpose of this current prospective study was to evaluate whether exclusion of CAD by multi-detector CT (MDCT) might potentially avoid systematic cardiac catheterization in these patients. Eighty-two patients (53 males, 62 +/- 13 years) scheduled to undergo valve surgery underwent 40-slice MDCT before invasive quantitative coronary angiography (QCA). According to QCA, 15 patients had CAD (5 one-vessel, 6 two-vessel and 4 three-vessel disease). The remaining 67 patients had no CAD. On a per-vessel basis, MDCT correctly identified 27/29 (sensitivity 93%) vessels with and excluded 277/299 vessels (specificity 93%) without CAD. On a per-patient basis, MDCT correctly identified 14/15 patients with (sensitivity 93%) and 60/67 patients without CAD (specificity 90%). Positive and negative predictive values of MDCT were 67% and 98%. Performing invasive angiography only in patients with abnormal MDCT might have avoided QCA in 60/82 (73%). MDCT could be potentially useful in the preoperative evaluation of patients with valve disease. By selecting only those patients with coronary lesions to undergo invasive coronary angiography, it could avoid cardiac catheterization in a large number of patients without CAD.

  12. MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY PATTERNS OF BRONCHOESPHAGEAL ARTERY HYPERTROPHY AND SYSTEMIC-TO-PULMONARY FISTULA IN DOGS.

    PubMed

    Ledda, Gianluca; Caldin, Marco; Mezzalira, Giorgia; Bertolini, Giovanna

    2015-01-01

    Anomalies involving arterial branches in the lungs are one of the causes of hemoptysis in humans and dogs. Congenital and acquired patterns of bronchoesophageal artery hypertrophy have been reported in humans based on CT characteristics. The purpose of this retrospective study was to describe clinical, echocardiographic, and multidetector computed tomography features of bronchoesophageal artery hypertrophy and systemic-to-pulmonary arterial communications in a sample of 14 dogs. Two main vascular patterns were identified in dogs that resembled congenital and acquired conditions reported in humans. Pattern 1 appeared as an aberrant origin of the right bronchoesophageal artery, normal origin of the left one, and enlargement of both the bronchial and esophageal branches that formed a dense network terminating in a pulmonary artery through an orifice. Pattern 2 appeared as a normal origin of both right and left bronchoesophageal arteries, with an enlarged and tortuous course along the bronchi to the periphery of the lung, where they communicated with subsegmental pulmonary arteries. Dogs having Pattern 1 also had paraesophageal and esophageal varices, with the latter being confirmed by videoendoscopy examination. Authors conclude that dogs with Pattern 1 should be differentiated from dogs with other congenital vascular systemic-to-pulmonary connections. Dogs having Pattern 2 should be evaluated for underlying pleural or pulmonary diseases. Bronchoesophageal artery hypertrophy can be accompanied by esophageal venous engorgement and should be included in the differential diagnosis for esophageal and paraesophageal varices in dogs.

  13. 3D Printing of CT Dataset: Validation of an Open Source and Consumer-Available Workflow.

    PubMed

    Bortolotto, Chandra; Eshja, Esmeralda; Peroni, Caterina; Orlandi, Matteo A; Bizzotto, Nicola; Poggi, Paolo

    2016-02-01

    The broad availability of cheap three-dimensional (3D) printing equipment has raised the need for a thorough analysis on its effects on clinical accuracy. Our aim is to determine whether the accuracy of 3D printing process is affected by the use of a low-budget workflow based on open source software and consumer's commercially available 3D printers. A group of test objects was scanned with a 64-slice computed tomography (CT) in order to build their 3D copies. CT datasets were elaborated using a software chain based on three free and open source software. Objects were printed out with a commercially available 3D printer. Both the 3D copies and the test objects were measured using a digital professional caliper. Overall, the objects' mean absolute difference between test objects and 3D copies is 0.23 mm and the mean relative difference amounts to 0.55 %. Our results demonstrate that the accuracy of 3D printing process remains high despite the use of a low-budget workflow.

  14. Investigation of the potential causes of partial scan artifacts in dynamic CT myocardial perfusion imaging

    NASA Astrophysics Data System (ADS)

    Tao, Yinghua; Speidel, Michael; Szczykutowicz, Timothy; Chen, Guang-Hong

    2014-03-01

    In recent years, there have been several findings regarding CT number variations (partial scan artifact or PSA) across time in dynamic myocardial perfusion studies with short scan gated reconstruction. These variations are correlated with the view angle range corresponding to the short scan acquisition for a given cardiac phase, which can vary from one cardiac cycle to another due to the asynchrony between heart rate and gantry rotation speed. In this study, we investigate several potential causes of PSA, including noise, beam hardening and scatter, using numerical simulations. In addition, we investigate partial scan artifact in a single source 64-slice diagnostic CT scanner in vivo data sets, and report its effect on perfusion analysis. Results indicated that among all three factors investigated, scatter can cause obvious partial scan artifact in dynamic myocardial perfusion imaging. Further, scatter is a low frequency phenomenon and is not heavily dependent on the changing contrasts, as both the frequency method and the virtual scan method are effective in reducing partial scan artifact. However, PSA does not necessarily lead to different blood volume maps compared to the full scan, because these maps are usually generated with a curve fitting procedure.

  15. Development and performance evaluation of an experimental fine pitch detector multislice CT scanner

    SciTech Connect

    Imai, Yasuhiro; Nukui, Masatake; Ishihara, Yotaro; Fujishige, Takashi; Ogata, Kentaro; Moritake, Masahiro; Kurochi, Haruo; Ogata, Tsuyoshi; Yahata, Mitsuru; Tang Xiangyang

    2009-04-15

    The authors have developed an experimental fine pitch detector multislice CT scanner with an ultrasmall focal spot x-ray tube and a high-density matrix detector through current CT technology. The latitudinal size of the x-ray tube focal spot was 0.4 mm. The detector dimension was 1824 channels (azimuthal direction)x32 rows (longitudinal direction) at row width of 0.3125 mm, in which a thinner reflected separator surrounds each detector cell coupled with a large active area photodiode. They were mounted on a commercial 64-slice CT scanner gantry while the scan field of view (50 cm) and gantry rotation speed (0.35 s) can be maintained. The experimental CT scanner demonstrated the spatial resolution of 0.21-0.22 mm (23.8-22.7 lp/cm) with the acrylic slit phantom and in-plane 50%-MTF 9.0 lp/cm and 10%-MTF 22.0 lp/cm. In the longitudinal direction, it demonstrated the spatial resolution of 0.24 mm with the high-resolution insert of the CATPHAN phantom and 0.34 mm as the full width at half maximum of the slice sensitivity profile. In low-contrast detectability, 3 mm at 0.3% was visualized at the CTDI{sub vol} of 47.2 mGy. Two types of 2.75 mm diameter vessel phantoms with in-stent stenosis at 25%, 50%, and 75% stair steps were scanned, and the reconstructed images can clearly resolve the stenosis at each case. The experimental CT scanner provides high-resolution imaging while maintaining low-contrast detectability, demonstrating the potentiality for clinical applications demanding high spatial resolution, such as imaging of inner ear, lung, and bone, or low-contrast detectability, such as imaging of coronary artery.

  16. Automatic liver segmentation method featuring a novel filter for multiphase multidetector-row helical computed tomography.

    PubMed

    Hirose, Tomohiro; Nitta, Norihisa; Tsudagawa, Masaru; Takahashi, Masashi; Murata, Kiyoshi

    2011-01-01

    To introduce an automatic liver segmentation method that includes a novel filter for multiphase multidetector-row helical computed tomography. We acquired 3-phase multidetector-row computed tomographic scans that included unenhanced, arterial, and portal phases. The liver was segmented using our novel adaptive linear prediction filter designed to reduce the difference between filter input and output values in the liver region and to increase these values outside the liver region. The segmentation algorithm produced a mean dice similarity coefficient (DSC) value of 91.4%. The application of our adaptive linear prediction filter was effective in automatically extracting liver regions.

  17. Validation of Multi-Detector Computed Tomography as a Non-Invasive Method for Measuring Ovarian Volume in Macaques (Macaca fascicularis)

    PubMed Central

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

    2013-01-01

    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

  18. 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

  19. Evaluation of posterior clinoid process pneumatization by multidetector computed tomography.

    PubMed

    Burulday, Veysel; Akgül, Mehmet Hüseyin; Muluk, Nuray Bayar; Ozveren, Mehmet Faik; Kaya, Ahmet

    2016-10-21

    In the present study, we investigated the types and ratio of posterior clinoid process (PCP) pneumatization in paranasal sinus multidetector computed tomography (MDCT). Paranasal MDCT images of 541 subjects (227 males, 314 females), between 15 and 65 years old, were included into the study. Pneumatization of anterior clinoid process and pneumatization types (I, II, or III) were evaluated in the males and females. PCP pneumatization was detected in 20.7 % of the males and 11.5 % of the females. Right, left, and bilateral PCP pneumatizations were detected in 7.9, 5.7, and 7.0 % of the males and 2.9, 3.2, and 4.5 % of the females, respectively. PCP pneumatization of the males is significantly higher than the females. The most detected type of pneumatization was type I (61.2 %) for all groups. In right, left, and bilateral pneumatizations separately, type I pneumatization was the most detected pneumatization type with the ratio of the 70.4, 65.2, and 50.0 %, respectively. In males, type I (61.7 %), and similarly in females, type I (60.6 %) pneumatization were detected more. Type II and type III pneumatizations were detected in decreasing order in both groups. In younger subjects, pneumatization of posterior clinoid process was found as higher, and in older subjects, PCP pneumatization was found as lower. Sclerosis process related to the aging may be responsible for the lower pneumatization ratios in older subjects. Structure of the surrounding regions of PCP is important for surgical procedures related to cavernous sinus, basilar apex aneurysms, and mass lesions. Preoperative radiological examinations are useful for operative planning. Any anomalies to PCP can cause unnecessary injury to the neurovascular complex structure around the cavernous sinus or postclinoidectomy CSF fistulas. Posterior clinoidectomies should be avoided in patients with type III PCP pneumatization to prevent CSF fistulas.

  20. Prediction of Small Bowel Obstruction Caused by Bezoars Using Risk Factor Categories on Multidetector Computed Tomographic Findings

    PubMed Central

    Kuang, Lian-qin; Cheng, Cheng

    2016-01-01

    Objectives. The aim of this study was to detect factors associated with small bowel obstruction (SBO) caused by bezoars on multidetector computed tomographic findings. Methods. We retrospectively reviewed 61 patients who had bezoars in the small bowels on MDCT. The patients were divided into SBO patients group and non-SBO patients group. The mean values of the diameter, volume, and CT attenuation as well as location and characteristics of the bezoars were compared between the two groups. Multivariate analysis was performed to determine factors associated with SBO. Results. There were 32 patients (52.5%) in the SBO group and 29 patients (47.5%) in the non-SBO group. The bezoars in the SBO group had greater values of each mean diameter and mean volume than those in the non-SBO group (3.2 ± 0.5 cm versus 1.6 ± 0.7 cm, P < 0.0001, 14.9 ± 6.4 cm3 versus 2.5 ± 2.7 cm3, P < 0.0001, resp.) and had a lower CT attenuation than the non-SBO group (55.5 ± 23.4 versus 173.0 ± 68.0, P < 0.0001). The SBO group had higher prevalence of phytobezoar appearance (75.0% versus 10.3%, P < 0.0001). Major diameters of bezoar and phytobezoar were significant independent risk factors associated with SBO (odds ratio = 36.09, 8.26, resp., and P = 0.0004, 0.044, resp.). Conclusions. Major diameter of bezoar or phytobezoar is a potential risk factor associated with SBO. PMID:27403434

  1. [Evaluation of left ventricular function with a 16-slice multidetector tomograph (MDCT-16): correlation with cardiovascular magnetic resonance imaging].

    PubMed

    de la Peña-Almaguer, Erasmo; Azpiri López, José Ramón; González-Camid, Felipe de Jesús; Ponce de León, Enrique; Flores-Ramírez, Ramiro; Zamarripa, Rafael; Loera, Javier; Rodríguez, Daniel; González Quijano, Rafael; Azpiri-Magallanes, Marcela; Jaramillo Estrada, Samuel; Assad Morell, José Luis

    2005-01-01

    The evaluation of Left ventricular function has both prognostic as well as therapeutic implications in patients with heart disease. Non-invasive coronary angiography with computed tomography using 16 slices (MDCT-16) allows to obtain images of the coronary anatomy due to its high spatial and temporal resolution, and also, to obtain data regarding Left ventricular function. The objective of this study was to correlate the use of MDCT-16 for the evaluation of the Left ventricular parameters using MRI as the Standard of reference. MRI: Se A 1.5 Tesla GE CvI Scanner optimized for cardiovascular applications was used. Using an ECG gated steady state fast precession sequence (SSFP, Thickness 10 mm, Flip Angle 45, FOV 36 cm. NEX 1, Frequency 256, Phase 128, Partial FOV 0.75, 16VPS), 6 to 8 short axis images of from base to apex of the left ventricle were obtained. Tomography: Using a 16 slice Multidetector tomograph (GE Lightspeed) and using ECG synchronization, images of the heart were obtained after the administration of 80 mls. of no-ionic contrast. The images were reconstructed off-line to obtain from 6 to 8 slices in a similar fashion to that of MR. Both studies were independently analyzed by 2 operators who obtained the ventricular function data. Linear correlation and a Paired T Student test was used to analyze the data and was considered significant when p < 0.05. 20 consecutive patients were evaluated with MDCT-16 and MRI, 18 males, mean age 52 +/- 15 years. There was no significant difference among the measurements for cardiac CT and MRI of the end-diastolic volume (EDV) and end-sistolic volume (ESV), stroke volume (SV), LV Mass or LV ejection fraction (LVEF). This results show a high correlation among the clinically relevant ventricular function parameters evaluated by cardiovascular CT and MRI. This findings suggest that ventricular function can be successfully evaluated along with the coronary anatomy using MDCT-16.

  2. Airway remodeling measured by multidetector computed tomography is increased in severe asthma and correlates with pathology

    PubMed Central

    Aysola, Ravi S.; Hoffman, Eric A.; Gierada, David; Wenzel, Sally; Cook-Granroth, Janice; Tarsi, Jaime; Zheng, Jie; Schechtman, Kenneth B.; Ramkumar, Thiruvamoor P.; Cochran, Rebecca; E, Xueping; Christie, Chandrika; Newell, John; Fain, Sean; Altes, Talissa A.; Castro, Mario

    2010-01-01

    Background To prospectively apply an automated, quantitative 3-D approach to imaging and airway analysis to assess airway remodeling in asthma. Methods Using the Pulmonary Workstation (VIDA Diagnostics) that enables quantitative airway segment measurements of low-dose, thin section (0.625-1.25 mm) multidetector-row CT (MDCT), we compared airway wall thickness (WT) and area (WA) in 123 subjects participating in a prospective multicenter cohort study, NIH Severe Asthma Research Program (SARP): severe asthma (n=63), mild-moderate asthma (n=35), and normal (n=25). A subset of these subjects underwent fiberoptic bronchoscopy and endobronchial biopsies (n=32). WT and WA were corrected for total airway diameter and area - WT%, WA%. Results Subjects with severe asthma had significantly greater WT% than mild-moderate asthma and normals [17.2±1.5 v 16.5±1.6, p=0.014 and 16.3±1.2, p=0.031, respectively] and greater WA% compared to mild-moderate asthma and normal [56.6±2.9 v 54.7±3.3, p=.005 and 54.6±2.4, p=0.003, respectively]. Both WT% and WA% were inversely correlated with baseline FEV1% (r=-0.39, p<0.0001 and -0.40, p<0.0001, respectively) and positively correlated with response to bronchodilator (r=0.28, p=0.002 and r=0.35, p<0.0001, respectively). Airway epithelial thickness on biopsy correlated with WT% (r=0.47, p=0.007) and WA% (r=0.52, p=0.003). In the same individual, there is considerable regional heterogeneity in airway wall thickness. Conclusion Severe asthmatics have thicker airway walls on MDCT than mild asthmatics or normals, which correlates with pathologic measures of remodeling and the degree of airflow obstruction. MDCT may be a useful technique for assessing airway remodeling in asthma, but overlap among groups limits the diagnostic value in individual subjects. PMID:18641116

  3. Patient doses using multidetector computed tomography scanners in Kenya.

    PubMed

    Korir, G K; Wambani, J S; Korir, I K

    2012-08-01

    Assessment of patient dose attributed to multislice computed tomography (CT) examination. A questionnaire method was developed and used in recording the patient dose and scanning parameters for the head, chest, abdomen and lumbar spine examinations. The patient doses due to brain, chest and abdomen examination were above the international diagnostic reference levels (DRLs) by factors of between one and four. The study demonstrated that the use of multislice CT elevates patient radiation dose, justifying the need for local optimised scanning protocols and the use of institutional DRL for dose management without affecting diagnostic image quality.

  4. CT Enterography

    MedlinePlus

    ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... may increase the risk of an unusual adverse effect. Women should always inform their physician and the ...

  5. [Comparative assessment of ct-bypass angiography and invasive coronary angiography in patients after coronary bypass surgery in the late postoperative period].

    PubMed

    Men'kov, I A; Trufanov, G E; Zhelezniak, I S; Rud', S D; Kniazev, E A

    2013-10-01

    The aim of the study was to evaluate the diagnostic accuracy of ct-bypass angiography in the evaluation of significant stenosis and occlusion of grafts, recipient and nongrafted vessels in patients after coronary bypass surgery in the late postoperative period. Ct-bypass angiography was performed on 64-slice ct scanner with a slice thickness of 0.5 mm and a gantry rotation time of 0.4 s. All results were compared with quantitative invasive coronary angiography. 43 patients with 113 grafts were included in the study. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy for the evaluation of significant stenosis were 94%, 95%, 88%, 98%, 95%, respectively. Diagnostic accuracy for the evaluation of significant stenosis in the recipient and nongrafted vessels were 91% and 90%, respectively. The diagnostic accuracy for the evaluation graft occlusion, recipient and nongrafted vessels was 100%, 100% and 98%, respectively. Ct-bypass angiography allows accurate non-invasive assessment of significant stenosis and occlusion of coronary bypass grafts and native coronary arteries in patients after coronary bypass surgery in the late postoperative period.

  6. Study of statistical properties of hybrid statistic in coherent multidetector compact binary coalescences search

    NASA Astrophysics Data System (ADS)

    Haris, K.; Pai, Archana

    2016-05-01

    In this article, we revisit the coherent gravitational wave search problem of compact binary coalescences with multidetector network consisting of advanced interferometers like LIGO-Virgo. Based on the loss of the optimal multidetector signal-to-noise ratio (SNR), we construct a hybrid statistic as a best of maximum-likelihood-ratio (MLR) statistic tuned for face-on and face-off binaries. The statistical properties of the hybrid statistic is studied. The performance of this hybrid statistic is compared with that of the coherent MLR statistic for generic inclination angles. Owing to the single synthetic data stream, the hybrid statistic gives few false alarms compared to the multidetector MLR statistic and small fractional loss in the optimum SNR for a large range of binary inclinations. We demonstrate that, for a LIGO-Virgo network and binary inclination ɛ <7 0 ° and ɛ >11 0 ° , the hybrid statistic captures more than 98% of the network optimum matched filter SNR with a low false alarm rate. The Monte Carlo exercise with two distributions of incoming inclination angles—namely, U [cos ɛ ] and a more realistic distribution proposed by B. F. Schutz [Classical Quantum Gravity 28, 125023 (2011)]—are performed with the hybrid statistic and give approximately 5% and 7% higher detection probabilities, respectively, compared to the two stream multidetector MLR statistic for a fixed false alarm probability of 1 0-5.

  7. CT and MR imaging findings in patients with acquired heart disease at risk for sudden cardiac death.

    PubMed

    Sparrow, Patrick J; Merchant, Naeem; Provost, Yves L; Doyle, Deirdre J; Nguyen, Elsie T; Paul, Narinder S

    2009-01-01

    Noninvasive imaging is an important screening and diagnostic tool in conditions associated with sudden cardiac death. The most common cause of sudden cardiac death is coronary artery disease, with myocarditis, cardiac sarcoidosis, and dilated and infiltrative cardiomyopathies being less common acquired causes. Common risk factors for sudden cardiac death, regardless of the disease process, include severe ventricular dysfunction and the presence of macroscopic scar seen at delayed contrast material-enhanced imaging. Recent advances in electrocardiographically (ECG) gated cardiac magnetic resonance (MR) imaging and multidetector computed tomography (CT) have led to increased referrals for cross-sectional imaging; thus, cardiac radiologists should be familiar with the disease entities associated with sudden cardiac death. Inflammatory processes and cardiomyopathies are best depicted with cardiac MR imaging. Steady-state free precession cine sequences coupled with inversion-recovery prepared gradient-echo T1-weighted sequences performed after the intravenous administration of gadolinium-based contrast material should form the basis of cardiac MR imaging protocols for cardiomyopathy. A clinical history that is suggestive of myocardial ischemia, specific requests to exclude coronary artery disease, or contraindications for MR imaging may imply that multidetector CT would be more appropriate. Nevertheless, both cardiac MR imaging and ECG-gated multidetector CT offer robust diagnosis and risk stratification for individual disease processes associated with sudden cardiac death.

  8. SU-E-I-25: Determining Tube Current, Tube Voltage and Pitch Suitable for Low- Dose Lung Screening CT

    SciTech Connect

    Williams, K; Matthews, K

    2014-06-01

    Purpose: The quality of a computed tomography (CT) image and the dose delivered during its acquisition depend upon the acquisition parameters used. Tube current, tube voltage, and pitch are acquisition parameters that potentially affect image quality and dose. This study investigated physicians' abilities to characterize small, solid nodules in low-dose CT images for combinations of current, voltage and pitch, for three CT scanner models. Methods: Lung CT images was acquired of a Data Spectrum anthropomorphic torso phantom with various combinations of pitch, tube current, and tube voltage; this phantom was used because acrylic beads of various sizes could be placed within the lung compartments to simulate nodules. The phantom was imaged on two 16-slice scanners and a 64-slice scanner. The acquisition parameters spanned a range of estimated CTDI levels; the CTDI estimates from the acquisition software were verified by measurement. Several experienced radiologists viewed the phantom lung CT images and noted nodule location, size and shape, as well as the acceptability of overall image quality. Results: Image quality for assessment of nodules was deemed unsatisfactory for all scanners at 80 kV (any tube current) and at 35 mA (any tube voltage). Tube current of 50 mA or more at 120 kV resulted in similar assessments from all three scanners. Physician-measured sphere diameters were closer to actual diameters for larger spheres, higher tube current, and higher kV. Pitch influenced size measurements less for larger spheres than for smaller spheres. CTDI was typically overestimated by the scanner software compared to measurement. Conclusion: Based on this survey of acquisition parameters, a low-dose CT protocol of 120 kV, 50 mA, and pitch of 1.4 is recommended to balance patient dose and acceptable image quality. For three models of scanners, this protocol resulted in estimated CTDIs from 2.9–3.6 mGy.

  9. SU-F-207-16: CT Protocols Optimization Using Model Observer

    SciTech Connect

    Tseng, H; Fan, J; Kupinski, M

    2015-06-15

    Purpose: To quantitatively evaluate the performance of different CT protocols using task-based measures of image quality. This work studies the task of size and the contrast estimation of different iodine concentration rods inserted in head- and body-sized phantoms using different imaging protocols. These protocols are designed to have the same dose level (CTDIvol) but using different X-ray tube voltage settings (kVp). Methods: Different concentrations of iodine objects inserted in a head size phantom and a body size phantom are imaged on a 64-slice commercial CT scanner. Scanning protocols with various tube voltages (80, 100, and 120 kVp) and current settings are selected, which output the same absorbed dose level (CTDIvol). Because the phantom design (size of the iodine objects, the air gap between the inserted objects and the phantom) is not ideal for a model observer study, the acquired CT images are used to generate simulation images with four different sizes and five different contracts iodine objects. For each type of the objects, 500 images (100 x 100 pixels) are generated for the observer study. The observer selected in this study is the channelized scanning linear observer which could be applied to estimate the size and the contrast. The figure of merit used is the correct estimation ratio. The mean and the variance are estimated by the shuffle method. Results: The results indicate that the protocols with 100 kVp tube voltage setting provides the best performance for iodine insert size and contrast estimation for both head and body phantom cases. Conclusion: This work presents a practical and robust quantitative approach using channelized scanning linear observer to study contrast and size estimation performance from different CT protocols. Different protocols at same CTDIvol setting could Result in different image quality performance. The relationship between the absorbed dose and the diagnostic image quality is not linear.

  10. Musculoskeletal applications of flat-panel volume CT.

    PubMed

    Reichardt, Benjamin; Sarwar, Ammar; Bartling, Soenke H; Cheung, Arnold; Grasruck, Michael; Leidecker, Christianne; Bredella, Miriam A; Brady, Thomas J; Gupta, Rajiv

    2008-12-01

    Flat-panel volume computed tomography (fpVCT) is a recent development in imaging. We discuss some of the musculoskeletal applications of a high-resolution flat-panel CT scanner. FpVCT has four main advantages over conventional multidetector computed tomography (MDCT): high-resolution imaging; volumetric coverage; dynamic imaging; omni-scanning. The overall effective dose of fpVCT is comparable to that of MDCT scanning. Although current fpVCT technology has higher spatial resolution, its contrast resolution is slightly lower than that of MDCT (5-10HU vs. 1-3HU respectively). We discuss the efficacy and potential utility of fpVCT in various applications related to musculoskeletal radiology and review some novel applications for pediatric bones, soft tissues, tumor perfusion, and imaging of tissue-engineered bone growth. We further discuss high-resolution CT and omni-scanning (combines fluoroscopic and tomographic imaging).

  11. Likelihood of aneurysmal subarachnoid haemorrhage in patients with normal unenhanced CT, CSF xanthochromia on spectrophotometry and negative CT angiography.

    PubMed

    Rana, A K; Turner, H E; Deans, K A

    2013-01-01

    Patients with suspected subarachnoid haemorrhage, a normal noncontrast computed tomography (CT) and cerebrospinal fluid (CSF) evidence of haemoglobin breakdown products often undergo CT angiography (CTA). If this is normal, then invasive catheter angiography may be offered. In current clinical practice, haemoglobin breakdown products are detected by spectrophotometry rather than visible xanthochromia, and CTA is performed on multidetector scanners. The aim of this study was to determine if such patients should still have a catheter angiography, given the associated risks. Patients positive for CSF spectrophotometry (n=26) were retrospectively identified from the clinical biochemistry information system and imaging data from the electronic radiology records were reviewed. Discharge letters were consulted to relate the biochemistry and radiology results to the final diagnosis. 15 patients with CT angiography were found. Nine patients had normal CT angiography. No causative aneurysms had been missed. One patient had small, coincidental aneurysms missed on initial reading of the CTA. The likelihood of a clinically significant aneurysm in a patient who is CT negative, lumbar puncture positive and CTA negative is low. Double reporting of negative CT angiograms may be advisable.

  12. Implementation and characterization of a 320-slice volumetric CT scanner for simulation in radiation oncology.

    PubMed

    Coolens, C; Breen, S; Purdie, T G; Owrangi, A; Publicover, J; Bartolac, S; Jaffray, D A

    2009-11-01

    Effective target definition and broad employment of treatment response assessment with dynamic contrast-enhanced CT in radiation oncology requires increased speed and coverage for use within a single bolus injection. To this end, a novel volumetric CT scanner (Aquilion One, Toshiba, Tochigi Pref., Japan) has been installed at the Princess Margaret Hospital for implementation into routine CT simulation. This technology offers great advantages for anatomical and functional imaging in both scan speed and coverage. The aim of this work is to investigate the system's imaging performance and quality as well as CT quantification accuracy which is important for radiotherapy dose calculations. The 320-slice CT scanner uses a 160 mm wide-area (2D) solid-state detector design which provides the possibility to acquire a volumetric axial length of 160 mm without moving the CT couch. This is referred to as "volume" and can be scanned with a rotation speed of 0.35-3 s. The scanner can also be used as a 64-slice CT scanner and perform conventional (axial) and helical acquisitions with collimation ranges of 1-32 and 16-32 mm, respectively. Commissioning was performed according to AAPM Reports TG 66 and 39 for both helical and volumetric imaging. Defrise and other cone-beam image analysis tests were performed. Overall, the imaging spatial resolution and geometric efficiency (GE) were found to be very good (>10 lp/mm, <1 mm spatial integrity and GE160 mm=85%) and within the AAPM guidelines as well as IEC recommendations. Although there is evidence of some cone-beam artifacts when scanning the Defrise phantom, image quality was found to be good and sufficient for treatment planning (soft tissue noise <10 HU). Measurements of CT number stability and contrast-to-noise values across the volume indicate clinically acceptable scan accuracy even at the field edge. Initial experience with this exciting new technology confirms its accuracy for routine CT simulation within radiation oncology

  13. Implementation and characterization of a 320-slice volumetric CT scanner for simulation in radiation oncology

    SciTech Connect

    Coolens, C.; Breen, S.; Purdie, T. G.; Owrangi, A.; Publicover, J.; Bartolac, S.; Jaffray, D. A.

    2009-11-15

    Purpose: Effective target definition and broad employment of treatment response assessment with dynamic contrast-enhanced CT in radiation oncology requires increased speed and coverage for use within a single bolus injection. To this end, a novel volumetric CT scanner (Aquilion One, Toshiba, Tochigi Pref., Japan) has been installed at the Princess Margaret Hospital for implementation into routine CT simulation. This technology offers great advantages for anatomical and functional imaging in both scan speed and coverage. The aim of this work is to investigate the system's imaging performance and quality as well as CT quantification accuracy which is important for radiotherapy dose calculations. Methods: The 320-slice CT scanner uses a 160 mm wide-area (2D) solid-state detector design which provides the possibility to acquire a volumetric axial length of 160 mm without moving the CT couch. This is referred to as ''volume'' and can be scanned with a rotation speed of 0.35-3 s. The scanner can also be used as a 64-slice CT scanner and perform conventional (axial) and helical acquisitions with collimation ranges of 1-32 and 16-32 mm, respectively. Commissioning was performed according to AAPM Reports TG 66 and 39 for both helical and volumetric imaging. Defrise and other cone-beam image analysis tests were performed. Results: Overall, the imaging spatial resolution and geometric efficiency (GE) were found to be very good (>10 lp/mm, <1 mm spatial integrity and GE{sub 160mm}=85%) and within the AAPM guidelines as well as IEC recommendations. Although there is evidence of some cone-beam artifacts when scanning the Defrise phantom, image quality was found to be good and sufficient for treatment planning (soft tissue noise <10 HU). Measurements of CT number stability and contrast-to-noise values across the volume indicate clinically acceptable scan accuracy even at the field edge. Conclusions: Initial experience with this exciting new technology confirms its accuracy for

  14. A reliable radiographic measurement for evaluation of normal distal tibiofibular syndesmosis: a multi-detector computed tomography study in adults.

    PubMed

    Chen, Yanxi; Qiang, Minfei; Zhang, Kun; Li, Haobo; Dai, Hao

    2015-01-01

    Syndesmotic injury may be difficult to diagnose, and radiological evaluation is very important. The purpose of this study was to offer a series of reliable and repeatable normal tibiofibular syndesmosis parameters in diagnosing injuries of the syndesmosis. Multi-detector computed tomography (MDCT) and radiographs of the distal tibiofibular syndesmosis in 484 cases were retrospectively reviewed. Relevant parameters included the tibiofibular clear space (TCS), the tibiofibular overlap (TFO), the depth of the incisura fibularis (IFD), and the height of the incisura fibularis (IFH), which were measured by novel three-dimensional (3-D) and two-dimensional (2-D) techniques. The distance between the measuring plane of the distal tibiofibular syndesmosis and the tibial plafond was measured. Intra- and inter-rater reliability was assessed by intraclass correlation coefficient (ICC) and the root mean square standard deviation (RMS-SD), to determine measurement precision. Sex differences of parameters were analyzed using analysis of covariance (ANCOVA) with body height as the covariate. Paired sample t-testing was used to compare parameters in different image modalities, including radiography, and 2-D and 3-D CT. The reliability of the 3-D images measurement (ICC range, 0.907 to 0.972) was greater than that for the 2-D axial images (ICC range, 0.895 to 0.927), and the AP view radiographs (ICC range, 0.742 to 0.838). The intra-rater RMS-SD of the 3-D CT, 2-D CT and radiographic measurements were less than 0.94 mm, 0.26 mm, and 2.87 mm, respectively. The measuring plane of the distal tibiofibular syndesmosis showed the sex difference, which was 12.1 mm proximal to the tibial plafond in the male group and 7.8 mm in the female group. In this plane, the parameters for tibiofibular syndesmosis were measured in different image modalities. All variables were significantly different between females and males (p < 0.05). 3-D measurement technique could be helpful to identify

  15. Three-dimensional image reconstruction of an anorectal malformation with multidetector-row helical computed tomography technology.

    PubMed

    Watanabe, Yoshio; Ando, Hisami; Seo, Takahiko; Kaneko, Kentaro; Katsuno, Shinsuke; Shinohara, Tsuyoshi; Mori, Kensaku; Toriwaki, Junichiro

    2003-05-01

    The presentation of the surgical anatomy of anorectal malformation by standard anatomical figures is not suitable for individual anorectoplasty. It is essential to understand the anatomy of the pelvic muscle (striated muscle complex: SMC) including the external anal sphincter and their three-dimensional (3D) configuration in each patient. Thus, we studied the SMC three-dimensionally with multidetector-row helical computed tomography (MRH-CT) preoperatively, and evaluated its usefulness. Fourteen patients with anorectal malformations before anorectoplasty (types: high n=6, intermediate n=2, low n=6) and two patients without anorectal malformations as controls (total: male n=8, female n=8) were investigated. An image of pelvic region was prepared with a slice thickness of 0.5 mm and a reconstruction pitch of 0.5 mm. A 3D reconstruction on a conventional personal computer (PC) was made with a volume rendering method, and assisted by our own software. The SMC was analyzed with three modified modes of 3D reconstruction corresponding to the surrounding tissues. A length of the parasagittal muscle, and both the sagittal and transverse width of the vertical fibers in the SMC at the connection to the parasagittal muscle were measured on a 3D image and then compared among three different types and controls. To eliminate variations in age, a length index was used to allow comparison. The 3D configuration of the SMC was different in every case. The arranged image mode, which displayed the SMC and the pelvic bones simultaneously, enabled to use conventional knowledge in cysto-urethrography. The length of the parasagittal muscle was longest in the high type but the width of the vertical fibers was smallest. Anatomical figures of the SMC including the external anal sphincter were clearly demonstrated on a PC in every anorectal malformation by our program. A 3D reconstruction image provides positional information on the SMC for the body surface and pelvic bone at the same time

  16. An improved analytical model for CT dose simulation with a new look at the theory of CT dose

    SciTech Connect

    Dixon, Robert L.; Munley, Michael T.; Bayram, Ersin

    2005-12-15

    Gagne [Med. Phys. 16, 29-37 (1989)] has previously described a model for predicting the sensitivity and dose profiles in the slice-width (z) direction for CT scanners. The model, developed prior to the advent of multidetector CT scanners, is still widely used; however, it does not account for the effect of anode tilt on the penumbra or include the heel effect, both of which are increasingly important for the wider beams (up to 40 mm) of contemporary, multidetector scanners. Additionally, it applied only on (or near) the axis of rotation, and did not incorporate the photon energy spectrum. The improved model described herein transcends all of the aforementioned limitations of the Gagne model, including extension to the peripheral phantom axes. Comparison of simulated and measured dose data provides experimental validation of the model, including verification of the superior match to the penumbra provided by the tilted-anode model, as well as the observable effects on the cumulative dose distribution. The initial motivation for the model was to simulate the quasiperiodic dose distribution on the peripheral, phantom axes resulting from a helical scan series in order to facilitate the implementation of an improved method of CT dose measurement utilizing a short ion chamber, as proposed by Dixon [Med. Phys. 30, 1272-1280 (2003)]. A more detailed set of guidelines for implementing such measurements is also presented in this paper. In addition, some fundamental principles governing CT dose which have not previously been clearly enunciated follow from the model, and a fundamental (energy-based) quantity dubbed 'CTDI-aperture' is introduced.

  17. Combination of FDG PET/CT and contrast-enhanced MSCT in detecting lymph node metastasis of esophageal cancer.

    PubMed

    Tan, Ru; Yao, Shu-Zhan; Huang, Zhao-Qin; Li, Jun; Li, Xin; Tan, Hai-Hua; Liu, Qing-Wei

    2014-01-01

    Lymph node metastasis is believed to be a dependent nega