Coronary CT Angiography-derived Fractional Flow Reserve: Machine Learning Algorithm versus Computational Fluid Dynamics Modeling.

PubMed

Tesche, Christian; De Cecco, Carlo N; Baumann, Stefan; Renker, Matthias; McLaurin, Tindal W; Duguay, Taylor M; Bayer, Richard R; Steinberg, Daniel H; Grant, Katharine L; Canstein, Christian; Schwemmer, Chris; Schoebinger, Max; Itu, Lucian M; Rapaka, Saikiran; Sharma, Puneet; Schoepf, U Joseph

2018-04-10

Purpose To compare two technical approaches for determination of coronary computed tomography (CT) angiography-derived fractional flow reserve (FFR)-FFR derived from coronary CT angiography based on computational fluid dynamics (hereafter, FFR CFD ) and FFR derived from coronary CT angiography based on machine learning algorithm (hereafter, FFR ML )-against coronary CT angiography and quantitative coronary angiography (QCA). Materials and Methods A total of 85 patients (mean age, 62 years ± 11 [standard deviation]; 62% men) who had undergone coronary CT angiography followed by invasive FFR were included in this single-center retrospective study. FFR values were derived on-site from coronary CT angiography data sets by using both FFR CFD and FFR ML . The performance of both techniques for detecting lesion-specific ischemia was compared against visual stenosis grading at coronary CT angiography, QCA, and invasive FFR as the reference standard. Results On a per-lesion and per-patient level, FFR ML showed a sensitivity of 79% and 90% and a specificity of 94% and 95%, respectively, for detecting lesion-specific ischemia. Meanwhile, FFR CFD resulted in a sensitivity of 79% and 89% and a specificity of 93% and 93%, respectively, on a per-lesion and per-patient basis (P = .86 and P = .92). On a per-lesion level, the area under the receiver operating characteristics curve (AUC) of 0.89 for FFR ML and 0.89 for FFR CFD showed significantly higher discriminatory power for detecting lesion-specific ischemia compared with that of coronary CT angiography (AUC, 0.61) and QCA (AUC, 0.69) (all P < .0001). Also, on a per-patient level, FFR ML (AUC, 0.91) and FFR CFD (AUC, 0.91) performed significantly better than did coronary CT angiography (AUC, 0.65) and QCA (AUC, 0.68) (all P < .0001). Processing time for FFR ML was significantly shorter compared with that of FFR CFD (40.5 minutes ± 6.3 vs 43.4 minutes ± 7.1; P = .042). Conclusion The FFR ML algorithm performs equally in detecting lesion-specific ischemia when compared with the FFR CFD approach. Both methods outperform accuracy of coronary CT angiography and QCA in the detection of flow-limiting stenosis. © RSNA, 2018.

A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT.

PubMed

Badea, Cristian T; Hedlund, Laurence W; Johnson, G Allan

2013-01-01

CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.

A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT

PubMed Central

Badea, Cristian T.; Hedlund, Laurence W.; Johnson, G. Allan

2013-01-01

CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging. PMID:27006920

Carotid stenosis assessment with multi-detector CT angiography: comparison between manual and automatic segmentation methods.

PubMed

Zhu, Chengcheng; Patterson, Andrew J; Thomas, Owen M; Sadat, Umar; Graves, Martin J; Gillard, Jonathan H

2013-04-01

Luminal stenosis is used for selecting the optimal management strategy for patients with carotid artery disease. The aim of this study is to evaluate the reproducibility of carotid stenosis quantification using manual and automated segmentation methods using submillimeter through-plane resolution Multi-Detector CT angiography (MDCTA). 35 patients having carotid artery disease with >30 % luminal stenosis as identified by carotid duplex imaging underwent contrast enhanced MDCTA. Two experienced CT readers quantified carotid stenosis from axial source images, reconstructed maximum intensity projection (MIP) and 3D-carotid geometry which was automatically segmented by an open-source toolkit (Vascular Modelling Toolkit, VMTK) using NASCET criteria. Good agreement among the measurement using axial images, MIP and automatic segmentation was observed. Automatic segmentation methods show better inter-observer agreement between the readers (intra-class correlation coefficient (ICC): 0.99 for diameter stenosis measurement) than manual measurement of axial (ICC = 0.82) and MIP (ICC = 0.86) images. Carotid stenosis quantification using an automatic segmentation method has higher reproducibility compared with manual methods.

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.

Implementation of Size-Dependent Local Diagnostic Reference Levels for CT Angiography.

PubMed

Boere, Hub; Eijsvoogel, Nienke G; Sailer, Anna M; Wildberger, Joachim E; de Haan, Michiel W; Das, Marco; Jeukens, Cecile R L P N

2018-05-01

Diagnostic reference levels (DRLs) are established for standard-sized patients; however, patient dose in CT depends on patient size. The purpose of this study was to introduce a method for setting size-dependent local diagnostic reference levels (LDRLs) and to evaluate these LDRLs in comparison with size-independent LDRLs and with respect to image quality. One hundred eighty-four aortic CT angiography (CTA) examinations performed on either a second-generation or third-generation dual-source CT scanner were included; we refer to the second-generation dual-source CT scanner as "CT1" and the third-generation dual-source CT scanner as "CT2." The volume CT dose index (CTDI vol ) and patient diameter (i.e., the water-equivalent diameter) were retrieved by dose-monitoring software. Size-dependent DRLs based on a linear regression of the CTDI vol versus patient size were set by scanner type. Size-independent DRLs were set by the 5th and 95th percentiles of the CTDI vol values. Objective image quality was assessed using the signal-to-noise ratio (SNR), and subjective image quality was assessed using a 4-point Likert scale. The CTDI vol depended on patient size and scanner type (R 2 = 0.72 and 0.78, respectively; slope = 0.05 and 0.02 mGy/mm; p < 0.001). Of the outliers identified by size-independent DRLs, 30% (CT1) and 67% (CT2) were adequately dosed when considering patient size. Alternatively, 30% (CT1) and 70% (CT2) of the outliers found with size-dependent DRLs were not identified using size-independent DRLs. A negative correlation was found between SNR and CTDI vol (R 2 = 0.36 for CT1 and 0.45 for CT2). However, all outliers had a subjective image quality score of sufficient or better. We introduce a method for setting size-dependent LDRLs in CTA. Size-dependent LDRLs are relevant for assessing the appropriateness of the radiation dose for an individual patient on a specific CT scanner.

Evaluation of computed tomography in patients with atypical angina or chest pain clinically referred for invasive coronary angiography: randomised controlled trial

PubMed Central

Rief, Matthias; Martus, Peter; Kendziora, Benjamin; Feger, Sarah; Dreger, Henryk; Priem, Sascha; Knebel, Fabian; Böhm, Marko; Schlattmann, Peter; Hamm, Bernd; Schönenberger, Eva; Laule, Michael; Zimmermann, Elke

2016-01-01

Objective To evaluate whether invasive coronary angiography or computed tomography (CT) should be performed in patients clinically referred for coronary angiography with an intermediate probability of coronary artery disease. Design Prospective randomised single centre trial. Setting University hospital in Germany. Participants 340 patients with suspected coronary artery disease and a clinical indication for coronary angiography on the basis of atypical angina or chest pain. Interventions 168 patients were randomised to CT and 172 to coronary angiography. After randomisation one patient declined CT and 10 patients declined coronary angiography, leaving 167 patients (88 women) and 162 patients (78 women) for analysis. Allocation could not be blinded, but blinded independent investigators assessed outcomes. Main outcome measure The primary outcome measure was major procedural complications within 48 hours of the last procedure related to CT or angiography. Results Cardiac CT reduced the need for coronary angiography from 100% to 14% (95% confidence interval 9% to 20%, P<0.001) and was associated with a significantly greater diagnostic yield from coronary angiography: 75% (53% to 90%) v 15% (10% to 22%), P<0.001. Major procedural complications were uncommon (0.3%) and similar across groups. Minor procedural complications were less common in the CT group than in the coronary angiography group: 3.6% (1% to 8%) v 10.5% (6% to 16%), P=0.014. CT shortened the median length of stay in the angiography group from 52.9 hours (interquartile range 49.5-76.4 hours) to 30.0 hours (3.5-77.3 hours, P<0.001). Overall median exposure to radiation was similar between the CT and angiography groups: 5.0 mSv (interquartile range 4.2-8.7 mSv) v 6.4 mSv (3.4-10.7 mSv), P=0.45. After a median follow-up of 3.3 years, major adverse cardiovascular events had occurred in seven of 167 patients in the CT group (4.2%) and six of 162 (3.7%) in the coronary angiography group (adjusted hazard ratio 0.90, 95% confidence interval 0.30 to 2.69, P=0.86). 79% of patients stated that they would prefer CT for subsequent testing. The study was conducted at a University hospital in Germany and thus the performance of CT may be different in routine clinical practice. The prevalence was lower than expected, resulting in an underpowered study for the predefined primary outcome. Conclusions CT increased the diagnostic yield and was a safe gatekeeper for coronary angiography with no increase in long term events. The length of stay was shortened by 22.9 hours with CT, and patients preferred non-invasive testing. Trial registration ClinicalTrials.gov NCT00844220. PMID:27777234

Evaluation of computed tomography in patients with atypical angina or chest pain clinically referred for invasive coronary angiography: randomised controlled trial.

PubMed

Dewey, Marc; Rief, Matthias; Martus, Peter; Kendziora, Benjamin; Feger, Sarah; Dreger, Henryk; Priem, Sascha; Knebel, Fabian; Böhm, Marko; Schlattmann, Peter; Hamm, Bernd; Schönenberger, Eva; Laule, Michael; Zimmermann, Elke

2016-10-24

 To evaluate whether invasive coronary angiography or computed tomography (CT) should be performed in patients clinically referred for coronary angiography with an intermediate probability of coronary artery disease.  Prospective randomised single centre trial.  University hospital in Germany.  340 patients with suspected coronary artery disease and a clinical indication for coronary angiography on the basis of atypical angina or chest pain.  168 patients were randomised to CT and 172 to coronary angiography. After randomisation one patient declined CT and 10 patients declined coronary angiography, leaving 167 patients (88 women) and 162 patients (78 women) for analysis. Allocation could not be blinded, but blinded independent investigators assessed outcomes.  The primary outcome measure was major procedural complications within 48 hours of the last procedure related to CT or angiography.  Cardiac CT reduced the need for coronary angiography from 100% to 14% (95% confidence interval 9% to 20%, P<0.001) and was associated with a significantly greater diagnostic yield from coronary angiography: 75% (53% to 90%) v 15% (10% to 22%), P<0.001. Major procedural complications were uncommon (0.3%) and similar across groups. Minor procedural complications were less common in the CT group than in the coronary angiography group: 3.6% (1% to 8%) v 10.5% (6% to 16%), P=0.014. CT shortened the median length of stay in the angiography group from 52.9 hours (interquartile range 49.5-76.4 hours) to 30.0 hours (3.5-77.3 hours, P<0.001). Overall median exposure to radiation was similar between the CT and angiography groups: 5.0 mSv (interquartile range 4.2-8.7 mSv) v 6.4 mSv (3.4-10.7 mSv), P=0.45. After a median follow-up of 3.3 years, major adverse cardiovascular events had occurred in seven of 167 patients in the CT group (4.2%) and six of 162 (3.7%) in the coronary angiography group (adjusted hazard ratio 0.90, 95% confidence interval 0.30 to 2.69, P=0.86). 79% of patients stated that they would prefer CT for subsequent testing. The study was conducted at a University hospital in Germany and thus the performance of CT may be different in routine clinical practice. The prevalence was lower than expected, resulting in an underpowered study for the predefined primary outcome.  CT increased the diagnostic yield and was a safe gatekeeper for coronary angiography with no increase in long term events. The length of stay was shortened by 22.9 hours with CT, and patients preferred non-invasive testing.Trial registration ClinicalTrials.gov NCT00844220. 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.

Intravenous volume tomographic pulmonary angiography imaging

NASA Astrophysics Data System (ADS)

Ning, Ruola; Strang, John G.; Chen, Biao; Conover, David L.; Yu, Rongfeng

1999-05-01

This study presents a new intravenous (IV) tomographic angiography imaging technique, called intravenous volume tomographic digital angiography (VTDA) for cross sectional pulmonary angiography. While the advantages of IV-VTDA over spiral CT in terms of volume scanning time and resolution have been validated and reported in our previous papers for head and neck vascular imaging, the superiority of IV-VTDA over spiral CT for cross sectional pulmonary angiography has not been explored yet. The purpose of this study is to demonstrate the advantage of isotropic resolution of IV-VTDA in the x, y and z directions through phantom and animal studies, and to explore its clinical application for detecting clots in pulmonary angiography. A prototype image intensifier-based VTDA imaging system has been designed and constructed by modifying a GE 8800 CT scanner. This system was used for a series of phantom and dog studies. A pulmonary vascular phantom was designed and constructed. The phantom was scanned using the prototype VTDA system for direct 3D reconstruction. Then the same phantom was scanned using a GE CT/i spiral CT scanner using the routine pulmonary CT angiography protocols. IV contrast injection and volume scanning protocols were developed during the dog studies. Both VTDA reconstructed images and spiral CT images of the specially designed phantom were analyzed and compared. The detectability of simulated vessels and clots was assessed as the function of iodine concentration levels, oriented angles, and diameters of the vessels and clots. A set of 3D VTDA reconstruction images of dog pulmonary arteries was obtained with different IV injection rates and isotropic resolution in the x, y and z directions. The results of clot detection studies in dog pulmonary arteries have also been shown. This study presents a new tomographic IV angiography imaging technique for cross sectional pulmonary angiography. The results of phantom and animal studies indicate that IV-VTDA is superior to spiral CT for cross sectional pulmonary angiography.

Intra-arterial Ultra-low-Dose CT Angiography of Lower Extremity in Diabetic Patients

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

Özgen, Ali, E-mail: draliozgen@hotmail.com; Sanioğlu, Soner; Bingöl, Uğur Anıl

2016-08-15

PurposeTo image lower extremity arteries by CT angiography using a very low-dose intra-arterial contrast medium in patients with high risk of developing contrast-induced nephropathy (CIN).Materials and MethodsThree cases with long-standing diabetes mellitus and signs of lower extremity atherosclerotic disease were evaluated by CT angiography using 0.1 ml/kg of the body weight of contrast medium given via 10-cm-long 4F introducer by puncturing the CFA. Images were evaluated by an interventional radiologist and a cardiovascular surgeon. Density values of the lower extremity arteries were also calculated. Findings in two cases were compared with digital subtraction angiography images performed for percutaneous revascularization. Blood creatininemore » levels were followed for possible CIN.ResultsIntra-arterial CT angiography images were considered diagnostic in all patients and optimal in one patient. No patient developed CIN after intra-arterial CT angiography, while one patient developed CIN after percutaneous intervention.ConclusionIntra-arterial CT angiography of lower extremity might be performed in selected patients with high risk of developing CIN. Our limited experience suggests that as low as of 0.1 ml/kg of the body weight of contrast medium may result in adequate diagnostic imaging.« less

[Comparative evaluation of ultrasonography, computerized tomography, angiography and lipiodol CT in defining extent of hepatocarcinoma. A multicenter study].

PubMed

Dalla Palma, L; Pozzi Mucelli, R; Sponza, M; Bartolozzi, C; De Santis, M; Gandini, G; Mannella, P; Matricardi, L; Rossi, C; Simonetti, G

1995-03-01

The authors report the results of a multicentric trial on hepatocellular carcinoma (HCC) patients, whose lesions were confirmed with biopsy or by high (> 400 ng/ml) alpha-fetoprotein levels. The series consisted of 149 patients examined in 8 different centers and submitted to ultrasonography (US), Computed Tomography (CT) before and after contrast agent administration, angiography and Lipiodol CT. According to lesion size and number, the patients were divided with each imaging modality into three groups: a) group 1: unifocal HCC < 5 cm diameter; b) group 2: multifocal HCC with 2-3 nodules and/or tumor mass < 80 ml; c) multifocal HCC with more than 3 nodules (with total tumor mass not exceeding 40% of liver volume) or with total tumor mass > 80 ml. In 77 patients all the examinations were available for comparison. US and CT diagnosed more patients as belonging to group 1 than angiography and Lipiodol CT, while more patients were classified as groups 2 and 3 with angiography and Lipiodol CT, meaning that US and CT may understage some HCC cases (about 15%) because they show a lower number of nodules. This observation was confirmed by the direct comparison between US and Lipiodol CT (in 114 patients), CT and Lipiodol CT (in 103 patients) and angiography and Lipiodol CT (in 116 patients). US and Lipiodol CT were in disagreement in 18 cases, CT and Lipiodol CT in 16 cases and angiography and Lipiodol CT in 13 cases. In most of these cases, Lipiodol CT showed more lesions than the other techniques. The size of the undetected lesions was small, ranging few mm to 2 cm in nearly all cases. To conclude, the results of this multicentric trial show that Lipiodol CT is a fundamental tool to evaluate HCC extent. In contrast, conventional CT appeared not to add any significant piece of information and can therefore be excluded from the diagnostic protocol of HCC.

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.

Navigation with Electromagnetic Tracking for Interventional Radiology Procedures

PubMed Central

Wood, Bradford J.; Zhang, Hui; Durrani, Amir; Glossop, Neil; Ranjan, Sohan; Lindisch, David; Levy, Eliott; Banovac, Filip; Borgert, Joern; Krueger, Sascha; Kruecker, Jochen; Viswanathan, Anand; Cleary, Kevin

2008-01-01

PURPOSE To assess the feasibility of the use of preprocedural imaging for guide wire, catheter, and needle navigation with electromagnetic tracking in phantom and animal models. MATERIALS AND METHODS An image-guided intervention software system was developed based on open-source software components. Catheters, needles, and guide wires were constructed with small position and orientation sensors in the tips. A tetrahedral-shaped weak electromagnetic field generator was placed in proximity to an abdominal vascular phantom or three pigs on the angiography table. Preprocedural computed tomographic (CT) images of the phantom or pig were loaded into custom-developed tracking, registration, navigation, and rendering software. Devices were manipulated within the phantom or pig with guidance from the previously acquired CT scan and simultaneous real-time angiography. Navigation within positron emission tomography (PET) and magnetic resonance (MR) volumetric datasets was also performed. External and endovascular fiducials were used for registration in the phantom, and registration error and tracking error were estimated. RESULTS The CT scan position of the devices within phantoms and pigs was accurately determined during angiography and biopsy procedures, with manageable error for some applications. Preprocedural CT depicted the anatomy in the region of the devices with real-time position updating and minimal registration error and tracking error (<5 mm). PET can also be used with this system to guide percutaneous biopsies to the most metabolically active region of a tumor. CONCLUSIONS Previously acquired CT, MR, or PET data can be accurately codisplayed during procedures with reconstructed imaging based on the position and orientation of catheters, guide wires, or needles. Multimodality interventions are feasible by allowing the real-time updated display of previously acquired functional or morphologic imaging during angiography, biopsy, and ablation. PMID:15802449

Computer-aided evaluation of low-dose and low-contrast agent third-generation dual-source CT angiography prior to transcatheter aortic valve implantation (TAVI).

PubMed

Dankerl, Peter; Hammon, Matthias; Seuss, Hannes; Tröbs, Monique; Schuhbaeck, Annika; Hell, Michaela M; Cavallaro, Alexander; Achenbach, Stephan; Uder, Michael; Marwan, Mohamed

2017-05-01

To evaluate the performance of computer-aided evaluation software for a comprehensive workup of patients prior to transcatheter aortic valve implantation (TAVI) using low-contrast agent and low radiation dose third-generation dual-source CT angiography. We evaluated 30 consecutive patients scheduled for TAVI. All patients underwent ECG-triggered high-pitch dual-source CT angiography of the aortic root and aorta with a standardized contrast agent volume (30 ml Imeron350, flow rate 4 ml/s) and low-dose (100 kv/350 mAs) protocol. An expert (10 years of experience) manually evaluated aortic root and iliac access dimensions (distance between coronary ostia and aortic annulus, minimal/maximal diameters and area-derived diameter of the aortic annulus) and best CT-predicted fluoroscopic projection angle as the reference standard. Utilizing computer-aided software (syngo.via), the same pre-TAVI workup was performed and compared to the reference standard. Mean CTDI[Formula: see text] was 3.46 mGy and mean DLP 217.6 ± 12.1 mGy cm, corresponding to a mean effective dose of 3.7 ± 0.2 mSv. Computer-aided evaluation was successful in all but one patient. Compared to the reference standard, Bland-Altman analysis indicated very good agreement for the distances between aortic annulus and coronary ostia (RCA: mean difference 0.8 mm; 95 % CI 0.4-1.2 mm; LM: mean difference 0.9 mm; 95 % CI 0.5-1.3 mm); however, we demonstrated a systematic overestimation of annulus- derived diameter using the software (mean difference 44.4 mm[Formula: see text]; 95 % CI 30.4-58.3 mm[Formula: see text]). Based on respective annulus dimensions, the recommended prosthesis size (Edwards SAPIEN 3) matched in 26 out of the 29 patients (90 %). CT-derived fluoroscopic projection angles showed an excellent agreement for both methods. Out of 58 iliac arteries, 15 (25 %) arteries could not be segmented by the software. Preprocessing time of the software was 71 ± 11 s (range 51-96 s), and reading time with the software was 118 ± 31 s (range 68-201 s). In the workup of pre-TAVI CT angiography, computer-aided evaluation of low-contrast, low-dose examinations is feasible with good agreement and quick reading time. However, a systematic overestimation of the aortic annulus area is observed.

Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children.

PubMed

Ayyala, Rama S; Zurakowski, David; Lee, Edward Y

2015-11-01

Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand administration of IV contrast agent and 30 (65%; 10.2 ± 4.2 years; range 4-18 years) had mechanical administration of IV contrast agent. All 46 abdominal CT angiography studies were of diagnostic quality based on qualitative evaluation (all ≥3). All abdominal CT angiography studies from both groups showed diagnostic quality of contrast enhancement (>150 HU) at both the celiac axis and the inferior mesenteric artery (IMA) levels. The contrast enhancement of the abdominal aorta was not significantly different between the IV contrast administration methods at either the celiac axis level (360 ± 158 vs. 353 ± 116, P = 0.24) or the IMA level (340 ± 140 vs. 351 ± 90, P = 0.27), adjusting for age. Diagnostic-quality abdominal CT angiography can be achieved using hand administration of IV contrast agent in infants and young children (≤5 years).

Coronary CT angiography with single-source and dual-source CT: comparison of image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated protocols.

PubMed

Sabarudin, Akmal; Sun, Zhonghua; Yusof, Ahmad Khairuddin Md

2013-09-30

This study is conducted to investigate and compare image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated coronary CT angiography (CCTA) with the use of single-source CT (SSCT) and dual-source CT (DSCT). A total of 209 patients who underwent CCTA with suspected coronary artery disease scanned with SSCT (n=95) and DSCT (n=114) scanners using prospective ECG-triggered and retrospective ECG-gated protocols were recruited from two institutions. The image was assessed by two experienced observers, while quantitative assessment was performed by measuring the image noise, the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). Effective dose was calculated using the latest published conversion coefficient factor. A total of 2087 out of 2880 coronary artery segments were assessable, with 98.0% classified as of sufficient and 2.0% as of insufficient image quality for clinical diagnosis. There was no significant difference in overall image quality between prospective ECG-triggered and retrospective gated protocols, whether it was performed with DSCT or SSCT scanners. Prospective ECG-triggered protocol was compared in terms of radiation dose calculation between DSCT (6.5 ± 2.9 mSv) and SSCT (6.2 ± 1.0 mSv) scanners and no significant difference was noted (p=0.99). However, the effective dose was significantly lower with DSCT (18.2 ± 8.3 mSv) than with SSCT (28.3 ± 7.0 mSv) in the retrospective gated protocol. Prospective ECG-triggered CCTA reduces radiation dose significantly compared to retrospective ECG-gated CCTA, while maintaining good image quality. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Coronary Computed Tomographic Angiography-Derived Fractional Flow Reserve for Therapeutic Decision Making.

PubMed

Tesche, Christian; Vliegenthart, Rozemarijn; Duguay, Taylor M; De Cecco, Carlo N; Albrecht, Moritz H; De Santis, Domenico; Langenbach, Marcel C; Varga-Szemes, Akos; Jacobs, Brian E; Jochheim, David; Baquet, Moritz; Bayer, Richard R; Litwin, Sheldon E; Hoffmann, Ellen; Steinberg, Daniel H; Schoepf, U Joseph

2017-12-15

This study investigated the performance of coronary computed tomography angiography (cCTA) with cCTA-derived fractional flow reserve (CT-FFR) compared with invasive coronary angiography (ICA) with fractional flow reserve (FFR) for therapeutic decision making in patients with suspected coronary artery disease (CAD). Seventy-four patients (62 ± 11 years, 62% men) with at least 1 coronary stenosis of ≥50% on clinically indicated dual-source cCTA, who had subsequently undergone ICA with FFR measurement, were retrospectively evaluated. CT-FFR values were computed using an on-site machine-learning algorithm to assess the functional significance of CAD. The therapeutic strategy (optimal medical therapy alone vs revascularization) and the appropriate revascularization procedure (percutaneous coronary intervention vs coronary artery bypass grafting) were selected using cCTA-CT-FFR. Thirty-six patients (49%) had a functionally significant CAD based on ICA-FFR. cCTA-CT-FFR correctly identified a functionally significant CAD and the need of revascularization in 35 of 36 patients (97%). When revascularization was deemed indicated, the same revascularization procedure (32 percutaneous coronary interventions and 3 coronary artery bypass grafting) was chosen in 35 of 35 patients (100%). Overall, identical management strategies were selected in 73 of the 74 patients (99%). cCTA-CT-FFR shows excellent performance to identify patients with and without the need for revascularization and to select the appropriate revascularization strategy. cCTA-CT-FFR as a noninvasive "one-stop shop" has the potential to change diagnostic workflows and to directly inform therapeutic decision making in patients with suspected CAD. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic performance of multi-slice CT angiography combined with enterography for small bowel obstruction and intestinal ischaemia.

PubMed

He, Bosheng; Gu, Jinhua; Huang, Sheng; Gao, Xuesong; Fan, Jinhe; Sheng, Meihong; Wang, Lin; Gong, Shenchu

2017-02-01

This study was performed to evaluate the diagnostic performance of multi-slice CT angiography combined with enterography in determining the cause and location of obstruction as well as intestinal ischaemia in patients with small bowel obstruction (SBO). This study retrospectively summarized the image data of 57 SBO patients who received both multi-slice CT angiography and enterography examination between December 2012 and May 2013. The CT diagnoses of SBO and intestinal ischaemia were correlated with the findings at surgery or digital subtraction angiography, which were set as standard references. Multi-slice CT angiography and enterography indicated that the cause of SBO in three patients was misjudged, suggesting a diagnostic accuracy of 94.7%. In one patient the level of obstruction was incorrect, demonstrating a diagnostic accuracy of 98.2%. Based on the results of the receiver operating characteristic (ROC) curve analysis, the diagnostic criterion for ischaemic SBO was at least two of the four CT signs (circumferential bowel wall thickening, reduced enhancement of the intestinal wall, mesenteric oedema and mesenteric vascular engorgement). The criterion yielded a sensitivity of 94.4%, a specificity of 92.3%, a positive predicted value of 85.0% and a negative predicted value of 97.3%, and the area under curve (AUC) was 0.92 (95% CI, 0.85-0.99). Multi-slice CT angiography and enterography have high diagnostic value in identifying the cause and site of SBO. In addition, the suggested diagnostic criterion using CT signs is helpful for diagnosing intestinal ischaemia in SBO patients. © 2016 The Royal Australian and New Zealand College of Radiologists.

Spontaneous rectus sheath hematoma: The utility of CT angiography.

PubMed

Pierro, Antonio; Cilla, Savino; Modugno, Pietro; Centritto, Enrico Maria; De Filippo, Carlo Maria; Sallustio, Giuseppina

2018-04-01

We described the utility of computed tomography (CT) angiography in detection of bleeding vessels for a rapid percutaneous arterial embolization of the spontaneous rectus sheath hematoma. A 70-year-old woman comes to our attention with acute abdominal pain and a low hemoglobin level. An unenhanced CT was performed demonstrating a large rectus sheath hematoma. A conservative management was initially established. Despite this therapy, the abdominal pain increased together with a further decrease of hemoglobin values. A CT angiography was then performed, demonstrating an active bleeding within the hematoma and addressing the patient to a rapid percutaneous arterial embolization.

Benefit of cone-beam computed tomography angiography in acute management of angiographically undetectable ruptured arteriovenous malformations.

PubMed

Rahal, Jason P; Malek, Adel M

2013-10-01

Ruptured arteriovenous malformations (AVMs) are a frequent cause of intracerebral hemorrhage (ICH). In some cases, compression from the associated hematoma in the acute setting can partially or completely occlude an AVM, making it invisible on conventional angiography techniques. The authors report on the successful use of cone-beam CT angiography (CBCT-A) to precisely identify the underlying angioarchitecture of ruptured AVMs that are not visible on conventional angiography. Three patients presented with ICH for which they underwent examination with CBCT-A in addition to digital subtraction angiography and other imaging modalities, including MR angiography and CT angiography. All patients underwent surgical evacuation due to mass effect from the hematoma. Clinical history, imaging studies, and surgical records were reviewed. Hematoma volumes were calculated. In all 3 cases, CBCT-A demonstrated detailed anatomy of an AVM where no lesion or just a suggestion of a draining vein had been seen with other imaging modalities. Magnetic resonance imaging demonstrated enhancement in 1 patient; CT angiography demonstrated a draining vein in 1 patient; 2D digital subtraction angiography and 3D rotational angiography demonstrated a suggestion of a draining vein in 2 cases and no finding in the third. In the 2 patients in whom CBCT-A was performed prior to surgery, the demonstrated AVM was successfully resected without evidence of a residual lesion. In the third patient, CBCT-A allowed precise targeting of the AVM nidus using Gamma Knife radiosurgery. Cone-beam CT angiography should be considered in the evaluation and subsequent treatment of ICH due to ruptured AVMs. In cases in which the associated hematoma compresses the AVM nidus, CBCT-A can have higher sensitivity and anatomical accuracy than traditional angiographic modalities, including digital subtraction angiography.

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.

The utility of 64 channel multidetector CT angiography for evaluating the renal vascular anatomy and possible variations: a pictorial essay.

PubMed

Kumar, Sheo; Neyaz, Zafar; Gupta, Archna

2010-01-01

The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment.

Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.

PubMed

Rosow, David E; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I; Mueller, Peter R; Fernández-del Castillo, Carlos; Warshaw, Andrew L; Thayer, Sarah P

2005-12-01

Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.

Image Quality and Radiation Exposure Comparison of a Double High-Pitch Acquisition for Coronary Computed Tomography Angiography Versus Standard Retrospective Spiral Acquisition in Patients With Atrial Fibrillation.

PubMed

Prazeres, Carlos Eduardo Elias Dos; Magalhães, Tiago Augusto; de Castro Carneiro, Adriano Camargo; Cury, Roberto Caldeira; de Melo Moreira, Valéria; Bello, Juliana Hiromi Silva Matsumoto; Rochitte, Carlos Eduardo

The aim of this study was to compare image quality and radiation dose of coronary computed tomography (CT) angiography performed with dual-source CT scanner using 2 different protocols in patients with atrial fibrillation. Forty-seven patients with AF underwent 2 different acquisition protocols: double high-pitch (DHP) spiral acquisition and retrospective spiral acquisition. The image quality was ranked according to a qualitative score by 2 experts: 1, no evident motion; 2, minimal motion not influencing coronary artery luminal evaluation; and 3, motion with impaired luminal evaluation. A third expert solved any disagreement. A total of 732 segments were evaluated. The DHP group (24 patients, 374 segments) showed more segments classified as score 1 than the retrospective spiral acquisition group (71.3% vs 37.4%). Image quality evaluation agreement was high between observers (κ = 0.8). There was significantly lower radiation exposure for the DHP group (3.65 [1.29] vs 23.57 [10.32] mSv). In this original direct comparison, a DHP spiral protocol for coronary CT angiography acquisition in patients with atrial fibrillation resulted in lower radiation exposure and superior image quality compared with conventional spiral retrospective acquisition.

Establishing a successful coronary CT angiography program in the emergency department: official writing of the Fellow and Resident Leaders of the Society of Cardiovascular Computed Tomography (FiRST).

PubMed

Maroules, Christopher D; Blaha, Michael J; El-Haddad, Mohamed A; Ferencik, Maros; Cury, Ricardo C

2013-01-01

Coronary CT angiography is an effective, evidence-based strategy for evaluating acute chest pain in the emergency department for patients at low-to-intermediate risk of acute coronary syndrome. Recent multicenter trials have reported that coronary CT angiography is safe, reduces time to diagnosis, facilitates discharge, and may lower overall cost compared with routine care. Herein, we provide a 10-step approach for establishing a successful coronary CT angiography program in the emergency department. The importance of strategic planning and multidisciplinary collaboration is emphasized. Patient selection and preparation guidelines for coronary CT angiography are reviewed with straightforward protocols that can be adapted and modified to clinical sites, depending on available cardiac imaging capabilities. Technical parameters and patient-specific modifications are also highlighted to maximize the likelihood of diagnostic quality examinations. Practical suggestions for quality control, process monitoring, and standardized reporting are reviewed. Finally, the role of a "triple rule-out" protocol is featured in the context of acute chest pain evaluation in the emergency department. Copyright © 2013 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

The optimal imaging strategy for patients with stable chest pain: a cost-effectiveness analysis.

PubMed

Genders, Tessa S S; Petersen, Steffen E; Pugliese, Francesca; Dastidar, Amardeep G; Fleischmann, Kirsten E; Nieman, Koen; Hunink, M G Myriam

2015-04-07

The optimal imaging strategy for patients with stable chest pain is uncertain. To determine the cost-effectiveness of different imaging strategies for patients with stable chest pain. Microsimulation state-transition model. Published literature. 60-year-old patients with a low to intermediate probability of coronary artery disease (CAD). Lifetime. The United States, the United Kingdom, and the Netherlands. Coronary computed tomography (CT) angiography, cardiac stress magnetic resonance imaging, stress single-photon emission CT, and stress echocardiography. Lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. The strategy that maximized QALYs and was cost-effective in the United States and the Netherlands began with coronary CT angiography, continued with cardiac stress imaging if angiography found at least 50% stenosis in at least 1 coronary artery, and ended with catheter-based coronary angiography if stress imaging induced ischemia of any severity. For U.K. men, the preferred strategy was optimal medical therapy without catheter-based coronary angiography if coronary CT angiography found only moderate CAD or stress imaging induced only mild ischemia. In these strategies, stress echocardiography was consistently more effective and less expensive than other stress imaging tests. For U.K. women, the optimal strategy was stress echocardiography followed by catheter-based coronary angiography if echocardiography induced mild or moderate ischemia. Results were sensitive to changes in the probability of CAD and assumptions about false-positive results. All cardiac stress imaging tests were assumed to be available. Exercise electrocardiography was included only in a sensitivity analysis. Differences in QALYs among strategies were small. Coronary CT angiography is a cost-effective triage test for 60-year-old patients who have nonacute chest pain and a low to intermediate probability of CAD. Erasmus University Medical Center.

Diagnostic Accuracy of Computed Tomography Angiography as Compared to Conventional Angiography in Patients Undergoing Noncoronary Cardiac Surgery

PubMed Central

Joshi, Hasit; Shah, Ronak; Prajapati, Jayesh; Bhangdiya, Vipin; Shah, Jayal; Kandre, Yogini; Shah, Komal

2016-01-01

Objective: To compare the diagnostic accuracy of multi-slice computed tomography (MSCT) angiography with conventional angiography in patients undergoing major noncoronary cardiac surgeries. Materials and Methods: We studied fifty major noncoronary cardiac surgery patients scheduled for invasive coronary angiography, 29 (58%) female and 21 (42%) male. Inclusion criteria of the study were age of the patients ≥40 years, having low or intermediate probability of coronary artery disease (CAD), left ventricular ejection fraction (LVEF) >35%, and patient giving informed consent for undergoing MSCT and conventional coronary angiography. The patients with LVEF <35%, high pretest probability of CAD, and hemodynamically unstable were excluded from the study. Results: The diagnostic accuracy of CT coronary angiography was evaluated regarding true positive, true negative values. The overall sensitivity and specificity of CT angiography technique was 100% (95% confidence interval [CI]: 39.76%–100%) and 91.30% (95% CI: 79.21%–97.58%). The positive (50%; 95% CI: 15.70%–84.30%) and negative predictive values (100%; 95% CI: 91.59%–100%) of CT angiography were also fairly high in these patients. Conclusion: Our study suggests that this non-invasive technique may improve perioperative risk stratification in patients undegoing non-cardiac surgery. PMID:27867455

Performance of turbo high-pitch dual-source CT for coronary CT angiography: first ex vivo and patient experience.

PubMed

Morsbach, Fabian; Gordic, Sonja; Desbiolles, Lotus; Husarik, Daniela; Frauenfelder, Thomas; Schmidt, Bernhard; Allmendinger, Thomas; Wildermuth, Simon; Alkadhi, Hatem; Leschka, Sebastian

2014-08-01

To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA). First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms). Subjective image quality regarding the presence of motion artefacts was interpreted by two readers on a four-point scale (1, excellent; 4, non-diagnostic). Objective image quality was assessed by calculating distortion vectors. Thereafter, 20 consecutive patients (median, 50 years) undergoing clinically indicated CCTA were included. In the phantom study, image quality was rated diagnostic up to the HR75 bpm, with object distortion being 1 mm or less. Distortion increased above 1 mm at HR of 80-90 bpm. Patients had a mean HR of 66 bpm (47-78 bpm). Coronary segments were of diagnostic image quality for all patients with HR up to 73 bpm. Average effective radiation dose in patients was 0.6 ± 0.3 mSv. Our combined phantom and patient study indicates that CCTA with turbo high-pitch third-generation dual-source 192-slice CT can be performed at HR up to 75 bpm while maintaining diagnostic image quality, being associated with an average radiation dose of 0.6 mSv. • CCTA is feasible with the turbo high-pitch mode. • Turbo high-pitch CCTA provides diagnostic image quality up to 73 bpm. • The radiation dose of high-pitch CCTA is 0.6 mSv on average.

Automatic segmentation and co-registration of gated CT angiography datasets: measuring abdominal aortic pulsatility

NASA Astrophysics Data System (ADS)

Wentz, Robert; Manduca, Armando; Fletcher, J. G.; Siddiki, Hassan; Shields, Raymond C.; Vrtiska, Terri; Spencer, Garrett; Primak, Andrew N.; Zhang, Jie; Nielson, Theresa; McCollough, Cynthia; Yu, Lifeng

2007-03-01

Purpose: To develop robust, novel segmentation and co-registration software to analyze temporally overlapping CT angiography datasets, with an aim to permit automated measurement of regional aortic pulsatility in patients with abdominal aortic aneurysms. Methods: We perform retrospective gated CT angiography in patients with abdominal aortic aneurysms. Multiple, temporally overlapping, time-resolved CT angiography datasets are reconstructed over the cardiac cycle, with aortic segmentation performed using a priori anatomic assumptions for the aorta and heart. Visual quality assessment is performed following automatic segmentation with manual editing. Following subsequent centerline generation, centerlines are cross-registered across phases, with internal validation of co-registration performed by examining registration at the regions of greatest diameter change (i.e. when the second derivative is maximal). Results: We have performed gated CT angiography in 60 patients. Automatic seed placement is successful in 79% of datasets, requiring either no editing (70%) or minimal editing (less than 1 minute; 12%). Causes of error include segmentation into adjacent, high-attenuating, nonvascular tissues; small segmentation errors associated with calcified plaque; and segmentation of non-renal, small paralumbar arteries. Internal validation of cross-registration demonstrates appropriate registration in our patient population. In general, we observed that aortic pulsatility can vary along the course of the abdominal aorta. Pulsation can also vary within an aneurysm as well as between aneurysms, but the clinical significance of these findings remain unknown. Conclusions: Visualization of large vessel pulsatility is possible using ECG-gated CT angiography, partial scan reconstruction, automatic segmentation, centerline generation, and coregistration of temporally resolved datasets.

Novel Application of Postmortem CT Angiography for Evaluation of the Intracranial Vascular Anatomy in Cadaver Heads.

PubMed

van Eijk, Ruben P A; van der Zwan, Albert; Bleys, Ronald L A W; Regli, Luca; Esposito, Giuseppe

2015-12-01

Postmortem CT angiography is a common procedure used to visualize the entire human vasculature. For visualization of a specific organ's vascular anatomy, casting is the preferred method. Because of the permanent and damaging nature of casting, the organ cannot be further used as an experimental model after angiography. Therefore, there is a need for a minimally traumatic method to visualize organ-specific vascular anatomy. The purpose of this study was to develop and evaluate a contrast enhancement technique that is capable of visualizing the intracranial vascular anatomy while preserving the anatomic integrity in cadaver heads. Seven human heads were used in this study. Heads were prepared by cannulating the vertebral and internal carotid arteries. Contrast agent was injected as a mixture of tap water, polyethylene glycol 600, and an iodinated contrast agent. Postmortem imaging was executed on a 64-MDCT scanner. Primary image review and 3D reconstruction were performed on a CT workstation. Clear visualization of the major cerebral arteries and smaller intracranial branches was achieved. Adequate visualization was obtained for both the anterior and posterior intracranial circulation. The minimally traumatic angiography method preserved the vascular integrity of the cadaver heads. A novel application of postmortem CT angiography is presented here. The technique can be used for radiologic evaluation of the intracranial circulation in cadaver heads. After CT angiography, the specimen can be used for further experimental or laboratory testing and teaching purposes.

Adaptive prospective ECG-triggered sequence coronary angiography in dual-source CT without heart rate control: Image quality and diagnostic performance.

PubMed

Pan, Chang-Jie; Qian, Nong; Wang, Tao; Tang, Xiao-Qiang; Xue, Yue-Jun

2013-02-01

The aim of this study was to evaluate the accuracy of using second generation dual-source CT (DSCT) to obtain high quality images and diagnostic performance and to reduce the radiation dose in adaptive prospective electrocardiography (ECG)-triggered sequence (CorAdSeq) CT coronary angiography (CTCA) without heart rate control. No prescan β-blockers were administered. Un-enhanced CT and CTCA with adaptive prospective CorAdSeq scanning without heart rate control were performed in 683 consecutive patients divided into two body mass index (BMI) groups: BMI <25 kg/m(2) (group A, n=412) and BMI ≥25 kg/m(2) (group B, n=271). The image quality and quantitative stenosis of all coronary segments with a diameter ≥1 mm were assessed. The mean heart rate (MHR), heart rate variability (HRV) and radiation dose values were recorded. In 426 cases, the diagnostic performance was evaluated using quantitative conventional coronary angiography as the reference standard. Diagnostic image quality was obtained in 98.5% of segments in group A and in 98.8% of segments in group B, with no significant differences between the groups. No correlations were observed between the image quality score and MHR or HRV (P=0.492, P=0.564, respectively). The effective radiation doses in groups A and B were 2.57±1.01 mSv and 6.36±1.88 mSv, respectively. The sensitivities and specificities of diagnosing coronary heart disease per patient were 99.6% and 97.8% in group A and 99.5% and 97.5% in group B, respectively (P>0.05). Adaptive prospective CorAdSeq scanning, without heart rate control, by second generation DSCT had a high image quality and diagnostic performance for coronary artery stenosis with lower radiation doses.

Impact of coronary calcium score on the prevalence of coronary artery stenosis on dual source CT coronary angiography in caucasian patients with an intermediate risk.

PubMed

Meyer, Mathias; Henzler, Thomas; Fink, Christian; Vliegenthart, Rozemarijn; Barraza, J Michael; Nance, John W; Apfaltrer, Paul; Schoenberg, Stefan O; Wasser, Klaus

2012-11-01

To investigate the prevalence of significant coronary artery stenosis on coronary computed tomography angiography (cCTA) in symptomatic Caucasian patients with an intermediate risk score at different levels of coronary artery calcification (CAC). In total, 383 consecutive symptomatic Caucasian patients (147 females, 60 ± 13 years) with an intermediate risk score underwent nonenhanced CT for CAC scoring immediately before contrast-enhanced cCTA on a dual-source CT scanner. Additionally clinically indicated invasive coronary angiography (ICA) was performed in 90 patients. The prevalence of significant coronary artery stenosis (>50%) on cCTA and ICA was correlated at different CAC score levels. Of 121 patients with a zero CAC score, none had significant coronary artery stenosis on cCTA or ICA. Coronary CTA diagnosed in 54 of 70 patients with high CAC score (>400), a significant stenosis. Subsequent ICA confirmed significant stenosis in 30 of 32 patients. Sensitivity and a negative predictive value of CAC score ruling out significant stenosis on cCTA were 100% and 100%, respectively, using cutoff value of zero and specificity and positive predictive value to predict significant stenosis on cCTA were 79% and 51%, respectively, using a cutoff value of >400. Significant coronary artery stenosis is extremely unlikely, with an estimated risk of 4 in 1000 patients in symptomatic Caucasian patients with an intermediate risk score and negative CAC score. To reduce radiation exposure, radiation-free tests should be considered for differential diagnosis of chest pain in these patients. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Variations of the superficial middle cerebral vein: classification using three-dimensional CT angiography.

PubMed

Suzuki, Y; Matsumoto, K

2000-05-01

Classification of variations of the superficial middle cerebral vein (SMCV) remains ambiguous. We propose a new classification system based on embryologic development for preoperative examination. Three-dimensional CT angiography was used to evaluate 500 SMCVs (in 250 patients). The outflow vessels from the SMCV were classified into seven types on the basis of embryologic development. The 3D CT angiograms in axial stereoscopic and oblique views and multiple intensity projection images were evaluated by the same neurosurgeon on two occasions. Inconsistent interpretations were regarded as equivocal. Three-dimensional CT angiography clearly depicted the SMCV running along the lesser wing or the middle cranial fossa. However, the outflow vessel could not be confirmed as the sphenoparietal, cavernous, or emissary type in 39 (8%) of the sides. SMCVs running in the middle cranial fossa to join the transverse sinus or superior petrosal sinus were accurately identified. SMCVs were present in 456 sides: 62% entered the sphenoparietal sinus or the cavernous sinus and 12% joined the emissary vein. Nine vessels were the superior petrosal type, 10 the basal type, 12 the squamosal type, and 44 the undeveloped type. Three-dimensional CT angiography can depict the vessels and their anatomic relationship to the bone structure, allowing identification of the SMCV variant in individual patients. Preoperative planning for skull base surgery requires such information to reduce the invasiveness of the procedure. With the use of our classification system, 3D CT angiography can provide exact and practical information concerning the SMCV.

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

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

Kudoh, Kouichi, E-mail: cdk70770@par.odn.ne.jp; Kadota, Masataka; Nakayama, Yoshiharu

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.

[Initial experience of percutaneous coronary intervention guided by computed tomography coronary angiography derived roadmap and magnetic navigation system].

PubMed

Zhang, Qiu; Kong, De-yu; Li, Chun-jian; Chen, Bo; Jia, En-zhi; Chen, Lei-Lei; Jia, Qing-zhe; Dai, Zhen-hua; Zhu, Tian-tian; Chen, Jun; Liu, Jie; Zhu, Tie-bing; Yang, Zhi-jian; Cao, Ke-jiang

2013-02-01

To evaluate the feasibility, efficacy and safety of the percutaneous coronary intervention (PCI)guided by computed tomography (CT) coronary angiography derived roadmap and magnetic navigation system (MNS). During June 2011 and May 2012, thirty consecutive patients receiving elective PCI were enrolled, coronary artery disease was primarily diagnosed by dual-source CT coronary angiography (DSCT-CA) at outpatient clinic and successively proved by coronary artery angiography in the hospital. Target vessels from pre-procedure DSCT-CA were transferred to the magnetic navigation system, and consequently edited, reconstructed, and projected onto the live fluoroscopic screen as roadmap. Parameters including characters of the target lesions, time, contrast volume, radiation dosage for guidewire crossing, and complications of the procedure were recorded. Thirty patients with 36 lesions were recruited and intervened by PCI. Among the target lesions, sixteen were classified as type A, 11 as type B1, 8 as type B2, 1 as type C. The average length of the target lesions was (22.0 ± 9.8) mm, and the average stenosis of the target lesions was (81.3 ± 10.3)%. Under the guidance of CT roadmap and MNS, 36 target lesions were crossed by the magnetic guidewires, with a lesion crossing ratio of 100%. The time of placement of the magnetic guidewires was 92.5 (56.6 - 131.3) seconds. The contrast volume and the radiation dosage for guidewire placement were 0.0 (0.0 - 3.0) ml and 235.0 (123.5 - 395.1) µGym(2)/36.5 (21.3 - 67.8) mGy, respectively. Guidewires were successfully placed in 21 (58.3%) lesions without contrast agent. All enrolled vessels were successfully treated, and there were no MNS associated complications. It is feasible, effective and safe to initiate PCI under the guidance of CT derived roadmap and MNS. This method might be helpful for the guidewire placement in the treatment of total occlusions.

Comparison of computed tomography pulmonary angiography and point-of-care tests for pulmonary thromboembolism diagnosis in dogs.

PubMed

Goggs, R; Chan, D L; Benigni, L; Hirst, C; Kellett-Gregory, L; Fuentes, V L

2014-04-01

To evaluate the feasibility of CT pulmonary angiography for identification of naturally occurring pulmonary thromboembolism in dogs using predefined diagnostic criteria and to assess the ability of echocardiography, cardiac troponins, D-dimers and kaolin-activated thromboelastography to predict the presence of pulmonary thromboembolism in dogs. Twelve dogs with immune-mediated haemolytic anaemia and evidence of respiratory distress were prospectively evaluated. Dogs were sedated immediately before CT pulmonary angiography using intravenous butorphanol. Spiral CT pulmonary angiography was performed with a 16 detector-row CT scanner using a pressure injector to infuse contrast media through peripheral intravenous catheters. Pulmonary thromboembolism was diagnosed using predefined criteria. Contemporaneous tests included echocardiography, arterial blood gas analysis, kaolin-activated thromboelastography, D-dimers and cardiac troponins. Based on predefined criteria, four dogs were classified as pulmonary thromboembolism positive, three dogs were suspected to have pulmonary thromboembolism and the remaining five dogs had negative scans. The four dogs identified with pulmonary thromboembolism all had discrete filling defects in main or lobar pulmonary arteries. None of the contemporaneous tests was discriminant for pulmonary thromboembolism diagnosis, although the small sample size was limiting. CT pulmonary angiography can be successfully performed in dogs under sedation, even in at-risk patients with respiratory distress and can both confirm and rule out pulmonary thromboembolism in dogs. © 2014 British Small Animal Veterinary Association.

Cost identification of abdominal aortic aneurysm imaging by using time and motion analyses.

PubMed

Rubin, G D; Armerding, M D; Dake, M D; Napel, S

2000-04-01

To compare the costs of performing helical computed tomographic (CT) angiography with three-dimensional rendering versus intraarterial digital subtraction angiography (DSA) for preoperative imaging of abdominal aortic aneurysms (AAAs). A single observer determined the variable direct costs of performing nine intraarterial DSA and 10 CT angiographic examinations in age- and general health-matched patients with AAA by using time and motion analyses. All personnel directly involved in the cases were tracked, and the involvement times were recorded to the nearest minute. All material items used during the procedures were recorded. The cost of labor was determined from personnel reimbursement data, and the cost of materials, from vendor pricing. The variable direct costs of laboratory tests and using the ambulatory treatment unit for postprocedural monitoring, as well as all fixed direct costs, were assessed from hospital accounting records. The total costs were determined for each procedure and compared by using the Student t test and calculating the CIs. The mean total direct cost of intraarterial DSA (+/- SD) was $1,052 +/- 71, and that of CT angiography was $300 +/- 30, which are significantly different (P < 4.1 x 10(-11)). With 95% confidence, intraarterial DSA cost 3.2-3.7 times more than CT angiography for the assessment of AAA. Assuming equal diagnostic utility and procedure-related morbidity, institutions may have substantial cost savings whenever CT angiography can replace intraarterial DSA for imaging AAAs.

Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know.

PubMed

Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

2016-01-01

Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted.

Comparison Between Prospectively Electrocardiogram-Gated High-Pitch Mode and Retrospectively Electrocardiogram-Gated Mode for Dual-Source CT Coronary Angiography.

PubMed

Koplay, Mustafa; Celik, Mahmut; Avcı, Ahmet; Erdogan, Hasan; Demir, Kenan; Sivri, Mesut; Nayman, Alaaddin

2015-01-01

We aimed to report the image quality, relationship between heart rate and image quality, amount of contrast agent given to the patients and radiation doses in coronary CT angiography (CTA) obtained by using high-pitch prospectively ECG-gated "Flash Spiral" technique (method A) or retrospectively ECG-gated technique (method B) using 128×2-slice dual-source CT. A total of 110 patients who were evaluated with method A and method B technique with a 128×2-detector dual-source CT device were included in the study. Patients were divided into three groups based on their heart rates during the procedure, and a relationship between heart rate and image quality were evaluated. The relationship between heart rate, gender and radiation dose received by the patients was compared. A total of 1760 segments were evaluated in terms of image quality. Comparison of the relationship between heart rate and image quality revealed a significant difference between heart rate <60 beats/min group and >75 beats/min group whereas <60 beats/min and 60-75 beats/min groups did not differ significantly. The average effective dose for coronary CTA was calculated as 1.11 mSv (0.47-2.01 mSv) for method A and 8.22 mSv (2.19-12.88 mSv) for method B. Method A provided high quality images with doses as low as <1 mSv in selected patients who have low heart rates with a high negative predictive value to rule out coronary artery disease. Although method B increases the amount of effective dose, it provides high diagnostic quality images for patients who have a high heart rate and arrhythmia which makes it is difficult to obtain images.

Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children

PubMed Central

Chakravarthy, Murali; Sunilkumar, Gubbihalli; Pargaonkar, Sumant; Hosur, Rajathadri; Harivelam, Chidananda; Kavaraganahalli, Deepak; Srinivasan, Pradeep

2015-01-01

Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the “apnea group” were compared with those in “nonapnea group.” After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored. Results: We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann–Whitney U, Fischer's exact test and Pearson's Chi-square test). In the induced apnea group, overall image quality was considered excellent in 89% (n = 33) of the studies, while in the “no apnea group,” only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%). In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in contrast to nonapnea group (P < 0.000). Conclusion: The image quality of cardiac CT angiography greatly improves, and motion artifact significantly decreases with the use of induced apnea in pediatrics patients being evaluated for congenital heart disease. This technique poses no additional morbidity of significance. PMID:25849686

Transient cortical blindness after coronary angiography.

PubMed Central

Parry, R; Rees, J R; Wilde, P

1993-01-01

Transient visual loss lasting three days developed after transfemoral coronary angiography in a 62 year old man. Computed tomography (CT) showed bilateral leakage of contrast medium into the occipital cortex. A repeat CT scan after his sight recovered showed clearance of contrast with no underlying infarction. A breakdown of the blood-brain barrier with direct neurotoxicity of the contrast media seemed to be the cause of these neurological changes after coronary angiography which apparently have not been reported before. Images PMID:8280526

Contrast Enhancement of the Right Ventricle during Coronary CT Angiography--Is It Necessary?

PubMed

Kok, Madeleine; Kietselaer, Bas L J H; Mihl, Casper; Altintas, Sibel; Nijssen, Estelle C; Wildberger, Joachim E; Das, Marco

2015-01-01

It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography.

Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

PubMed Central

Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

2016-01-01

Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted. PMID:26728701

German cardiac CT registry: indications, procedural data and clinical consequences in 7061 patients undergoing cardiac computed tomography.

PubMed

Marwan, Mohamed; Achenbach, Stephan; Korosoglou, Grigorios; Schmermund, Axel; Schneider, Steffen; Bruder, Oliver; Hausleiter, Jörg; Schroeder, Stephen; Barth, Sebastian; Kerber, Sebastian; Leber, Alexander; Moshage, Werner; Senges, Jochen

2018-05-01

Cardiac computed tomography permits quantification of coronary calcification as well as detection of coronary artery stenoses after contrast enhancement. Moreover, cardiac CT offers high-resolution morphologic and functional imaging of cardiac structures which is valuable for various structural heart disease interventions and electrophysiology procedures. So far, only limited data exist regarding the spectrum of indications, image acquisition parameters as well as results and clinical consequences of cardiac CT examinations using state-of-the-art CT systems in experienced centers. Twelve cardiology centers with profound expertise in cardiovascular imaging participated in the German Cardiac CT Registry. Criteria for participation included adequate experience in cardiac CT as well of the availability of a 64-slice or newer CT system. Between 2009 and 2014, 7061 patients were prospectively enrolled. For all cardiac CT examinations, patient parameters, procedural data, indication and clinical consequences of the examination were documented. Mean patient age was 61 ± 12 years, 63% were males. The majority (63%) of all cardiac CT examinations were performed in an outpatient setting, 37% were performed during an inpatient stay. 91% were elective and 9% were scheduled in an acute setting. In most examinations (48%), reporting was performed by cardiologists, in 4% by radiologists and in 47% of the cases as a consensus reading. Cardiac CT was limited to native acquisitions for assessment of coronary artery calcification in 9% of patients, only contrast-enhanced coronary CT angiography was performed in 16.6% and combined native and contrast-enhanced coronary CT angiography was performed in 57.7% of patients. Non-coronary cardiac CT examinations constituted 16.6% of all cases. Coronary artery calcification assessment was performed using prospectively ECG-triggered acquisition in 76.9% of all cases. The median dose length product (DLP) was 42 mGy cm (estimated effective radiation dose of 0.6 mSv). Coronary CT angiography was performed using prospectively ECG-triggered acquisition in 77.3% of all cases. Tube voltage was 120 kV in 67.8% of patients and 100 kV in 30.7% of patients, with a resultant median DLP of 256 mGy cm (estimated effective dose of 3.6 mSv). Clinical consequences of cardiac CT were as follows: in 46.8% of the cases, invasive coronary angiography could be avoided; ischemia testing was recommended in 4.7% of the cases, invasive coronary angiography was recommended in 16.4% of the cases and change in medication in 21.6% of the examinations. Cardiac CT is performed in the majority of patients for non-invasive evaluation of the coronary arteries. CT frequently resulted in medication change, and otherwise planned downstream testing including invasive angiography could be avoided in a high percentage of patients. Radiation exposure in experienced centers is relatively low.

The pattern of renal vessels in live related potential donors pool. A multislice computed tomography angiography review.

PubMed

Mishra, Anuj; Ehtuish, Ehtuish F

2006-06-01

To assess the renal vessel anatomy, compare the findings with the perioperative findings, to determine the sensitivity of multislice computed tomography (CT) angiography in the work-up of live potential donors and to discuss and compare the results of the present study with the reported results using single slice CT, magnetic resonance (MRI) and conventional angiography (CA). Retrospective analysis of the angiographic data of 118 of prospective live related kidney donors was carried out from October 2004 to August 2005 at the National Organ Transplant Centre, Tripoli Central Hospital, Libya. All donors underwent renal angiography on multislice (16-slice) CT scan using 80 cc intravenous contrast with 1.25 mm slice thickness followed by maximum intensity projection (MIP) and volume rendering techniques (VRT) post-processing algorithms. The number of vessels, vessel bifurcation, vessel morphology and venous anatomy were analyzed and the findings were compared with the surgical findings. Multislice spiral CT angiography (MSCTA) showed clear delineation of the main renal arteries in all donors with detailed vessel morphology. The study revealed 100% sensitivity in detection of accessory renal vessels, with an overall incidence of 26.7%, which is the most common distribution in the parahilar region. The present study showed 100% sensitivity in the visualization and detection of main and accessory renal vessels. These results were comparable with conventional angiography which has so far been considered as the gold standard and were found superior in specificity and accuracy to the use of single slice CT (SSCT) and MR in the angiographic work-up of live renal donors. Due to improved detection of accessory vessels less than 2 mm in diameter, a higher incidence of aberrant vessels was seen on the right side as has been suggested so far.

Diagnostic accuracy for macroscopic classification of nodular hepatocellular carcinoma: comparison of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and angiography-assisted computed tomography.

PubMed

Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori; Ito, Takanori; Sone, Yasuhiro; Okuda, Seiji; Ogawa, Sadanobu; Igura, Takumi; Imai, Yasuharu

2015-01-01

The macroscopic type of hepatocellular carcinoma (HCC) is a predictor of prognosis. We clarified the diagnostic value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in the macroscopic classification of nodular hepatocellular carcinoma (HCC) as compared to angiography-assisted computed tomography (CT). A total of 71 surgically resected nodular HCCs with a maximum diameter of ≤5 cm were investigated. HCCs were evaluated preoperatively using Gd-EOB-DTPA-enhanced MRI and angiography-assisted CT. HCCs were pathologically classified as simple nodular (SN), SN with extranodular growth (SN-EG), or confluent multinodular (CMN). SN-EG and CMN were grouped as non-SN. Five readers independently reviewed the images using a five-point scale. We examined the accuracy of both imaging modalities in differentiating between SN and non-SN HCC. Overall, the area under the receiver operating characteristic curve (A z ) for the diagnosis of non-SN did not differ between Gd-EOB-DTPA-enhanced MRI and angiography-assisted CT [0.879 (95% confidence interval (CI), 0.779-0.937) and 0.845 (95% CI, 0.723-0.919), respectively]. For HCCs >2 cm, the A z for Gd-EOB-DTPA-enhanced MRI was greater than 0.9. The sensitivity, specificity, and accuracy of Gd-EOB-DTPA-enhanced MRI for identifying non-SN were equal to or higher than values with angiography-assisted CT in all three categories (all tumors, ≤2 cm, and >2 cm), but the differences were not statistically significant. Using Gd-EOB-DTPA-enhanced MRI to assess the macroscopic findings in nodular HCC was equal or superior to using angiography-assisted CT.

Detecting active pelvic arterial haemorrhage on admission following serious pelvic fracture in multiple trauma patients.

PubMed

Brun, Julien; Guillot, Stéphanie; Bouzat, Pierre; Broux, Christophe; Thony, Frédéric; Genty, Céline; Heylbroeck, Christophe; Albaladejo, Pierre; Arvieux, Catherine; Tonetti, Jérôme; Payen, Jean-Francois

2014-01-01

The early diagnosis of pelvic arterial haemorrhage is challenging for initiating treatment by transcatheter arterial embolization (TAE) in multiple trauma patients. We use an institutional algorithm focusing on haemodynamic status on admission and on a whole-body CT scan in stabilized patients to screen patients requiring TAE. This study aimed to assess the effectiveness of this approach. This retrospective cohort study included 106 multiple trauma patients admitted to the emergency room with serious pelvic fracture [pelvic abbreviated injury scale (AIS) score of 3 or more]. Of the 106 patients, 27 (25%) underwent pelvic angiography leading to TAE for active arterial haemorrhage in 24. The TAE procedure was successful within 3h of arrival in 18 patients. In accordance with the algorithm, 10 patients were directly admitted to the angiography unit (n=8) and/or operating room (n=2) for uncontrolled haemorrhagic shock on admission. Of the remaining 96 stabilized patients, 20 had contrast media extravasation on pelvic CT scan that prompted pelvic angiography in 16 patients leading to TAE in 14. One patient underwent a pelvic angiography despite showing no contrast media extravasation on pelvic CT scan. All 17 stabilized patients who underwent pelvic angiography presented a more severely compromised haemodynamic status on admission, and they required more blood products during their initial management than the 79 patients who did not undergo pelvic angiography. The incidence of unstable pelvic fractures was however comparable between the two groups. Overall, haemodynamic instability and contrast media extravasation on the CT-scan identified 26 out of the 27 patients who required subsequent pelvic angiography leading to TAE in 24. An algorithm focusing on haemodynamic status on arrival and on the whole-body CT scan in stabilized patients may be effective at triaging multiple trauma patients with serious pelvic fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of standard- and low-tube voltage 320-detector row volume CT angiography in detection of intracranial aneurysms with digital subtraction angiography as gold standard.

PubMed

Sun, Gang; Ding, Juan; Lu, Yang; Li, Min; Li, Li; Li, Guo-ying; Zhang, Xu-ping

2012-03-01

The aim of this study was to prospectively assess the effect of low-tube voltage (80 kVp) 320-detector row volume computed tomographic (CT) angiography (L-VCTA) in the detection of intracranial aneurysms, with three-dimensional (3D) spin digital subtraction angiography (DSA) as the gold standard. Forty-eight patients with clinically suspected subarachnoid hemorrhages were divided into two groups. One group underwent L-VCTA and DSA, while the other group underwent conventional-tube voltage (120 kVp) volume CT angiography (C-VCTA) and DSA. Vascular enhancement, image quality, detection accuracy of aneurysms, and radiation dose were compared between the two groups. For objective image quality, the L-VCTA group had higher mean vessel attenuation, correlated with higher image noise and lower signal-to-noise ratio, than the C-VCTA group. For subjective image quality, there were no significant differences between the two groups regarding scores for arterial enhancement, depiction of small arterial detail, interference of venous structures, and overall image quality scores. The mean effective dose for the L-VCTA group was significantly lower than for the C-VCTA group (0.56 ± 0.25 vs 1.84 ± 0.002 mSv), with a reduction of radiation dose of 69.73%. With 3D DSA as the reference standard, the sensitivity, specificity, and accuracy in the L-VCTA and C-VCTA groups were 94.12%, 100%, 94.4% and 100%, 100%, and 100%, respectively. In both groups, there were significant correlations for maximum aneurysm diameter measurements between volume CT angiography and 3D DSA; no statistical difference in the mean maximum diameter of each aneurysm was measured between volume CT angiography and 3D DSA. L-VCTA is helpful in detecting intracranial aneurysms, with results similar to those of 3D DSA, but at a lower radiation dose than C-VCTA. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Timely Antecedent CT or MRI Can Help Predict Hemorrhage Site of Posttreatment Head and Neck Cancer, With Digital Subtraction Angiography Used as the Reference Standard.

PubMed

Ku, Yi-Kang; Wong, Yon-Cheong; Fu, Chen-Ju; Tseng, Hsiao-Jung; Wang, Li-Jen; Wang, Chao-Jan; Chin, Shy-Chyi

2016-04-01

We investigated the timing of CT and MRI performed before digital subtraction angiography (DSA) in the prediction of hemorrhage sites in patients with head and neck cancers who present with acute oral or neck bleeding after receiving treatment. A total of 123 DSA examinations that evaluated 123 oral or neck bleeding events in 85 patients were analyzed. The last CT or MRI examinations performed within a time frame of 0-337 days before transarterial embolization were reviewed retrospectively, with three findings (pseudoaneurysm, air-containing necrotic tissue, and residual tumor) used to predict hemorrhage sites. DSA findings of pseudoaneurysm or active contrast extravasation were used as a reference standard. The sensitivity of CT and MRI for correctly predicting hemorrhage sites was used to determine the optimal timing of CT or MRI examinations performed before DSA. A total of 8.9% of the DSA examinations (11/123) had equivocal findings but were followed by another bleeding event for which DSA findings were positive. CT or MRI was statistically significantly better at predicting hemorrhage sites in patients with bleeding events associated with nonhypopharyngeal cancers (p = 0.019) than in those with bleeding events associated with hypopharyngeal cancers. The sensitivity of CT or MRI in the prediction of hemorrhage sites was statistically significantly higher for the common carotid artery and the internal carotid artery when CT or MRI was performed less than 30 days before bleeding events occurred. Prediction of hemorrhagic sites was better with the use of CT angiography than with the use of enhanced CT or MRI, although it was not statistically significant. DSA findings can temporarily be equivocal. CT or MRI examinations performed within 30 days of bleeding events can predict the site of hemorrhage. If no CT or MRI findings from the past 30 days are available, we suggest performing emergent CT angiography for the sake of obtaining better arterial detail.

The utility of postmortem computed tomography selective coronary angiography in parallel with autopsy.

PubMed

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

2013-12-01

Historically, coronary angiography of the isolated heart has played an important role in the detection of stenotic or occlusive lesions that are difficult to identify by autopsy alone. Meanwhile, although the application of multidetector computed tomography (MDCT) to forensic fields has accelerated recently, isolated single organ angiography with MDCT is rarely performed. In this article, we present an evaluation of postmortem selective coronary CT angiography of the isolated heart with MDCT and discuss its utility for autopsy. First, in a preliminary experiment using pig coronary artery, we examined the behavior of water soluble contrast material on postmortem computed tomography angiography (PMCTA) and found that better angiographic images were acquired when the viscosity of the contrast material was increased and CT was performed under conditions of sustained perfusion. Based on these results, we devised a selective coronary angiography procedure using a pressurized bag for drip infusion that can be performed easily, quickly, and at low cost. The angiographic images obtained provided useful supportive evidence of autopsy findings suggestive of ischemic heart disease. With active discussions underway in forensic fields on the proper use of postmortem computed tomography, PMCTA has also naturally attracted attention as it compensates for some of the shortcomings of CT alone. Although PMCTA typically involves whole-body angiography, if we view PMCTA as one of the many useful and supplementary tools available for autopsy, then isolated heart angiography continues to have utility in autopsy today.

Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

PubMed

Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

2017-06-01

To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

Portable head computed tomography scanner--technology and applications: experience with 3421 scans.

PubMed

Carlson, Andrew P; Yonas, Howard

2012-10-01

The use of head computed tomography (CT) is standard in the management of acute brain injury; however, there are inherent risks of transport of critically ill patients. Portable CT can be brought to the patient at any location. We describe the clinical use of a portable head CT scanner (CereTom: NeuroLogica: Danvers, MA) that can be brought to the patient's bedside or to other locations such as the operating room or angiography suite. Between June of 2006 and December of 2009, a total of 3421 portable CTs were performed. A total of 3278 (95.8%) were performed in the neuroscience intensive care unit (ICU) for an average of 2.6 neuroscience ICU CT scans per day. Other locations where CTs were performed included other ICUs (n = 97), the operating room (n = 53), the emergency department (n = 1), and the angiography suite (n = 2). Most studies were non-contrasted head CT, though other modalities including xenon/CT, contrasted CT, and CT angiography were performed. Portable head CT can reliably and consistently be performed at the patient's bedside. This should lead to decreased transportation-related morbidity and improved rapid decision making in the ICU, OR, and other locations. Further studies to confirm this clinical advantage are needed. Copyright © 2011 by the American Society of Neuroimaging.

High-pitch dual-source CT angiography without ECG-gating for imaging the whole aorta: intraindividual comparison with standard pitch single-source technique without ECG-gating

PubMed Central

Manna, Carmelinda; Silva, Mario; Cobelli, Rocco; Poggesi, Sara; Rossi, Cristina; Sverzellati, Nicola

2017-01-01

PURPOSE We aimed to perform intraindividual comparison of computed tomography (CT) parameters, image quality, and radiation exposure between standard CT angiography (CTA) and high-pitch dual source (DS)-CTA, in subjects undergoing serial CTA of thoracoabdominal aorta. METHODS Eighteen subjects with thoracoabdominal CTA by standard technique and high-pitch DS-CTA technique within 6 months of each other were retrieved for intraindividual comparison of image quality in thoracic and abdominal aorta. Quantitative analysis was performed by comparison of mean aortic attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Qualitative analysis was performed by visual assessment of motion artifacts and diagnostic confidence. Radiation exposure was quantified by effective dose. Image quality was apportioned to radiation exposure by means of figure of merit. RESULTS Mean aortic attenuation and noise were higher in high-pitch DS-CTA of thoracoabdominal aorta, whereas SNR and CNR were similar in thoracic aorta and significantly lower in high-pitch DS-CTA of abdominal aorta (P = 0.024 and P = 0.016). High-pitch DS-CTA was significantly better in the first segment of thoracic aorta. Effective dose was reduced by 72% in high-pitch DS-CTA. CONCLUSION High-pitch DS-CTA without electrocardiography-gating is an effective technique for imaging aorta with very low radiation exposure and with significant reduction of motion artifacts in ascending aorta; however, the overall quality of high-pitch DS-CTA in abdominal aorta is lower than standard CTA. PMID:28703104

Early detection of lung cancer using ultra-low-dose computed tomography in coronary CT angiography scans among patients with suspected coronary heart disease.

PubMed

Zanon, Matheus; Pacini, Gabriel Sartori; de Souza, Vinicius Valério Silveiro; Marchiori, Edson; Meirelles, Gustavo Souza Portes; Szarf, Gilberto; Torres, Felipe Soares; Hochhegger, Bruno

2017-12-01

To assess whether an additional chest ultra-low-dose CT scan to the coronary CT angiography protocol can be used for lung cancer screening among patients with suspected coronary artery disease. 175 patients underwent coronary CT angiography for assessment of coronary artery disease, additionally undergoing ultra-low-dose CT screening to early diagnosis of lung cancer in the same scanner (80kVp and 15mAs). Patients presenting pulmonary nodules were followed-up for two years, repeating low-dose CTs in intervals of 3, 6, or 12 months based on nodule size and growth rate in accordance with National Comprehensive Cancer Network guidelines. Ultra-low-dose CT identified 71 patients with solitary pulmonary nodules (41%), with a mean diameter of 5.50±4.00mm. Twenty-eight were >6mm, and in 79% (n=22) of these cases they were false positive findings, further confirmed by follow-up (n=20), resection (n=1), or biopsy (n=1). Lung cancer was detected in six patients due to CT screening (diagnostic yield: 3%). Among these, four cases could not be detected in the cardiac field of view. Most patients were in early stages of the disease. Two patients diagnosed at advanced stages died due to cancer complications. The addition of the ultra-low-dose CT scan represented a radiation dose increment of 1.22±0.53% (effective dose, 0.11±0.03mSv). Lung cancer might be detected using additional ultra-low-dose protocols in coronary CT angiography scans among patients with suspected coronary artery disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFR(CT): outcome and resource impacts study.

PubMed

Douglas, Pamela S; Pontone, Gianluca; Hlatky, Mark A; Patel, Manesh R; Norgaard, Bjarne L; Byrne, Robert A; Curzen, Nick; Purcell, Ian; Gutberlet, Matthias; Rioufol, Gilles; Hink, Ulrich; Schuchlenz, Herwig Walter; Feuchtner, Gudrun; Gilard, Martine; Andreini, Daniele; Jensen, Jesper M; Hadamitzky, Martin; Chiswell, Karen; Cyr, Derek; Wilk, Alan; Wang, Furong; Rogers, Campbell; De Bruyne, Bernard

2015-12-14

In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFR(CT) (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFR(CT)-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFR(CT) arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53-69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFR(CT) results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFR(CT)) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFR(CT) arms. Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Differentiation of early from advanced coronary atherosclerotic lesions: systematic comparison of CT, intravascular US, and optical frequency domain imaging with histopathologic examination in ex vivo human hearts.

PubMed

Maurovich-Horvat, Pál; Schlett, Christopher L; Alkadhi, Hatem; Nakano, Masataka; Stolzmann, Paul; Vorpahl, Marc; Scheffel, Hans; Tanaka, Atsushi; Warger, William C; Maehara, Akiko; Ma, Shixin; Kriegel, Matthias F; Kaple, Ryan K; Seifarth, Harald; Bamberg, Fabian; Mintz, Gary S; Tearney, Guillermo J; Virmani, Renu; Hoffmann, Udo

2012-11-01

To establish an ex vivo experimental setup for imaging coronary atherosclerosis with coronary computed tomographic (CT) angiography, intravascular ultrasonography (US), and optical frequency domain imaging (OFDI) and to investigate their ability to help differentiate early from advanced coronary plaques. All procedures were performed in accordance with local and federal regulations and the Declaration of Helsinki. Approval of the local Ethics Committee was obtained. Overall, 379 histologic cuts from nine coronary arteries from three donor hearts were acquired, coregistered among modalities, and assessed for the presence and composition of atherosclerotic plaque. To assess the discriminatory capacity of the different modalities in the detection of advanced lesions, c statistic analysis was used. Interobserver agreement was assessed with the Cohen κ statistic. Cross sections without plaque at coronary CT angiography and with fibrous plaque at OFDI almost never showed advanced lesions at histopathologic examination (odds ratio [OR]: 0.02 and 0.06, respectively; both P<.0001), while mixed plaque at coronary CT angiography, calcified plaque at intravascular US, and lipid-rich plaque at OFDI were associated with advanced lesions (OR: 2.49, P=.0003; OR: 2.60, P=.002; and OR: 31.2, P<.0001, respectively). OFDI had higher accuracy for discriminating early from advanced lesions than intravascular US and coronary CT angiography (area under the receiver operating characteristic curve: 0.858 [95% confidence interval {CI}: 0.802, 0.913], 0.631 [95% CI: 0.554, 0.709], and 0.679 [95% CI: 0.618, 0.740]; respectively, P<.0001). Interobserver agreement was excellent for OFDI and coronary CT angiography (κ=0.87 and 0.85, respectively) and was good for intravascular US (κ=0.66). Systematic and standardized comparison between invasive and noninvasive modalities for coronary plaque characterization in ex vivo specimens demonstrated that coronary CT angiography and intravascular US are reasonably associated with plaque composition and lesion grading according to histopathologic findings, while OFDI was strongly associated. These data may help to develop initial concepts of sequential imaging strategies to identify patients with advanced coronary plaques. © RSNA, 2012

Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography.

PubMed

Laspas, Fotios; Tsantioti, Dimitra; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John

2011-04-01

Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR ≤65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure.

Bone suppression in CT angiography data by region-based multiresolution segmentation

NASA Astrophysics Data System (ADS)

Blaffert, Thomas; Wiemker, Rafael; Lin, Zhong Min

2003-05-01

Multi slice CT (MSCT) scanners have the advantage of high and isotropic image resolution, which broadens the range of examinations for CT angiography (CTA). A very important method to present the large amount of high-resolution 3D data is the visualization by maximum intensity projections (MIP). A problem with MIP projections in angiography is that bones often hide the vessels of interest, especially the scull and vertebral column. Software tools for a manual selection of bone regions and their suppression in the MIP are available, but processing is time-consuming and tedious. A highly computer-assisted of even fully automated suppression of bones would considerably speed up the examination and probably increase the number of examined cases. In this paper we investigate the suppression (or removal) of bone regions in 3D CT data sets for vascular examinations of the head with a visualization of the carotids and the circle of Willis.

Image quality and radiation dose of lower extremity CT angiography at 70 kVp on an integrated circuit detector dual-source computed tomography.

PubMed

Qi, Li; Zhao, Yan'E; Zhou, Chang Sheng; Spearman, James V; Renker, Matthias; Schoepf, U Joseph; Zhang, Long Jiang; Lu, Guang Ming

2015-06-01

Despite the well-established requirement for radiation dose reduction there are few studies examining the potential for lower extremity CT angiography (CTA) at 70 kVp. To compare the image quality and radiation dose of lower extremity CTA at 70 kVp using a dual-source CT system with an integrated circuit detector to similar studies at 120 kVp. A total of 62 patients underwent lower extremity CTA. Thirty-one patients were examined at 70 kVp using a second generation dual-source CT with an integrated circuit detector (70 kVp group) and 31 patients were evaluated at 120 kVp using a first generation dual-source CT (120 kVp group). The attenuation and image noise were measured and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Two radiologists assessed image quality. Radiation dose was compared. The mean attenuation of the 70 kVp group was higher than the 120 kVp group (575 ± 149 Hounsfield units [HU] vs. 258 ± 38 HU, respectively, P < 0.001) as was SNR (44.0 ± 22.0 vs 32.7 ± 13.3, respectively, P = 0.017), CNR (39.7 ± 20.6 vs 26.6 ± 11.7, respectively, P = 0.003) and the mean image quality score (3.7 ± 0.1 vs. 3.2 ± 0.3, respectively, P < 0.001). The inter-observer agreement was good for the 70 kVp group and moderate for the 120 kVp group. The dose-length product was lower in the 70 kVp group (264.5 ± 63.1 mGy × cm vs. 412.4 ± 81.5 mGy × cm, P < 0.001). Lower extremity CTA at 70 kVp allows for lower radiation dose with higher SNR, CNR, and image quality when compared with standard 120 kVp. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Limits of the possible: diagnostic image quality in coronary angiography with third-generation dual-source CT.

PubMed

Ochs, Marco M; Siepen, Fabian Aus dem; Fritz, Thomas; Andre, Florian; Gitsioudis, Gitsios; Korosoglou, Grigorios; Seitz, Sebastian; Bogomazov, Yuriy; Schlett, Christopher L; Sokiranski, Roman; Sommer, Andre; Gückel, Friedemann; Brado, Matthias; Kauczor, Hans-Ulrich; Görich, Johannes; Friedrich, Matthias G W; Katus, Hugo A; Buss, Sebastian J

2017-07-01

The usage of coronary CT angiography (CTA) is appropriate in patients with acute or chronic chest pain; however the diagnostic accuracy may be challenged with increased Agatston score (AS), increased heart rate, arrhythmia and severe obesity. Thus, we aim to determine the potential of the recently introduced third-generation dual-source CT (DSCT) for CTA in a 'real-life' clinical setting. Two hundred and sixty-eight consecutive patients (age: 67 ± 10 years; BMI: 27 ± 5 kg/m²; 61% male) undergoing clinically indicated CTA with DSCT were included in the retrospective single-center analysis. A contrast-enhanced volume dataset was acquired in sequential (SSM) (n = 151) or helical scan mode (HSM) (n = 117). Coronary segments were classified in diagnostic or non-diagnostic image quality. A subset underwent invasive angiography to determine the diagnostic accuracy of CTA. SSM (96.8 ± 6%) and HSM (97.5 ± 8%) provided no significant differences in the overall diagnostic image quality. However, AS had significant influence on diagnostic image quality exclusively in SSM (B = 0.003; p = 0.0001), but not in HSM. Diagnostic image quality significantly decreased in SSM in patients with AS ≥2,000 (p = 0.03). SSM (sensitivity: 93.9%; specificity: 96.7%; PPV: 88.6%; NPV: 98.3%) and HSM (sensitivity: 97.4%; specificity: 94.3%; PPV: 86.0%; NPV: 99.0%) provided comparable diagnostic accuracy (p = n.s.). SSM yielded significantly lower radiation doses as compared to HSM (2.1 ± 2.0 vs. 5.1 ± 3.3 mSv; p = 0.0001) in age and BMI-matched cohorts. SSM in third-generation DSCT enables significant dose savings and provides robust diagnostic image quality in patients with AS ≤2000 independent of heart rate, heart rhythm or obesity.

Prevalence of non-cardiovascular findings on CT angiography in children with congenital heart disease.

PubMed

Malik, Archana; Hellinger, Jeffrey C; Servaes, Sabah; Schwartz, Mathew C; Keller, Marc S; Epelman, Monica

2017-03-01

CT angiography is gaining broader acceptance in the evaluation of children with known or suspected congenital heart disease. These studies include non-cardiovascular structures such as the mediastinum, lung parenchyma and upper abdominal organs. It is important to inspect all these structures for potential abnormalities that might be clinically important and, in some cases, may impact care plans. To determine the prevalence of non-cardiovascular findings in CT angiography of children with congenital heart disease. During 28 months, 300 consecutive children (170 males; mean age: 7.1 years, age range: 6 h-26 years), referred from a tertiary pediatric cardiology center, underwent clinically indicated CT angiography to evaluate known or suspected congenital heart disease. Slightly more than half (n = 169) of the patients were postoperative or post-intervention. Examinations were retrospectively reviewed, and non-cardiovascular findings were recorded and tabulated by organ system, congenital heart disease and operative procedure in conjunction with outcomes from medical charts. Non-cardiovascular findings were identified in 83% (n = 250 / 300) of the studies for a total of 857 findings. In 221 patients (n = 73.7% of 300) a total of 813 non-cardiovascular findings were clinically significant, while in 9.7% (n = 29 / 300) of patients, 5.1% (n = 44 / 857) of the findings were nonsignificant. In 38.3% (n = 115 / 300) of patients with significant non-cardiovascular pathology, the findings were unexpected and directly impacted patient care plans. Commonly involved organs with non-cardiovascular findings were the lungs with 280 non-cardiovascular findings in 176 / 300 (58.7%) of patients, the airway with 139 non-cardiovascular findings in 103 / 300 (34.3%) of patients and the liver with 108 non-cardiovascular findings in 72 / 300 (24.0%) of patients. Syndromic associations were noted in 22% (n = 66 / 300) of the patients. Non-cardiovascular findings are common in children with congenital heart disease who undergo CT angiography. Based upon our study population, if a child with congenital heart disease has a CT angiography, five out of six will have non-cardiovascular findings, while nearly three out of four (73.7%; 221 / 300) will have significant non-cardiovascular findings. Close attention to the non-cardiovascular structures in children with congenital heart disease presenting for a CT angiography is recommended as in nearly 40% of these children, findings were unexpected and directly altered patient care.

Improved aortic enhancement in CT angiography using slope-based triggering with table speed optimization: a pilot study.

PubMed

Bashir, Mustafa R; Weber, Paul W; Husarik, Daniela B; Howle, Laurens E; Nelson, Rendon C

2012-08-01

To assess whether a scan triggering technique based on the slope of the time-attenuation curve combined with table speed optimization may improve arterial enhancement in aortic CT angiography compared to conventional threshold-based triggering techniques. Measurements of arterial enhancement were performed in a physiologic flow phantom over a range of simulated cardiac outputs (2.2-8.1 L/min) using contrast media boluses of 80 and 150 mL injected at 4 mL/s. These measurements were used to construct computer models of aortic attenuation in CT angiography, using cardiac output, aortic diameter, and CT table speed as input parameters. In-plane enhancement was calculated for normal and aneurysmal aortic diameters. Calculated arterial enhancement was poor (<150 HU) along most of the scan length using the threshold-based triggering technique for low cardiac outputs and the aneurysmal aorta model. Implementation of the slope-based triggering technique with table speed optimization improved enhancement in all scenarios and yielded good- (>200 HU; 13/16 scenarios) to excellent-quality (>300 HU; 3/16 scenarios) enhancement in all cases. Slope-based triggering with table speed optimization may improve the technical quality of aortic CT angiography over conventional threshold-based techniques, and may reduce technical failures related to low cardiac output and slow flow through an aneurysmal aorta.

The Role of Intraoperative Cerebral Angiography in Transorbital Intracranial Penetrating Trauma: A Case Report and Literature Review.

PubMed

Riley, Jonathan P; Boucher, Andrew B; Kim, Denise S; Barrow, Daniel L; Reynolds, Matthew R

2017-01-01

Transorbital intracranial penetrating trauma with a retained intracranial foreign body is a rare event lacking a widely accepted diagnostic and therapeutic algorithm. Intraoperative catheter angiography (IOA) has been advocated by some authorities to rule out cerebrovascular injury before and/or after removal of the object, but no standard of care currently exists. A 19-year-old man was involved in a construction site accident whereby a framing nail penetrated the left globe, traversed the lateral bony orbit, and terminated in the midtemporal lobe. No hematoma or injury to the middle cerebral arteries (MCAs) was apparent on noncontrast head computed tomography (CT) or CT angiography, respectively. The foreign body was removed in the operating room under direct visualization after a frontotemporal craniotomy without incident. No significant venous or arterial bleeding was encountered. All visualized MCA branches appeared intact. Indocyanine green videoangiography performed immediately after object removal showed adequate filling of the MCA branches. Given these uneventful clinical and radiographic findings, IOA was not performed. Postoperative head CT and CT angiography showed no obvious neurovascular injury. On postoperative day 2, the patient was noted to have an expressive aphasia. Cerebral angiography showed absent antegrade filling of the angular artery with some retrograde perfusion. Magnetic resonance imaging confirmed an ischemic infarction in the midtemporal lobe. The patient's expressive aphasia improved to near baseline during his hospitalization and he made an excellent clinical recovery. In transorbital intracranial penetrating trauma with a retained intracranial object, we advocate microsurgical removal of the object under direct visualization followed immediately by IOA. IOA should be strongly considered even in the setting of minimal intraoperative bleeding and normal findings on videoangiography (a course of action that was not followed in the present case). Given that CT angiography and intraoperative videoangiography may miss a potentially treatable traumatic arterial injury, IOA can help determine whether cerebral revascularization may be necessary. Copyright © 2016 Elsevier Inc. All rights reserved.

Computed tomography imaging and angiography - principles.

PubMed

Kamalian, Shervin; Lev, Michael H; Gupta, Rajiv

2016-01-01

The evaluation of patients with diverse neurologic disorders was forever changed in the summer of 1973, when the first commercial computed tomography (CT) scanners were introduced. Until then, the detection and characterization of intracranial or spinal lesions could only be inferred by limited spatial resolution radioisotope scans, or by the patterns of tissue and vascular displacement on invasive pneumoencaphalography and direct carotid puncture catheter arteriography. Even the earliest-generation CT scanners - which required tens of minutes for the acquisition and reconstruction of low-resolution images (128×128 matrix) - could, based on density, noninvasively distinguish infarct, hemorrhage, and other mass lesions with unprecedented accuracy. Iodinated, intravenous contrast added further sensitivity and specificity in regions of blood-brain barrier breakdown. The advent of rapid multidetector row CT scanning in the early 1990s created renewed enthusiasm for CT, with CT angiography largely replacing direct catheter angiography. More recently, iterative reconstruction postprocessing techniques have made possible high spatial resolution, reduced noise, very low radiation dose CT scanning. The speed, spatial resolution, contrast resolution, and low radiation dose capability of present-day scanners have also facilitated dual-energy imaging which, like magnetic resonance imaging, for the first time, has allowed tissue-specific CT imaging characterization of intracranial pathology. © 2016 Elsevier B.V. All rights reserved.

Computed tomography versus invasive coronary angiography: design and methods of the pragmatic randomised multicentre DISCHARGE trial.

PubMed

Napp, Adriane E; Haase, Robert; Laule, Michael; Schuetz, Georg M; Rief, Matthias; Dreger, Henryk; Feuchtner, Gudrun; Friedrich, Guy; Špaček, Miloslav; Suchánek, Vojtěch; Fuglsang Kofoed, Klaus; Engstroem, Thomas; Schroeder, Stephen; Drosch, Tanja; Gutberlet, Matthias; Woinke, Michael; Maurovich-Horvat, Pál; Merkely, Béla; Donnelly, Patrick; Ball, Peter; Dodd, Jonathan D; Quinn, Martin; Saba, Luca; Porcu, Maurizio; Francone, Marco; Mancone, Massimo; Erglis, Andrejs; Zvaigzne, Ligita; Jankauskas, Antanas; Sakalyte, Gintare; Harań, Tomasz; Ilnicka-Suckiel, Malgorzata; Bettencourt, Nuno; Gama-Ribeiro, Vasco; Condrea, Sebastian; Benedek, Imre; Čemerlić Adjić, Nada; Adjić, Oto; Rodriguez-Palomares, José; Garcia Del Blanco, Bruno; Roditi, Giles; Berry, Colin; Davis, Gershan; Thwaite, Erica; Knuuti, Juhani; Pietilä, Mikko; Kępka, Cezary; Kruk, Mariusz; Vidakovic, Radosav; Neskovic, Aleksandar N; Díez, Ignacio; Lecumberri, Iñigo; Geleijns, Jacob; Kubiak, Christine; Strenge-Hesse, Anke; Do, The-Hoang; Frömel, Felix; Gutiérrez-Ibarluzea, Iñaki; Benguria-Arrate, Gaizka; Keiding, Hans; Katzer, Christoph; Müller-Nordhorn, Jacqueline; Rieckmann, Nina; Walther, Mario; Schlattmann, Peter; Dewey, Marc

2017-07-01

More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate noninvasive test for detection and exclusion of coronary artery disease (CAD). To investigate the comparative effectiveness of CT and ICA, we designed the European pragmatic multicentre DISCHARGE trial funded by the 7th Framework Programme of the European Union (EC-GA 603266). In this trial, patients with a low-to-intermediate pretest probability (10-60 %) of suspected CAD and a clinical indication for ICA because of stable chest pain will be randomised in a 1-to-1 ratio to CT or ICA. CT and ICA findings guide subsequent management decisions by the local heart teams according to current evidence and European guidelines. Major adverse cardiovascular events (MACE) defined as cardiovascular death, myocardial infarction and stroke as a composite endpoint will be the primary outcome measure. Secondary and other outcomes include cost-effectiveness, radiation exposure, health-related quality of life (HRQoL), socioeconomic status, lifestyle, adverse events related to CT/ICA, and gender differences. The DISCHARGE trial will assess the comparative effectiveness of CT and ICA. • Coronary artery disease (CAD) is a major cause of morbidity and mortality. • Invasive coronary angiography (ICA) is the reference standard for detection of CAD. • Noninvasive computed tomography angiography excludes CAD with high sensitivity. • CT may effectively reduce the approximately 2 million negative ICAs in Europe. • DISCHARGE addresses this hypothesis in patients with low-to-intermediate pretest probability for CAD.

Variations in the origins of the thyroid arteries on CT angiography.

PubMed

Esen, Kaan; Ozgur, Anil; Balci, Yuksel; Tok, Sermin; Kara, Engin

2018-02-01

To investigate the anatomical variations in the origins of the thyroid arteries on CT angiography images. The presence and the origins of the superior thyroid artery, the inferior thyroid artery, and the thyroidea ima artery were retrospectively evaluated based on carotid CT angiography examinations. The bifurcation level of the common carotid artery with respect to the cervical vertebrae and disc spaces was also determined. A total of 640 patients were included in the study. The right and left superior thyroid arteries arose from the external carotid artery in 413 (64.5%) and 254 (39.7%) patients, from the bifurcation of the common carotid artery in 131 (20.5%) and 148 (23.1%) patients, and from the common carotid artery in 90 (14.1%) and 226 (35.3%) patients, respectively. We could not observe the right and the left superior thyroid arteries in 6 (0.9%) and 12 (1.9%) of the patients, respectively. However, the right and left inferior thyroid arteries were not identified in 14 (2.2%) and 45 (7%) of the patients, respectively. The thyroidea ima artery was detected in 2.3% of the patients. The visualization of thyroid arteries on CT angiography images enables the anatomy of the arterial supply system of the thyroid gland to be explored in a noninvasive manner prior to surgery.

Prospectively ECG-triggered high-pitch coronary angiography with third-generation dual-source CT at 70 kVp tube voltage: feasibility, image quality, radiation dose, and effect of iterative reconstruction.

PubMed

Hell, Michaela M; Bittner, Daniel; Schuhbaeck, Annika; Muschiol, Gerd; Brand, Michael; Lell, Michael; Uder, Michael; Achenbach, Stephan; Marwan, Mohamed

2014-01-01

Low tube voltage reduces radiation exposure in coronary CT angiography (CTA). Using 70 kVp tube potential has so far not been possible because CT systems were unable to provide sufficiently high tube current with low voltage. We evaluated feasibility, image quality (IQ), and radiation dose of coronary CTA using a third-generation dual-source CT system capable of producing 450 mAs tube current at 70 kVp tube voltage. Coronary CTA was performed in 26 consecutive patients with suspected coronary artery disease, selected for body weight <100 kg and heart rate <60 beats/min. High-pitch spiral acquisition was used. Filtered back projection (FBP) and iterative reconstruction (IR) algorithms were applied. IQ was assessed using a 4-point rating scale (1 = excellent, 4 = nondiagnostic) and objective parameters. Mean age was 62 ± 9 years (46% males; mean body mass index, 27.7 ± 3.8 kg/m(2); mean heart rate, 54 ± 5 beats/min). Mean dose-length product was 20.6 ± 1.9 mGy × cm; mean estimated effective radiation dose was 0.3 ± 0.03 mSv. Diagnostic IQ was found in 365 of 367 (FBP) and 366 of 367 (IR) segments (P nonsignificant). IQ was rated "excellent" in 53% (FBP) and 86% (IR) segments (P = .001) and "nondiagnostic" in 2 (FBP) and 1 segment (IR) (P nonsignificant). Mean IQ score was lesser in FBP vs IR (1.5 ± 0.4 vs 1.1 ± 0.2; P < .001). Image noise was lower in IR vs FBP (60 ± 10 HU vs 74 ± 8 HU; P < .001). In patients <100 kg and with a regular heart rate <60 beats/min, third-generation dual-source CT using high-pitch spiral acquisition and 70 kVp tube voltage is feasible and provides both robust IQ and very low radiation exposure. Copyright © 2014 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Computerized tomography with 3-dimensional reconstruction for the evaluation of renal size and arterial anatomy in the living kidney donor.

PubMed

Janoff, Daniel M; Davol, Patrick; Hazzard, James; Lemmers, Michael J; Paduch, Darius A; Barry, John M

2004-01-01

Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes. Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions. The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%. CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

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

PubMed

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

2011-03-01

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

A case of laparoscopic high anterior resection of rectosigmoid colon cancer associated with a horseshoe kidney using preoperative 3D-CT angiography.

PubMed

Kubo, Naoki; Furusawa, Norihiko; Imai, Shinichiro; Terada, Masaru

2018-06-27

Horseshoe kidney is a congenital malformation in which the bilateral kidneys are fused. It is frequently complicated by other congenital malformations and is often accompanied by anomalies of the ureteropelvic and vascular systems, which must be evaluated to avoid iatrogenic injury. We report a case of laparoscopic high anterior resection of rectosigmoid colon cancer associated with a horseshoe kidney using preoperative 3D-CT angiography. A 52-year-old Japanese man with lower abdominal pain underwent lower endoscopy, revealing a type 2 lesion in the rectosigmoid colon. He was diagnosed with rectosigmoid colon cancer with multiple lung metastases and a horseshoe kidney on computed tomography (CT) scan. Three-dimensional (3D)-CT angiography showed an aberrant renal artery at the isthmus from 3 cm under the inferior mesenteric artery (IMA) branch of the aorta. Laparoscopic anterior rectal resection was performed. During the operation, the inferior mesenteric artery, left ureter, left gonadal vessels, and hypogastric nerve plexus could be seen passing over the horseshoe kidney isthmus and were preserved. The left branch of aberrant renal artery that was close to IMA was also detected and preserved. To prevent intraoperative misidentification, 3D-CT angiography should be performed preoperatively to ascertain the precise positional relationships between the extra renal arteries and the kidney. We always must consider anomalous locations of renal vessels, ureter, gonadal vessels, and lumbar splanchnic nerve to avoid laparoscopic iatrogenic injury in patients with a horseshoe kidney.

[Spiral CT angiography in practice].

PubMed

Pavcec, Zlatko; Zokalj, Ivan; Rumboldt, Zoran; Pal, Andrej; Saghir, Hussein; Ozretić, David; Latin, Branko; Perhoć, Zeljka; Marotti, Miljenko

2005-01-01

Incidence of vascular diseases and development of new radiologic techniques in the last three decades has given strong impuls for introduction of non-invasive vascular diagnostic methods. Thanks to the introduction of Doppler ultrasound, new types of computed tomography (CT) and magnetic resonance (MR) scanners, non-invasive vascular diagnostic methods are replacing conventional invasive (catheter) angiographic methods. Computed tomographic angiography (CTA) is a noninvasive vascular diagnostic method based on continuous scanning with CT scanner during intravenous application of contrast material. Performing of CTA is possible after introduction of spiral CT technique whose characteristics are short imaging time and volumetric data acquisition. The main goal of this article, based on our experiences, is to review the role of CTA, performed on single-slice CT scanner, in managment of patients with vascular pathology.

Is CT angiography of the pulmonary arteries indicated in patients with high clinical probability of pulmonary embolism?

PubMed

Martínez Montesinos, L; Plasencia Martínez, J M; García Santos, J M

When a diagnostic test confirms clinical suspicion, the indicated treatment can be administered. A problem arises when the diagnostic test does not confirm the initially suspected diagnosis; when the suspicion is grounded in clinically validated predictive rules and is high, the problem is even worse. This situation arises in up to 40% of patients with high suspicion for acute pulmonary embolism, raising the question of whether CT angiography of the pulmonary arteries should be done systematically. This paper reviews the literature about this issue and lays out the best evidence about the relevant recommendations for patients with high clinical suspicion of acute pulmonary embolism and negative findings on CT angiography. It also explains the probabilistic concepts derived from Bayes' theorem that can be useful for ascertaining the most appropriate approach in these patients. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Cerebral ischaemia: A neuroradiological study

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

Bories, J.

1985-01-01

After a brief clinical and pathophysiological approach, the papers presented in this book are devoted to CT and angiography. Concerning CT, a particular study has been made of cerebral arterial territories on cuts parallel to the orbito-meatal line: these are very important in making the differential diagnosis from some tumors. Also concerning CT, a paper has been devoted to cerebral ''lacunae.'' The term ''lacuna'' as far as CT imaging is concerned, should be reserved only for those hypodense areas corresponding to small cavities containing fluid, which are sequelae of infarcts in the territory of penetrating arteries. Before this sequellar statemore » come all the evolutive states of a small deep infarct. The angiographic study specifies the indications of angiography in the study of cerebral ischemia, and the techniques to be used. It shows the main etiologic aspects. Because of the important place of vascular surgery today, it seemed necessary to show also the main post operative angiographic aspects. After CT and angiography, some pages are reserved to more modern techniques. Finally, some pages are devoted to certain particular associations and etiologies: childhood, cardiopathies, migraine, oral contraception and end with venous infarction.« less

Comprehensive CT Evaluation in Acute Ischemic Stroke: Impact on Diagnosis and Treatment Decisions

PubMed Central

Löve, Askell; Siemund, Roger; Andsberg, Gunnar; Cronqvist, Mats; Holtås, Stig; Björkman-Burtscher, Isabella

2011-01-01

Background. With modern CT imaging a comprehensive overview of cerebral macro- and microcirculation can be obtained within minutes in acute ischemic stroke. This opens for patient stratification and individualized treatment. Methods. Four patients with acute ischemic stroke of different aetiologies and/or treatments were chosen for illustration of the comprehensive CT protocol and its value in subsequent treatment decisions. The patients were clinically evaluated according to the NIHSS-scale, examined with the comprehensive CT protocol including both CT angiography and CT perfusion, and followed up by MRI. Results. The comprehensive CT examination protocol increased the examination time but did not delay treatment initiation. In some cases CT angiography revealed the cause of stroke while CT perfusion located and graded the perfusion defect with reasonable accuracy, confirmed by follow-up MR-diffusion. In the presented cases findings of the comprehensive CT examination influenced the treatment strategy. Conclusions. The comprehensive CT examination is a fast and safe method allowing accurate diagnosis and making way for individualized treatment in acute ischemic stroke. PMID:21603175

Dual-Energy Computed Tomography Angiography of the Head and Neck With Single-Source Computed Tomography: A New Technical (Split Filter) Approach for Bone Removal.

PubMed

Kaemmerer, Nadine; Brand, Michael; Hammon, Matthias; May, Matthias; Wuest, Wolfgang; Krauss, Bernhard; Uder, Michael; Lell, Michael M

2016-10-01

Dual-energy computed tomographic angiography (DE-CTA) has been demonstrated to improve the visualization of the head and neck vessels. The aim of this study was to test the potential of split-filter single-source dual-energy CT to automatically remove bone from the final CTA data set. Dual-energy CTA was performed in 50 consecutive patients to evaluate the supra-aortic arteries, either to grade carotid artery stenosis or to rule out traumatic dissections. Dual-energy CTA was performed on a 128-slice single-source CT system equipped with a special filter array to separate the 120-kV spectrum into a high- and a low-energy spectrum for DE-based automated bone removal. Image quality of fully automated bone suppression and subsequent manual optimization was evaluated by 2 radiologists on maximum intensity projections using a 4-grade scoring system. The effect of image reconstruction with an iterative metal artifact reduction algorithm on DE postprocessing was tested using a 3-grade scoring system, and the time demand for each postprocessing step was measured. Two patients were excluded due to insufficient arterial contrast enhancement; in the remaining 48 patients, automated bone removal could be performed successfully. The addition of iterative metal artifact reduction algorithm improved image quality in 58.3% of the cases. After manual optimization, DE-CTA image quality was rated excellent in 7, good in 29, and moderate in 10 patients. Interobserver agreement was high (κ = 0.85). Stenosis grading was not influenced using DE-CTA with bone removal as compared with the original CTA. The time demand for DE image reconstruction was significantly higher than for single-energy reconstruction (42.1 vs 20.9 seconds). Our results suggest that bone removal in DE-CTA of the head and neck vessels with a single-source CT is feasible and can be performed within acceptable time and moderate user interaction.

Methodological quality of diagnostic accuracy studies on non-invasive coronary CT angiography: influence of QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) items on sensitivity and specificity.

PubMed

Schueler, Sabine; Walther, Stefan; Schuetz, Georg M; Schlattmann, Peter; Dewey, Marc

2013-06-01

To evaluate the methodological quality of diagnostic accuracy studies on coronary computed tomography (CT) angiography using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) tool. Each QUADAS item was individually defined to adapt it to the special requirements of studies on coronary CT angiography. Two independent investigators analysed 118 studies using 12 QUADAS items. Meta-regression and pooled analyses were performed to identify possible effects of methodological quality items on estimates of diagnostic accuracy. The overall methodological quality of coronary CT studies was merely moderate. They fulfilled a median of 7.5 out of 12 items. Only 9 of the 118 studies fulfilled more than 75 % of possible QUADAS items. One QUADAS item ("Uninterpretable Results") showed a significant influence (P = 0.02) on estimates of diagnostic accuracy with "no fulfilment" increasing specificity from 86 to 90 %. Furthermore, pooled analysis revealed that each QUADAS item that is not fulfilled has the potential to change estimates of diagnostic accuracy. The methodological quality of studies investigating the diagnostic accuracy of non-invasive coronary CT is only moderate and was found to affect the sensitivity and specificity. An improvement is highly desirable because good methodology is crucial for adequately assessing imaging technologies. • Good methodological quality is a basic requirement in diagnostic accuracy studies. • Most coronary CT angiography studies have only been of moderate design quality. • Weak methodological quality will affect the sensitivity and specificity. • No improvement in methodological quality was observed over time. • Authors should consider the QUADAS checklist when undertaking accuracy studies.

CT versus MR Techniques in the Detection of Cervical Artery Dissection.

PubMed

Hanning, Uta; Sporns, Peter B; Schmiedel, Meilin; Ringelstein, Erich B; Heindel, Walter; Wiendl, Heinz; Niederstadt, Thomas; Dittrich, Ralf

2017-11-01

Spontaneous cervical artery dissection (sCAD) is an important etiology of juvenile stroke. The gold standard for the diagnosis of sCAD is convential angiography. However, magnetic resonance imaging (MRI)/MR angiography (MRA) and computed tomography (CT)/CT angiography (CTA) are frequently used alternatives. New developments such as multislice CT/CTA have enabled routine acquisition of thinner sections with rapid imaging times. The goal of this study was to compare the capability of recent developed 128-slice CT/CTA to MRI/MRA to detect radiologic features of sCAD. Retrospective review of patients with suspected sCAD (n = 188) in a database of our Stroke center (2008-2014), who underwent CT/CTA and MRI/MRA on initial clinical work-up. A control group of 26 patients was added. All Images were evaluated concerning specific and sensitive radiological features for dissection by two experienced neuroradiologists. Imaging features were compared between the two modalities. Forty patients with 43 dissected arteries received both modalities (29 internal carotid arteries [ICAs] and 14 vertebral arteries [VAs]). All CADs were identified in CT/CTA and MRI/MRA. The features intimal flap, stenosis, and lumen irregularity appeared in both modalities. One high-grade stenosis was identified by CT/CTA that was expected occluded on MRI/MRA. Two MRI/MRA-confirmed pseudoaneurysms were missed by CT/CTA. None of the controls evidenced specific imaging signs for dissection. CT/CTA is a reliable and better available alternative to MRI/MRA for diagnosis of sCAD. CT/CTA should be used to complement MRI/MRA in cases where MRI/MRA suggests occlusion. Copyright © 2017 by the American Society of Neuroimaging.

[Preoperative CT angiography for planning free perforator flaps in breast reconstruction].

PubMed

Kuekrek, H; Müller, D; Paepke, S; Dobritz, M; Machens, H-G; Giunta, R E

2011-04-01

Preoperative Doppler ultrasonography for planning free perforator flaps is widely established to identify preoperatively perforators. The method allows one to localise the penetrating point of the perforator through the abdominal fascia. By this means it is not possible to see the intramuscular course or the position of the perforator in relation to the inferior epigastric artery. Lately the technique of computed tomographic angiography provides an opportunity for visualising the course of perforator vessels in these tissues. This paper summarises our experience with the preoperative CT angiography in our breast centre. Since spring 2009 we have reconstructed the breasts of 44 female patients by using free flaps from the lower abdominal wall. 6 of these were bilateral. In a total number of 50 breast reconstructions we used 23 deep inferior epigastric perforator (DIEP) flaps and 27 muscle-sparing transverse rectus abdominis muscle (TRAM) flaps. In addition to the preoperative ultrasonography, a CT angiography of the lower abdomen was conducted in 29 patients. On average they showed at least 2 perforators on the left as well as right abdominal sides, which could be used as flap vessels based on their signal intensity. Based on their estimated microsurgical dissection complexity, the perforator vessels could be classified into 3 groups: 1) direct perforators of category A with short intramuscular course (39%), 2) perforators with long intramuscular course of category B (50%) and 3) "turn around" perforators of category C, which pass medially around the rectus abdominis (11%). The technique of CT angiography permits a reliable preoperative visualisation of perforators in their entire course and facilitates the selection of the supplying perforator as well as the intraoperative procedure for the surgeon. The suggested classification of perforators into 3 groups simplifies the preoperative assessment of the microsurgical dissection effort. Compared to the commonly used Doppler ultrasonography there are disadvantages like the additional cost factor and the radiation exposure. However, in our experience the more detailed planning increases the safety of flap raising and reduces surgery time, so that we consider CT angiography a positive tool to facilitate free perforator flaps. © Georg Thieme Verlag KG Stuttgart · New York.

Development of a fluorescent x-ray source for medical imaging

NASA Astrophysics Data System (ADS)

Toyofuku, F.; Tokumori, K.; Nishimura, K.; Saito, T.; Takeda, T.; Itai, Y.; Hyodo, K.; Ando, M.; Endo, M.; Naito, H.; Uyama, C.

1995-02-01

A fluorescent x-ray source for medical imaging, such as K-edge subtraction angiography and monochromatic x-ray CT, has been developed. Using a 6.5 GeV accumulation ring in Tsukuba, fluorescent x rays, which range from about 30 to 70 keV are generated by irradiating several target materials. Measurements have been made of output intensities and energy spectra for different target angles and extraction angles. The intensities of fluorescent x rays at a 30 mA beam current are on the order of 1-3×106 photons/mm2/s at 30 cm from the local spot where the incident beam is collimated to 1 mm2. A phantom which contains three different contrast media (iodine, barium, gadolinium) was used for the K-edge energy subtraction, and element selective CT images were obtained.

Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

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

Koike, Yuya, E-mail: r06118@hotmail.co.jp; Nishimura, Jun-ichi, E-mail: jun-ichi-n@nifty.com; Hase, Soichiro, E-mail: haseman@hotmail.co.jp

PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasationmore » of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.« less

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

PubMed

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

2007-06-01

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

Superselective intra-arterial hepatic injection of indocyanine green (ICG) for fluorescence image-guided segmental positive staining: experimental proof of the concept.

PubMed

Diana, Michele; Liu, Yu-Yin; Pop, Raoul; Kong, Seong-Ho; Legnèr, Andras; Beaujeux, Remy; Pessaux, Patrick; Soler, Luc; Mutter, Didier; Dallemagne, Bernard; Marescaux, Jacques

2017-03-01

Intraoperative liver segmentation can be obtained by means of percutaneous intra-portal injection of a fluorophore and illumination with a near-infrared light source. However, the percutaneous approach is challenging in the minimally invasive setting. We aimed to evaluate the feasibility of fluorescence liver segmentation by superselective intra-hepatic arterial injection of indocyanine green (ICG). Eight pigs (mean weight: 26.01 ± 5.21 kg) were involved. Procedures were performed in a hybrid experimental operative suite equipped with the Artis Zeego ® , multiaxis robotic angiography system. A pneumoperitoneum was established and four laparoscopic ports were introduced. The celiac trunk was catheterized, and a microcatheter was advanced into different segmental hepatic artery branches. A near-infrared laparoscope (D-Light P, Karl Storz) was used to detect the fluorescent signal. To assess the correspondence between arterial-based fluorescence demarcation and liver volume, metallic markers were placed along the fluorescent border, followed by a 3D CT-scanning, after injecting intra-arterial radiological contrast (n = 3). To assess the correspondence between arterial and portal supplies, percutaneous intra-portal angiography and intra-arterial angiography were performed simultaneously (n = 1). Bright fluorescence signal enhancing the demarcation of target segments was obtained from 0.1 mg/mL, in matter of seconds. Correspondence between the volume of hepatic segments and arterial territories was confirmed by CT angiography. Higher background fluorescence noise was found after positive staining by intra-portal ICG injection, due to parenchymal accumulation and porto-systemic shunting. Intra-hepatic arterial ICG injection, rapidly highlights hepatic target segment borders, with a better signal-to-background ratio as compared to portal vein injection, in the experimental setting.

[Giant aneurysm of posterior comunicating artery (PCoA) in cerebral panarteriography and CT angiography (CTA)].

PubMed

Jaźwiec, Przemysław; Chwiszczuk, Luiza; Sasiadek, Marek; Całka, Karol; Kuniej, Tomasz; Plucińska, Irena

2008-01-01

We present a case of 32-year-old woman, who was admitted to the Department of Neurology in the emergency mode, due to: instantaneous pupillary dilation (mydriasis), ptosis of the left eyeball and double vision. We performed plain CT, panarteriography of cerebral vessels, CT angiography with RT3D (volume-rendered three-dimensional) reconstruction images. On the base of imaging studies the diagnosis of giant saccular aneurysm of the left posterior communicating artery was established. The patient was operated on and the giant aneurysm of left posterior communicating artery was clipped, confirming radiological diagnosis. During operation and postoperative period no complications were noted.

Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients.

PubMed

Dormagen, Johann B; Tötterman, Anna; Røise, Olav; Sandvik, Leiv; Kløw, Nils-E

2010-02-01

Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm(2). AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm(2) posteriorly and >29 cm(2) anteriorly revealed specificity of 0.85 and 0.86, respectively. CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may contribute equally to effective assessment of injured arteries.

Does clinical pretest probability influence image quality and diagnostic accuracy in dual-source coronary CT angiography?

PubMed

Thomas, Christoph; Brodoefel, Harald; Tsiflikas, Ilias; Bruckner, Friederike; Reimann, Anja; Ketelsen, Dominik; Drosch, Tanja; Claussen, Claus D; Kopp, Andreas; Heuschmid, Martin; Burgstahler, Christof

2010-02-01

To prospectively evaluate the influence of the clinical pretest probability assessed by the Morise score onto image quality and diagnostic accuracy in coronary dual-source computed tomography angiography (DSCTA). In 61 patients, DSCTA and invasive coronary angiography were performed. Subjective image quality and accuracy for stenosis detection (>50%) of DSCTA with invasive coronary angiography as gold standard were evaluated. The influence of pretest probability onto image quality and accuracy was assessed by logistic regression and chi-square testing. Correlations of image quality and accuracy with the Morise score were determined using linear regression. Thirty-eight patients were categorized into the high, 21 into the intermediate, and 2 into the low probability group. Accuracies for the detection of significant stenoses were 0.94, 0.97, and 1.00, respectively. Logistic regressions and chi-square tests showed statistically significant correlations between Morise score and image quality (P < .0001 and P < .001) and accuracy (P = .0049 and P = .027). Linear regression revealed a cutoff Morise score for a good image quality of 16 and a cutoff for a barely diagnostic image quality beyond the upper Morise scale. Pretest probability is a weak predictor of image quality and diagnostic accuracy in coronary DSCTA. A sufficient image quality for diagnostic images can be reached with all pretest probabilities. Therefore, coronary DSCTA might be suitable also for patients with a high pretest probability. Copyright 2010 AUR. Published by Elsevier Inc. All rights reserved.

Direct Endoscopic Intratumoral Injection of Onyx for the Preoperative Embolization of a Recurrent Juvenile Nasal Angiofibroma

PubMed Central

Hira, A.; Chao, K.

2011-01-01

Summary Percutaneous injection of embolization material within head and neck tumors is being described as an alternative or adjunct to transarterial embolization. Access in these reports is by computed tomography (CT) guidance, which is cumbersome given the need to transport the patient from the CT scanner to angiography suite. We describe a case of direct percutaneous onyx embolization of juvenile nasal angiofibroma following endoscopic access in the angiography suite including self-sustained onyx combustion during surgical electrocautery. PMID:22192553

Arteriovenous fistula complicating iliac artery pseudo aneurysm: diagnosis by CT angiography.

PubMed

Huawei, L; Bei, D; Huan, Z; Zilai, P; Aorong, T; Kemin, C

2002-01-01

Fistula formation to the inferior vena cava is a rare complication of aortic aneurysm which is often misdiagnosed clinically. In one hundred of reported arteriocaval fistulae, none was originating from the right common iliac artery. We report a case of ileo-caval fistula due to a iatrogenic pseudoaneurysm. High resolution 3D imaging using breath-hold CT angiography is highly specific in identifying the location, extent of the aortocaval fistula as well as the neighbouring anatomic structures.

Pre-operative CT angiography and three-dimensional image post processing for deep inferior epigastric perforator flap breast reconstructive surgery.

PubMed

Lam, D L; Mitsumori, L M; Neligan, P C; Warren, B H; Shuman, W P; Dubinsky, T J

2012-12-01

Autologous breast reconstructive surgery with deep inferior epigastric artery (DIEA) perforator flaps has become the mainstay for breast reconstructive surgery. CT angiography and three-dimensional image post processing can depict the number, size, course and location of the DIEA perforating arteries for the pre-operative selection of the best artery to use for the tissue flap. Knowledge of the location and selection of the optimal perforating artery shortens operative times and decreases patient morbidity.

Multi-detector row computed tomography angiography of peripheral arterial disease

PubMed Central

Dijkshoorn, Marcel L.; Pattynama, Peter M. T.; Myriam Hunink, M. G.

2007-01-01

With the introduction of multi-detector row computed tomography (MDCT), scan speed and image quality has improved considerably. Since the longitudinal coverage is no longer a limitation, multi-detector row computed tomography angiography (MDCTA) is increasingly used to depict the peripheral arterial runoff. Hence, it is important to know the advantages and limitations of this new non-invasive alternative for the reference test, digital subtraction angiography. Optimization of the acquisition parameters and the contrast delivery is important to achieve a reliable enhancement of the entire arterial runoff in patients with peripheral arterial disease (PAD) using fast CT scanners. The purpose of this review is to discuss the different scanning and injection protocols using 4-, 16-, and 64-detector row CT scanners, to propose effective methods to evaluate and to present large data sets, to discuss its clinical value and major limitations, and to review the literature on the validity, reliability, and cost-effectiveness of multi-detector row CT in the evaluation of PAD. PMID:17882427

Coronary artery calcium score and CT angiography in asymptomatic elderly patients with high pretest probability for coronary artery disease.

PubMed

Imanzadeh, Amir; George, Elizabeth; Kondo, Takeshi; Takase, Shinichi; Amanuma, Makoto; Rybicki, Frank J; Kumamaru, Kanako K

2016-02-01

To evaluate the role of coronary artery calcium scoring (CACS) and/or coronary CT angiography (CCTA) in asymptomatic elderly patients with high pretest probability for coronary artery disease (CAD). Forty-eight consecutive asymptomatic elderly (>65 years) subjects who had a high pretest probability and underwent CACS/CCTA were included. Each CCTA was evaluated for adequacy for assessment of coronary stenosis. Significant stenosis (>50% diameter narrowing) was assessed on evaluable CT images and by invasive catheter angiography (ICA). All subjects were men with mean CACS of 880 ± 1779. Among those with low (0-99), intermediate (100-399), and high (400-999) CACS, ICA-verified significant stenosis was present in 8% (1/13), 23% (2/13), and 67% (8/12), respectively. Among those with very high CACS (≥ 1000) (n = 10), 90% of CCTAs were not evaluable for stenosis. In asymptomatic elderly subjects with high pretest probability, CACS followed by CCTA may be considered for those with intermediate to high CACS.

Fractional Flow Reserve and Coronary Computed Tomographic Angiography: A Review and Critical Analysis.

PubMed

Hecht, Harvey S; Narula, Jagat; Fearon, William F

2016-07-08

Invasive fractional flow reserve (FFR) is now the gold standard for intervention. Noninvasive functional imaging analyses derived from coronary computed tomographic angiography (CTA) offer alternatives for evaluating lesion-specific ischemia. CT-FFR, CT myocardial perfusion imaging, and transluminal attenuation gradient/corrected contrast opacification have been studied using invasive FFR as the gold standard. CT-FFR has demonstrated significant improvement in specificity and positive predictive value compared with CTA alone for predicting FFR of ≤0.80, as well as decreasing the frequency of nonobstructive invasive coronary angiography. High-risk plaque characteristics have also been strongly implicated in abnormal FFR. Myocardial computed tomographic perfusion is an alternative method with promising results; it involves more radiation and contrast. Transluminal attenuation gradient/corrected contrast opacification is more controversial and may be more related to vessel diameter than stenosis. Important considerations remain: (1) improvement of CTA quality to decrease unevaluable studies, (2) is the diagnostic accuracy of CT-FFR sufficient? (3) can CT-FFR guide intervention without invasive FFR confirmation? (4) what are the long-term outcomes of CT-FFR-guided treatment and how do they compare with other functional imaging-guided paradigms? (5) what degree of stenosis on CTA warrants CT-FFR? (6) how should high-risk plaque be incorporated into treatment decisions? (7) how will CT-FFR influence other functional imaging test utilization, and what will be the effect on the practice of cardiology? (8) will a workstation-based CT-FFR be mandatory? Rapid progress to date suggests that CTA-based lesion-specific ischemia will be the gatekeeper to the cardiac catheterization laboratory and will transform the world of intervention. © 2016 American Heart Association, Inc.

3D Deep Learning Angiography (3D-DLA) from C-arm Conebeam CT.

PubMed

Montoya, J C; Li, Y; Strother, C; Chen, G-H

2018-05-01

Deep learning is a branch of artificial intelligence that has demonstrated unprecedented performance in many medical imaging applications. Our purpose was to develop a deep learning angiography method to generate 3D cerebral angiograms from a single contrast-enhanced C-arm conebeam CT acquisition in order to reduce image artifacts and radiation dose. A set of 105 3D rotational angiography examinations were randomly selected from an internal data base. All were acquired using a clinical system in conjunction with a standard injection protocol. More than 150 million labeled voxels from 35 subjects were used for training. A deep convolutional neural network was trained to classify each image voxel into 3 tissue types (vasculature, bone, and soft tissue). The trained deep learning angiography model was then applied for tissue classification into a validation cohort of 8 subjects and a final testing cohort of the remaining 62 subjects. The final vasculature tissue class was used to generate the 3D deep learning angiography images. To quantify the generalization error of the trained model, we calculated the accuracy, sensitivity, precision, and Dice similarity coefficients for vasculature classification in relevant anatomy. The 3D deep learning angiography and clinical 3D rotational angiography images were subjected to a qualitative assessment for the presence of intersweep motion artifacts. Vasculature classification accuracy and 95% CI in the testing dataset were 98.7% (98.3%-99.1%). No residual signal from osseous structures was observed for any 3D deep learning angiography testing cases except for small regions in the otic capsule and nasal cavity compared with 37% (23/62) of the 3D rotational angiographies. Deep learning angiography accurately recreated the vascular anatomy of the 3D rotational angiography reconstructions without a mask. Deep learning angiography reduced misregistration artifacts induced by intersweep motion, and it reduced radiation exposure required to obtain clinically useful 3D rotational angiography. © 2018 by American Journal of Neuroradiology.

Safety of an i.v. β-adrenergic blockade protocol for heart rate optimization before coronary CT angiography.

PubMed

Kassamali, Rahil H; Kim, Daniel H; Patel, Hiten; Raichura, Nitin; Hoey, Edward T D; Hodson, James; Hussain, Shahid

2014-10-01

The purpose of this study was to assess the safety of heart rate optimization by use of β-adrenergic blockade solely by the i.v. route before coronary CT angiography. The records of 679 patients undergoing CT coronary angiography after receiving i.v. β-adrenergic blockade were retrospectively analyzed. Health screening was completed before scanning, and heart rate was optimized by administration of i.v. metoprolol titrated to a maximum of 70 mg to achieve a heart rate less than 65 beats/min. The median i.v. dose was 20 mg (range, 5-70 mg). The 679 patients analyzed had a total of 10 complications (1.47%). Major complications, defined as not resolving with observation and analgesia alone, occurred in only three patients (0.44%). These complications included a second-degree atrioventricular block. A total of 299 patients (44.0%) needed more than 20 mg of i.v. metoprolol to achieve target heart rate. Only three patients needed the maximum i.v. dose of 70 mg metoprolol. Target heart rate was reached successfully in 666 patients (98.1%) with doses of less than 70 mg. This study did not show a statistically significant association between increasing complication frequency and increasing dose. This study showed that high doses of i.v. metoprolol can be used effectively and with a low rate of major complications to control heart rate before coronary CT angiography in correctly screened patients.

Recent Update on Radiation Dose Assessment for the State-of-the-Art Coronary Computed Tomography Angiography Protocols.

PubMed

Tan, Sock Keow; Yeong, Chai Hong; Ng, Kwan Hoong; Abdul Aziz, Yang Faridah; Sun, Zhonghua

2016-01-01

This study aimed to measure the absorbed doses in selected organs for prospectively ECG-triggered coronary computed tomography angiography (CCTA) using five different generations CT scanners in a female adult anthropomorphic phantom and to estimate the effective dose (HE). Prospectively ECG-triggered CCTA was performed using five commercially available CT scanners: 64-detector-row single source CT (SSCT), 2 × 32-detector-row-dual source CT (DSCT), 2 × 64-detector-row DSCT and 320-detector-row SSCT scanners. Absorbed doses were measured in 34 organs using pre-calibrated optically stimulated luminescence dosimeters (OSLDs) placed inside a standard female adult anthropomorphic phantom. HE was calculated from the measured organ doses and compared to the HE derived from the air kerma-length product (PKL) using the conversion coefficient of 0.014 mSv∙mGy-1∙cm-1 for the chest region. Both breasts and lungs received the highest radiation dose during CCTA examination. The highest HE was received from 2 × 32-detector-row DSCT scanner (6.06 ± 0.72 mSv), followed by 64-detector-row SSCT (5.60 ± 0.68 and 5.02 ± 0.73 mSv), 2 × 64-detector-row DSCT (1.88 ± 0.25 mSv) and 320-detector-row SSCT (1.34 ± 0.48 mSv) scanners. HE calculated from the measured organ doses were about 38 to 53% higher than the HE derived from the PKL-to-HE conversion factor. The radiation doses received from a prospectively ECG-triggered CCTA are relatively small and are depending on the scanner technology and imaging protocols. HE as low as 1.34 and 1.88 mSv can be achieved in prospectively ECG-triggered CCTA using 320-detector-row SSCT and 2 × 64-detector-row DSCT scanners.

Recent Update on Radiation Dose Assessment for the State-of-the-Art Coronary Computed Tomography Angiography Protocols

PubMed Central

Tan, Sock Keow; Yeong, Chai Hong; Ng, Kwan Hoong; Abdul Aziz, Yang Faridah; Sun, Zhonghua

2016-01-01

Objectives This study aimed to measure the absorbed doses in selected organs for prospectively ECG-triggered coronary computed tomography angiography (CCTA) using five different generations CT scanners in a female adult anthropomorphic phantom and to estimate the effective dose (HE). Materials and Methods Prospectively ECG-triggered CCTA was performed using five commercially available CT scanners: 64-detector-row single source CT (SSCT), 2 × 32-detector-row-dual source CT (DSCT), 2 × 64-detector-row DSCT and 320-detector-row SSCT scanners. Absorbed doses were measured in 34 organs using pre-calibrated optically stimulated luminescence dosimeters (OSLDs) placed inside a standard female adult anthropomorphic phantom. HE was calculated from the measured organ doses and compared to the HE derived from the air kerma-length product (PKL) using the conversion coefficient of 0.014 mSv∙mGy-1∙cm-1 for the chest region. Results Both breasts and lungs received the highest radiation dose during CCTA examination. The highest HE was received from 2 × 32-detector-row DSCT scanner (6.06 ± 0.72 mSv), followed by 64-detector-row SSCT (5.60 ± 0.68 and 5.02 ± 0.73 mSv), 2 × 64-detector-row DSCT (1.88 ± 0.25 mSv) and 320-detector-row SSCT (1.34 ± 0.48 mSv) scanners. HE calculated from the measured organ doses were about 38 to 53% higher than the HE derived from the PKL-to-HE conversion factor. Conclusion The radiation doses received from a prospectively ECG-triggered CCTA are relatively small and are depending on the scanner technology and imaging protocols. HE as low as 1.34 and 1.88 mSv can be achieved in prospectively ECG-triggered CCTA using 320-detector-row SSCT and 2 × 64-detector-row DSCT scanners. PMID:27552224

Visualization of an actively bleeding cortical vessel into the subdural space by CT angiography.

PubMed

Dalfino, John C; Boulos, Alan S

2010-10-01

Spontaneous subdural hematomas of arterial origin are rare with only a few published case reports in the literature. In the CT era, vessel imaging of extra-axial hematomas is not commonly performed. In this case report we present a patient with a large, spontaneous acute subdural hematoma that demonstrated active contrast extravasation from a small cortical vessel on CT angiography. During surgical evacuation the vessel was confirmed to be a small cortical artery that was bulging through the arachnoid membrane and bleeding into the subdural space. The historical, radiographic, and clinical aspects of this unusual cause of subdural hematoma are discussed. (c) 2010 Elsevier B.V. All rights reserved.

Coronary Artery Disease: Analysis of Diagnostic Performance of CT Perfusion and MR Perfusion Imaging in Comparison with Quantitative Coronary Angiography and SPECT-Multicenter Prospective Trial.

PubMed

Rief, Matthias; Chen, Marcus Y; Vavere, Andrea L; Kendziora, Benjamin; Miller, Julie M; Bandettini, W Patricia; Cox, Christopher; George, Richard T; Lima, João; Di Carli, Marcelo; Plotkin, Michail; Zimmermann, Elke; Laule, Michael; Schlattmann, Peter; Arai, Andrew E; Dewey, Marc

2018-02-01

Purpose To compare the diagnostic performance of stress myocardial computed tomography (CT) perfusion with that of stress myocardial magnetic resonance (MR) perfusion imaging in the detection of coronary artery disease (CAD). Materials and Methods All patients gave written informed consent prior to inclusion in this institutional review board-approved study. This two-center substudy of the prospective Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) multicenter trial included 92 patients (mean age, 63.1 years ± 8.1 [standard deviation]; 73% male). All patients underwent perfusion CT and perfusion MR imaging with either adenosine or regadenoson stress. The predefined reference standards were combined quantitative coronary angiography (QCA) and single-photon emission CT (SPECT) or QCA alone. Results from coronary CT angiography were not included, and diagnostic performance was evaluated with the Mantel-Haenszel test stratified by disease status. Results The prevalence of CAD was 39% (36 of 92) according to QCA and SPECT and 64% (59 of 92) according to QCA alone. When compared with QCA and SPECT, per-patient diagnostic accuracy of perfusion CT and perfusion MR imaging was 63% (58 of 92) and 75% (69 of 92), respectively (P = .11); sensitivity was 92% (33 of 36) and 83% (30 of 36), respectively (P = .45); and specificity was 45% (25 of 56) and 70% (39 of 56), respectively (P < .01). When compared with QCA alone, diagnostic accuracy of CT perfusion and MR perfusion imaging was 82% (75 of 92) and 74% (68 of 92), respectively (P = .27); sensitivity was 90% (53 of 59) and 69% (41 of 59), respectively (P < .01); and specificity was 67% (22 of 33) and 82% (27 of 33), respectively (P = .27). Conclusion This multicenter study shows that the diagnostic performance of perfusion CT is similar to that of perfusion MR imaging in the detection of CAD. © RSNA, 2017 Online supplemental material is available for this article.

Sensitivity and specificity of the hyperdense artery sign for arterial obstruction in acute ischemic stroke.

PubMed

Mair, Grant; Boyd, Elena V; Chappell, Francesca M; von Kummer, Rüdiger; Lindley, Richard I; Sandercock, Peter; Wardlaw, Joanna M

2015-01-01

In acute ischemic stroke, the hyperdense artery sign (HAS) on noncontrast computed tomography (CT) is thought to represent intraluminal thrombus and, therefore, is a surrogate of arterial obstruction. We sought to assess the accuracy of HAS as a marker of arterial obstruction by thrombus. The Third International Stroke Trial (IST-3) was a randomized controlled trial testing the use of intravenous thrombolysis for acute ischemic stroke in patients who did not clearly meet the prevailing license criteria. Some participating IST-3 centers routinely performed CT or MR angiography at baseline. One reader assessed all relevant scans independently, blinded to all other data; we checked observer reliability. We combined IST-3 data with a systematic review and meta-analysis of all studies that assessed the accuracy of HAS using angiography (any modality). IST-3 had 273 patients with baseline CT or MR angiography and was the largest study of HAS accuracy. The meta-analysis (n=902+273=1175, including IST-3) found sensitivity and specificity of HAS for arterial obstruction on angiography to be 52% and 95%, respectively. HAS was more commonly identified in proximal than distal arteries (47% versus 37%; P=0.015), and its sensitivity increased with thinner CT slices (r=-0.73; P=0.001). Neither extent of obstruction nor time after stroke influenced HAS accuracy. When present in acute ischemic stroke, HAS indicates a high likelihood of arterial obstruction, but its absence indicates only a 50/50 chance of normal arterial patency. Thin-slice CT improves sensitivity of HAS detection. http://www.controlled-trials.com/ISRCTN25765518. Unique identifier: ISRCTN25765518. © 2014 American Heart Association, Inc.

Use of ECG-gated computed tomography, echocardiography and selective angiography in five dogs with pulmonic stenosis and one dog with pulmonic stenosis and aberrant coronary arteries.

PubMed

Laborda-Vidal, P; Pedro, B; Baker, M; Gelzer, A R; Dukes-McEwan, J; Maddox, T W

2016-12-01

Pulmonic stenosis (PS) is the most common congenital cardiac disease in dogs. Boxers and English bulldogs are among the most commonly affected breeds and also commonly associated with an aberrant coronary artery (CA). If an aberrant CA is suspected and balloon valvuloplasty indicated, an intra-operative angiography is recommended prior to the procedure. ECG-gated computed tomography (CT) can be used to screen for CA anomalies in a quick and minimally-invasive way (preventing side effects associated with selective catheter angiography) and allowing early planning of the procedure. The aim of this case series was to report CT findings associated with PS diagnosed by echocardiography. Our database was retrospectively searched for cases of dogs with PS diagnosed by echocardiography, where an ECG-gated CT was performed. A total of six cases were retrieved: all were diagnosed with severe PS. Four dogs had concurrent congenital defects: two dogs had a patent ductus arteriosus, one dog had a ventricular septal defect and an overriding aorta, one dog had an aberrant CA. Detailed CT findings of all cases were reported, including one case of a patent ductus arteriosus and an overriding aorta not identified by transthoracic echocardiography. In addition, an abnormal single left coronary ostium, with a pre-pulmonic right CA was described. In conclusion, despite echocardiography remaining the gold standard for diagnosis and assessment of PS, ECG-gated-CT angiography is a complementary diagnostic method that may provide additional relevant information, shorten surgery/anaesthesia time and reduce the amount of radiation to which the clinician is subjected. Copyright © 2016 Elsevier B.V. All rights reserved.

Value of Image Fusion in Coronary Angiography for the Detection of Coronary Artery Bypass Grafts.

PubMed

Plessis, Julien; Warin Fresse, Karine; Cahouch, Zachary; Manigold, Thibaut; Letocart, Vincent; Le Gloan, Laurianne; Guyomarch, Béatrice; Guerin, Patrice

2016-06-10

Coronary angiography is more complex in patients with coronary artery bypass grafts (CABG). Image fusion is a new technology that allows the overlay of a computed tomography (CT) three-dimension (3D) model with fluoroscopic images in real time. This single-center prospective study included 66 previous CABG patients undergoing coronary and bypass graft angiography. Image fusion coronary angiographies (fusion group, 20 patients) were compared to conventional coronary angiographies (control group, 46 patients). The fusion group included patients for whom a previous chest CT scan with contrast was available. For patients in this group, aorta and CABG were reconstructed in 3D from CT acquisitions and merged in real time with fluoroscopic images. The following parameters were compared: time needed to localize the CABG; procedure duration; air kerma (AK); dose area product (DAP); and volume of contrast media injected. Results are expressed as median. There were no significant differences between the 2 groups in patient demographics and procedure characteristics (access site, number of bypass to be found, and interventional cardiologist's experience). The time to localize CABG was significantly shorter in the fusion group (7.3 versus 12.4 minutes; P=0.002), as well as the procedure duration (20.6 versus 25.6 minutes; P=0.002), AK (610 versus 814 mGy; P=0.02), DAP (4390 versus 5922.5 cGy·cm(2); P=0.02), and volume of iodinated contrast media (85 versus 116 cc; P=0.002). 3D image fusion improves the CABG detection in coronary angiography and reduces the time necessary to localize CABG, total procedure time duration, radiation exposure, and volume of contrast media. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Submillisievert coronary CT angiography with adaptive prospective ECG-triggered sequence acquisition and iterative reconstruction in patients with high heart rate on the dual-source CT.

PubMed

Tang, Pei-Hua; Du, Ben-Jun; Fang, Xiang-Ming; Hu, Xiao-Yun; Qian, Ping-Yan; Gao, Quan-Sheng

2016-11-22

To assess the application value of submillisievert coronary CT angiography (CCTA) in patients with a high heart rate (HR) acquired with adaptive prospective ECG-triggered sequence acquisition and iterative reconstruction on the secondary generation dual-source CT. A total of 120 consecutive high-HR patients suspected with coronary artery disease underwent CCTA and invasive coronary angiography (ICA) within two weeks. Patients were randomly assigned into three groups: group A (n = 40), where the patients underwent retrospectively ECG-triggered acquisition CCTA at 100 kVp; group B (n = 40), where the patients received adaptive prospective ECG-triggered sequence acquisition at 100 kVp; and group C (n = 40), where the patients performed adaptive prospective ECG-triggered sequence acquisition at 80 kVp with iterative reconstruction. The mean CT values, signal noise ratios (SNR) and contrast noise ratios (CNR) in the ascending aorta and coronary arteries of the three groups were measured and compared. The image quality and radiation dose among the three groups were compared. The consistency of displaying the coronary stenosis of each group was assessed compared with the results of ICA as the gold standard. There was no significant difference in gender, age and body mass index (BMI) (all P > 0.05). The mean attenuations, SNRs and CNRs in the ascending aorta and coronary artery were not significantly different between group A and group B (P > 0.05). The mean attenuations of group C were significantly higher than group A and group B (P < 0.01), but the image noise and CNR were significantly lower in group C (P < 0.01). The number of appreciable segments among the three groups was not significantly different on a per-segment and per-vessel basis (P > 0.05). The subjective image quality among the three groups was not significantly different (P > 0.05). With the ICA result as a reference standard, there was good consistency in the evaluation of the coronary stenosis degree between CCTA and ICA (r > 0.75), as well as in the assessment of the coronary stenosis rate using the Bland- Altman analysis. The mean radiation dose in group B was half of that in group A. Moreover, the mean radiation dose in group C was less than one sixth of that in group A and less than 1 mSv (0.7±0.2 mSv). For patients with high HR, adaptive prospective ECG-triggered sequence acquisition on the FLASH dual-source CT results in equal image quality and half of the radiation dose reduction compared with retrospectively ECG-triggered spiral acquisition at the same tube voltage (100 kVp) and same R-R interval of exposure. In addition, adaptive prospective ECG-triggered sequence acquisition combined with low tube voltage and iterative reconstruction can further reduce the radiation dose to the submillisievert level without compromising image quality and the accuracy of assessing the coronary stenosis degree, and can be popularized as a routine technique.

CT angiography - chest

MedlinePlus

... aortic aneurysm - CTA chest; Venous thromboembolism - CTA lung; Blood clot - CTA lung; Embolus - CTA lung; CT pulmonary angiogram ... angiogram may be done: For symptoms that suggest blood clots in the lungs, such as chest pain, rapid ...

Virtual single source CT using dual source acquisition: Clinical applicability in run-off CT-angiography for intra-individual comparison of different scan protocols.

PubMed

Werncke, T; Hinrichs, J B; Alikhani, B; Maschke, S; Wacker, F K; Meyer, B C

2018-04-01

Virtual single source computed tomography (VSS-CT) acquisition on a dual source CT (DSCT) has been demonstrated to allow for dose-neutral intra-individual comparison of three acquisition protocols at different radiation dose levels (RDL) within one acquisition in a phantom. The purpose of this study was twofold: first to evaluate the applicability of VSS-CT in patients and second to optimize the task-dependent trade-off between radiation dose and image quality of lower extremity CT angiography (run-off CTA). In this IRB-approved prospective study 52 patients underwent run-off CTA between 06/2012 and 06/2013. VSS-CT acquisition was conducted using a first generation DSCT applying equal X-ray tube settings (120 kVp), collimation (2 × 32 × 0.6 mm), and slice thickness (1.0 mm) but different effective tube current-time products (tube A: 80 mAs, tube B: 40 mAs). Three different image datasets representing three different radiation dose levels (RDL40, RDL80, RDL120) were reconstructed using a soft kernel from the raw data of tube B, tube A or both tubes combined. Dose length products (DLP) of each raw data set were documented. Quantitative image quality (IQ) was assessed for five anatomical levels using image noise and contrast-to-noise ratio (CNR). To investigate dose efficiency of each acquisition, the dose-weighted CNR (CNRD) was determined. Qualitative IQ was evaluated by two blinded readers in consensus using a 5-point Likert scale and compared with a Friedman- and posthoc Wilcoxon test. Mean DLP was 200 ± 40, 400 ± 90 and 600 ± 130 mGy·cm for the RDL40, RDL80 and RDL120, respectively. Image noise and CNR were best for RDL120 and decreased significantly for RDL80 and RDL40, independent of the anatomic level (p < 0.001). CNRD showed no significant differences at the abdominal and pelvic level between the investigated radiation dose levels. However, for thigh to foot level a significant increase of CNRD was noted between RDL120, RDL80 and RDL40. Significant differences of qualitative IQ were observed between RDL120 and RDL40 from the abdominal to the foot level, whereas no difference was seen for the other dose levels. Radiation dose splitting with VSS-CT can be applied to run-off CTA facilitating intra-individual comparison of different acquisition protocols without additional radiation exposure. Furthermore, a radiation dose reduction potential for run-off CTA of approximately 1/3 as compared to the acquisition protocol recommended by the manufacturer could be identified in this study. Copyright © 2018 Elsevier B.V. All rights reserved.

Submillisievert standard-pitch CT pulmonary angiography with ultra-low dose contrast media administration: A comparison to standard CT imaging.

PubMed

Suntharalingam, Saravanabavaan; Mikat, Christian; Stenzel, Elena; Erfanian, Youssef; Wetter, Axel; Schlosser, Thomas; Forsting, Michael; Nassenstein, Kai

2017-01-01

To evaluate the image quality and radiation dose of submillisievert standard-pitch CT pulmonary angiography (CTPA) with ultra-low dose contrast media administration in comparison to standard CTPA. Hundred patients (56 females, 44 males, mean age 69.6±15.4 years; median BMI: 26.6, IQR: 5.9) with suspected pulmonary embolism were examined with two different protocols (n = 50 each, group A: 80 kVp, ref. mAs 115, 25 ml of contrast medium; group B: 100 kVp, ref. mAs 150, 60 ml of contrast medium) using a dual-source CT equipped with automated exposure control. Objective and subjective image qualities, radiation exposure as well as the frequency of pulmonary embolism were evaluated. There was no significant difference in subjective image quality scores between two groups regarding pulmonary arteries (p = 0.776), whereby the interobserver agreement was excellent (group A: k = 0.9; group B k = 1.0). Objective image analysis revealed that signal intensities (SI), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the pulmonary arteries were equal or significantly higher in group B. There was no significant difference in the frequency of pulmonary embolism (p = 0.65). Using the low dose and low contrast media protocol resulted in a radiation dose reduction by 71.8% (2.4 vs. 0.7 mSv; p<0.001). This 80 kVp standard pitch CTPA protocol with 25 ml contrast agent volume can obtain sufficient image quality to exclude or diagnose pulmonary emboli while reducing radiation dose by approximately 71%.

Recanalization and clinical outcome of occlusion sites at baseline CT angiography in the Interventional Management of Stroke III trial.

PubMed

Demchuk, Andrew M; Goyal, Mayank; Yeatts, Sharon D; Carrozzella, Janice; Foster, Lydia D; Qazi, Emmad; Hill, Michael D; Jovin, Tudor G; Ribo, Marc; Yan, Bernard; Zaidat, Osama O; Frei, Donald; von Kummer, Rüdiger; Cockroft, Kevin M; Khatri, Pooja; Liebeskind, David S; Tomsick, Thomas A; Palesch, Yuko Y; Broderick, Joseph P

2014-10-01

To use baseline computed tomographic (CT) angiography to analyze imaging and clinical end points in an Interventional Management of Stroke III cohort to identify patients who would benefit from endovascular stroke therapy. The primary clinical end point was 90-day dichotomized modified Rankin Scale (mRS) score. Secondary end points were 90-day mRS score distribution and 24-hour recanalization. Prespecified subgroup was baseline proximal occlusions (internal carotid, M1, or basilar arteries). Exploratory analyses were subsets with any occlusion and specific sites of occlusion (two-sided α = .01). Of 656 subjects, 306 (47%) underwent baseline CT angiography or magnetic resonance angiography. Of 306, 282 (92%) had arterial occlusions. At baseline CT angiography, proximal occlusions (n = 220) demonstrated no difference in primary outcome (41.3% [62 of 150] endovascular vs 38% [27 of 70] intravenous [IV] tissue-plasminogen activator [tPA]; relative risk, 1.07 [99% confidence interval: 0.67, 1.70]; P = .70); however, 24-hour recanalization rate was higher for endovascular treatment (n = 167; 84.3% [97 of 115] endovascular vs 56% [29 of 52] IV tPA; P < .001). Exploratory subgroup analysis for any occlusion at baseline CT angiography did not demonstrate significant differences between endovascular and IV tPA arms for primary outcome (44.7% [85 of 190] vs 38% [35 of 92], P = .29), although ordinal shift analysis of full mRS distribution demonstrated a trend toward more favorable outcome (P = .011). Carotid T- or L-type occlusion (terminal internal carotid artery [ICA] with M1 middle cerebral artery and/or A1 anterior cerebral artery involvement) or tandem (extracranial or intracranial) ICA and M1 occlusion subgroup also showed a trend favoring endovascular treatment over IV tPA alone for primary outcome (26% [12 of 46] vs 4% [one of 23], P = .047). Significant differences were identified between treatment arms for 24-hour recanalization in proximal occlusions; carotid T- or L-type and tandem ICA and M1 occlusions showed greater recanalization and a trend toward better outcome with endovascular treatment. Vascular imaging should be mandated in future endovascular trials to identify such occlusions. Online supplemental material is available for this article. © RSNA, 2014.

Occurrence of spot signs from hypodensity areas on precontrast CT in intracerebral hemorrhage.

PubMed

Nishiyama, Jun; Sorimachi, Takatoshi; Aoki, Rie; Inoue, Go; Matsumae, Mitsunori

2017-05-01

Both the spot signs, which is a bright spot on computed tomography angiography (CTA) source images, and hypodensity areas within a hematoma on precontrast CT scans, which presumably represent uncoagulated blood, have been reported to be predictive of hematoma enlargement in acute spontaneous intracerebral hematoma (ICH). The aim was to investigate densities on precontrast CT scans in an area within a hematoma that matched the locations of spot signs on CTA source images. In consecutive cases of spontaneous ICH admitted within 6 h after onset, early spot signs on CTA source images and delayed spot signs on delayed-phase CT scans 90 s after CTA were evaluated. Of 177 patients undergoing CTA, 41 (23.2%) showed early spot signs. Among 146 patients who underwent delayed-phase CT scans, 23 (15.8%) demonstrated delayed spot signs but not early spot signs. Spot signs originated from hypodensity areas, including densities <50 HU, in 30 of 35 patients (85.7%) with early spot signs and in 8 of 23 (34.8%) with delayed spot signs. Early spot signs arose from hypodensity areas more frequently than delayed spot signs (p < 0.05). Hematoma enlargement was observed in 10 of 24 patients (41.7%) with early spot signs, but in none with delayed spot signs. Some hypodensity areas within ICHs may indicate uncoagulated blood related to ongoing leakage, which are seen as spot signs. Minimum densities in hypodensity areas might correlate with the speed and volume of bleeding.

Imaging discordance between hepatic angiography versus Tc-99m-MAA SPECT/CT: a case series, technical discussion and clinical implications.

PubMed

Kao, Yung Hsiang; Tan, Eik Hock; Teo, Terence Kiat Beng; Ng, Chee Eng; Goh, Soon Whatt

2011-11-01

During pre-therapy evaluation for yttrium-90 (Y-90) radioembolization, it is uncommon to find severe imaging discordance between hepatic angiography versus technetium-99m-macroaggregated albumin (Tc-99m-MAA) single photon emission computed tomography with integrated low-dose CT (SPECT/CT). The reasons for severe imaging discordance are unclear, and literature is scarce. We describe 3 patients with severe imaging discordance, whereby tumor angiographic contrast hypervascularity was markedly mismatched to the corresponding Tc-99m-MAA SPECT/CT, and its clinical impact. The incidence of severe imaging discordance at our institution was 4% (3 of 74 cases). We postulate that imaging discordance could be due to a combination of 3 factors: (1) different injection rates between soluble contrast molecules versus Tc-99m-MAA; (2) different arterial flow hemodynamics between soluble contrast molecules versus Tc-99m-MAA; (3) eccentric release position of Tc-99m-MAA due to microcatheter tip location, inadvertently selecting non-target microparticle trajectories. Tc-99m-MAA SPECT/CT more accurately represents hepatic microparticle biodistribution than soluble contrast hepatic angiography and should be a key criterion in patient selection for Y-90 radioembolization. Tc-99m-MAA SPECT/CT provides more information than planar scintigraphy to guide radiation planning and clinical decision making. Severe imaging discordance at pre-therapy evaluation is ominous and should be followed up by changes to the final vascular approach during Y-90 radioembolization.

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

A BMI-adjusted ultra-low-dose CT angiography protocol for the peripheral arteries-Image quality, diagnostic accuracy and radiation exposure.

PubMed

Schreiner, Markus M; Platzgummer, Hannes; Unterhumer, Sylvia; Weber, Michael; Mistelbauer, Gabriel; Loewe, Christian; Schernthaner, Ruediger E

2017-08-01

To investigate radiation exposure, objective image quality, and the diagnostic accuracy of a BMI-adjusted ultra-low-dose CT angiography (CTA) protocol for the assessment of peripheral arterial disease (PAD), with digital subtraction angiography (DSA) as the standard of reference. In this prospective, IRB-approved study, 40 PAD patients (30 male, mean age 72 years) underwent CTA on a dual-source CT scanner at 80kV tube voltage. The reference amplitude for tube current modulation was personalized based on the body mass index (BMI) with 120 mAs for [BMI≤25] or 150 mAs for [2570%) was assessed by two readers independently and compared to subsequent DSA. Radiation exposure was assessed with the computed tomography dose index (CTDIvol) and the dosis-length product (DLP). Objective image quality was assessed via contrast- and signal-to-noise ratio (CNR and SNR) measurements. Radiation exposure and image quality were compared between the BMI groups and between the BMI-adjusted ultra-low-dose protocol and the low-dose institutional standard protocol (ISP). The BMI-adjusted ultra-low-dose protocol reached high diagnostic accuracy values of 94% for Reader 1 and 93% for Reader 2. Moreover, in comparison to the ISP, it showed significantly (p<0.001) lower CTDIvol (1.97±0.55mGy vs. 4.18±0.62 mGy) and DLP (256±81mGy x cm vs. 544±83mGy x cm) but similar image quality (p=0.37 for CNR). Furthermore, image quality was similar between BMI groups (p=0.86 for CNR). A CT protocol that incorporates low kV settings with a personalized (BMI-adjusted) reference amplitude for tube current modulation and iterative reconstruction enables very low radiation exposure CTA, while maintaining good image quality and high diagnostic accuracy in the assessment of PAD. Copyright © 2017 Elsevier B.V. All rights reserved.

Severe hematuria after transurethral electrocoagulation in a patient with an arteriovesical fistula

PubMed Central

2013-01-01

Background Arteriovesical fistulas are extremely rare. Only eleven cases were previously reported in the literature. They can occur iatrogenically, traumatically or spontaneously. Case presentation We report an unusual case of a 62-year-old woman with arteriovesical fistula that developed fatal hematuria after transurethral electrocoagulation. Computed tomography (CT) and selective angiography revealed a pseudoaneurysm of the right superior vesical artery with arteriovesical fistula formation, which was managed by transarterial embolization. Conclusions Contrast enhanced CT or CT angiography should be performed when a pulsatile hemorrhage is revealed during cystoscopy. Therapeutic vesical arterial embolization should be considered as a safe and effective procedure for arteriovesical fistulas. Transurethral electrocoagulation may cause severe hematuria for pulsatile bladder bleeding in patients with pelvic vascular malformation. PMID:24289138

Severe hematuria after transurethral electrocoagulation in a patient with an arteriovesical fistula.

PubMed

Zheng, Xiangyi; Lin, Yiwei; Chen, Bin; Zhou, Xianyong; Zhou, Xiaofeng; Shen, Yuehong; Xie, Liping

2013-12-01

Arteriovesical fistulas are extremely rare. Only eleven cases were previously reported in the literature. They can occur iatrogenically, traumatically or spontaneously. We report an unusual case of a 62-year-old woman with arteriovesical fistula that developed fatal hematuria after transurethral electrocoagulation. Computed tomography (CT) and selective angiography revealed a pseudoaneurysm of the right superior vesical artery with arteriovesical fistula formation, which was managed by transarterial embolization. Contrast enhanced CT or CT angiography should be performed when a pulsatile hemorrhage is revealed during cystoscopy. Therapeutic vesical arterial embolization should be considered as a safe and effective procedure for arteriovesical fistulas. Transurethral electrocoagulation may cause severe hematuria for pulsatile bladder bleeding in patients with pelvic vascular malformation.

The arterial supply of the nipple areola complex (NAC) and its relations: an analysis of angiographic CT imaging for breast pedicle design.

PubMed

Stirling, Aaron D; Murray, Conor P; Lee, Mark A

2017-10-01

To investigate the blood supply to the nipple areola complex (NAC) on thoracic CT angiograms (CTA) to improve breast pedicle design in reduction mammoplasty. In a single centre, CT scans of the thorax were retrospectively reviewed for suitability by a cardiothoracic radiologist. Suitable scans had one or both breasts visible in extended fields, with contrast enhancement of breast vasculature in a female patient. The arterial sources, intercostal space perforated, glandular/subcutaneous course, vessel entry point, and the presence of periareolar anastomoses were recorded for the NAC of each breast. From 69 patients, 132 breasts were suitable for inclusion. The most reproducible arterial contribution to the NAC was perforating branches arising from the internal thoracic artery (ITA) (n = 108, 81.8%), followed by the long thoracic artery (LTA) (n = 31, 23.5%) and anterior intercostal arteries (AI) (n = 21, 15.9%). Blood supply was superficial versus deep in (n = 86, 79.6%) of ITA sources, (n = 28, 90.3%) of LTA sources, and 10 (47.6%) of AI sources. The most vascularly reliable breast pedicle would be asymmetrical in 7.9% as a conservative estimate. We suggest that breast CT angiography can provide valuable information about NAC blood supply to aid customised pedicle design, especially in high-risk, large-volume breast reductions where the risk of vascular-dependent complications is the greatest and asymmetrical dominant vasculature may be present. Superficial ITA perforator supplies are predominant in a majority of women, followed by LTA- and AIA-based sources, respectively.

The psychological impact of test results following diagnostic coronary CT angiography.

PubMed

Devcich, Daniel A; Ellis, Christopher J; Broadbent, Elizabeth; Gamble, Greg; Petrie, Keith J

2012-11-01

Coronary computed tomography (CT) angiography is an advanced cardiac imaging test commonly used for diagnosing early signs of ischemic heart disease. Despite its importance in cardiology, little is known about its psychological effect on patients. The present study sought to examine these effects in relation to illness perceptions, cardiac health behavior intentions, and subsequent health behaviors. Forty-five nonacute cardiac patients who were referred for diagnostic coronary CT angiography completed questionnaires prior to testing and following the receipt of test results, at which point illness perceptions and intentions to take cardiac medication, as well as diet and exercise intentions were measured. Exercise and dietary behaviors were measured at follow-up 6 weeks later. Changes on these variables were then compared between patients diagnosed with normal arteries and patients diagnosed with diseased arteries. Compared to positive-testing patients, patients with normal test results reported significant changes toward more positive illness perceptions following testing, with improvements in emotional effect of illness, illness concern, consequences, and personal control of illness. The illness perception of treatment control was seen as more important among positive-testing patients, whereas both groups reported increases in illness coherence. Health behavior intentions (cardiac medication intentions and exercise intentions) increased for positive-testing patients only, as did physical activity at follow-up. Diagnosis-dependent psychological effects can be detected following coronary CT angiography. These effects have important implications for patient health and health care in diagnostic contexts, and the results from this study can be used to guide further research in this area.

Determination of split renal function using dynamic CT-angiography: preliminary results.

PubMed

Helck, Andreas; Schönermarck, Ulf; Habicht, Antje; Notohamiprodjo, Mike; Stangl, Manfred; Klotz, Ernst; Nikolaou, Konstantin; la Fougère, Christian; Clevert, Dirk Andrè; Reiser, Maximilian; Becker, Christoph

2014-01-01

To determine the feasibility of a dynamic CT angiography-protocol with regard to simultaneous assessment of renal anatomy and function. 7 healthy potential kidney donors (58 ± 7 years) underwent a dynamic computed tomography angiography (CTA) using a 128-slice CT-scanner with continuous bi-directional table movement, allowing the coverage of a scan range of 18 cm within 1.75 sec. Twelve scans of the kidneys (n = 14) were acquired every 3.5 seconds with the aim to simultaneously obtain CTA and renal function data. Image quality was assessed quantitatively (HU-measurements) and qualitatively (grade 1-4, 1 = best). The glomerular filtration rate (GFR) was calculated by a modified Patlak method and compared with the split renal function obtained with renal scintigraphy. Mean maximum attenuation was 464 ± 58 HU, 435 ± 48 HU and 277 ± 29 HU in the aorta, renal arteries, and renal veins, respectively. The abdominal aorta and all renal vessels were depicted excellently (grade 1.0). The image quality score for cortex differentiation was 1.6 ± 0.49, for the renal parenchyma 2.4 ± 0.49. GFR obtained from dynamic CTA correlated well with renal scintigraphy with a correlation coefficient of r = 0.84; P = 0.0002 (n = 14). The average absolute deviation was 1.6 mL/min. The average effective dose was 8.96 mSv. Comprehensive assessment of renal anatomy and function is feasible using a single dynamic CT angiography examination. The proposed protocol may help to improve management in case of asymmetric kidney function as well as to simplify evaluation of potential living kidney donors.

[Vascular malformations in the Williams-Beuren syndrome: report of three new cases].

PubMed

Sator, Hicham; Rhouni, Fatima Ezzahra; Benjouad, Ibitihale; Rhouni, Fatima Ezzahra; Benjouad, Ibitihale; Dafiri, Rachida; Chat, Latifa

2016-01-01

The Williams-Beuren syndrome is a rare genetic disease. It combines classically specific facial dysmorphism, cardiovascular malformations and specific neuropsychological profile. We report three cases of Williams-Beuren syndrome in children with particular emphasis on vascular abnormalities observed on CT angiography and MR angiography.

Intraoperative computed tomography.

PubMed

Tonn, J C; Schichor, C; Schnell, O; Zausinger, S; Uhl, E; Morhard, D; Reiser, M

2011-01-01

Intraoperative computed tomography (iCT) has gained increasing impact among modern neurosurgical techniques. Multislice CT with a sliding gantry in the OR provides excellent diagnostic image quality in the visualization of vascular lesions as well as bony structures including skull base and spine. Due to short acquisition times and a high spatial and temporal resolution, various modalities such as iCT-angiography, iCT-cerebral perfusion and the integration of intraoperative navigation with automatic re-registration after scanning can be performed. This allows a variety of applications, e.g. intraoperative angiography, intraoperative cerebral perfusion studies, update of cerebral and spinal navigation, stereotactic procedures as well as resection control in tumour surgery. Its versatility promotes its use in a multidisciplinary setting. Radiation exposure is comparable to standard CT systems outside the OR. For neurosurgical purposes, however, new hardware components (e.g. a radiolucent headholder system) had to be developed. Having a different range of applications compared to intraoperative MRI, it is an attractive modality for intraoperative imaging being comparatively easy to install and cost efficient.

Selecting a CT scanner for cardiac imaging: the heart of the matter.

PubMed

Lewis, Maria A; Pascoal, Ana; Keevil, Stephen F; Lewis, Cornelius A

2016-09-01

Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA.

Cost-effectiveness of follow-up of pulmonary nodules incidentally detected on cardiac computed tomographic angiography in patients with suspected coronary artery disease.

PubMed

Goehler, Alexander; McMahon, Pamela M; Lumish, Heidi S; Wu, Carol C; Munshi, Vidit; Gilmore, Michael; Chung, Jonathan H; Ghoshhajra, Brian B; Mark, Daniel; Truong, Quynh A; Gazelle, G Scott; Hoffmann, Udo

2014-08-19

Pulmonary nodules (PNs) are often detected incidentally during coronary computed tomographic (CT) angiography, which is increasingly being used to evaluate patients with chest pain symptoms. However, the efficiency of following up on incidentally detected PN is unknown. We determined demographic and clinical characteristics of stable symptomatic patients referred for coronary CT angiography in whom incidentally detected PNs warranted follow-up. A validated lung cancer simulation model was populated with data from these patients, and clinical and economic consequences of follow-up per Fleischner guidelines versus no follow-up were simulated. Of the 3665 patients referred for coronary CT angiography, 591 (16%) had PNs requiring follow-up. The mean age of patients with PNs was 59±10 years; 66% were male; 67% had ever smoked; and 21% had obstructive coronary artery disease. The projected overall lung cancer incidence was 5.8% in these patients, but the majority died of coronary artery disease (38%) and other causes (57%). Follow-up of PNs was associated with a 4.6% relative reduction in cumulative lung cancer mortality (absolute mortality: follow-up, 4.33% versus non-follow-up, 4.54%), more downstream testing (follow-up, 2.34 CTs per patient versus non-follow-up, 1.01 CTs per patient), and an average increase in quality-adjusted life of 7 days. Costs per quality-adjusted life-year gained were $154 700 to follow up the entire cohort and $129 800 per quality-adjusted life-year when only smokers were included. Follow-up of PNs incidentally detected in patients undergoing coronary CT angiography for chest pain evaluation is associated with a small reduction in lung cancer mortality. However, significant downstream testing contributes to limited efficiency, as demonstrated by a high cost per quality-adjusted life-year, especially in nonsmokers. © 2014 American Heart Association, Inc.

Dual energy CT at the synchrotron: a piglet model for neurovascular research.

PubMed

Schültke, Elisabeth; Kelly, Michael E; Nemoz, Christian; Fiedler, Stefan; Ogieglo, Lissa; Crawford, Paul; Paterson, Jessica; Beavis, Cole; Esteve, Francois; Brochard, Thierry; Renier, Michel; Requardt, Herwig; Dallery, Dominique; Le Duc, Geraldine; Meguro, Kotoo

2011-08-01

Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360°. CT images were reconstructed from two half-acquisitions with 720 projections each. The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models. Copyright © 2010. Published by Elsevier Ireland Ltd.

Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

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

Cai Weixing; Zhao Binghui; Conover, David

2012-01-15

Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow.more » From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.« less

Outcomes of CSF spectrophotometry in cases of suspected subarachnoid haemorrhage with negative CT: two years retrospective review in a Birmingham hospital.

PubMed

Bakr, A; Silva, D; Cramb, R; Flint, G; Foroughi, M

2017-04-01

The aim of this study was to evaluate the adherence to current guidelines for the investigation of suspected subarachnoid haemorrhage and the prevalence and outcome of computed tomography (CT)-negative aneurysmal subarachnoid haemorrhage. A retrospective review in a single large tertiary referral centre. A total of 796 patients, aged 16-90 years, who underwent lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) following a negative or equivocal CT scan between January 2012 and November 2013 (23 months). Xanthochromia reports were obtained using the hospital's department of biochemistry database and clinical data for these patients were reviewed using patient notes. Of 796 CSF reports reviewed, 728 (91%) were negative for xanthochromia, 31 (4%) were positive and 37 (5%) were equivocal. Only 2 out of the 31 patients with positive spectrophotometry results were subsequently found to have an underlying aneurysm on CT angiography. A further 9 out of these 31 patients underwent digital subtraction angiography, with no cerebral aneurysms being detected. Amongst the 37 patients with equivocal xanthochromia reports, 13 underwent CT angiography and only 1 cerebral aneurysm was detected. In patients with clinically suspected SAH but who have negative or questionable CT findings, CSF analysis is likely to be negative in the vast majority of cases, which was 91% in our series. In patients yielding positive or equivocal CSF results the likelihood of an aneurysm being detected is low, amounting to three out of 68 or approximately one in 23 (approximately 4%). Overall in suspected SAH cases where CT scan has been negative, the rate for the detection of cerebral aneurysm is three out of 796 cases (0.4%).

Advanced CT acquisition protocol with a third-generation dual-source CT scanner and iterative reconstruction technique for comprehensive prosthetic heart valve assessment.

PubMed

Faure, Marguerite E; Swart, Laurens E; Dijkshoorn, Marcel L; Bekkers, Jos A; van Straten, Marcel; Nieman, Koen; Parizel, Paul M; Krestin, Gabriel P; Budde, Ricardo P J

2018-05-01

Multidetector CT (MDCT) is a valuable tool for functional prosthetic heart valve (PHV) assessment. However, radiation exposure remains a concern. We assessed a novel CT-acquisition protocol for comprehensive PHV evaluation at limited dose. Patients with a PHV were scanned using a third-generation dual-source CT scanner (DSCT) and iterative reconstruction technique (IR). Three acquisitions were obtained: a non-enhanced scan; a contrast-enhanced, ECG-triggered, arterial CT angiography (CTA) scan with reconstructions at each 5 % of the R-R interval; and a delayed high-pitch CTA of the entire chest. Image quality was scored on a five-point scale. Radiation dose was obtained from the reported CT dose index (CTDI) and dose length product (DLP). We analysed 43 CT examinations. Mean image quality score was 4.1±1.4, 4.7±0.5 and 4.2±0.6 for the non-contrast-enhanced, arterial and delayed acquisitions, respectively, with a total mean image quality of 4.3±0.7. Mean image quality for leaflet motion was 3.9±1.4. Mean DLP was 28.2±17.1, 457.3±168.6 and 68.5±47.2 mGy.cm for the non-contrast-enhanced (n=40), arterial (n=43) and delayed acquisition (n=43), respectively. The mean total DLP was 569±208 mGy.cm and mean total radiation dose was 8.3±3.0 mSv (n=43). Comprehensive assessment of PHVs is possible using DSCT and IR at moderate radiation dose. • Prosthetic heart valve dysfunction is a potentially life-threatening condition. • Dual-source CT can adequately assess valve leaflet motion and anatomy. • We assessed a comprehensive protocol with three acquisitions for PHV evaluation. • This protocol is associated with good image quality and limited dose.

Uncommon incidental pseudoaneurysm. Diagnostic and management challenges.

PubMed

Hadidy, Azmy M; Samara, Osama A; Takrouri, Heba S; Al-Ryalat, Nosaiba T; Al-Smady, Moaath M; Ryalat, Soukaina T; Abu-Khalaf, Mahmoad M

2009-08-01

To analyze patients with uncommon incidental pseudoaneurysms, secondary to non-catheterization causes, and to discuss the peculiar clinical spectrum, and focus on some aspects of difference from post-catheterization pseudoaneurysms. Eleven patients, 8 males and 3 females, were studied retrospectively in Jordan University Hospital, Amman, Jordan, between 2002-2008. Radiological studies performed included duplex sonography (DS), computed tomography (CT), conventional angiography, magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA). Pseudoaneurysms were most commonly encountered in young males (63.6%), especially in the lower limb vessels (36%). Clinical findings were suggestive of pseudoaneurysms in 27% of our cases. Four out of the 8 DS scans showed the neck of pseudoaneurysms, and the to and fro waveform, the strongest indicators for pseudoaneurysms. Both CT with intravenous contrast and angiography failed to establish the diagnosis in one out of 5 cases. The MRI with MRA showed the pseudoaneurysms in 2 patients that underwent the scan. Incidental pseudoaneurysms are considered following iatrogenic procedures, penetrating, or blunt traumas with variable delay time. Young healthy males are at increased risks, as opposed to elderly females with calcified vessels in post-catheterization cases. Duplex sonography is less sensitive in incidental than post-catheterization pseudoaneurysms. The CT scan with intravenous contrast has high accuracy in establishing the diagnosis in small, or medium sized pseudoaneurysms. The MRI and MRA are accurate valuable studies and comparable to conventional angiography.

[Dual energy CT angiography of the carotid arteries: quality, bone subtraction, and radiation dosage using tube voltage 80/140 kV versus 100/140 kV].

PubMed

Santos Armentia, E; Tardáguila de la Fuente, G; Castellón Plaza, D; Delgado Sánchez-Gracián, C; Prada González, R; Fernández Fernández, L; Tardáguila Montero, F

2014-01-01

To study the differences in vascular image quality, bone subtraction, and dose of radiation of dual energy CT angiography of the supraaortic trunks using different tube voltages. We reviewed the CT angiograms of the supraaortic trunks in 46 patients acquired with a 128-slice dual source CT scanner using two voltage protocols (80/140 kV and 100/140 kV). The "head bone removal" tool was used for postprocessing. We divided the arteries into 15 segments. In each segment, we evaluated the image quality of the vessels and the effectiveness of bone removal in multiplanar reconstructions (MPR) and in maximum intensity projections (MIP) with each protocol, analyzing the trabecular and cortical bones separately. We also evaluated the dose of radiation received. Of the 46 patients, 13 were studied using 80/140 kV and 33 with 100/140 kV. There were no significant differences between the two groups in age or sex. Image quality in four segments was better in the group examined with 100/140 kV. Cortical bone removal in MPR and MIP and trabecular bone removal in MIP were also better in the group examined with 100/140 kV. The dose of radiation received was significantly higher in the group examined with 100/140 kV (1.16 mSv with 80/140 kV vs. 1.59 mSv with 100/140 kV). Using 100/140 kV increases the dose of radiation but improves the quality of the study of arterial segments and bone subtraction. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Submillisievert standard-pitch CT pulmonary angiography with ultra-low dose contrast media administration: A comparison to standard CT imaging

PubMed Central

Mikat, Christian; Stenzel, Elena; Erfanian, Youssef; Wetter, Axel; Schlosser, Thomas; Forsting, Michael

2017-01-01

Objectives To evaluate the image quality and radiation dose of submillisievert standard-pitch CT pulmonary angiography (CTPA) with ultra-low dose contrast media administration in comparison to standard CTPA. Materials and methods Hundred patients (56 females, 44 males, mean age 69.6±15.4 years; median BMI: 26.6, IQR: 5.9) with suspected pulmonary embolism were examined with two different protocols (n = 50 each, group A: 80 kVp, ref. mAs 115, 25 ml of contrast medium; group B: 100 kVp, ref. mAs 150, 60 ml of contrast medium) using a dual-source CT equipped with automated exposure control. Objective and subjective image qualities, radiation exposure as well as the frequency of pulmonary embolism were evaluated. Results There was no significant difference in subjective image quality scores between two groups regarding pulmonary arteries (p = 0.776), whereby the interobserver agreement was excellent (group A: k = 0.9; group B k = 1.0). Objective image analysis revealed that signal intensities (SI), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the pulmonary arteries were equal or significantly higher in group B. There was no significant difference in the frequency of pulmonary embolism (p = 0.65). Using the low dose and low contrast media protocol resulted in a radiation dose reduction by 71.8% (2.4 vs. 0.7 mSv; p<0.001). Conclusions This 80 kVp standard pitch CTPA protocol with 25 ml contrast agent volume can obtain sufficient image quality to exclude or diagnose pulmonary emboli while reducing radiation dose by approximately 71%. PMID:29045463

Imaging in the evaluation of renovascular disease

PubMed Central

Roebuck, Derek J.; McLaren, Clare A.; Marks, Stephen D.

2009-01-01

Renovascular disease (RVD) is an important cause of hypertension in children, as it often is amenable to potentially curative treatment. Imaging aimed at finding RVD therefore needs to have high sensitivity so as not to miss important findings. Digital subtraction angiography is the gold standard investigation. Doppler ultrasonography, computed tomography (CT) angiography and magnetic resonance (MR) angiography can all be helpful, but none has, at present, high enough sensitivity to rule out RVD in a child with a suggestion of that diagnosis. PMID:19856000

A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation

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

Rupcich, Franco; Badal, Andreu; Kyprianou, Iacovos

Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360 Degree-Sign through anthropomorphic voxelized female chest and head (0 Degree-Sign and 30 Degree-Sign tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tablesmore » of normalized dose deposition for several radiosensitive organs quantifying the organ dose per emitted photon for each incident photon energy and projection angle for coronary angiography and brain perfusion acquisitions. The values in a table can be multiplied by an incident spectrum and number of photons at each projection angle and then summed across all energies and angles to estimate total organ dose. Scanner-specific organ dose may be approximated by normalizing the database-estimated organ dose by the database-estimated CTDI{sub vol} and multiplying by a physical CTDI{sub vol} measurement. Two examples are provided demonstrating how to use the tables to estimate relative organ dose. In the first, the change in breast and lung dose during coronary angiography CT scans is calculated for reduced kVp, angular tube current modulation, and partial angle scanning protocols relative to a reference protocol. In the second example, the change in dose to the eye lens is calculated for a brain perfusion CT acquisition in which the gantry is tilted 30 Degree-Sign relative to a nontilted scan. Results: Our database provides tables of normalized dose deposition for several radiosensitive organs irradiated during coronary angiography and brain perfusion CT scans. Validation results indicate total organ doses calculated using our database are within 1% of those calculated using Monte Carlo simulations with the same geometry and scan parameters for all organs except red bone marrow (within 6%), and within 23% of published estimates for different voxelized phantoms. Results from the example of using the database to estimate organ dose for coronary angiography CT acquisitions show 2.1%, 1.1%, and -32% change in breast dose and 2.1%, -0.74%, and 4.7% change in lung dose for reduced kVp, tube current modulated, and partial angle protocols, respectively, relative to the reference protocol. Results show -19.2% difference in dose to eye lens for a tilted scan relative to a nontilted scan. The reported relative changes in organ doses are presented without quantification of image quality and are for the sole purpose of demonstrating the use of the proposed database. Conclusions: The proposed database and calculation method enable the estimation of organ dose for coronary angiography and brain perfusion CT scans utilizing any spectral shape and angular tube current modulation scheme by taking advantage of the precalculated Monte Carlo simulation results. The database can be used in conjunction with image quality studies to develop optimized acquisition techniques and may be particularly beneficial for optimizing dual kVp acquisitions for which numerous kV, mA, and filtration combinations may be investigated.« less

Feasibility of high-pitch spiral dual-source CT angiography in children with complex congenital heart disease compared to retrospective-gated spiral acquisition.

PubMed

Li, T; Zhao, S; Liu, J; Yang, L; Huang, Z; Li, J; Luo, C; Li, X

2017-10-01

To investigate the use of second-generation dual-source high-pitch computed tomography in obtaining confident diagnostic image quality using a low radiation dose in young patients with congenital heart disease (CHD). From July 2014 to June 2016, 50 consecutive children <4 years with complex CHD underwent electrocardiography (ECG)-triggered dual-source computed tomography (CT). The patients were assigned randomly to two groups: high-pitch (pitch 3.4) spiral dual-source CT acquisition (group A) and retrospectively spiral dual-source CT acquisition (group B). The image quality, diagnostic accuracy, coronary artery origin, course demonstration, and radiation exposure were compared between the two groups. Fifty examinations were performed (group A, 25; group B, 25). There were no significant differences in image quality, diagnostic accuracy, coronary artery origin, and course demonstration between the two groups. The image quality scores were 1.3±0.4 in group A and 1.1±0.3 in group B (p=0.2). The diagnostic accuracy was 100% in both groups. The coronary arteries were traceable in 80% in group A and 84% in group B (p=0.7). A single coronary artery was identified in one case in group A and the left anterior descending (LAD) branch originated from the right coronary artery (RCA) in one case in group B. There were significant differences in the effective doses between the two groups (0.40±0.20 mSv in group A and 2.7±1.0 mSv in group B, p<0.05). Intra-cardiac and extra-cardiac malformation, coronary artery origin, and course malformation can be visualised clearly using a high-pitch ECG-triggered dual-source CT with a low radiation dose and good image quality in patients with CHD. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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

2014-12-01

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

CT coronary angiography and exercise ECG in a population with chest pain and low-to-intermediate pre-test likelihood of coronary artery disease.

PubMed

Maffei, Erica; Seitun, Sara; Martini, Chiara; Palumbo, Alessandro; Tarantini, Giuseppe; Berti, Elena; Grilli, Roberto; Tedeschi, Carlo; Messalli, Giancarlo; Guaricci, Andrea; Weustink, Annick C; Mollet, Nico Ra; Cademartiri, Filippo

2010-12-01

To evaluate diagnostic accuracy of exercise ECG (ex-ECG) versus 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in a population with low-to-intermediate pre-test likelihood of coronary artery disease (CAD). Retrospective single centre. Tertiary academic hospital. 177 consecutive patients (88 men, 89 women, mean age 53.5±7.6 years) with chest pain and low-to-intermediate pre-test likelihood of CAD were retrospectively enrolled. All patients underwent ex-ECG, CT-CA and invasive coronary angiography (ICA). A lumen diameter reduction of ≥50% was considered as significant stenosis for CT-CA. Ex-ECG was classified as positive, negative or non-diagnostic. were compared with ICA. Diagnostic accuracy of CT-CA and ex-ECG was calculated using ICA as the reference standard. A parallel comparative analysis using a cut-off value of 70% for significant lumen reduction was also performed too. Results ICA disclosed an absence of significant stenosis (≥50% luminal narrowing) in 85.3% (151/177) patients, single-vessel disease in 9.0% (16/177) patients and multivessel disease in 5.6% (10/177) patients. Prevalence of obstructive disease at ICA was 14.7% (26/177). Sensitivity, specificity, positive and negative predictive values at the patient level were 100.0%, 98.7%, 92.9%, 100%, respectively, for CT-CA and 46.2%, 16.6%, 8.7%, 64.1%, respectively, for ex-ECG. Agreement between CT-CA and ex-ECG was 20.9%. CT-CA performed equally well in men and women, while ex-ECG had a better performance in men. After considering the cut-off value of 70% for significant stenosis, the difference between CT-CA and ex-ECG remained significant (p<0.01), with a low agreement (21.5%). CT-CA provides optimal diagnostic performance in patients with atypical chest pain and low-to-intermediate risk of CAD. Ex-ECG has poor diagnostic accuracy in this population. Concerns are related to risk of radiation dose versus the benefits of correct disease stratification.

Computed tomography angiography in acute stroke (revisiting the 4Ps of imaging).

PubMed

Varadharajan, Shriram; Saini, Jitender; Acharya, Ullas V; Gupta, Arun Kumar

2016-02-01

Imaging in acute stroke has traditionally focussed on the 4Ps-parenchyma, pipes, perfusion, and penumbra-and has increasingly relied upon advanced techniques including magnetic resonance imaging to evaluate such patients. However, as per European Magnetic Resonance Forum estimates, the availability of magnetic resonance imaging scanners for the general population in India (0.5 per million inhabitants) is quite low as compared to Europe (11 per million) and United States (35 per million), with most of them only present in urban cities. On the other hand, computed tomography (CT) is more widely available and has reduced scanning duration. Computed tomography angiography of cervical and intracranial vessels is relatively simpler to perform with extended coverage and can provide all pertinent information required in such patients. This imaging review will discuss relevant imaging findings on CT angiography in patients with acute ischemic stroke through illustrated cases. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of Collaterals and Clot Burden Using Time-Resolved C-Arm Conebeam CT Angiography in the Angiography Suite: A Feasibility Study.

PubMed

Yang, P; Niu, K; Wu, Y; Struffert, T; Doerfler, A; Holter, P; Aagaard-Kienitz, B; Strother, C; Chen, G-H

2017-04-01

The assessment of collaterals and clot burden in patients with acute ischemic stroke provides important information about treatment options and clinical outcome. Time-resolved C-arm conebeam CT angiography has the potential to provide accurate and reliable evaluations of collaterals and clot burden in the angiographic suite. Experience with this technique is extremely limited, and feasibility studies are needed to validate this technique. Our purpose was to present such a feasibility study. Ten C-arm conebeam CT perfusion datasets from 10 subjects with acute ischemic stroke acquired before endovascular treatment were retrospectively processed to generate time-resolved conebeam CTA. From time-resolved conebeam CTA, 2 experienced readers evaluated the clot burden and collateral flow in consensus by using previously reported scoring systems and assessed the clinical value of this novel imaging technique independently. Interobserver agreement was analyzed by using the intraclass correlation analysis method. Clot burden and collateral flow can be assessed by using the commonly accepted scoring systems for all eligible cases. Additional clinical information (eg, the quantitative dynamic information of collateral flow) can be obtained from this new imaging technique. Two readers agreed that time-revolved C-arm conebeam CTA is the preferred method for evaluating the clot burden and collateral flow compared with other conventional imaging methods. Comprehensive evaluations of clot burden and collateral flow are feasible by using time-resolved C-arm conebeam CTA data acquired in the angiography suite. This technique further enriches the imaging tools in the angiography suite to enable a "one-stop- shop" imaging workflow for patients with acute ischemic stroke. © 2017 by American Journal of Neuroradiology.

Optimal reconstruction interval in dual source CT coronary angiography: a single-center experience in 285 patients

PubMed Central

Akgöz, Ayça; Akata, Deniz; Hazırolan, Tuncay; Karçaaltıncaba, Muşturay

2014-01-01

PURPOSE We aimed to evaluate the visibility of coronary arteries and bypass-grafts in patients who underwent dual source computed tomography (DSCT) angiography without heart rate (HR) control and to determine optimal intervals for image reconstruction. MATERIALS AND METHODS A total of 285 consecutive cases who underwent coronary (n=255) and bypass-graft (n=30) DSCT angiography at our institution were identified retrospectively. Patients with atrial fibrillation were excluded. Ten datasets in 10% increments were reconstructed in all patients. On each dataset, the visibility of coronary arteries was evaluated using the 15-segment American Heart Association classification by two radiologists in consensus. RESULTS Mean HR was 76±16.3 bpm, (range, 46–127 bpm). All coronary segments could be visualized in 277 patients (97.19%). On a segment-basis, 4265 of 4275 (99.77%) coronary artery segments were visible. All segments of 56 bypass-grafts in 30 patients were visible (100%). Total mean segment visibility scores of all coronary arteries were highest at 70%, 40%, and 30% intervals for all HRs. The optimal reconstruction intervals to visualize the segments of all three coronary arteries in descending order were 70%, 60%, 80%, and 30% intervals in patients with a mean HR <70 bpm; 40%, 70%, and 30% intervals in patients with a mean HR 70–100 bpm; and 40%, 50%, and 30% in patients with a mean HR >100 bpm. CONCLUSION Without beta-blocker administration, DSCT coronary angiography offers excellent visibility of vascular segments using both end-systolic and mid-late diastolic reconstructions at HRs up to 100 bpm, and only end-systolic reconstructions at HRs over 100 bpm. PMID:24834490

The dream of a one-stop-shop: Meta-analysis on myocardial perfusion CT.

PubMed

Pelgrim, Gert Jan; Dorrius, Monique; Xie, Xueqian; den Dekker, Martijn A M; Schoepf, U Joseph; Henzler, Thomas; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

2015-12-01

To determine the diagnostic performance of computed tomography (CT) perfusion techniques for the detection of functionally relevant coronary artery disease (CAD) in comparison to reference standards, including invasive coronary angiography (ICA), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). PubMed, Web of Knowledge and Embase were searched from January 1, 1998 until July 1, 2014. The search yielded 9475 articles. After duplicate removal, 6041 were screened on title and abstract. The resulting 276 articles were independently analyzed in full-text by two reviewers, and included if the inclusion criteria were met. The articles reporting diagnostic parameters including true positive, true negative, false positive and false negative were subsequently evaluated for the meta-analysis. Results were pooled according to CT perfusion technique, namely snapshot techniques: single-phase rest, single-phase stress, single-phase dual-energy stress and combined coronary CT angiography [rest] and single-phase stress, as well the dynamic technique: dynamic stress CT perfusion. Twenty-two articles were included in the meta-analysis (1507 subjects). Pooled per-patient sensitivity and specificity of single-phase rest CT compared to rest SPECT were 89% (95% confidence interval [CI], 82-94%) and 88% (95% CI, 78-94%), respectively. Vessel-based sensitivity and specificity of single-phase stress CT compared to ICA-based >70% stenosis were 82% (95% CI, 64-92%) and 78% (95% CI, 61-89%). Segment-based sensitivity and specificity of single-phase dual-energy stress CT in comparison to stress MRI were 75% (95% CI, 60-85%) and 95% (95% CI, 80-99%). Segment-based sensitivity and specificity of dynamic stress CT perfusion compared to stress SPECT were 77% (95% CI, 67-85) and 89% (95% CI, 78-95%). For combined coronary CT angiography and single-phase stress CT, vessel-based sensitivity and specificity in comparison to ICA-based >50% stenosis were 84% (95% CI, 67-93%) and 93% (95% CI, 89-96%). This meta-analysis shows considerable variation in techniques and reference standards for CT of myocardial blood supply. While CT seems sensitive and specific for evaluation of hemodynamically relevant CAD, studies so far are limited in size. Standardization of myocardial perfusion CT technique is essential. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Diagnostic performance of coronary CT angiography carried out with a novel whole-heart coverage high-definition CT scanner in patients with high heart rate.

PubMed

Andreini, Daniele; Mushtaq, Saima; Pontone, Gianluca; Conte, Edoardo; Guglielmo, Marco; Annoni, Andrea; Baggiano, Andrea; Formenti, Alberto; Ditali, Valentina; Mancini, Maria Elisabetta; Zanchi, Simone; Melotti, Eleonora; Trabattoni, Daniela; Montorsi, Piero; Ravagnani, Paolo Mario; Fiorentini, Cesare; Bartorelli, Antonio L; Pepi, Mauro

2018-04-15

Aim of the study was to evaluate image quality, radiation exposure and diagnostic accuracy of coronary CT angiography (CCTA) performed with a novel cardiac CT scanner in patients with very high heart rate (HR). We prospectively enrolled 202 patients (111 men, mean age 66±8years) with suspected coronary artery disease who underwent CCTA with a whole-organ volumetric CT scanner. The HR during the scan was ≥80bpm in 100 patients (Group 1), while it was ≤65bpm in the remaining 102 patients (Group 2). In all patients, image quality score and coronary interpretability were evaluated and effective dose (ED) was recorded. In 86 of the 202 enrolled patients (40 patients in Group 1, 46 patients in Group 2) who were referred for a clinically indicated invasive coronary angiography (ICA) within 6months, diagnostic accuracy of CCTA vs. ICA was evaluated. Mean image quality and coronary interpretability were very high in both Groups (Likert=3.35 vs. 3.39 and 97.3% [1542/1584 segments] and 98% [1569/1600 segments] in Group 1 and Group 2, respectively). Mean ED was lower in Group 2 (1.1±0.5mSv) compared to Group 1 (2.9±1.6mSv). In Group 1, sensitivity and specificity of CCTA for detection of >50% stenosis vs. ICA were 95.2% and 98.9% in a segment-based analysis and 100% and 81.8% in a patient-based analysis, respectively. The whole organ high-definition CT scanner allows evaluating coronary arteries in patients with high HR with excellent image quality, coronary interpretability and low radiation exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed

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

2011-03-01

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

Pitfalls in 16-detector row CT of the coronary arteries.

PubMed

Nakanishi, Tadashi; Kayashima, Yasuyo; Inoue, Rintaro; Sumii, Kotaro; Gomyo, Yukihiko

2005-01-01

Recently developed 16-detector row computed tomography (CT) has been introduced as a reliable noninvasive imaging modality for evaluating the coronary arteries. In most cases, with appropriate premedication that includes beta-blockers and nitroglycerin, ideal data sets can be acquired from which to obtain excellent-quality coronary CT angiograms, most often with multiplanar reformation, thin-slab maximum intensity projection, and volume rendering. However, various artifacts associated with data creation and reformation, postprocessing methods, and image interpretation can hamper accurate diagnosis. These artifacts can be related to pulsation (nonassessable segments, pseudostenosis) as well as rhythm disorders, respiratory issues, partial volume averaging effect, high-attenuation entities, inappropriate scan pitch, contrast material enhancement, and patient body habitus. Some artifacts have already been resolved with technical advances, whereas others represent partially inherent limitations of coronary CT angiography. Familiarity with the pitfalls of coronary angiography with 16-detector row CT, coupled with the knowledge of both the normal anatomy and anatomic variants of the coronary arteries, can almost always help radiologists avoid interpretive errors in the diagnosis of coronary artery stenosis. (c) RSNA, 2005.

Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3(rd) generation dual-source CT.

PubMed

Mangold, Stefanie; Wichmann, Julian L; Schoepf, U Joseph; Poole, Zachary B; Canstein, Christian; Varga-Szemes, Akos; Caruso, Damiano; Bamberg, Fabian; Nikolaou, Konstantin; De Cecco, Carlo N

2016-10-01

To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3(rd) generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120 kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9 % of examinations without significant differences for proximal and distal attenuation (all p ≥ .0516), whereas image noise was rated significantly higher at 70 kV compared to ≥100 kV (all p < .0266). However, no significant differences were observed in SNR or CNR at 70-120 kV (all p ≥ .0829). Mean ED at 70-120 kV was 1.5 ± 1.2 mSv, 2.4 ± 1.5 mSv, 3.6 ± 2.7 mSv, 5.9 ± 4.0 mSv, 7.9 ± 4.2 mSv, and 10.7 ± 4.1 mSv, respectively (all p ≤ .0414). Correlation analysis showed a moderate association between tube voltage and BMI (r = .639). ATVS allows individual tube voltage adaptation for CCTA performed with 3(rd) generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. • Automated tube voltage selection allows an individual tube voltage adaption in CCTA. • A tube voltage-based reduction of contrast medium volume is feasible. • Image quality was maintained while radiation exposure was significantly decreased. • A moderate association between tube voltage and body mass index was found.

Learning-based automatic detection of severe coronary stenoses in CT angiographies

NASA Astrophysics Data System (ADS)

Melki, Imen; Cardon, Cyril; Gogin, Nicolas; Talbot, Hugues; Najman, Laurent

2014-03-01

3D cardiac computed tomography angiography (CCTA) is becoming a standard routine for non-invasive heart diseases diagnosis. Thanks to its high negative predictive value, CCTA is increasingly used to decide whether or not the patient should be considered for invasive angiography. However, an accurate assessment of cardiac lesions using this modality is still a time consuming task and needs a high degree of clinical expertise. Thus, providing automatic tool to assist clinicians during the diagnosis task is highly desirable. In this work, we propose a fully automatic approach for accurate severe cardiac stenoses detection. Our algorithm uses the Random Forest classi cation to detect stenotic areas. First, the classi er is trained on 18 CT cardiac exams with CTA reference standard. Then, then classi cation result is used to detect severe stenoses (with a narrowing degree higher than 50%) in a 30 cardiac CT exam database. Features that best captures the di erent stenoses con guration are extracted along the vessel centerlines at di erent scales. To ensure the accuracy against the vessel direction and scale changes, we extract features inside cylindrical patterns with variable directions and radii. Thus, we make sure that the ROIs contains only the vessel walls. The algorithm is evaluated using the Rotterdam Coronary Artery Stenoses Detection and Quantication Evaluation Framework. The evaluation is performed using reference standard quanti cations obtained from quantitative coronary angiography (QCA) and consensus reading of CTA. The obtained results show that we can reliably detect severe stenosis with a sensitivity of 64%.

Sublingual Nitroglycerin Administration in Coronary Computed Tomography Angiography: a Systematic Review.

PubMed

Takx, Richard A P; Suchá, Dominika; Park, Jakob; Leiner, Tim; Hoffmann, Udo

2015-12-01

To systematically investigate the literature for the influence of sublingual nitroglycerin administration on coronary diameter, the number of evaluable segments, image quality, heart rate and blood pressure, and diagnostic accuracy of coronary computed tomography (CT) angiography. A systematic search was performed in PubMed, EMBASE and Web of Science. The studies were evaluated for the effect of sublingual nitroglycerin on coronary artery diameter, evaluable segments, objective and subjective image quality, systemic physiological effects and diagnostic accuracy. Due to the heterogeneous reporting of outcome measures, a narrative synthesis was applied. Of the 217 studies identified, nine met the inclusion criteria: seven reported on the effect of nitroglycerin on coronary artery diameter, six on evaluable segments, four on image quality, five on systemic physiological effects and two on diagnostic accuracy. Sublingual nitroglycerin administration resulted in an improved evaluation of more coronary segments, in particular, in smaller coronary branches, better image quality and improved diagnostic accuracy. Side effects were mild and were alleviated without medical intervention. Sublingual nitroglycerin improves the coronary diameter, the number of assessable segments, image quality and diagnostic accuracy of coronary CT angiography without major side effects or systemic physiological changes. • Sublingual nitroglycerin administration results in significant coronary artery dilatation. • Nitroglycerin increases the number of evaluable coronary branches. • Image quality is improved the most in smaller coronary branches. • Nitroglycerin increases the diagnostic accuracy of coronary CT angiography. • Most side effects are mild and do not require medical intervention.

Marketing cardiac CT programs.

PubMed

Scott, Jason

2010-01-01

There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

Image fusion-guided portal vein puncture during transjugular intrahepatic portosystemic shunt placement.

PubMed

Rouabah, K; Varoquaux, A; Caporossi, J M; Louis, G; Jacquier, A; Bartoli, J M; Moulin, G; Vidal, V

2016-11-01

The purpose of this study was to assess the feasibility and utility of image fusion (Easy-TIPS) obtained from pre-procedure CT angiography and per-procedure real-time fluoroscopy for portal vein puncture during transjugular intrahepatic portosystemic shunt (TIPS) placement. Eighteen patients (15 men, 3 women) with a mean age of 63 years (range: 48-81 years; median age, 65 years) were included in the study. All patients underwent TIPS placement by two groups of radiologists (one group with radiologists of an experience<3 years and one with an experience≥3 years) using fusion imaging obtained from three-dimensional computed tomography angiography of the portal vein and real-time fluoroscopic images of the portal vein. Image fusion was used to guide the portal vein puncture during TIPS placement. At the end of the procedure, the interventional radiologists evaluated the utility of fusion imaging for portal vein puncture during TIPS placement. Mismatch between three-dimensional computed tomography angiography and real-time fluoroscopic images of the portal vein on image fusion was quantitatively analyzed. Posttreatment CT time, number of the puncture attempts, total radiation exposure and radiation from the retrograde portography were also recorded. Image fusion was considered useful for portal vein puncture in 13/18 TIPS procedures (72%). The mean posttreatment time to obtain fusion images was 16.4minutes. 3D volume rendered CT angiography images was strictly superimposed on direct portography in 10/18 procedures (56%). The mismatch mean value was 0.69cm in height and 0.28cm laterally. A mean number of 4.6 portal vein puncture attempts was made. Eight patients required less than three attempts. The mean radiation dose from retrograde portography was 421.2dGy.cm 2 , corresponding to a mean additional exposure of 19%. Fusion imaging resulting from image fusion from pre-procedural CT angiography is feasible, safe and makes portal puncture easier during TIPS placement. Copyright © 2016 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

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

Cavagna, Enrico; D'Andrea, Paolo; Schiavon, Francesco

Purpose: To evaluate failing hemodialysis arteriovenous fistulas with helical CT angiography (CTA), MR angiography (MRA), and digital subtraction angiography (DSA), and to compare the efficacy of the three techniques in detecting the number, location, grade, and extent of stenoses and in assessing the technical results of percutaneous transluminal angioplasty (PTA) and stenting.Methods: Thirteen patients with Brescia-Cimino arteriovenous fistula malfunction underwent MRA and CTA of the fistula and, within 1 week, DSA. A total of 11 PTAs were performed; in three cases an MR-compatible stent was placed. DSA served as the gold standard for comparison in all patients. The presence, site,more » and number of stenoses or occlusions and the technical results of percutaneous procedures were assessed with DSA, CTA, and MRA.Results: MRA underestimated a single stenosis in one patient; CTA and MRA did not overestimate any stenosis. Significant artifacts related to stent geometry and/or underlying metal were seen in MRA sequences in two cases.Conclusions: CT and MRI can provide information regarding the degree of vascular impairment, helping to stratify patients into those who can have PTA (single or multiple stenoses) versus those who require an operative procedure (occlusion). Conventional angiography can be reserved for candidates for percutaneous intervention.« less

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography.

PubMed

Liu, Xiujuan; Tao, Haiquan; Xiao, Xigang; Guo, Binbin; Xu, Shangcai; Sun, Na; Li, Maotong; Xie, Li; Wu, Changjun

2018-07-01

This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging. Copyright © 2018 Elsevier B.V. All rights reserved.

Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage.

PubMed

Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Yoshiya, Kazuhisa; Shimazu, Takeshi; Tomiyama, Noriyuki

2014-04-01

Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage.

One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography.

PubMed

Yamasaki, Yuzo; Nagao, Michinobu; Kawanami, Satoshi; Kamitani, Takeshi; Sagiyama, Koji; Yamanouchi, Torahiko; Sakamoto, Ichiro; Yamamura, Kenichiro; Yabuuchi, Hidetake; Honda, Hiroshi

2017-02-01

To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. • Quantification of left-to-right shunting can be performed reliably and accurately by CT. • The sizes of defects and rims can be measured accurately using 256-slice CT. • 256-slice CT permits pretreatment evaluation of ASD non-invasively and comprehensively.

Influence of Nitroglycerin on Coronary Artery CT Imaging in Cardiovascular Diseases.

PubMed

Zhang, PeiYing

2015-06-01

This study was designed to observe the influence of nitroglycerin on the quality of coronary artery imaging when CT is used for coronary heart disease. Data of 150 cardiology inpatients were collected from Department of Cardiology of our hospital from November 2013 to August 2014 for this study. All the subjects were diagnosed with multislice CT and coronary angiography after admission. The patients were then divided into two groups, the nitroglycerin group of 75 cases who took nitroglycerin and the control group of 75 cases who took no nitroglycerin. A total of 320 mixed plaques (pathological characteristics of calcified ingredients and non-calcified ingredients), including 290 calcified mixed plaques of type I, (mainly with calcified plaques and purely calcified plaques), and 30 non-calcified plaques of type II, (mainly with non-calcified ingredients or pure non-calcified plaques) were scanned. CT coronary angiography showed that the detection rate of type I plaque was 65.5 % in control group and 34.8 % in nitroglycerin group, whereas the detection rate of type II plaque was 30 % in control group and 70 % in nitroglycerin group. The difference for both type I and type II was statistically significant (p < 0.05). In Comparison with control group, the increase in diameter of 1-13 vascular segments in nitroglycerin group was statistically significant (p < 0.05). Taking nitroglycerin can improve the display resolution of coronary angiography, and shows better display for type I than type II plaques.

Accuracy and Specific Value of Cardiovascular 3D-Models in Pediatric CT-Angiography.

PubMed

Hammon, Matthias; Rompel, Oliver; Seuss, Hannes; Dittrich, Sven; Uder, Michael; Rüffer, Andrè; Cesnjevar, Robert; Ehret, Nicole; Glöckler, Martin

2017-12-01

Computed tomography (CT)-angiography is routinely performed prior to catheter-based and surgical treatment in congenital heart disease. To date, little is known about the accuracy and advantage of different 3D-reconstructions in CT-data. Exact anatomical information is crucial. We analyzed 35 consecutive CT-angiographies of infants with congenital heart disease. All datasets are reconstructed three-dimensionally using volume rendering technique (VRT) and threshold-based segmentation (stereolithographic model, STL). Additionally, the two-dimensional maximum intensity projection (MIP) reconstructs two-dimensional data. In each dataset and resulting image, measurements of vascular diameters for four different vessels were estimated and compared to the reference standard, measured via multiplanar reformation (MPR). The resulting measurements obtained via the STL-images, MIP-images, and the VRT-images were compared with the reference standard. There was a significant difference (p < 0.05) between measurements. The mean difference was 0.0 for STL-images, -0.1 for MIP-images, and -0.3 for VRT-images. The range of the differences was -0.7 to 1.0 mm for STL-images, -0.6 to 0.5 mm for MIP-images and -1.1 to 0.7 mm for VRT-images. There was an excellent correlation between the STL-, MIP-, VRT-measurements, and the reference standard. Inter-reader reliability was excellent (p < 0.01). STL-models of cardiovascular structures are more accurate than the traditional VRT-models. Additionally, they can be standardized and are reproducible.

Acute Subdural Hematoma and Subarachnoid Hemorrhage Caused by Ruptured Cortical Artery Aneurysm: Case Report and Review of Literature

PubMed Central

Shekarchizadeh, Ahmad; Masih, Saburi; Reza, Pourkhalili; Seif, Bahram

2017-01-01

The present report describes an acute subdural hematoma (ASDH) associated with subarachnoid hemorrhage (SAH), due to ruptured cortical aneurysm. To our knowledge, extremely rare cases of this sort have been reported so far. A 23-year-old male patient without previous trauma presented with severe headache and rapidly decreasing level of consciousness to decerebrate status. Computed tomography (CT) scan has demonstrated an ASDH together with SAH. Hematoma has immediately been evacuated without any evaluation by angiography. After evacuation of the thick subdural clot, a 10-mm aneurysm was revealed on a precentral artery of frontal cortex, which was ligated. However, after 35 days the patient discharged with left side hemiparesis and dysphasia, and just after several months of admission he got symptom free. Ruptured cortical aneurysm should be considered as one of the causes of spontaneous ASDH. Vascular anomaly investigations are suggested for these cases, thus CT angiography or digital subtraction angiography has to be considered if clinical condition allows. PMID:28503501

Limited utility of MRA for acute bowel ischemia after portal venous phase CT.

PubMed

Shetty, Anup S; Mellnick, Vincent M; Raptis, Constantine; Loch, Ronald; Owen, Joseph; Bhalla, Sanjeev

2015-10-01

Mesenteric ischemia and ischemic colitis are uncommon but potentially life-threatening causes of acute abdominal pain. Portal venous phase computed tomography (CT) is routinely ordered in the emergency room setting for abdominal pain, but subsequent MR angiography may be requested for additional evaluation of the mesenteric vasculature. We compare the concordance of CT and magnetic resonance angiography (MRA) for acute bowel ischemia. Thirty-two patients who underwent contrast-enhanced MRA for bowel ischemia after having undergone CT evaluation within the preceding 2 weeks were identified. A retrospective review of imaging, treatment history, surgical, and pathology reports was conducted. Two radiologists each reviewed the imaging studies in a blinded fashion. Ten cases of bowel ischemia were confirmed by endoscopy and/or surgical pathology. CT correctly identified bowel findings in all cases. Intraobserver agreement between CT and MRA for all vessels was 0.68 and 0.63, highest for the superior mesenteric artery. Interobserver agreement was 0.74 for MRA and 0.78 for CT. Vascular findings were only directly mentioned in 10 of 32 CT reports (and 7 of 10 cases with confirmed bowel ischemia). MRA only detected two additional or alternative diagnoses. Portal venous phase CT and MRA demonstrate a high degree of concordance for vascular evaluation. Reviewed CT examinations were sufficient to assess the patency of the mesenteric vasculature, but vascular findings were not reported in most cases. A direct description within the report may have obviated the request for further MR imaging. MRA adds little value after portal venous CT in assessing bowel ischemia.

Pituitary Imaging.

PubMed

Pressman, Barry D

2017-09-01

Modern pituitary imaging is MRI. However, computed tomography (CT) still has limited usefulness. In addition, because CT offers much better bone detail and calcium detection, there are some cases in which such additional information is necessary. Before the advent of CT, plain radiography, pneumoencephalography, and angiography were used to diagnose pituitary masses. More recently, CT, and then especially MRI, made it possible to primarily delineate lesions within and around the pituitary gland rather than depend on secondary information that could only suggest their presence. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of 3×2 tables with an intention to diagnose approach to assess clinical performance of diagnostic tests: meta-analytical evaluation of coronary CT angiography studies

PubMed Central

Schuetz, Georg M; Schlattmann, Peter

2012-01-01

Objective To determine whether a 3×2 table, using an intention to diagnose approach, is better than the “classic” 2×2 table at handling transparent reporting and non-evaluable results, when assessing the accuracy of a diagnostic test. Design Based on a systematic search for diagnostic accuracy studies of coronary computed tomography (CT) angiography, full texts of relevant studies were evaluated to determine whether they could calculate an alternative 3×2 table. To quantify an overall effect, we pooled diagnostic accuracy values according to a meta-analytical approach. Data sources Medline (via PubMed), Embase (via Ovid), and ISI Web of Science electronic databases. Eligibility criteria Prospective English or German language studies comparing coronary CT with conventional coronary angiography in all patients and providing sufficient data for a patient level analysis. Results 120 studies (10 287 patients) were eligible. Studies varied greatly in their approaches to handling non-evaluable findings. We found 26 studies (including 2298 patients) that allowed us to calculate both 2×2 tables and 3×2 tables. Using a bivariate random effects model, we compared the 2×2 table with the 3×2 table, and found significant differences for pooled sensitivity (98.2 (95% confidence interval 96.7 to 99.1) v 92.7 (88.5 to 95.3)), area under the curve (0.99 (0.98 to 1.00) v 0.93 (0.91 to 0.95)), positive likelihood ratio (9.1 (6.2 to 13.3) v 4.4 (3.3 to 6.0)), and negative likelihood ratio (0.02 (0.01 to 0.04) v 0.09 (0.06 to 0.15); (P<0.05)). Conclusion Parameters for diagnostic performance significantly decrease if non-evaluable results are included by a 3×2 table for analysis (intention to diagnose approach). This approach provides a more realistic picture of the clinical potential of diagnostic tests. PMID:23097549

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

Ierardi, Anna Maria; Duka, Ejona; Radaelli, Alessandro

AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImagemore » co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration.« less

Fractional flow reserve by computerized tomography and subsequent coronary revascularization

PubMed Central

Packard, René R. Sevag; Li, Dong; Budoff, Matthew J.; Karlsberg, Ronald P.

2017-01-01

Aims Fractional flow reserve by computerized tomography (FFR-CT) provides non-invasive functional assessment of the hemodynamic significance of coronary artery stenosis. We determined the FFR-CT values, receiver operator characteristic (ROC) curves, and predictive ability of FFR-CT for actual standard of care guided coronary revascularization. Methods and results Consecutive outpatients who underwent coronary CT angiography (coronary CTA) followed by invasive angiography over a 24-month period from 2012 to 2014 were identified. Studies that fit inclusion criteria (n = 75 patients, mean age 66, 75% males) were sent for FFR-CT analysis, and results stratified by coronary artery calcium (CAC) scores. Coronary CTA studies were re-interpreted in a blinded manner, and baseline FFR-CT values were obtained retrospectively. Therefore, results did not interfere with clinical decision-making. Median FFR-CT values were 0.70 in revascularized (n = 69) and 0.86 in not revascularized (n = 138) coronary arteries (P < 0.001). Using clinically established significance cut-offs of FFR-CT ≤0.80 and coronary CTA ≥70% stenosis for the prediction of clinical decision-making and subsequent coronary revascularization, the positive predictive values were 74 and 88% and negative predictive values were 96 and 84%, respectively. The area under the curve (AUC) for all studied territories was 0.904 for coronary CTA, 0.920 for FFR-CT, and 0.941 for coronary CTA combined with FFR-CT (P = 0.001). With increasing CAC scores, the AUC decreased for coronary CTA but remained higher for FFR-CT (P < 0.05). Conclusion The addition of FFR-CT provides a complementary role to coronary CTA and increases the ability of a CT-based approach to identify subsequent standard of care guided coronary revascularization. PMID:27469588

Image Fusion for Radiosurgery, Neurosurgery and Hypofractionated Radiotherapy.

PubMed

Inoue, Hiroshi K; Nakajima, Atsushi; Sato, Hiro; Noda, Shin-Ei; Saitoh, Jun-Ichi; Suzuki, Yoshiyuki

2015-03-01

Precise target detection is essential for radiosurgery, neurosurgery and hypofractionated radiotherapy because treatment results and complication rates are related to accuracy of the target definition. In skull base tumors and tumors around the optic pathways, exact anatomical evaluation of cranial nerves are important to avoid adverse effects on these structures close to lesions. Three-dimensional analyses of structures obtained with MR heavy T2-images and image fusion with CT thin-sliced sections are desirable to evaluate fine structures during radiosurgery and microsurgery. In vascular lesions, angiography is most important for evaluations of whole structures from feeder to drainer, shunt, blood flow and risk factors of bleeding. However, exact sites and surrounding structures in the brain are not shown on angiography. True image fusions of angiography, MR images and CT on axial planes are ideal for precise target definition. In malignant tumors, especially recurrent head and neck tumors, biologically active areas of recurrent tumors are main targets of radiosurgery. PET scan is useful for quantitative evaluation of recurrences. However, the examination is not always available at the time of radiosurgery. Image fusion of MR diffusion images with CT is always available during radiosurgery and useful for the detection of recurrent lesions. All images are fused and registered on thin sliced CT sections and exactly demarcated targets are planned for treatment. Follow-up images are also able to register on this CT. Exact target changes, including volume, are possible in this fusion system. The purpose of this review is to describe the usefulness of image fusion for 1) skull base, 2) vascular, 3) recurrent target detection, and 4) follow-up analyses in radiosurgery, neurosurgery and hypofractionated radiotherapy.

Image Fusion for Radiosurgery, Neurosurgery and Hypofractionated Radiotherapy

PubMed Central

Nakajima, Atsushi; Sato, Hiro; Noda, Shin-ei; Saitoh, Jun-ichi; Suzuki, Yoshiyuki

2015-01-01

Precise target detection is essential for radiosurgery, neurosurgery and hypofractionated radiotherapy because treatment results and complication rates are related to accuracy of the target definition. In skull base tumors and tumors around the optic pathways, exact anatomical evaluation of cranial nerves are important to avoid adverse effects on these structures close to lesions. Three-dimensional analyses of structures obtained with MR heavy T2-images and image fusion with CT thin-sliced sections are desirable to evaluate fine structures during radiosurgery and microsurgery. In vascular lesions, angiography is most important for evaluations of whole structures from feeder to drainer, shunt, blood flow and risk factors of bleeding. However, exact sites and surrounding structures in the brain are not shown on angiography. True image fusions of angiography, MR images and CT on axial planes are ideal for precise target definition. In malignant tumors, especially recurrent head and neck tumors, biologically active areas of recurrent tumors are main targets of radiosurgery. PET scan is useful for quantitative evaluation of recurrences. However, the examination is not always available at the time of radiosurgery. Image fusion of MR diffusion images with CT is always available during radiosurgery and useful for the detection of recurrent lesions. All images are fused and registered on thin sliced CT sections and exactly demarcated targets are planned for treatment. Follow-up images are also able to register on this CT. Exact target changes, including volume, are possible in this fusion system. The purpose of this review is to describe the usefulness of image fusion for 1) skull base, 2) vascular, 3) recurrent target detection, and 4) follow-up analyses in radiosurgery, neurosurgery and hypofractionated radiotherapy. PMID:26180676

Influence of the motion correction algorithm on the quality and interpretability of images of single-source 64-detector coronary CT angiography among patients grouped by heart rate.

PubMed

Machida, Haruhiko; Lin, Xiao-Zhu; Fukui, Rika; Shen, Yun; Suzuki, Shigeru; Tanaka, Isao; Ishikawa, Takuya; Tate, Etsuko; Ueno, Eiko

2015-02-01

We retrospectively investigated the effect of the motion correction algorithm (MCA) on image quality and interpretability by heart rate (HR) in coronary CT angiography (CCTA). For 105 patients (6 HR groups) undergoing CCTA, 2 readers independently graded the image quality of the 4 major coronary arteries reconstructed with and without MCA at diastole with HR ≤64 bpm and at systole and diastole ≥65 bpm using a 5-point scale. For each HR group and cardiac phase, we compared per-vessel and per-segment image quality using Wilcoxon signed rank test and percentages of interpretable image quality (scores 3-5) among without MCA at diastole with HR ≤64 bpm, as a reference, with MCA at diastole ≤69 bpm and at systole 70-79 bpm using the chi-square test. The motion correction algorithm reconstruction provided similar or better image quality and interpretability in all groups, with 96-100 % per-vessel (P = 0.008 for the right coronary artery; otherwise, P > 0.05) and 99 % per-segment interpretable image quality (P = 0.0002) at diastole with HR ≤69 bpm and at systole 70-79 bpm compared to the reference (88-100 and 97 %, respectively). MCA reconstruction preserved image quality and interpretability of CCTA with HR ≤79 bpm.

F-18 Choline PET angiography of the pelvic arteries: evaluation of image quality and comparison with contrast-enhanced CT.

PubMed

Freesmeyer, Martin; Drescher, Robert

2015-01-01

The purpose was to show the feasibility of F-18 choline positron emission tomography (PET) angiography for the evaluation of abdominal and iliac arteries. Thirty-five patients were examined and image quality was scored. Findings were correlated with contrast-enhanced computed tomography. Image quality was best in the aorta and common iliac arteries (100% and 93% of vessels). Negative predictive values of PET angiography were excellent (100%), and positive predictive values were impaired by disease overestimation. PET angiography is technically feasible and of good image quality in large arteries. In selected cases, it may become an alternative to established angiographic methods. Copyright © 2015 Elsevier Inc. All rights reserved.

Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

PubMed

Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

2005-03-01

The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

18F-FDG-PET/CT Angiography for the Diagnosis of Infective Endocarditis.

PubMed

Roque, A; Pizzi, M N; Cuéllar-Calàbria, H; Aguadé-Bruix, S

2017-02-01

This article reviews the current imaging role of 18 F-fluordeoxyglucose positron emission computed tomography ( 18 F-FDG-PET/CT) combined with cardiac CT angiography (CTA) in infective endocarditis and discusses the strengths and limitations of this technique. The diagnosis of infective endocarditis affecting prosthetic valves and intracardiac devices is challenging because echocardiography and, therefore, the modified Duke criteria have well-recognized limitations in this clinical scenario. The high sensitivity of 18 F-FDG-PET/CT for the detection of infection associated with the accurate definition of structural damage by gated cardiac CTA in a combined technique (PET/CTA) has provided a significant increase in diagnostic sensitivity for the detection of IE. PET/CTA has proven to be a useful diagnostic tool in patients with suspected infective endocarditis. The additional information provided by this technique improves diagnostic performance in prosthetic valve endocarditis when it is used in combination with the Duke criteria. The findings obtained in PET/CTA studies have been included as a major criterion in the recently updated diagnostic algorithm in infective endocarditis guidelines.

Impact of routine cerebral CT angiography on treatment decisions in infective endocarditis.

PubMed

Meshaal, Marwa Sayed; Kassem, Hussein Heshmat; Samir, Ahmad; Zakaria, Ayman; Baghdady, Yasser; Rizk, Hussein Hassan

2015-01-01

Infective endocarditis (IE) is commonly complicated by cerebral embolization and hemorrhage secondary to intracranial mycotic aneurysms (ICMAs). These complications are associated with poor outcome and may require diagnostic and therapeutic plans to be modified. However, routine screening by brain CT and CT angiography (CTA) is not standard practice. We aimed to study the impact of routine cerebral CTA on treatment decisions for patients with IE. From July 2007 to December 2012, we prospectively recruited 81 consecutive patients with definite left-sided IE according to modified Duke's criteria. All patients had routine brain CTA conducted within one week of admission. All patients with ICMA underwent four-vessel conventional angiography. Invasive treatment was performed for ruptured aneurysms, aneurysms ≥ 5 mm, and persistent aneurysms despite appropriate therapy. Surgical clipping was performed for leaking aneurysms if not amenable to intervention. The mean age was 30.43 ± 8.8 years and 60.5% were males. Staph aureus was the most common organism (32.3%). Among the patients, 37% had underlying rheumatic heart disease, 26% had prosthetic valves, 23.5% developed IE on top of a structurally normal heart and 8.6% had underlying congenital heart disease. Brain CT/CTA revealed that 51 patients had evidence of cerebral embolization, of them 17 were clinically silent. Twenty-six patients (32%) had ICMA, of whom 15 were clinically silent. Among the patients with ICMAs, 11 underwent endovascular treatment and 2 underwent neurovascular surgery. The brain CTA findings prompted different treatment choices in 21 patients (25.6%). The choices were aneurysm treatment before cardiac surgery rather than at follow-up, valve replacement by biological valve instead of mechanical valve, and withholding anticoagulation in patients with prosthetic valve endocarditis for fear of aneurysm rupture. Routine brain CT/CTA resulted in changes in the treatment plan in a significant proportion of patients with IE, even those without clinically evident neurological disease. Routine brain CT/CTA may be indicated in all hospitalized patients with IE.

3.0Tesla magnetic resonance angiography (MRA) for comprehensive renal evaluation of living renal donors: pilot study with computerized tomography angiography (CTA) comparison.

PubMed

Gulati, Mittul; Dermendjian, Harout; Gómez, Ana M; Tan, Nelly; Margolis, Daniel J; Lu, David S; Gritsch, H Albin; Raman, Steven S

2016-01-01

Most living related donor (LRD) kidneys are harvested laparoscopically. Renal vascular anatomy helps determine donor suitability for laparoscopic nephrectomy. Computed tomography angiography (CTA) is the current gold standard for preoperative imaging; magnetic resonance angiography (MRA) offers advantages including lack of ionizing radiation and lower incidence of contrast reactions. We evaluated 3.0T MRA for assessing renal anatomy of LRDs. Thirty consecutive LRDs underwent CTA followed by 3.0T MRA. Data points included number and branching of vessels, incidental findings, and urothelial opacification. Studies were individually evaluated by three readers blinded to patient data. Studies were reevaluated in consensus with discrepancies revealed, and final consensus results were labeled "truth". Compared with consensus "truth", both computed tomography (CT) and magnetic resonance imaging were highly accurate for assessment of arterial and venous anatomy, although CT was superior for detection of late venous confluence as well as detection of renal stones. Both modalities were comparable in opacification of lower ureters and bladder; MRA underperformed CTA for opacification of upper urinary tracts. 3.0T MRA enabled excellent detection of comprehensive renal anatomy compared to CTA in LRDs. Copyright © 2016 Elsevier Inc. All rights reserved.

Noninvasive coronary artery angiography using electron beam computed tomography

NASA Astrophysics Data System (ADS)

Rumberger, John A.; Rensing, Benno J.; Reed, Judd E.; Ritman, Erik L.; Sheedy, Patrick F., II

1996-04-01

Electron beam computed tomography (EBCT), also known as ultrafast-CT or cine-CT, uses a unique scanning architecture which allows for multiple high spatial resolution electrocardiographic triggered images of the beating heart. A recent study has demonstrated the feasibility of qualitative comparisons between EBCT derived 3D coronary angiograms and invasive angiography. Stenoses of the proximal portions of the left anterior descending and right coronary arteries were readily identified, but description of atherosclerotic narrowing in the left circumflex artery (and distal epicardial disease) was not possible with any degree of confidence. Although these preliminary studies support the notion that this approach has potential, the images overall were suboptimal for clinical application as an adjunct to invasive angiography. Furthermore, these studies did not examine different methods of EBCT scan acquisition, tomographic slice thicknesses, extent of scan overlap, or other segmentation, thresholding, and interpolation algorithms. Our laboratory has initiated investigation of these aspects and limitations of EBCT coronary angiography. Specific areas of research include defining effects of cardiac orientation; defining the effects of tomographic slice thickness and intensity (gradient) versus positional (shaped based) interpolation; and defining applicability of imaging each of the major epicardial coronary arteries for quantitative definition of vessel size, cross-sectional area, taper, and discrete vessel narrowing.

Imaging of acute and chronic thromboembolic disease: state of the art.

PubMed

Ruggiero, A; Screaton, N J

2017-05-01

Acute pulmonary embolism (PE) is a life-threatening condition that requires prompt diagnosis and treatment. Recent advances in imaging allow acute and rapid recognition even by the non-specialist radiologist. Most acute emboli resolve on anticoagulation without sequelae; however, some emboli fail to fully resolve becoming endothelialised with the development of chronic thromboembolic disease (CTED). Increased pulmonary vascular resistance arising from CTED may lead to chronic thromboembolic pulmonary hypertension (CTEPH) a debilitating disease affecting up to 5% of survivors of acute PE. Diagnostic evaluation is more complex in CTEPH/CTED than acute PE with subtle imaging features often being overlooked or misinterpreted. Differentiation of acute from chronic PE and from other forms of pulmonary hypertension has profound therapeutic implications. Diverse imaging techniques are available to diagnose and monitor PEs both in the acute and chronic setting. Broadly they include techniques that provide data on lung parenchymal perfusion (ventilation-perfusion [VQ] scintigraphy), angiographic techniques (computed tomography [CT], magnetic resonance imaging [MRI], and invasive angiography) or a combination of both (MR angiography and time-resolved angiography or dual-energy CT angiography). This review aims to describe state of the art imaging highlighting the strength and weaknesses of individual techniques in the diagnosis of acute and chronic PE. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Pre-test probability of obstructive coronary stenosis in patients undergoing coronary CT angiography: Comparative performance of the modified diamond-Forrester algorithm versus methods incorporating cardiovascular risk factors.

PubMed

Ferreira, António Miguel; Marques, Hugo; Tralhão, António; Santos, Miguel Borges; Santos, Ana Rita; Cardoso, Gonçalo; Dores, Hélder; Carvalho, Maria Salomé; Madeira, Sérgio; Machado, Francisco Pereira; Cardim, Nuno; de Araújo Gonçalves, Pedro

2016-11-01

Current guidelines recommend the use of the Modified Diamond-Forrester (MDF) method to assess the pre-test likelihood of obstructive coronary artery disease (CAD). We aimed to compare the performance of the MDF method with two contemporary algorithms derived from multicenter trials that additionally incorporate cardiovascular risk factors: the calculator-based 'CAD Consortium 2' method, and the integer-based CONFIRM score. We assessed 1069 consecutive patients without known CAD undergoing coronary CT angiography (CCTA) for stable chest pain. Obstructive CAD was defined as the presence of coronary stenosis ≥50% on 64-slice dual-source CT. The three methods were assessed for calibration, discrimination, net reclassification, and changes in proposed downstream testing based upon calculated pre-test likelihoods. The observed prevalence of obstructive CAD was 13.8% (n=147). Overestimations of the likelihood of obstructive CAD were 140.1%, 9.8%, and 18.8%, respectively, for the MDF, CAD Consortium 2 and CONFIRM methods. The CAD Consortium 2 showed greater discriminative power than the MDF method, with a C-statistic of 0.73 vs. 0.70 (p<0.001), while the CONFIRM score did not (C-statistic 0.71, p=0.492). Reclassification of pre-test likelihood using the 'CAD Consortium 2' or CONFIRM scores resulted in a net reclassification improvement of 0.19 and 0.18, respectively, which would change the diagnostic strategy in approximately half of the patients. Newer risk factor-encompassing models allow for a more precise estimation of pre-test probabilities of obstructive CAD than the guideline-recommended MDF method. Adoption of these scores may improve disease prediction and change the diagnostic pathway in a significant proportion of patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Radiation exposure to operating staff during rotational flat-panel angiography and C-arm cone beam computed tomography (CT) applications.

PubMed

Schulz, Boris; Heidenreich, Ralf; Heidenreich, Monika; Eichler, Katrin; Thalhammer, Axel; Naeem, Naguib Nagy Naguib; Vogl, Thomas Josef; Zangos, Stefan

2012-12-01

To evaluate the radiation exposure for operating personnel associated with rotational flat-panel angiography and C-arm cone beam CT. Using a dedicated angiography-suite, 2D and 3D examinations of the liver were performed on a phantom to generate scattered radiation. Exposure was measured with a dosimeter at predefined heights (eye, thyroid, breast, gonads and knee) at the physician's location. Analysis included 3D procedures with a field of view (FOV) of 24 cm × 18 cm (8s/rotation, 20s/rotation and 5s/2 rotations), and 47 cm×18 cm (16s/2 rotations) and standard 2D angiography (10s, FOV 24 cm×18 cm). Measurements showed the highest radiation dose at the eye and thyroid level. In comparison to 2D-DSA (3.9 μSv eye-exposure), the 3D procedures caused an increased radiation exposure both in standard FOV (8s/rotation: 28.0 μSv, 20s/rotation: 79.3 μSv, 5s/2 rotations: 32.5 μSv) and large FOV (37.6 μSv). Proportional distributions were measured for the residual heights. With the use of lead glass, irradiation of the eye lens was reduced to 0.2 μSv (2D DSA) and 10.6 μSv (3D technique with 20s/rotation). Rotational flat-panel angiography and C-arm cone beam applications significantly increase radiation exposure to the attending operator in comparison to 2D angiography. Our study indicates that the physician should wear protective devices and leave the examination room when performing 3D examinations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device.

PubMed

Fiechter, Michael; Ghadri, Jelena R; Wolfrum, Mathias; Kuest, Silke M; Pazhenkottil, Aju P; Nkoulou, Rene N; Herzog, Bernhard A; Gebhard, Cathérine; Fuchs, Tobias A; Gaemperli, Oliver; Kaufmann, Philipp A

2012-03-01

Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization. Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as "no match". All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p < 0.001 vs matched) underwent catheterization and 3 (8%, p < 0.001 vs matched) were revascularized. Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization.

Subtraction coronary CT angiography using second-generation 320-detector row CT.

PubMed

Yoshioka, Kunihiro; Tanaka, Ryoichi; Muranaka, Kenta; Sasaki, Tadashi; Ueda, Takanori; Chiba, Takuya; Takeda, Kouta; Sugawara, Tsuyoshi

2015-06-01

The purpose of this study was to explore the feasibility of subtraction coronary computed tomography angiography (CCTA) by second-generation 320-detector row CT in patients with severe coronary artery calcification using invasive coronary angiography (ICA) as the gold standard. This study was approved by the institutional board, and all subjects provided written consent. Twenty patients with calcium scores of >400 underwent conventional CCTA and subtraction CCTA followed by ICA. A total of 82 segments were evaluated for image quality using a 4-point scale and the presence of significant (>50 %) luminal stenosis by two independent readers. The average image quality was 2.3 ± 0.8 with conventional CCTA and 3.2 ± 0.6 with subtraction CCTA (P < 0.001). The percentage of segments with non-diagnostic image quality was 43.9 % on conventional CCTA versus 8.5 % on subtraction CCTA (P = 0.004). The segment-based diagnostic accuracy for detecting significant stenosis according to ICA revealed an area under the receiver operating characteristics curve of 0.824 (95 % confidence interval [CI], 0.750-0.899) for conventional CCTA and 0.936 (95 % CI 0.889-0.936) for subtraction CCTA (P = 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value for conventional CCTA were 88.2, 62.5, 62.5, and 88.2 %, respectively, and for subtraction CCTA they were 94.1, 85.4, 82.1, and 95.3 %, respectively. As compared to conventional, subtraction CCTA using a second-generation 320-detector row CT showed improvement in diagnostic accuracy at segment base analysis in patients with severe calcifications.

Non-contrast 3D time-of-flight magnetic resonance angiography for visualization of intracranial aneurysms in patients with absolute contraindications to CT or MRI contrast.

PubMed

Yanamadala, Vijay; Sheth, Sameer A; Walcott, Brian P; Buchbinder, Bradley R; Buckley, Deidre; Ogilvy, Christopher S

2013-08-01

The preoperative evaluation of patients with intracranial aneurysms typically includes a contrast-enhanced vascular study, such as computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography. However, there are numerous absolute and relative contraindications to the administration of imaging contrast agents, including pregnancy, severe contrast allergy, and renal insufficiency. Evaluation of patients with contrast contraindications thus presents a unique challenge. We identified three patients with absolute contrast contraindications who presented with intracranial aneurysms. One patient was pregnant, while the other two had previous severe anaphylactic reactions to iodinated contrast. Because of these contraindications to intravenous contrast, we performed non-contrast time-of-flight MRA with 3D reconstruction (TOF MRA with 3DR) with maximum intensity projections and volume renderings as part of the preoperative evaluation prior to successful open surgical clipping of the aneurysms. In the case of one paraclinoid aneurysm, a high-resolution non-contrast CT scan was also performed to assess the relationship of the aneurysm to the anterior clinoid process. TOF MRA with 3DR successfully identified the intracranial aneurysms and adequately depicted the surrounding microanatomy. Intraoperative findings were as predicted by the preoperative imaging studies. The aneurysms were successfully clip-obliterated, and the patients had uneventful post-operative courses. These cases demonstrate that non-contrast imaging is a viable modality to assess intracranial aneurysms as part of the surgical planning process in patients with contrast contraindications. TOF MRA with 3DR, in conjunction with high-resolution non-contrast CT when indicated, provides adequate visualization of the microanatomy of the aneurysm and surrounding structures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Acceptance of Combined Coronary CT Angiography and Myocardial CT Perfusion versus Conventional Coronary Angiography in Patients with Coronary Stents—Intraindividual Comparison

PubMed Central

Martus, Peter; Laule, Michael; Dewey, Marc; Schönenberger, Eva

2015-01-01

Objectives To evaluate how well patients with coronary stents accept combined coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) compared with conventional coronary angiography (CCA). Background While combined CTA and CTP may improve diagnostic accuracy compared with CTA alone, patient acceptance of CTA/CTP remains to be defined. Methods A total of 90 patients with coronary stents prospectively underwent CTA/CTP (both with contrast agent, CTP with adenosine) and CCA as part of the CARS-320 study. In this group, an intraindividual comparison of patient acceptance of CTA, CTP, and CCA was performed. Results CTP was experienced to be significantly more painful than CTA (p<0.001) and was associated with a higher frequency of dyspnea (p<0.001). Comparison of CTA/CTP with CCA revealed no significant differences in terms of pain (p = 0.141) and comfort (p = 0.377). Concern before CTA/CTP and CCA and overall satisfaction were likewise not significantly different (p = 0.097 and p = 0.123, respectively). Nevertheless, about two thirds (n = 60, 68%) preferred CTA/CTP to CCA (p<0.001). Moreover, patients felt less helpless during CTA/CTP than during CCA (p = 0.026). Lack of invasiveness and absence of pain were the most frequently mentioned advantages of CTA/CTP over CCA in our patient population. Conclusions CCA and combined CTA/CTP are equally well accepted by patients; however, more patients prefer CTA/CTP. CTP was associated with more intense pain than CTA and more frequently caused dyspnea than CTA alone. Trial Registration ClinicalTrials.gov NCT00967876 PMID:26327127

Prospective Coronary Heart Disease Screening in Asymptomatic Hodgkin Lymphoma Patients Using Coronary Computed Tomography Angiography: Results and Risk Factor Analysis

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

Girinsky, Theodore, E-mail: girinsky.theodore@orange.fr; M’Kacher, Radhia; Lessard, Nathalie

Purpose: To prospectively investigate the coronary artery status using coronary CT angiography (CCTA) in patients with Hodgkin lymphoma treated with combined modalities and mediastinal irradiation. Methods and Materials: All consecutive asymptomatic patients with Hodgkin lymphoma entered the study during follow-up, from August 2007 to May 2012. Coronary CT angiography was performed, and risk factors were recorded along with leukocyte telomere length (LTL) measurements. Results: One hundred seventy-nine patients entered the 5-year study. The median follow-up was 11.6 years (range, 2.1-40.2 years), and the median interval between treatment and the CCTA was 9.5 years (range, 0.5-40 years). Coronary artery abnormalities were demonstrated in 46 patientsmore » (26%). Coronary CT angiography abnormalities were detected in nearly 15% of the patients within the first 5 years after treatment. A significant increase (34%) occurred 10 years after treatment (P=.05). Stenoses were mostly nonostial. Severe stenoses were observed in 12 (6.7%) of the patients, entailing surgery with either angioplasty with stent placement or bypass grafting in 10 of them (5.5%). A multivariate analysis demonstrated that age at treatment, hypertension, and hypercholesterolemia, as well as radiation dose to the coronary artery origins, were prognostic factors. In the group of patients with LTL measurements, hypertension and LTL were the only independent risk factors. Conclusions: The findings suggest that CCTA can identify asymptomatic individuals at risk of acute coronary artery disease who might require either preventive or curative measures. Conventional risk factors and the radiation dose to coronary artery origins were independent prognostic factors. The prognostic value of LTL needs further investigation.« less

Accuracy, image quality, and radiation dose of prospectively ECG-triggered high-pitch dual-source CT angiography in infants and children with complex coarctation of the aorta.

PubMed

Xu, Jian; Zhao, Hongliang; Wang, Xiaoying; Bai, Yuxiang; Liu, Liwen; Liu, Ying; Wei, Mengqi; Li, Jian; Zheng, Minwen

2014-10-01

To evaluate the diagnostic accuracy, image quality, and radiation dose of prospective electrocardiogram (ECG)-triggered high-pitch dual-source computed tomography (DSCT) in infants and young children with complex coarctation of the aorta (CoA). Forty pediatric patients aged < 4 years with suspected CoA underwent prospective ECG-triggered high-pitch DSCT angiography and transthoracic echocardiography (TTE). Surgery and/or conventional cardiac angiography (CCA) were performed in all patients. The diagnostic accuracy of DSCT angiography and TTE was compared to the surgical and/or CCA findings. The causes of misdiagnosis and miss were analyzed, and the advantages and limitation of both imaging modalities were evaluated. Image quality of DSCT was evaluated, and effective radiation dose was calculated. The sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of DSCT in evaluation of complex CoA were 92.37%, 98.51%, 97.32%, 93.57%, and 96.25%, respectively. There was a significant difference in the accuracy between DSCT and TTE (χ² = 9.9, P＜.05). For a total of 80 extracardiac anomalies, the sensitivity (98.8%, 79/80) of DSCT was greater than that of TTE (62.5%; 50 of 80). On the contrary, for 38 cardiac anomalies, the sensitivity (78.9%, 30 of 38) of DSCT was lesser than that of TTE (100%; 38 of 38). The mean score of image quality was 4.27 ± 0.73. The mean effective radiation dose was 0.20 ± 0.09 mSv. Prospective ECG-triggered high-pitch DSCT may be a clinical feasible modality in the evaluation of pediatric patients with complex CoA, providing adequate image quality, high diagnostic accuracy, and low radiation dose. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Application of the Low-dose One-stop-shop Cardiac CT Protocol with Third-generation Dual-source CT.

PubMed

Lin, Lu; Wang, Yining; Yi, Yan; Cao, Jian; Kong, Lingyan; Qian, Hao; Zhang, Hongzhi; Wu, Wei; Wang, Yun; Jin, Zhengyu

2017-02-20

Objective To evaluate the feasibility of a low-dose one-stop-shop cardiac CT imaging protocol with third-generation dual-source CT (DSCT). Methods Totally 23 coronary artery disease (CAD) patients were prospectively enrolled between March to September in 2016. All patients underwent an ATP stress dynamic myocardial perfusion imaging (MPI) (data acquired prospectively ECG-triggered during end systole by table shuttle mode in 32 seconds) at 70 kV combined with prospectively ECG-triggered high-pitch coronary artery angiography (CCTA) on a third-generation DSCT system. Myocardial blood flow (MBF) was quantified and compared between perfusion normal and abnormal myocardial segments based on AHA-17-segment model. CCTA images were evaluated qualitatively based on SCCT-18-segment model and the effective dose(ED) was calculated. In patients with subsequent catheter coronary angiography (CCA) as reference,the diagnosis performance of MPI (for per-vessel ≥50% and ≥70% stenosis) and CCTA (for≥50% stenosis) were assessed. Results Of 23 patients who had completed the examination of ATP stress MPI plus CCTA,12 patients received follow-up CCA. At ATP stress MPI,77 segments (19.7%) in 13 patients (56.5%) had perfusion abnormalities. The MBF values of hypo-perfused myocardial segments decreased significantly compared with normal segments [(93±22)ml/(100 ml·min) vs. (147±27)ml/(100 ml·min);t=15.978,P=0.000]. At CCTA,93.9% (308/328) of the coronary segments had diagnostic image quality. With CCA as the reference standard,the per-vessel and per-segment sensitivity,specificity,and accuracy of CCTA for stenosis≥50% were 94.1%,93.5%,and 93.7% and 90.9%,97.8%,and 96.8%,and the per-vessel sensitivity,specificity and accuracy of ATP stress MPI for stenosis≥50% and ≥70% were 68.7%,100%,and 89.5% and 91.7%,100%,and 97.9%. The total ED of MPI and CCTA was (3.9±1.3) mSv [MPI:(3.5±1.2) mSv,CCTA:(0.3±0.1) mSv]. Conclusion The third-generation DSCT stress dynamic MPI at 70 kV combined with prospectively ECG-triggered high-pitch CCTA is a feasible and reliable tool for clinical diagnosis,with remarkably reduced radiation dose.

[Image fusion of gated-SPECT and CT angiography in coronary artery disease. Importance of anatomic-functional correlation].

PubMed

Nazarena Pizzi, M; Aguadé Bruix, S; Cuéllar Calabria, H; Aliaga, V; Candell Riera, J

2010-01-01

A 77-year old patient was admitted for acute coronary syndrome without ST elevation. His risk was stratified using the myocardial perfusion gated SPECT, mild inferior ischemia being observed. Thus, medical therapy was optimized and the patient was discharged. He continued with exertional dyspnea so a coronary CT angiography was performed. It revealed severe lesions in the proximal RCA. SPECT-CT fusion images correlated the myocardial perfusion defect with a posterior descending artery from the RCA, in a co-dominant coronary area. Subsequently, cardiac catheterism was indicated for his treatment. The current use of image fusion studies is limited to patients in whom it is difficult to attribute a perfusion defect to a specific coronary artery. In our patient, the fusion images helped to distinguish between the RCA and the circumflex artery as the culprit artery of ischemia. Copyright © 2010 Elsevier España, S.L. y SEMNIM. All rights reserved.

Craniofacial duplication (diprosopus): CT, MR imaging, and MR angiography findings case report.

PubMed

Hähnel, Stefan; Schramm, Peter; Hassfeld, Stefan; Steiner, Hans H; Seitz, Angelika

2003-01-01

Diprosopus is one of the rarest malformations in humans. In addition to the facial structures, the cerebral frontal lobes were duplicated in this case. Three pairs of anterior cerebral arteries were detected, and the rostral parts of the superior sagittal sinus were duplicated. Computed tomography, magnetic resonance (MR) imaging, and MR angiography allowed study of the degree of duplicative changes in diprosopus, especially for planning cosmetic correction. Copyright RSNA, 2002

Traumatic Inferior Gluteal Artery Pseudoaneurysm and Arteriovenous Fistula Managed with Emergency Transcatheter Embolization

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

Keeling, A. N.; Naughton, P. A.; Leahy, A. L.

We present a case of blunt trauma to the buttock resulting in an inferior gluteal artery pseudoaneurysm and arteriovenous fistula. The characteristic diagnostic features on CT angiography and digital subtraction angiography (DSA), along with the emergency percutaneous management of this traumatic vascular injury, are described. A review of the literature demonstrates inferior gluteal artery pseudoaneurysm is a rare condition, while successful treatment with glue embolization is previously unreported.

Carotid artery stents on CT angiography: in vitro comparison of different stent designs and sizes using 16-, 64- and 320-row CT scanners.

PubMed

Lettau, Michael; Kotter, Elmar; Bendszus, Martin; Hähnel, Stefan

2014-10-01

CT angiography (CTA) is an increasingly used method for evaluation of stented vessel segments. Our aim was to compare the appearance of different carotid artery stents in vitro on CTA using different CT scanners. Of particular interest was the measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether CTA can be used to detect in-stent restenosis. CTA appearances of 16 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. CTA was performed using 16-, 64- and 320-row CT scanners. For each stent, artificial lumen narrowing (ALN) was calculated. ALN ranged from 18.77% to 59.86%. ALN in different stents differed significantly. In most stents, ALN decreased with increasing stent diameter. In all but one stents, ALN using sharp image kernels was significantly lower than ALN using medium image kernels. Considering all stents, ALN did not significantly differ using different CT scanners or imaging protocols. CTA evaluation of vessel patency after stent placement is possible, but is considerably impaired by ALN. Investigators should be informed about the method of choice for every stent and stent manufacturers should be aware of potential artifacts caused by their stents during noninvasive diagnostic methods such as CTA. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Diagnostic accuracy of high-definition CT coronary angiography in high-risk patients.

PubMed

Iyengar, S S; Morgan-Hughes, G; Ukoumunne, O; Clayton, B; Davies, E J; Nikolaou, V; Hyde, C J; Shore, A C; Roobottom, C A

2016-02-01

To assess the diagnostic accuracy of computed tomography coronary angiography (CTCA) using a combination of high-definition CT (HD-CTCA) and high level of reader experience, with invasive coronary angiography (ICA) as the reference standard, in high-risk patients for the investigation of coronary artery disease (CAD). Three hundred high-risk patients underwent HD-CTCA and ICA. Independent experts evaluated the images for the presence of significant CAD, defined primarily as the presence of moderate (≥ 50%) stenosis and secondarily as the presence of severe (≥ 70%) stenosis in at least one coronary segment, in a blinded fashion. HD-CTCA was compared to ICA as the reference standard. No patients were excluded. Two hundred and six patients (69%) had moderate and 178 (59%) had severe stenosis in at least one vessel at ICA. The sensitivity, specificity, positive predictive value, and negative predictive value were 97.1%, 97.9%, 99% and 93.9% for moderate stenosis, and 98.9%, 93.4%, 95.7% and 98.3%, for severe stenosis, on a per-patient basis. The combination of HD-CTCA and experienced readers applied to a high-risk population, results in high diagnostic accuracy comparable to ICA. Modern generation CT systems in experienced hands might be considered for an expanded role. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Influence of cardiac motion on stent lumen visualization in third generation dual-source CT employing a pulsatile heart model.

PubMed

Petri, Nils; Gassenmaier, Tobias; Allmendinger, Thomas; Flohr, Thomas; Voelker, Wolfram; Bley, Thorsten A

2017-02-01

To detect an in-stent restenosis, an invasive coronary angiography is commonly performed. Owing to the risk associated with this procedure, a non-invasive method to detect or exclude an in-stent restenosis is desirable. The purpose of this study was to evaluate the influence of cardiac motion on stent lumen visibility in a third-generation dual-source CT scanner (SOMATOM Force; Siemens Healthcare, Forchheim, Germany), employing a pulsatile heart model (CoroSim ® ; Mecora, Aachen, Germany). 13 coronary stents with a diameter of 3.0 mm were implanted in plastic tubes filled with a contrast medium and then fixed onto the pulsatile phantom heart model. The scans were performed while the heart model mimicked the heartbeat. Coronary stents were scanned in an orientation parallel to the scanner z-axis. The evaluation of the stents was performed by employing a medium sharp convolution kernel optimized for vascular imaging. The mean visible stent lumen was reduced from 65.6 ± 5.7% for the stents at rest to 60.8 ± 4.4% for the stents in motion (p-value: <0.001). While the difference in lumen visibility between stents in motion and at rest was significant, the use of this third-generation dual-source CT scanner enabled a high stent lumen visibility under the influence of cardiac motion. Whether this translates into a clinical setting has to be evaluated in further patient studies. Advances in knowledge: The employed modern CT scanner enables a high stent lumen visibility even under the influence of cardiac motion, which is important to detect or exclude an in-stent restenosis.

Treatment of Venous Aortorenal Bypass Graft Aneurysm Using a Stent-Graft

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

Novotny, Jiri, E-mail: jino@medicon.cz; Peregrin, Jan H.; Stribrna, Jarmila

2010-02-15

We present the case of a 77-year-old male patient who had undergone a bilateral venous aortorenal bypass graft 30 years previously. Thirteen years previously, the patient was shown to have a decrease in renal function, with mild shrinking of both kidneys; additionally, a stenosis was found in the left proximal anastomosis. At the most recent follow-up visit (1 year previously), ultrasound revealed an aneurysm (42 mm in diameter) of the left renal bypass graft; the finding was confirmed by CT angiography. A significant ostial stenosis of the left renal bypass graft was also confirmed. It was decided to place amore » self-expandable stent-graft into the aneurysm while also attempting to dilate the stenosis. Proximal endoleak after stent-graft placement necessitated the implantation of another, balloon-expandable stent-graft into the bypass graft ostium. Postprocedural angiography and follow-up by CT angiography at 3 months confirmed good patency of the stent-grafts and complete thrombosis of the aneurysmal sac, with preserved kidney perfusion. Renal function remained unaltered, while the hypertension is better controlled.« less

Multi-phase post-mortem CT-angiography: a pathologic correlation study on cardiovascular sudden death

PubMed Central

Turillazzi, Emanuela; Frati, Paola; Pascale, Natascha; Pomara, Cristoforo; Grilli, Giampaolo; Viola, Rocco Valerio; Fineschi, Vittorio

2016-01-01

Multi-phase post-mortem CT-angiography (MPMCTA) has the great potential to increase the quality of the post-mortem investigation, especially in the area of sudden death; however, its role as routine complement to the pathology toolbox is still questioned as it needs to be further standardized. The aim of this study is to investigate the contribution of MPMCTA in cases of sudden unexplained death in adults and in particular in sudden cardiovascular death. Sixty-eight sudden unexpected deaths of adults were investigated at our institution between 2012 and 2013. Ten cases underwent MPMCTA and autopsy and were included in the study. Before the angiographic step by complete filling of the vascular system, prior to any manipulation of the body, a non-contrast CT-scan was carried out. Image reconstructions were performed on a CT workstation (Vitrea) and two radiologists experienced with post mortem imaging interpreted the MPMCTA findings. In all 10 cases, we could state a good correlation between combination of post-mortem CT and MPMCTA and autopsy procedures, confirming a high diagnostic sensitivity. With this case series we want to illustrate the advantages offered by performing MPMCTA when facing a sudden death, regardless of specific suspicion for acute coronary syndrome or other vascular or ischemic disease. PMID:27928228

Cortical venous thrombosis following exogenous androgen use for bodybuilding.

PubMed

Sveinsson, Olafur; Herrman, Lars

2013-02-05

There are only a few reports of patients developing cerebral venous sinus thrombosis (CVST) after androgen therapy. We present a young man who developed cortical venous thrombosis after using androgens to increase muscle mass. He was hospitalised for parasthesia and dyspraxia in the left hand followed by a generalised tonic-clonic seizure. At admission, he was drowsy, not fully orientated, had sensory inattention, pronation drift and a positive extensor response, all on the left side. The patient had been using anabolic steroids (dainabol 20 mg/day) for the last month for bodybuilding. CT angiography showed a right cortical venous thrombosis. Anticoagulation therapy was started with intravenous heparin for 11 days and oral anticoagulation (warfarin) thereafter. A control CT angiography 4 months later showed resolution of the thrombosis. He recovered fully.

Advantages of contrast-enhanced ultrasonography over computed tomography for the detection of persistent type II endoleak after embolization: A case report.

PubMed

Cury, Maysa Heineck; Cury, Marcus Vinícius Martins; Godoy, Marcos Roberto; Matielo, Marcelo Fernando

2016-10-01

The aim of this case report is to describe the use of contrast-enhanced ultrasonography in the detection of a type II endoleak after prior embolization with Onyx. A 74-year-old male patient with hypertension previously underwent endovascular repair of a 7.1-cm infrarenal aortic aneurysm. CT angiography surveillance revealed a type II endoleak associated with aneurysm sac expansion. Selective transarterial embolization of the endoleak was performed, but it was not possible to detect the persistent endoleak using CT angiography because of image artifacts caused by Onyx. Contrast-enhanced ultrasonography enabled us to detect the persistent endoleak in this patient. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:522-526, 2016. © 2016 Wiley Periodicals, Inc.

Hybrid ECG-gated versus non-gated 512-slice CT angiography of the aorta and coronary artery: image quality and effect of a motion correction algorithm.

PubMed

Lee, Ji Won; Kim, Chang Won; Lee, Geewon; Lee, Han Cheol; Kim, Sang-Pil; Choi, Bum Sung; Jeong, Yeon Joo

2018-02-01

Background Using the hybrid electrocardiogram (ECG)-gated computed tomography (CT) technique, assessment of entire aorta, coronary arteries, and aortic valve can be possible using single-bolus contrast administration within a single acquisition. Purpose To compare the image quality of hybrid ECG-gated and non-gated CT angiography of the aorta and evaluate the effect of a motion correction algorithm (MCA) on coronary artery image quality in a hybrid ECG-gated aorta CT group. Material and Methods In total, 104 patients (76 men; mean age = 65.8 years) prospectively randomized into two groups (Group 1 = hybrid ECG-gated CT; Group 2 = non-gated CT) underwent wide-detector array aorta CT. Image quality, assessed using a four-point scale, was compared between the groups. Coronary artery image quality was compared between the conventional reconstruction and motion correction reconstruction subgroups in Group 1. Results Group 1 showed significant advantages over Group 2 in aortic wall, cardiac chamber, aortic valve, coronary ostia, and main coronary arteries image quality (all P < 0.001). All Group 1 patients had diagnostic image quality of the aortic wall and left ostium. The MCA significantly improved the image quality of the three main coronary arteries ( P < 0.05). Moreover, per-vessel interpretability improved from 92.3% to 97.1% with the MCA ( P = 0.013). Conclusion Hybrid ECG-gated CT significantly improved the heart and aortic wall image quality and the MCA can further improve the image quality and interpretability of coronary arteries.

Perimesencephalic nonaneurysmal subarachnoid hemorrhage caused by transverse sinus thrombosis: A case report and review of literature.

PubMed

Fu, Fang-Wang; Rao, Jie; Zheng, Yuan-Yuan; Song, Liang; Chen, Wei; Zhou, Qi-Hui; Yang, Jian-Guang; Ke, Jiang-Qiong; Zheng, Guo-Qing

2017-08-01

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is characterized by a pattern of extravasated blood restricted to the perimesencephalic cisterns, normal angiographic findings, and an excellent prognosis with an uneventful course and low risks of complication. The precise etiology of bleeding in patients with PNSAH has not yet been established. The most common hypothesis is that PNSAH is venous in origin. Intracranial venous hypertension has been considered as the pivotal factor in the pathogenesis of PNSAH. The underlying venous pathology such as straight sinus stenosis, jugular vein occlusion may contribute to PNSAH. We describe a patient in whom transverse sinus thrombosis preceded intracranial venous hypertension and PNSAH. These findings supported that the source of the subarachnoid hemorrhage is venous in origin. A 45-year-old right-handed man was admitted to the hospital with a sudden onset of severe headache associated with nausea, vomiting, and mild photophobia for 6 hours. The patient was fully conscious and totally alert. An emergency brain computed tomography (CT) revealed an acute subarachnoid hemorrhage restricted to the perimesencephalic cisterns. CT angiography revealed no evidence of an intracranial aneurysm or underlying vascular malformation. Digital subtraction angiography of arterial and capillary phases confirmed the CT angiographic findings. Assessment of the venous phase demonstrated right transverse sinus thrombosis. Magnetic resonance imaging confirmed the diagnosis of cerebral venous sinus thrombosis (CVST). Lumbar puncture revealed an opening pressure of 360 mmH2O, suggestive of intracranial venous hypertension. Grave disease was diagnosed by endocrinological investigation. Low-molecular-weight heparin, followed by oral warfarin, was initiated immediately as the treatment for cerebral venous sinus thrombosis and PNSAH. The patient discharged without any neurologic defect after 3 weeks of hospital stay. MR venography revealed recanalization of right transverse sinus at the 6-month follow-up. No clinical or neuroimaging evidence of relapse was detected at 12 months follow-up. Hyperthyroidism may contribute to the development of CVST. The presence of acute transverse sinus thrombosis, as a cause of PNSAH, provides further support for the hypothesis that the source of PNSAH is venous in origin and intracranial venous hypertension plays a critical role in the pathogenesis of PNSAH.

Angiographic CT: in vitro comparison of different carotid artery stents-does stent orientation matter?

PubMed

Lettau, Michael; Bendszus, Martin; Hähnel, Stefan

2013-06-01

Our aim was to evaluate the in vitro visualization of different carotid artery stents on angiographic CT (ACT). Of particular interest was the influence of stent orientation to the angiography system by measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether ACT can be used to detect restenosis within the stent. ACT appearances of 17 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. Stents were placed in different orientations to the angiography system. Standard algorithm image reconstruction and stent-optimized algorithm image reconstruction was performed. For each stent, ALN was calculated. With standard algorithm image reconstruction, ALN ranged from 19.0 to 43.6 %. With stent-optimized algorithm image reconstruction, ALN was significantly lower and ranged from 8.2 to 18.7 %. Stent struts could be visualized in all stents. Differences in ALN between the different stent orientations to the angiography system were not significant. ACT evaluation of vessel patency after stent placement is possible but is impaired by ALN. Stent orientation of the stents to the angiography system did not significantly influence ALN. Stent-optimized algorithm image reconstruction decreases ALN but further research is required to define the visibility of in-stent stenosis depending on image reconstruction.

iPad-based primary 2D reading of CT angiography examinations of patients with suspected acute gastrointestinal bleeding: preliminary experience.

PubMed

Faggioni, L; Neri, E; Bargellini, I; Scalise, P; Calcagni, F; Mantarro, A; D'Ippolito, G; Bartolozzi, C

2015-03-01

To evaluate the effectiveness of the iPad (Apple Inc., Cupertino, CA) for two-dimensional (2D) reading of CT angiography (CTA) studies performed for suspected acute non-variceal gastrointestinal bleeding. 24 CTA examinations of patients with suspected acute gastrointestinal bleeding confirmed (19/24, 79.2%) or ruled out (5/24, 20.8%) by digital subtraction angiography (DSA) were retrospectively reviewed by three independent readers on a commercial picture archiving communication system (PACS) workstation and on an iPad with Retina Display® 64 GB (Apple Inc.). The time needed to complete reading of every CTA examination was recorded, as well as the rate of detection of arterial bleeding and identification of suspected bleeding arteries on both devices. Overall, the area under the receiver operating characteristic curve, sensitivity, specificity, positive- and negative-predictive values for bleeding detection were not significantly different while using the iPad and workstation (0.774 vs 0.847, 0.947 vs 0.895, 0.6 vs 0.8, 0.9 vs 0.944 and 0.750 vs 0.667, respectively; p > 0.05). In DSA-positive cases, the iPad and workstation allowed correct identification of the bleeding source in 17/19 cases (89.5%) and 15/19 cases (78.9%), respectively (p > 0.05). Finally, the time needed to complete reading of every CTA study was significantly shorter using the iPad (169 ± 74 vs 222 ± 70 s, respectively; p < 0.01). Compared with a conventional PACS workstation, iPad-based preliminary 2D reading of CTA studies has comparable diagnostic accuracy for detection of acute gastrointestinal bleeding and can be significantly faster. The iPad could be used by on-call interventional radiologists for immediate decision on percutaneous embolization in patients with suspected acute gastrointestinal bleeding.

Optimization of window settings for standard and advanced virtual monoenergetic imaging in abdominal dual-energy CT angiography.

PubMed

Caruso, Damiano; Parinella, Ashley H; Schoepf, U Joseph; Stroebel, Maxwell H; Mangold, Stefanie; Wichmann, Julian L; Varga-Szemes, Akos; Ball, B Devon; De Santis, Domenico; Laghi, Andrea; De Cecco, Carlo N

2017-03-01

To determine the optimal window setting for displaying virtual monoenergetic reconstructions of third generation dual-source, dual-energy CT (DECT) angiography of the abdomen. Forty-five patients were evaluated with DECT angiography (90/150 kV, 180/90 ref. mAs). Three datasets were reconstructed: standard linear blending (M_0.6), 70 keV traditional virtual monoenergetic (M70), and 40 keV advanced noise-optimized virtual monoenergetic (M40+). The best window setting (width and level, W/L) was assessed by two blinded observers and was correlated with aortic attenuation to obtain the Optimized W/L setting (O-W/L). Subjective image quality was assessed, and vessel diameters were measured to determine any possible influences between different W/L settings. Repeated measures of variance were used to evaluate comparison of W/L values, image quality, and vessel sizing between M_0.6, M70, and M40+. The Best W/L (B-W/L) for M70 and M40+ was 880/280 and 1410/450, respectively. Results from regression analysis inferred an O-W/L of 850/270 for M70 and 1350/430 for M40+. Significant differences for W and L were found between the Best and the Optimized W/L for M40+, and between M70 and M40+ for both the Best and Optimized W/L. No significant differences for vessel measurements were found using the O-W/L for M40+ compared to the standard M_0.6 (p ≥ 0.16), and significant differences were observed when using the B-W/L with M40+ compared to M_0.6 (p ≤ 0.04). In order to optimize virtual monoenergetic imaging with both traditional M70 and advanced M40+, adjusting the W/L settings is necessary. Our results suggest a W/L setting of 850/270 for M70 and 1350/430 for M40+.

Long-term prognostic impact of CT-Leaman score in patients with non-obstructive CAD: Results from the COronary CT Angiography EvaluatioN For Clinical Outcomes InteRnational Multicenter (CONFIRM) study.

PubMed

Andreini, Daniele; Pontone, Gianluca; Mushtaq, Saima; Gransar, Heidi; Conte, Edoardo; Bartorelli, Antonio L; Pepi, Mauro; Opolski, Maksymilian P; Ó Hartaigh, Bríain; Berman, Daniel S; Budoff, Matthew J; Achenbach, Stephan; Al-Mallah, Mouaz; Cademartiri, Filippo; Callister, Tracy Q; Chang, Hyuk-Jae; Chinnaiyan, Kavitha; Chow, Benjamin J W; Cury, Ricardo; Delago, Augustin; Hadamitzky, Martin; Hausleiter, Joerg; Feuchtner, Gudrun; Kim, Yong-Jin; Kaufmann, Philipp A; Leipsic, Jonathon; Lin, Fay Y; Maffei, Erica; Raff, Gilbert; Shaw, Leslee J; Villines, Todd C; Dunning, Allison; Marques, Hugo; Rubinshtein, Ronen; Hindoyan, Niree; Gomez, Millie; Min, James K

2017-03-15

Non-obstructive coronary artery disease (CAD) identified by coronary computed tomography angiography (CCTA) demonstrated prognostic value. CT-adapted Leaman score (CT-LeSc) showed to improve the prognostic stratification. Aim of the study was to evaluate the capability of CT-LeSc to assess long-term prognosis of patients with non-obstructive (CAD). From 17 centers, we enrolled 2402 patients without prior CAD history who underwent CCTA that showed non-obstructive CAD and provided complete information on plaque composition. Patients were divided into a group without CAD and a group with non-obstructive CAD (<50% stenosis). Segment-involvement score (SIS) and CT-LeSc were calculated. Outcomes were non-fatal myocardial infarction (MI) and the combined end-point of MI and all-cause mortality. Patient mean age was 56±12years. At follow-up (mean 59.8±13.9months), 183 events occurred (53 MI, 99 all-cause deaths and 31 late revascularizations). CT-LeSc was the only multivariate predictor of MI (HRs 2.84 and 2.98 in two models with Framingham and risk factors, respectively) and of MI plus all-cause mortality (HR 2.48 and 1.94 in two models with Framingham and risk factors, respectively). This was confirmed by a net reclassification analysis confirming that the CT-LeSc was able to correctly reclassify a significant proportion of patients (cNRI 0.28 and 0.23 for MI and MI plus all-cause mortality, respectively) vs. baseline model, whereas SIS did not. CT-LeSc is an independent predictor of major acute cardiac events, improving prognostic stratification of patients with non-obstructive CAD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluation of an adaptive detector collimation for prospectively ECG-triggered coronary CT angiography with third-generation dual-source CT.

PubMed

Messerli, Michael; Dewes, Patricia; Scholtz, Jan-Erik; Arendt, Christophe; Wildermuth, Simon; Vogl, Thomas J; Bauer, Ralf W

2018-05-01

To investigate the impact of an adaptive detector collimation on the dose parameters and accurateness of scan length adaption at prospectively ECG-triggered sequential cardiac CT with a wide-detector third-generation dual-source CT. Ideal scan lengths for human hearts were retrospectively derived from 103 triple-rule-out examinations. These measures were entered into the new scanner operated in prospectively ECG-triggered sequential cardiac scan mode with three different detector settings: (1) adaptive collimation, (2) fixed 64 × 0.6-mm collimation, and (3) fixed 96 × 0.6-mm collimation. Differences in effective scan length and deviation from the ideal scan length and dose parameters (CTDIvol, DLP) were documented. The ideal cardiac scan length could be matched by the adaptive collimation in every case while the mean scanned length was longer by 15.4% with the 64 × 0.6 mm and by 27.2% with the fixed 96 × 0.6-mm collimation. While the DLP was almost identical between the adaptive and the 64 × 0.6-mm collimation (83 vs. 89 mGycm at 120 kV), it was 62.7% higher with the 96 × 0.6-mm collimation (135 mGycm), p < 0.001. The adaptive detector collimation for prospectively ECG-triggered sequential acquisition allows for adjusting the scan length as accurate as this can only be achieved with a spiral acquisition. This technique allows keeping patient exposure low where patient dose would significantly increase with the traditional step-and-shoot mode. • Adaptive detector collimation allows keeping patient exposure low in cardiac CT. • With novel detectors the desired scan length can be accurately matched. • Differences in detector settings may cause 62.7% of excessive dose.

Overview of Imaging Tests

MedlinePlus

... Overview of Imaging Tests Angiography Computed Tomography (CT) Magnetic Resonance Imaging (MRI) Plain X-Rays Radionuclide Scanning ... and radionuclide scanning Sound waves, as in ultrasonography Magnetic fields, as in magnetic resonance imaging (MRI) Substances ...

Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

PubMed Central

Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

2013-01-01

Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

Evaluating distribution of the left branch of the middle colic artery and the left colic artery by CT angiography and colonography to classify blood supply to the splenic flexure.

PubMed

Fukuoka, Asako; Sasaki, Takahiro; Tsukikawa, Satoshi; Miyajima, Nobuyoshi; Ostubo, Takehito

2017-05-01

CT angiography has gained widespread acceptance for preoperative evaluation of blood supply in patients with colorectal cancer. However, there have been few reports that pertain to the splenic flexure, for which surgery is technically difficult. We used preoperative CT angiography and CT colonography to evaluate blood supply to the splenic flexure. We defined the splenic flexure as the junction of the distal third of the transverse colon and the proximal third of the descending colon. We reviewed 191 cases and considered the descending colon as divided into the proximal third and the distal two-thirds; we then determined which part of the descending colon the left colic artery (LCA) entered. We also considered the transverse colon as divided into the proximal two-thirds and the distal third, and evaluated which part of the transverse colon the left branch of the middle colic artery entered. We classified blood supply to the splenic flexure into six types, described by the feeder vessels: type 1, the LCA (39.7%); type 2, the left branch of the middle colic artery (17.8%); type 3, the LCA and the left branch of the middle colic artery (9.9%); type 4, the accessory left colic artery (4.1%); type 5, the LCA and the accessory left colic artery (2.6%); and type 6, the marginal artery (25.6%). We classified blood supply to the splenic flexure into more complex types than previous reports had. Because we dissect the lymph nodes according to the type of blood supply, knowing the type before splenic flexure surgery is crucial. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

SPECTRAL DOMAIN VERSUS SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF THE RETINAL CAPILLARY PLEXUSES IN SICKLE CELL MACULOPATHY.

PubMed

Jung, Jesse J; Chen, Michael H; Frambach, Caroline R; Rofagha, Soraya; Lee, Scott S

2018-01-01

To compare the spectral domain and swept source optical coherence tomography angiography findings in two cases of sickle cell maculopathy. A 53-year-old man and a 24-year-old man both with sickle cell disease (hemoglobin SS) presented with no visual complaints; Humphrey visual field testing demonstrated asymptomatic paracentral scotomas that extended nasally in the involved eyes. Clinical examination and multimodal imaging including spectral domain and swept source optical coherence tomography, and spectral domain optical coherence tomography angiography and swept source optical coherence tomography angiography (Carl Zeiss Meditec Inc, Dublin, CA) were performed. Fundus examination of both patients revealed subtle thinning of the macula. En-face swept source optical coherence tomography confirmed the extent of the thinning correlating with the functional paracentral scotomas on Humphrey visual field. Swept source optical coherence tomography B-scan revealed multiple confluent areas of inner nuclear thinning and significant temporal retinal atrophy. En-face 6 × 6-mm spectral domain optical coherence tomography angiography of the macula demonstrated greater loss of the deep capillary plexus compared with the superficial capillary plexus. Swept source optical coherence tomography angiography 12 × 12-mm imaging captured the same macular findings and loss of both plexuses temporally outside the macula. In these two cases of sickle cell maculopathy, deep capillary plexus ischemia is more extensive within the macula, whereas both the superficial capillary plexus and deep capillary plexus are involved outside the macula likely due to the greater oxygen demands and watershed nature of these areas. Swept source optical coherence tomography angiography clearly demonstrates the angiographic extent of the disease correlating with the Humphrey visual field scotomas and confluent areas of inner nuclear atrophy.

Identification of High-Risk Plaques Destined to Cause Acute Coronary Syndrome Using Coronary Computed Tomographic Angiography and Computational Fluid Dynamics.

PubMed

Lee, Joo Myung; Choi, Gilwoo; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Kim, Kyung-Jin; Tong, Yaliang; Kim, Hyun Jin; Grady, Leo; Doh, Joon-Hyung; Nam, Chang-Wook; Shin, Eun-Seok; Cho, Young-Seok; Choi, Su-Yeon; Chun, Eun Ju; Choi, Jin-Ho; Nørgaard, Bjarne L; Christiansen, Evald H; Niemen, Koen; Otake, Hiromasa; Penicka, Martin; de Bruyne, Bernard; Kubo, Takashi; Akasaka, Takashi; Narula, Jagat; Douglas, Pamela S; Taylor, Charles A; Kim, Hyo-Soo

2018-03-14

We investigated the utility of noninvasive hemodynamic assessment in the identification of high-risk plaques that caused subsequent acute coronary syndrome (ACS). ACS is a critical event that impacts the prognosis of patients with coronary artery disease. However, the role of hemodynamic factors in the development of ACS is not well-known. Seventy-two patients with clearly documented ACS and available coronary computed tomographic angiography (CTA) acquired between 1 month and 2 years before the development of ACS were included. In 66 culprit and 150 nonculprit lesions as a case-control design, the presence of adverse plaque characteristics (APC) was assessed and hemodynamic parameters (fractional flow reserve derived by coronary computed tomographic angiography [FFR CT ], change in FFR CT across the lesion [△FFR CT ], wall shear stress [WSS], and axial plaque stress) were analyzed using computational fluid dynamics. The best cut-off values for FFR CT , △FFR CT , WSS, and axial plaque stress were used to define the presence of adverse hemodynamic characteristics (AHC). The incremental discriminant and reclassification abilities for ACS prediction were compared among 3 models (model 1: percent diameter stenosis [%DS] and lesion length, model 2: model 1 + APC, and model 3: model 2 + AHC). The culprit lesions showed higher %DS (55.5 ± 15.4% vs. 43.1 ± 15.0%; p < 0.001) and higher prevalence of APC (80.3% vs. 42.0%; p < 0.001) than nonculprit lesions. Regarding hemodynamic parameters, culprit lesions showed lower FFR CT and higher △FFR CT , WSS, and axial plaque stress than nonculprit lesions (all p values <0.01). Among the 3 models, model 3, which included hemodynamic parameters, showed the highest c-index, and better discrimination (concordance statistic [c-index] 0.789 vs. 0.747; p = 0.014) and reclassification abilities (category-free net reclassification index 0.287; p = 0.047; relative integrated discrimination improvement 0.368; p < 0.001) than model 2. Lesions with both APC and AHC showed significantly higher risk of the culprit for subsequent ACS than those with no APC/AHC (hazard ratio: 11.75; 95% confidence interval: 2.85 to 48.51; p = 0.001) and with either APC or AHC (hazard ratio: 3.22; 95% confidence interval: 1.86 to 5.55; p < 0.001). Noninvasive hemodynamic assessment enhanced the identification of high-risk plaques that subsequently caused ACS. The integration of noninvasive hemodynamic assessments may improve the identification of culprit lesions for future ACS. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary CT Angiography and Computational Fluid Dynamic [EMERALD]; NCT02374775). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Diagnostic accuracy of 256-row multidetector CT coronary angiography with prospective ECG-gating combined with fourth-generation iterative reconstruction algorithm in the assessment of coronary artery bypass: evaluation of dose reduction and image quality.

PubMed

Ippolito, Davide; Fior, Davide; Franzesi, Cammillo Talei; Riva, Luca; Casiraghi, Alessandra; Sironi, Sandro

2017-12-01

Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose. To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol. Seventy-four non-obese patients with known coronary disease treated with artery bypass grafting were prospectively enrolled. All the patients underwent 256 MDCT (Brilliance iCT, Philips) CTCA using low-dose protocol (100 kV; 800 mAs; rotation time: 0.275 s) combined with prospective ECG-triggering acquisition and fourth-generation IR technique (iDose 4 ; Philips); all the lengths of the bypass graft were included in the evaluation. A control group of 42 similar patients was evaluated with a standard retrospective ECG-gated CTCA (100 kV; 800 mAs).On both CT examinations, ROIs were placed to calculate standard deviation of pixel values and intra-vessel density. Diagnostic quality was also evaluated using a 4-point quality scale. Despite the statistically significant reduction of radiation dose evaluated with DLP (study group mean DLP: 274 mGy cm; control group mean DLP: 1224 mGy cm; P value < 0.001). No statistical differences were found between PGA group and RGH group regarding intra-vessel density absolute values and SNR. Qualitative analysis, evaluated by two radiologists in "double blind", did not reveal any significant difference in diagnostic quality of the two groups. The development of high-speed MDCT scans combined with modern IR allows an accurate evaluation of CABG with prospective ECG-gating protocols in a single breath hold, obtaining a significant reduction in radiation dose.

Prospective ECG-gated high-pitch dual-source cardiac CT angiography in the diagnosis of congenital cardiovascular abnormalities: Radiation dose and diagnostic efficacy in a pediatric population.

PubMed

Koplay, M; Kizilca, O; Cimen, D; Sivri, M; Erdogan, H; Guvenc, O; Oc, M; Oran, B

2016-11-01

The goal of this study was to investigate the radiation dose and diagnostic efficacy of cardiac computed tomography angiography (CCTA) using prospective ECG-gated high-pitch dual-source computed tomography (DSCT) in the diagnosis of congenital cardiovascular abnormalities in pediatric population. One hundred five pediatric patients who were clinically diagnosed with congenital heart disease with suspected extracardiac vascular abnormalities were included in the study. All CCTAs were performed on a 128×2-section DSCT scanner. CCTA findings were compared with surgical and/or conventional cardiac angiography findings. Dose-length product (DLP) and effective doses (ED) were calculated for each patient. Patients were divided into 4 groups by age, and ED and DLP values were compared among groups. The image quality was evaluated using a five-point scale. CCTA showed 173 abnormalities in 105 patients. There were 2 patients with false positive and 3 with false negative findings. The sensitivity and specificity of CCTA were 98.3% and 99.9%, respectively. The positive predictive value and negative predictive value of CCT were 98.9% and 99.9%, respectively. The average DLP and ED values were 15.6±9.6 (SD) mGy.cm and 0.34±0.10 (SD) mSv, respectively. The mean image quality score was 4.8±0.5 (SD) in all patients. The inter-observer agreement for the image quality scores was good (κ=0.80). CCTA is an excellent imaging modality for evaluation of cardiovascular abnormalities and provides excellent image quality with very low radiation exposure when low-dose prospective ECG-triggered high-pitch DSCT is used. Copyright © 2016 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Prevalence of Imaging Biomarkers to Guide the Planning of Acute Stroke Reperfusion Trials.

PubMed

Jiang, Bin; Ball, Robyn L; Michel, Patrik; Jovin, Tudor; Desai, Manisha; Eskandari, Ashraf; Naqvi, Zack; Wintermark, Max

2017-06-01

Imaging biomarkers are increasingly used as selection criteria for stroke clinical trials. The goal of our study was to determine the prevalence of commonly studied imaging biomarkers in different time windows after acute ischemic stroke onset to better facilitate the design of stroke clinical trials using such biomarkers for patient selection. This retrospective study included 612 patients admitted with a clinical suspicion of acute ischemic stroke with symptom onset no more than 24 hours before completing baseline imaging. Patients with subacute/chronic/remote infarcts and hemorrhage were excluded from this study. Imaging biomarkers were extracted from baseline imaging, which included a noncontrast head computed tomography (CT), perfusion CT, and CT angiography. The prevalence of dichotomized versions of each of the imaging biomarkers in several time windows (time since symptom onset) was assessed and statistically modeled to assess time dependence (not lack thereof). We created tables showing the prevalence of the imaging biomarkers pertaining to the core, the penumbra and the arterial occlusion for different time windows. All continuous imaging features vary over time. The dichotomized imaging features that vary significantly over time include: noncontrast head computed tomography Alberta Stroke Program Early CT (ASPECT) score and dense artery sign, perfusion CT infarct volume, and CT angiography collateral score and visible clot. The dichotomized imaging features that did not vary significantly over time include the thresholded perfusion CT penumbra volumes. As part of the feasibility analysis in stroke clinical trials, this analysis and the resulting tables can help investigators determine sample size and the number needed to screen. © 2017 American Heart Association, Inc.

Establishing national diagnostic reference levels (DRLs) for computed tomography in Egypt.

PubMed

Salama, Dina Husseiny; Vassileva, Jenia; Mahdaly, Gamal; Shawki, Mona; Salama, Ahmad; Gilley, Debbie; Rehani, Madan Mohan

2017-07-01

To establish national diagnostic reference levels (DRLs) in Egypt for computed tomography (CT) examinations of adults and identify the potential for optimization. Data from 3762 individual patient's undergoing CT scans of head, chest (high resolution), abdomen, abdomen-pelvis, chest-abdomen-pelvis and CT angiography (aorta and both lower limbs) examinations in 50 CT facilities were collected. This represents 20% of facilities in the country and all of the 27 Governorates. Results were compared with DRLs of UK, USA, Canada, Japan, Australia and France. The Egyptian DRLs for CTDI vol in mGy are for head: 30, chest (high resolution): 22, abdomen (liver metastasis): 31, abdomen-pelvis: 31, chest-abdomen-pelvis: 33 and CT angiography (aorta and lower limbs): 37. The corresponding DRLs for DLP in mGy.cm are 1360, 420, 1425, 1325, 1320 and 1320. For head CT, the Egyptian DRL for CTDI vol is 2-3 times lower than the DRLs from other countries. However, the DRL in terms of DLP is in the same range or higher as compared to others. The Egyptian DRL for chest CT (high resolution) is similar to others for DLP but higher for CTDI vol . For abdomen and abdomen-pelvis DRLs for CTDI vol are higher than others. For DLP, the DRLs for abdomen are higher than DRL in UK and lower than those in Japan, while for abdomen-pelvis they are higher than other countries. Despite lower DRLs for CTDI vol , an important consistent problem appears to be higher scan range as DRLs for DLP are higher. Copyright © 2017 Associazione Italiana di Fisica Medica. All rights reserved.

[Multidisciplinary protocol for computed tomography imaging and angiographic embolization of splenic injury due to trauma: assessment of pre-protocol and post-protocol outcomes].

PubMed

Koo, M; Sabaté, A; Magalló, P; García, M A; Domínguez, J; de Lama, M E; López, S

2011-11-01

To assess conservative treatment of splenic injury due to trauma, following a protocol for computed tomography (CT) and angiographic embolization. To quantify the predictive value of CT for detecting bleeding and need for embolization. The care protocol developed by the multidisciplinary team consisted of angiography with embolization of lesions revealed by contrast extravasation under CT as well as embolization of grade III-V injuries observed, or grade I-II injuries causing hemodynamic instability and/or need for blood transfusion. We collected data on demographic variables, injury severity score (ISS), angiographic findings, and injuries revealed by CT. Pre-protocol and post-protocol outcomes were compared. The sensitivity and specificity of CT findings were calculated for all patients who required angiographic embolization. Forty-four and 30 angiographies were performed in the pre- and post-protocol periods, respectively. The mean (SD) ISSs in the two periods were 25 (11) and 26 (12), respectively. A total of 24 (54%) embolizations were performed in the pre-protocol period and 28 (98%) after implementation of the protocol. Two and 7 embolizations involved the spleen in the 2 periods, respectively; abdominal laparotomies numbered 32 and 25, respectively, and 10 (31%) vs 4 (16%) splenectomies were performed. The specificity and sensitivity values for contrast extravasation found on CT and followed by embolization were 77.7% and 79.5%. The implementation of this multidisciplinary protocol using CT imaging and angiographic embolization led to a decrease in the number of splenectomies. The protocol allows us to take a more conservative treatment approach.

[Review of pre- and post-treatment multidetector computed tomography findings in abdominal aortic aneurysms].

PubMed

Casula, E; Lonjedo, E; Cerverón, M J; Ruiz, A; Gómez, J

2014-01-01

The increase in the frequency of abdominal aortic aneurysms (AAA) and the widely accepted use of endovascular aneurysm repair (EVAR) as a first-line treatment or as an alternative to conventional surgery make it necessary for radiologists to have thorough knowledge of the pre- and post-treatment findings. The high image quality provided by multidetector computed tomography (MDCT) enables CT angiography to play a fundamental role in the study of AAA and in planning treatment. The objective of this article is to review the cases of AAA in which CT angiography was the main imaging technique, so that radiologists will be able to detect the signs related to this disease, to diagnose it, to plan treatment, and to detect complications in the postoperative period. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

Cortical venous thrombosis following exogenous androgen use for bodybuilding

PubMed Central

Sveinsson, Olafur; Herrman, Lars

2013-01-01

There are only a few reports of patients developing cerebral venous sinus thrombosis (CVST) after androgen therapy. We present a young man who developed cortical venous thrombosis after using androgens to increase muscle mass. He was hospitalised for parasthesia and dyspraxia in the left hand followed by a generalised tonic–clonic seizure. At admission, he was drowsy, not fully orientated, had sensory inattention, pronation drift and a positive extensor response, all on the left side. The patient had been using anabolic steroids (dainabol 20 mg/day) for the last month for bodybuilding. CT angiography showed a right cortical venous thrombosis. Anticoagulation therapy was started with intravenous heparin for 11 days and oral anticoagulation (warfarin) thereafter. A control CT angiography 4 months later showed resolution of the thrombosis. He recovered fully. PMID:23389726

Use of computed tomography findings and contrast extravasation in predicting the need for embolization with pelvic fractures.

PubMed

Bozeman, Matthew C; Cannon, Robert M; Trombold, John M; Smith, Jason W; Franklin, Glen A; Miller, Frank B; Richardson, J David; Harbrecht, Brian G

2012-08-01

Transarterial embolization (AE) can be a lifesaving procedure for severe hemorrhage associated with pelvic fractures. The purpose of this study was to identify demographic and radiographic findings that predict the need for embolization. We performed a retrospective review of all patients with at least one pelvic fracture and admission to the intensive care unit over a 35-month period. Computed tomography (CT) and pelvic radiographs were reviewed. Patient demographics, outcomes, time to angiography, and whether or not embolization was performed were determined. Statistical analysis was used to determine factors associated with the need for AE. Of the 327 total patients with pelvic fractures, 317 underwent CT scanning. Forty-four patients (13.5%) underwent angiography and 25 (7.6%) required therapeutic embolization. There were 39 total deaths (11.6%) with five deaths related to pelvic hemorrhage (1.5%). Multivariate analysis revealed that age older than 55 years (odds ratio [OR], 1.06; P < 0.001), systolic blood pressure less than 90 mmHg in the emergency department (OR, 11.64; P = 0.0008), and CT extravasation (OR, 147.152; P < 0.0001) were significantly associated with the need for embolization. Contrast extravasation was not present in 25 per cent of patients requiring therapeutic AE. The presence of contrast extravasation is highly associated with the need for pelvic embolization in patients with pelvic fractures, but its absence does not exclude the need for pelvic angiography.

Metal artifact reduction for flat panel detector intravenous CT angiography in patients with intracranial metallic implants after endovascular and surgical treatment

PubMed Central

Pjontek, Rastislav; Önenköprülü, Belgin; Scholz, Bernhard; Kyriakou, Yiannis; Schubert, Gerrit A; Othman, Ahmed; Wiesmann, Martin; Brockmann, Marc A

2016-01-01

Background Flat panel detector CT angiography with intravenous contrast agent injection (IV CTA) allows high-resolution imaging of cerebrovascular structures. Artifacts caused by metallic implants like platinum coils or clips lead to degradation of image quality and are a significant problem. Objective To evaluate the influence of a prototype metal artifact reduction (MAR) algorithm on image quality in patients with intracranial metallic implants. Methods Flat panel detector CT after intravenous application of 80 mL contrast agent was performed with an angiography system (Artis zee; Siemens, Forchheim, Germany) using a 20 s rotation protocol (200° rotation angle, 20 s acquisition time, 496 projections). The data before and after MAR of 26 patients with a total of 34 implants (coils, clips, stents) were independently evaluated by two blinded neuroradiologists. Results MAR improved the assessability of the brain parenchyma and small vessels (diameter <1 mm) in the neighborhood of metallic implants and at a distance of 6 cm (p<0.001 each, Wilcoxon test). Furthermore, MAR significantly improved the assessability of parent vessel patency and potential aneurysm remnants (p<0.005 each, McNemar test). MAR, however, did not improve assessability of stented vessels. Conclusions When an intravenous contrast protocol is used, MAR significantly ameliorates the assessability of brain parenchyma, vessels, and treated aneurysms in patients with intracranial coils or clips. PMID:26346458

Plaque imaging with CT—a comprehensive review on coronary CT angiography based risk assessment

PubMed Central

Kolossváry, Márton; Szilveszter, Bálint; Merkely, Béla

2017-01-01

CT based technologies have evolved considerably in recent years. Coronary CT angiography (CTA) provides robust assessment of coronary artery disease (CAD). Early coronary CTA imaging—as a gate-keeper of invasive angiography—has focused on the presence of obstructive stenosis. Coronary CTA is currently the only non-invasive imaging modality for the evaluation of non-obstructive CAD, which has been shown to contribute to adverse cardiac events. Importantly, improved spatial resolution of CT scanners and novel image reconstruction algorithms enable the quantification and characterization of atherosclerotic plaques. State-of-the-art CT imaging can therefore reliably assess the extent of CAD and differentiate between various plaque features. Recent studies have demonstrated the incremental prognostic value of adverse plaque features over luminal stenosis. Comprehensive coronary plaque assessment holds potential to significantly improve individual risk assessment incorporating adverse plaque characteristics, the extent and severity of atherosclerotic plaque burden. As a result, several coronary CTA based composite risk scores have been proposed recently to determine patients at high risk for adverse events. Coronary CTA became a promising modality for the evaluation of functional significance of coronary lesions using CT derived fractional flow reserve (FFR-CT) and/or rest/dynamic myocardial CT perfusion. This could lead to substantial reduction in unnecessary invasive catheterization procedures and provide information on ischemic burden of CAD. Discordance between the degree of stenosis and ischemia has been recognized in clinical landmark trials using invasive FFR. Both lesion stenosis and composition are possibly related to myocardial ischemia. The evaluation of lesion-specific ischemia using combined functional and morphological plaque information could ultimately improve the diagnostic performance of CTA and thus patient care. In this review we aimed to summarize current evidence on comprehensive coronary artery plaque assessment using coronary CTA. PMID:29255692

TH-AB-207A-03: Skin Dose to Patients Receiving Multiple CTA and CT Exams of the Head

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

Nawfel, RD; Young, G

Purpose: To measure patient skin dose from CT angiography (CTA) and CT exams of the head, and determine if patients having multiple exams could receive cumulative doses that approach or exceed deterministic thresholds. Methods: This study was HIPAA compliant and conducted with IRB approval. Patient skin doses were measured over a 4 month period using nanoDot OSL dosimeters placed on the head of 52 patients for two CT scanners. On each scanner, 26 patients received CT exams (scanner 1: 10 females, 16 males, mean age 64.2 years; scanner 2: 18 females, 8 males, mean age 61.2 years). CT exam dosemore » metrics, CTDIvol and dose-length product (DLP) were recorded for each exam. Additionally, skin dose was measured on an acrylic skull phantom in each scanner and on a neuro-interventional imaging system using clinical protocols. Measured dose data was used to estimate peak skin dose (PSD) for 4 patients receiving multiple exams including CTA, head CT, and cerebral angiography. Results: For scanner 1, the mean PSD for CTA exams (98.9 ± 5.3 mGy) and for routine head CT exams (39.2 ± 3.7 mGy) agreed reasonably well with the PSD measured on the phantom, 105.4 mGy and 40.0 mGy, respectively. Similarly for scanner 2, the mean PSD for CTA exams (98.8 ± 7.4 mGy) and for routine head CT exams (42.9 ± 9.4 mGy) compared well with phantom measurements, 95.2 mGy and 37.6 mGy, respectively. In addition, the mean PSD was comparable between scanners for corresponding patient exams, CTA and routine head CT respectively. PSD estimates ranged from 1.9 – 4.5 Gy among 4 patients receiving multiple exams. Conclusion: Patients having several exams including both CTA and routine head CT may receive cumulative doses approaching or exceeding the threshold for single dose deterministic effects.« less

Does angiography increase the risk of impairment in renal function during non-operative management of patients with blunt splenic injuries? A cross-sectional study in southern Taiwan

PubMed Central

Hsieh, Ting-Min; Tsai, Tzu-Hsien; Lin, Chih-Che; Hsieh, Ching-Hua

2016-01-01

Objectives The aim of the present study was to assess whether angiography after contrast-enhanced CT (CECT) as per the policy of non-operative management would add to the risk of acute kidney injury in patients with blunt splenic injuries (BSIs). Design Cross-sectional study. Setting Taiwan. Participants Patients with BSI aged >16 years, admitted to a level I trauma centre during the period of January 2004 to December 2014, were retrospectively reviewed. A total of 326 patients with BSI with CECT were included in the study, of whom 100 underwent subsequent angiography and 226 did not. Main outcome measures Incidence of contrast-induced nephropathy (CIN) and renal function as measured by the 48-hour serum creatinine (SCr) levels. Results No significant difference between the patients who underwent angiography and those who did not in terms of the initial haemoglobin (Hb), SCr or estimated glomerular filtration rate (eGFR) level on arrival at the emergency department, 48 hours later, or at discharge. No significant difference in the incidence of CIN was found between these two groups of patients regardless of the criteria for identifying CIN. In the group of patients aged ≥55 years, those who underwent angiography had a significantly worse 48-hour SCr level than those who did not undergo the treatment. In addition, there was no significant difference in the 48-hour SCr level between the two groups of patients when subgrouping the patients according to sex, large haemoperitoneum revealed on CT, systolic blood pressure, initial Hb, initial SCr and initial eGFR levels. Conclusions This study demonstrated that angiography does not increase the incidence of CIN, and was not a risk factor to renal function impairment in patients with BSI who had undergone CECT. PMID:27798008

Does angiography increase the risk of impairment in renal function during non-operative management of patients with blunt splenic injuries? A cross-sectional study in southern Taiwan.

PubMed

Hsieh, Ting-Min; Tsai, Tzu-Hsien; Lin, Chih-Che; Hsieh, Ching-Hua

2016-10-21

The aim of the present study was to assess whether angiography after contrast-enhanced CT (CECT) as per the policy of non-operative management would add to the risk of acute kidney injury in patients with blunt splenic injuries (BSIs). Cross-sectional study. Taiwan. Patients with BSI aged >16 years, admitted to a level I trauma centre during the period of January 2004 to December 2014, were retrospectively reviewed. A total of 326 patients with BSI with CECT were included in the study, of whom 100 underwent subsequent angiography and 226 did not. Incidence of contrast-induced nephropathy (CIN) and renal function as measured by the 48-hour serum creatinine (SCr) levels. No significant difference between the patients who underwent angiography and those who did not in terms of the initial haemoglobin (Hb), SCr or estimated glomerular filtration rate (eGFR) level on arrival at the emergency department, 48 hours later, or at discharge. No significant difference in the incidence of CIN was found between these two groups of patients regardless of the criteria for identifying CIN. In the group of patients aged ≥55 years, those who underwent angiography had a significantly worse 48-hour SCr level than those who did not undergo the treatment. In addition, there was no significant difference in the 48-hour SCr level between the two groups of patients when subgrouping the patients according to sex, large haemoperitoneum revealed on CT, systolic blood pressure, initial Hb, initial SCr and initial eGFR levels. This study demonstrated that angiography does not increase the incidence of CIN, and was not a risk factor to renal function impairment in patients with BSI who had undergone CECT. 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/.

Korean Guidelines for the Appropriate Use of Cardiac CT

PubMed Central

Kim, Young Jin; Kim, Sung Mok; Kim, Jeong A; Yang, Dong Hyun; Hong, Yoo Jin

2015-01-01

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease. PMID:25741189

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

PubMed

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

2010-10-01

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

Diagnostic yield and accuracy of coronary CT angiography after abnormal nuclear myocardial perfusion imaging.

PubMed

Meinel, Felix G; Schoepf, U Joseph; Townsend, Jacob C; Flowers, Brian A; Geyer, Lucas L; Ebersberger, Ullrich; Krazinski, Aleksander W; Kunz, Wolfgang G; Thierfelder, Kolja M; Baker, Deborah W; Khan, Ashan M; Fernandes, Valerian L; O'Brien, Terrence X

2018-06-15

We aimed to determine the diagnostic yield and accuracy of coronary CT angiography (CCTA) in patients referred for invasive coronary angiography (ICA) based on clinical concern for coronary artery disease (CAD) and an abnormal nuclear stress myocardial perfusion imaging (MPI) study. We enrolled 100 patients (84 male, mean age 59.6 ± 8.9 years) with an abnormal MPI study and subsequent referral for ICA. Each patient underwent CCTA prior to ICA. We analyzed the prevalence of potentially obstructive CAD (≥50% stenosis) on CCTA and calculated the diagnostic accuracy of ≥50% stenosis on CCTA for the detection of clinically significant CAD on ICA (defined as any ≥70% stenosis or ≥50% left main stenosis). On CCTA, 54 patients had at least one ≥50% stenosis. With ICA, 45 patients demonstrated clinically significant CAD. A positive CCTA had 100% sensitivity and 84% specificity with a 100% negative predictive value and 83% positive predictive value for clinically significant CAD on a per patient basis in MPI positive symptomatic patients. In conclusion, almost half (48%) of patients with suspected CAD and an abnormal MPI study demonstrate no obstructive CAD on CCTA.

Update on imaging techniques in oculoplastics

PubMed Central

Cetinkaya, Altug

2012-01-01

Imaging is a beneficial aid to the oculoplastic surgeon especially in orbital and lacrimal disorders when the pathology is not visible from outside. It is a powerful tool that may be benefited in not only diagnosis but also management and follow-up. The most common imaging modalities required are CT and MRI, with CT being more frequently ordered by oculoplastic surgeons. Improvements in technology enabled the acquisition times to shorten incredibly. Radiologists can now obtain images with superb resolution, and isolate the site and tissue of interest from other structures with special techniques. Better contrast agents and 3D imaging capabilities make complicated cases easier to identify. Color Doppler imaging is becoming more popular both for research and clinical purposes. Magnetic resonance angiography (MRA) added so much to the vascular system imaging recently. Although angiography is still the gold standard, new software and techniques rendered MRA as valuable as angiography in most circumstances. Stereotactic navigation, although in use for a long time, recently became the focus of interest for the oculoplastic surgeon especially in orbital decompressions. Improvements in radiology and nuclear medicine techniques of lacrimal drainage system imaging provided more detailed analysis of the system. PMID:23961020

Advances in cardiac CT contrast injection and acquisition protocols.

PubMed

Scholtz, Jan-Erik; Ghoshhajra, Brian

2017-10-01

Cardiac computed tomography (CT) imaging has become an important part of modern cardiovascular care. Coronary CT angiography (CTA) is the first choice imaging modality for non-invasive visualization of coronary artery stenosis. In addition, cardiac CT does not only provide anatomical evaluation, but also functional and valvular assessment, and myocardial perfusion evaluation. In this article we outline the factors which influence contrast enhancement, give an overview of current contrast injection and acquisition protocols, with focus on current emerging topics such as pre-transcatheter aortic valve replacement (TAVR) planning, cardiac CT for congenital heart disease (CHD) patients, and myocardial CT perfusion (CTP). Further, we point out areas where we see potential for future improvements in cardiac CT imaging based on a closer interaction between CT scanner settings and contrast injection protocols to tailor injections to patient- and exam-specific factors.

Advances in cardiac CT contrast injection and acquisition protocols

PubMed Central

Scholtz, Jan-Erik

2017-01-01

Cardiac computed tomography (CT) imaging has become an important part of modern cardiovascular care. Coronary CT angiography (CTA) is the first choice imaging modality for non-invasive visualization of coronary artery stenosis. In addition, cardiac CT does not only provide anatomical evaluation, but also functional and valvular assessment, and myocardial perfusion evaluation. In this article we outline the factors which influence contrast enhancement, give an overview of current contrast injection and acquisition protocols, with focus on current emerging topics such as pre-transcatheter aortic valve replacement (TAVR) planning, cardiac CT for congenital heart disease (CHD) patients, and myocardial CT perfusion (CTP). Further, we point out areas where we see potential for future improvements in cardiac CT imaging based on a closer interaction between CT scanner settings and contrast injection protocols to tailor injections to patient- and exam-specific factors. PMID:29255688

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

PubMed

Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

2008-01-01

Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

Mono-Energy Coronary Angiography with a Compact Synchrotron Source

NASA Astrophysics Data System (ADS)

Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noёl, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

2017-02-01

X-ray coronary angiography is an invaluable tool for the diagnosis of coronary artery disease. However, the use of iodine-based contrast media can be contraindicated for patients who present with chronic renal insufficiency or with severe iodine allergy. These patients could benefit from a reduced contrast agent concentration, possibly achieved through application of a mono-energetic x-ray beam. While large-scale synchrotrons are impractical for daily clinical use, the technology of compact synchrotron sources strongly advanced during the last decade. Here we present a quantitative analysis of the benefits a compact synchrotron source can offer in coronary angiography. Simulated projection data from quasi-mono-energetic and conventional x-ray tube spectra is used for a CNR comparison. Results show that compact synchrotron spectra would allow for a significant reduction of contrast media. Experimentally, we demonstrate the feasibility of coronary angiography at the Munich Compact Light Source, the first commercial installation of a compact synchrotron source.

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

Single Phase Dual-energy CT Angiography: One-stop-shop Tool for Evaluating Aneurysmal Subarachnoid Hemorrhage.

PubMed

Ni, Qian Qian; Tang, Chun Xiang; Zhao, Yan E; Zhou, Chang Sheng; Chen, Guo Zhong; Lu, Guang Ming; Zhang, Long Jiang

2016-05-25

Aneurysmal subarachnoid hemorrhages have extremely high case fatality in clinic. Early and rapid identifications of ruptured intracranial aneurysms seem to be especially important. Here we evaluate clinical value of single phase contrast-enhanced dual-energy CT angiograph (DE-CTA) as a one-stop-shop tool in detecting aneurysmal subarachnoid hemorrhage. One hundred and five patients who underwent true non-enhanced CT (TNCT), contrast-enhanced DE-CTA and digital subtraction angiography (DSA) were included. Image quality and detectability of intracranial hemorrhage were evaluated and compared between virtual non-enhanced CT (VNCT) images reconstructed from DE-CTA and TNCT. There was no statistical difference in image quality (P > 0.05) between VNCT and TNCT. The agreement of VNCT and TNCT in detecting intracranial hemorrhage reached 98.1% on a per-patient basis. With DSA as reference standard, sensitivity and specificity on a per-patient were 98.3% and 97.9% for DE-CTA in intracranial aneurysm detection. Effective dose of DE-CTA was reduced by 75.0% compared to conventional digital subtraction CTA. Thus, single phase contrast-enhanced DE-CTA is optimal reliable one-stop-shop tool for detecting intracranial hemorrhage with VNCT and intracranial aneurysms with DE-CTA with substantial radiation dose reduction compared with conventional digital subtraction CTA.

Fractional flow reserve based on computed tomography: an overview.

PubMed

Secchi, Francesco; Alì, Marco; Faggiano, Elena; Cannaò, Paola Maria; Fedele, Marco; Tresoldi, Silvia; Di Leo, Giovanni; Auricchio, Ferdinando; Sardanelli, Francesco

2016-04-28

Computed tomography coronary angiography (CTCA) is a technique proved to provide high sensitivity and negative predictive value for the identification of anatomically significant coronary artery disease (CAD) when compared with invasive X-ray coronary angiography. While the CTCA limitation of a ionizing radiation dose delivered to patients is substantially overcome by recent technical innovations, a relevant limitation remains the only anatomical assessment of coronary stenoses in the absence of evaluation of their functional haemodynamic significance. This limitation is highly important for those stenosis graded as intermediate at the anatomical assessment. Recently, non-invasive methods based on computational fluid dynamics were developed to calculate vessel-specific fractional flow reserve (FFR) using data routinely acquired by CTCA [computed tomographic fractional flow reserve (CT-FFR)]. Here we summarize methods for CT-FFR and review the evidence available in the literature up to June 26, 2016, including 16 original articles and one meta-analysis. The perspective of CT-FFR may greatly impact on CAD diagnosis, prognostic evaluation, and treatment decision-making. The aim of this review is to describe technical characteristics and clinical applications of CT-FFR, also in comparison with catheter-based invasive FFR, in order to make a cost-benefit balance in terms of clinical management and patient's health.

Single Phase Dual-energy CT Angiography: One-stop-shop Tool for Evaluating Aneurysmal Subarachnoid Hemorrhage

PubMed Central

Ni, Qian Qian; Tang, Chun Xiang; Zhao, Yan E; Zhou, Chang Sheng; Chen, Guo Zhong; Lu, Guang Ming; Zhang, Long Jiang

2016-01-01

Aneurysmal subarachnoid hemorrhages have extremely high case fatality in clinic. Early and rapid identifications of ruptured intracranial aneurysms seem to be especially important. Here we evaluate clinical value of single phase contrast-enhanced dual-energy CT angiograph (DE-CTA) as a one-stop-shop tool in detecting aneurysmal subarachnoid hemorrhage. One hundred and five patients who underwent true non-enhanced CT (TNCT), contrast-enhanced DE-CTA and digital subtraction angiography (DSA) were included. Image quality and detectability of intracranial hemorrhage were evaluated and compared between virtual non-enhanced CT (VNCT) images reconstructed from DE-CTA and TNCT. There was no statistical difference in image quality (P > 0.05) between VNCT and TNCT. The agreement of VNCT and TNCT in detecting intracranial hemorrhage reached 98.1% on a per-patient basis. With DSA as reference standard, sensitivity and specificity on a per-patient were 98.3% and 97.9% for DE-CTA in intracranial aneurysm detection. Effective dose of DE-CTA was reduced by 75.0% compared to conventional digital subtraction CTA. Thus, single phase contrast-enhanced DE-CTA is optimal reliable one-stop-shop tool for detecting intracranial hemorrhage with VNCT and intracranial aneurysms with DE-CTA with substantial radiation dose reduction compared with conventional digital subtraction CTA. PMID:27222163

The utility of dual-energy CT for metal artifact reduction from intracranial clipping and coiling.

PubMed

Mera Fernández, D; Santos Armentia, E; Bustos Fiore, A; Villanueva Campos, A M; Utrera Pérez, E; Souto Bayarri, M

2018-04-23

To assess the ability of dual-energy CT (DECT) to reduce metal-related artifacts in patients with clips and coils in head CT angiography, and to analyze the differences in this reduction between both type of devices. Thirteen patients (6 clips, 7 coils) were selected and retrospectively analized. Virtual monoenergetic images (MEI) with photon energies from 40 to 150 keV were obtained. Noise was measured at the area of maximum artifact. Subjective evaluation of streak artifact was performed by two radiologists independently. Differences between noise values in all groups were tested by using the ANOVA test. Mann-Whitney U test was used to compare the differences between clips and coils. Coheńs κ statistic was used to determine interobserver agreement. The lowest noise value was observed at high energy levels (p<0,05). Noise was higher in the coil group than in the clip group (p<0.001). Interobserver agreement was good (κ=0.72). TCED with MEI helps to minimize the artifact from clips ands coils in patients who undergo head CT angiography. The reduction of the artifact is greater in patients with surgical clipping than in patients with endovascular coiling. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

How to create a cardiac CT clinic.

PubMed

Dowe, David A

2007-02-01

Coronary computed tomography (CT) angiography is taking an exponentially increasing role in the diagnostic algorithm of suspected coronary artery disease. It has the immediate potential of replacing stress tests as the first study a patient receives if suspected of having coronary artery disease. In the near future, it will likely precede all elective, diagnostic cardiac catheterizations secondary to its extraordinary negative predictive value. This paper discusses the 3 building blocks of a successful cardiac CT clinic, image quality, service, and marketing. It then discusses the significant differences in establishing a cardiac CT clinic depending on if the radiologist is hospital based or private office based.

High-Pitch, Low-Voltage and Low-Iodine-Concentration CT Angiography of Aorta: Assessment of Image Quality and Radiation Dose with Iterative Reconstruction

PubMed Central

Shen, Yanguang; Sun, Zhonghua; Xu, Lei; Li, Yu; Zhang, Nan; Yan, Zixu; Fan, Zhanming

2015-01-01

Objective To assess the image quality of aorta obtained by dual-source computed tomography angiography (DSCTA), performed with high pitch, low tube voltage, and low iodine concentration contrast medium (CM) with images reconstructed using iterative reconstruction (IR). Methods One hundred patients randomly allocated to receive one of two types of CM underwent DSCTA with the electrocardiogram-triggered Flash protocol. In the low-iodine group, 50 patients received CM containing 270 mg I/mL and were scanned at low tube voltage (100 kVp). In the high-iodine CM group, 50 patients received CM containing 370 mg I/mL and were scanned at the tube voltage (120 kVp). The filtered back projection (FBP) algorithm was used for reconstruction in both groups. In addition, the IR algorithm was used in the low-iodine group. Image quality of the aorta was analyzed subjectively by a 3-point grading scale and objectively by measuring the CT attenuation in terms of the signal- and contrast-to-noise ratios (SNR and CNR, respectively). Radiation and CM doses were compared. Results The CT attenuation, subjective image quality assessment, SNR, and CNR of various aortic regions of interest did not differ significantly between two groups. In the low-iodine group, images reconstructed by FBP and IR demonstrated significant differences in image noise, SNR, and CNR (p<0.05). The low-iodine group resulted in 34.3% less radiation (4.4 ± 0.5 mSv) than the high-iodine group (6.7 ± 0.6 mSv), and 27.3% less iodine weight (20.36 ± 2.65 g) than the high-iodine group (28 ± 1.98 g). Observers exhibited excellent agreement on the aortic image quality scores (κ = 0.904). Conclusions CT images of aorta could be obtained within 2 s by using a DSCT Flash protocol with low tube voltage, IR, and low-iodine-concentration CM. Appropriate contrast enhancement was achieved while maintaining good image quality and decreasing the radiation and iodine doses. PMID:25643353

Multislice spiral CT angiography for evaluation of acute aortic syndrome.

PubMed

Zhao, De-Li; Liu, Xin-Ding; Zhao, Cheng-Lei; Zhou, Hai-Ting; Wang, Guo-Kun; Liang, Hong-Wei; Zhang, Jin-Ling

2017-10-01

To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS). The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated. Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively. In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS. © 2017, Wiley Periodicals, Inc.

[Pre- and post-test probability of obstructive coronary artery disease in two diagnostic strategies: relative contributions of exercise ECG and coronary CT angiography].

PubMed

Faria Alves, Miguel; Ferreira, António Miguel; Cardoso, Gonçalo; Saraiva Lopes, Ricardo; Correia, Maria da Graça; Machado Gil, Victor

2013-03-01

The purpose of this study was to assess the change in theoretical probability of coronary artery disease (CAD) in patients with suspected CAD undergoing coronary CT angiography (CCTA) as first line test vs. patients who underwent CCTA after an exercise ECG. Pre- and post-test probabilities of CAD were assessed in 158 patients with suspected CAD undergoing dual-source CCTA as the first-line test (Group A) and in 134 in whom CCTA was performed after an exercise ECG (Group B). Pre-test probabilities were calculated based on age, gender and type of chest pain. Post-test probabilities were calculated according to Bayes' theorem. There were no significant differences between the groups regarding pre-test probability (median 23.5% [13.3-37.8] in group A vs. 20.5% [13.4-34.5] in group B; p=0,479). In group A, the percentage of patients with intermediate likelihood of disease (10-90%) was 90% before testing and 15% after CCTA (p<0,001), while in group B, it was 95% before testing, 87% after exercise ECG (p=NS), and 17% after CCTA (p<0,001). Unlike exercise testing, CCTA is able to reclassify the risk in the majority of patients with an intermediate probability of obstructive CAD. The use of CCTA as a first-line diagnostic test for CAD may be beneficial in this setting. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

The importance of Tc-MAA SPECT/CT for therapy planning of radioembolization in a patient treated with bevacizumab.

PubMed

Ahmadzadehfar, Hojjat; Sabet, Amir; Meyer, Carsten; Habibi, Elham; Biersack, Hans-Jürgen; Ezziddin, Samer

2012-11-01

A 76-year-old man with colorectal cancer and hepatic metastases was referred to us for radioembolization of the liver. Angiography with 99mTc-MAA SPECT/CT was performed 8 weeks after the discontinuation of bevacizumab. 99mTc-MAA SPECT/CT showed a diffused intrahepatic tracer distribution with no focally accentuated accumulation in the tumorous region. The test was repeated 6 weeks later and Tc-MAA SPECT/CT showed this time a tumor accentuated tracer accumulation in the liver. Subsequently, the patient was treated with resin microspheres. Tc-MAA SPECT/CT allows a better evaluation of intrahepatic tracer accumulation of Tc-MAA and facilitates the determination of the most appropriate treatment time.

Paraplegia after contrast media application: a transient or devastating rare complication? Case report.

PubMed

Mielke, Dorothee; Kallenberg, Kai; Hartmann, Marius; Rohde, Veit

2016-05-01

The authors report the case of a 76-year-old man with a spinal dural arteriovenous fistula. The patient suffered from sudden repeated reversible paraplegia after spinal digital subtraction angiography as well as CT angiography. Neurotoxicity of contrast media (CM) is the most probable cause for this repeated short-lasting paraplegia. Intolerance to toxicity of CM to the vulnerable spinal cord is rare, and probably depends on the individual patient. This phenomenon is transient and can occur after both intraarterial and intravenous CM application.

Metal artifact reduction for flat panel detector intravenous CT angiography in patients with intracranial metallic implants after endovascular and surgical treatment.

PubMed

Pjontek, Rastislav; Önenköprülü, Belgin; Scholz, Bernhard; Kyriakou, Yiannis; Schubert, Gerrit A; Nikoubashman, Omid; Othman, Ahmed; Wiesmann, Martin; Brockmann, Marc A

2016-08-01

Flat panel detector CT angiography with intravenous contrast agent injection (IV CTA) allows high-resolution imaging of cerebrovascular structures. Artifacts caused by metallic implants like platinum coils or clips lead to degradation of image quality and are a significant problem. To evaluate the influence of a prototype metal artifact reduction (MAR) algorithm on image quality in patients with intracranial metallic implants. Flat panel detector CT after intravenous application of 80 mL contrast agent was performed with an angiography system (Artis zee; Siemens, Forchheim, Germany) using a 20 s rotation protocol (200° rotation angle, 20 s acquisition time, 496 projections). The data before and after MAR of 26 patients with a total of 34 implants (coils, clips, stents) were independently evaluated by two blinded neuroradiologists. MAR improved the assessability of the brain parenchyma and small vessels (diameter <1 mm) in the neighborhood of metallic implants and at a distance of 6 cm (p<0.001 each, Wilcoxon test). Furthermore, MAR significantly improved the assessability of parent vessel patency and potential aneurysm remnants (p<0.005 each, McNemar test). MAR, however, did not improve assessability of stented vessels. When an intravenous contrast protocol is used, MAR significantly ameliorates the assessability of brain parenchyma, vessels, and treated aneurysms in patients with intracranial coils or clips. 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/

Iterative CT shading correction with no prior information

NASA Astrophysics Data System (ADS)

Wu, Pengwei; Sun, Xiaonan; Hu, Hongjie; Mao, Tingyu; Zhao, Wei; Sheng, Ke; Cheung, Alice A.; Niu, Tianye

2015-11-01

Shading artifacts in CT images are caused by scatter contamination, beam-hardening effect and other non-ideal imaging conditions. The purpose of this study is to propose a novel and general correction framework to eliminate low-frequency shading artifacts in CT images (e.g. cone-beam CT, low-kVp CT) without relying on prior information. The method is based on the general knowledge of the relatively uniform CT number distribution in one tissue component. The CT image is first segmented to construct a template image where each structure is filled with the same CT number of a specific tissue type. Then, by subtracting the ideal template from the CT image, the residual image from various error sources are generated. Since forward projection is an integration process, non-continuous shading artifacts in the image become continuous signals in a line integral. Thus, the residual image is forward projected and its line integral is low-pass filtered in order to estimate the error that causes shading artifacts. A compensation map is reconstructed from the filtered line integral error using a standard FDK algorithm and added back to the original image for shading correction. As the segmented image does not accurately depict a shaded CT image, the proposed scheme is iterated until the variation of the residual image is minimized. The proposed method is evaluated using cone-beam CT images of a Catphan©600 phantom and a pelvis patient, and low-kVp CT angiography images for carotid artery assessment. Compared with the CT image without correction, the proposed method reduces the overall CT number error from over 200 HU to be less than 30 HU and increases the spatial uniformity by a factor of 1.5. Low-contrast object is faithfully retained after the proposed correction. An effective iterative algorithm for shading correction in CT imaging is proposed that is only assisted by general anatomical information without relying on prior knowledge. The proposed method is thus practical and attractive as a general solution to CT shading correction.

Acute lower extremity paralysis after lower extremity endovascular intervention.

PubMed

Öztürk, Semi; Kalyoncuoğlu, Muhsin; Durmuş, Gündüz; Topçu, Adem; Can, Mehmet

2017-04-01

A 61-year-old man underwent successful percutaneous revascularization of both lower limbs with multiple stent implantations. Paralysis of right lower limb was noticed after completion of procedure when transferring the patient from angiography table. Since hematoma compressing lumbosacral neural plexus could be a fatal complication, computed tomography (CT) image was taken. CT showed bulge of distended bladder compressing stent struts. Following placement of Foley catheter, condition improved and he was subsequently discharged uneventfully.

Real-time fusion of coronary CT angiography with x-ray fluoroscopy during chronic total occlusion PCI.

PubMed

Ghoshhajra, Brian B; Takx, Richard A P; Stone, Luke L; Girard, Erin E; Brilakis, Emmanouil S; Lombardi, William L; Yeh, Robert W; Jaffer, Farouc A

2017-06-01

The purpose of this study was to demonstrate the feasibility of real-time fusion of coronary computed tomography angiography (CTA) centreline and arterial wall calcification with x-ray fluoroscopy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Patients undergoing CTO PCI were prospectively enrolled. Pre-procedural CT scans were integrated with conventional coronary fluoroscopy using prototype software. We enrolled 24 patients who underwent CTO PCI using the prototype CT fusion software, and 24 consecutive CTO PCI patients without CT guidance served as a control group. Mean age was 66 ± 11 years, and 43/48 patients were men. Real-time CTA fusion during CTO PCI provided additional information regarding coronary arterial calcification and tortuosity that generated new insights into antegrade wiring, antegrade dissection/reentry, and retrograde wiring during CTO PCI. Overall CTO success rates and procedural outcomes remained similar between the two groups, despite a trend toward higher complexity in the fusion CTA group. This study demonstrates that real-time automated co-registration of coronary CTA centreline and calcification onto live fluoroscopic images is feasible and provides new insights into CTO PCI, and in particular, antegrade dissection reentry-based CTO PCI. • Real-time semi-automated fusion of CTA/fluoroscopy is feasible during CTO PCI. • CTA fusion data can be toggled on/off as desired during CTO PCI • Real-time CT calcium and centreline overlay could benefit antegrade dissection/reentry-based CTO PCI.

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

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

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 andmore » 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.« less

The Caudate Lobe: The Blind Spot in Radioembolization or an Overlooked Opportunity?

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

Braat, Manon N. G. J. A., E-mail: M.N.G.Braat-3@umcutrecht.nl; Hoven, Andor F. van den, E-mail: a.f.vandenhoven@umcutrecht.nl; Doormaal, Pieter J. van, E-mail: P.J.vanDoormaal-4@umcutrecht.nl

2016-06-15

PurposeThe caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken inter-individual differences in arterial vascularization. Unfortunately, this complexity is not specifically taken into account during radioembolization treatment (RE), potentially resulting in under- or overtreatment of the CL. The objective of this study was to evaluate the CL coverage in RE and determine the detection rate of the CL arteries on CT angiography during work-up.MethodsIn all consecutive patients who underwent RE treatment between May 2012–January 2015, {sup 99m}Tc-MAA SPECT/CT and posttreatment scans ({sup 90}Y-bremsstrahlung SPECT/CT, {sup 90}Y-PET/CT, or {sup 166}Ho-SPECT/CT) were reviewed for activity inmore » the CL. Pretreatment CT angiographies were reviewed for the visibility of the CL arteries.ResultsEighty-two patients were treated. In 32/82 (39 %) the CL was involved. In 6/32 (19 %) patients, no activity was seen on the posttreatment scan in the CL, whereas in 40/50 (80 %) patients without CL tumor involvement, the CL was treated. {sup 99m}Tc-MAA SPECT/CT and final posttreatment scans were discordant in 16/78 (21 %). {sup 99m}Tc-MAA SPECT/CT had a positive and negative predictive value of 94 % and 46 %, respectively, for activity in the CL after RE. In untreated CLs, significant hypertrophy was observed with a median volume increase of 33 % (p = 0.02). CL arteries were seldom visible on the pretreatment CT; the identification rate was 12–17 %.ConclusionCurrently in RE treatments, targeting or sparing of the CL is highly erratic and independent of tumor involvement. Intentional treatment or bypassing of the CL seems worthwhile to either improve tumor coverage or enhance the functional liver remnant.« less

Diagnosis of myocardial ischemia combining multiphase postmortem CT-angiography, histology, and postmortem biochemistry.

PubMed

Vanhaebost, Jessica; Ducrot, Kewin; de Froidmont, Sébastien; Scarpelli, Maria Pia; Egger, Coraline; Baumann, Pia; Schmit, Gregory; Grabherr, Silke; Palmiere, Cristian

2017-02-01

The aim of this study was to assess whether the identification of pathological myocardial enhancement at multiphase postmortem computed tomography angiography was correlated with increased levels of troponin T and I in postmortem serum from femoral blood as well as morphological findings of myocardial ischemia. We further aimed to investigate whether autopsy cases characterized by increased troponin T and I concentrations as well as morphological findings of myocardial ischemia were also characterized by pathological myocardial enhancement at multiphase postmortem computed tomography angiography. Two different approaches were used. In one, 40 forensic autopsy cases that had pathological enhancement of the myocardium (mean Hounsfield units ≥95) observed at postmortem angiography were retrospectively selected. In the second approach, 40 forensic autopsy cases that had a cause of death attributed to acute myocardial ischemia were retrospectively selected. The preliminary results seem to indicate that the identification of a pathological enhancement of the myocardium at postmortem angiography is associated with the presence of increased levels of cardiac troponins in postmortem serum and morphological findings of ischemia. Analogously, a pathological enhancement of the myocardium at postmortem angiography can be retrospectively found in the great majority of autopsy cases characterized by increased cardiac troponin levels in postmortem serum and morphological findings of myocardial ischemia. Multiphase postmortem computed tomography angiography is a useful tool in the postmortem setting for investigating ischemically damaged myocardium.

Three-Station Three-dimensional Bolus-Chase MR Angiography with Real-time Fluoroscopic Tracking

PubMed Central

Johnson, Casey P.; Weavers, Paul T.; Borisch, Eric A.; Grimm, Roger C.; Hulshizer, Thomas C.; LaPlante, Christine C.; Rossman, Phillip J.; Glockner, James F.; Young, Phillip M.

2014-01-01

Purpose To determine the feasibility of using real-time fluoroscopic tracking for bolus-chase magnetic resonance (MR) angiography of peripheral vasculature to image three stations from the aortoiliac bifurcation to the pedal arteries. Materials and Methods This prospective study was institutional review board approved and HIPAA compliant. Eight healthy volunteers (three men; mean age, 48 years; age range, 30–81 years) and 13 patients suspected of having peripheral arterial disease (five men; mean age, 67 years; age range, 47–81 years) were enrolled and provided informed consent. All subjects were imaged with the fluoroscopic tracking MR angiographic protocol. Ten patients also underwent a clinical computed tomographic (CT) angiographic runoff examination. Two readers scored the MR angiographic studies for vessel signal intensity and sharpness and presence of confounding artifacts and venous contamination at 35 arterial segments. Mean aggregate scores were assessed. The paired MR angiographic and CT angiographic studies also were scored for visualization of disease, reader confidence, and overall diagnostic quality and were compared by using a Wilcoxon signed rank test. Results Real-time fluoroscopic tracking performed well technically in all studies. Vessel segments were scored good to excellent in all but the following categories: For vessel signal intensity and sharpness, the abdominal aorta, iliac arteries, distal plantar arteries, and plantar arch were scored as fair to good; and for presence of confounding artifacts, the abdominal aorta and iliac arteries were scored as fair. The MR angiograms and CT angiograms did not differ significantly in any scoring category (reader 1: P = .50, .39, and .39; reader 2: P = .41, .61, and .33, respectively). CT scores were substantially better in 20% (four of 20) and 25% (five of 20) of the pooled evaluations for the visualization of disease and overall image quality categories, respectively, versus 5% (one of 20) for MR scores in both categories. Conclusion Three-station bolus-chase MR angiography with real-time fluoroscopic tracking provided high-spatial-resolution arteriograms of the peripheral vasculature, enabled precise triggering of table motion, and compared well with CT angiograms. © RSNA, 2014 Online supplemental material is available for this article. PMID:24635676

Noninvasive Fractional Flow Reserve Derived From Coronary CT Angiography: Clinical Data and Scientific Principles.

PubMed

Min, James K; Taylor, Charles A; Achenbach, Stephan; Koo, Bon Kwon; Leipsic, Jonathon; Nørgaard, Bjarne L; Pijls, Nico J; De Bruyne, Bernard

2015-10-01

Fractional flow reserve derived from coronary computed tomography angiography enables noninvasive assessment of the hemodynamic significance of coronary artery lesions and coupling of the anatomic severity of a coronary stenosis with its physiological effects. Since its initial demonstration of feasibility of use in humans in 2011, a significant body of clinical evidence has developed to evaluate the diagnostic performance of coronary computed tomography angiography-derived fractional flow reserve compared with an invasive fractional flow reserve reference standard. The purpose of this paper was to describe the scientific principles and to review the clinical data of this technology recently approved by the U.S. Food and Drug Administration. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Feasibility of a Single Contrast Bolus High-Pitch Pulmonary CT Angiography Protocol Followed by Low-Dose Retrospectively ECG-Gated Cardiac CT in Patients with Suspected Pulmonary Embolism.

PubMed

Schäfer, Julia Carmen; Haubenreisser, Holger; Meyer, Mathias; Grüttner, Joachim; Walter, Thomas; Borggrefe, Martin; Schoepf, Joseph U; Nance, John W; Schönberg, Stefan O; Henzler, Thomas

2018-06-01

 To prospectively evaluate the feasibility of single contrast bolus high-pitch CT pulmonary angiography (CTPA) subsequently followed by low-dose retrospectively ECG-gated cardiac CT (4D-cCT) in patients with suspected pulmonary embolism (PE) to accurately evaluate right ventricular (RV) function.  62 patients (33 female, age 65.1 ± 17.5 years) underwent high-pitch CTPA examination with 80cc of iodinated contrast material. 5 s after the end of the high-pitch CTPA study, a low-dose retrospectively ECG-gated cardiac CT examination was automatically started. The volume CT dose index (CTDI vol) and dose length product (DLP) were recorded in all patients and the effective dose was calculated. For the assessment of image quality, attenuation was measured as Hounsfield units (HUs) within various regions of interest (ROIs). These ROIs were used to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality was assessed using a five-point Likert scale. On 4D-cCT, the ejection fraction of both ventricles (RVEF, LVEF) as well as the ratio of RVEF and LVEF (RVEF/LVEF) was assessed. The statistical difference of all parameters between the PE and non-PE group was calculated.  The mean effective radiation dose was 4.22 ± 2.05 mSv. Attenuation measurements on CTPA showed the highest attenuation values in the main pulmonary artery (442.01 ± 187.64). On 4D-cCT attenuation values were highest in the descending aorta (560.59 ± 208.81). The CNR and SNR values on CTPA were highest within the main pulmonary artery (CNR = 12.43 ± 4.57; SNR = 15.14 ± 4.90). On 4D-cCT images, the highest SNR and CNR could be measured in the descending aorta (CNR = 10.26 ± 5.57; SNR = 10.86 ± 5.17). The mean LVEF was 60.73 %± 14.65 %, and the mean RVEF was 44.90 %± 9.54 %. The mean RVEF/LVEF was 0.79 ± 0.29. There was no significant difference between the PE and non-PE group for either of the parameters.  The investigated combined CTPA and 4D-cCT protocol is feasible using a single contrast bolus and allows the evaluation of RV function in patients with suspected PE. Further studies have to evaluate the additional value of this protocol regarding risk stratification in patients with PE.   · High-pitch CTPA is fast enough to leave sufficient contrast material within the heart that can be used for an additional low-dose functional cardiac CT examination.. · The tube current of the evaluated 4D-cCT is reduced over the entire cardiac cycle without any full dose peak.. · Low-dose cardiac CT subsequently performed after high-pitch CTPA allows for detailed analysis of RV function.. · Schäfer JC, Haubenreisser H, Meyer M et al. Feasibility of a Single Contrast Bolus High-Pitch Pulmonary CT Angiography Protocol Followed by Low-Dose Retrospectively ECG-Gated Cardiac CT in Patients with Suspected Pulmonary Embolism. Fortschr Röntgenstr 2018; 190: 542 - 550. © Georg Thieme Verlag KG Stuttgart · New York.

Mono-energy coronary angiography with a compact light source

NASA Astrophysics Data System (ADS)

Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noël, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

2017-03-01

While conventional x-ray tube sources reliably provide high-power x-ray beams for everyday clinical practice, the broad spectra that are inherent to these sources compromise the diagnostic image quality. For a monochromatic x-ray source on the other hand, the x-ray energy can be adjusted to optimal conditions with respect to contrast and dose. However, large-scale synchrotron sources impose high spatial and financial demands, making them unsuitable for clinical practice. During the last decades, research has brought up compact synchrotron sources based on inverse Compton scattering, which deliver a highly brilliant, quasi-monochromatic, tunable x-ray beam, yet fitting into a standard laboratory. One application that could benefit from the invention of these sources in clinical practice is coronary angiography. Being an important and frequently applied diagnostic tool, a high number of complications in angiography, such as renal failure, allergic reaction, or hyperthyroidism, are caused by the large amount of iodine-based contrast agent that is required for achieving sufficient image contrast. Here we demonstrate monochromatic angiography of a porcine heart acquired at the MuCLS, the first compact synchrotron source. By means of a simulation, the CNR in a coronary angiography image achieved with the quasi-mono-energetic MuCLS spectrum is analyzed and compared to a conventional x-ray-tube spectrum. The results imply that the improved CNR achieved with a quasi-monochromatic spectrum can allow for a significant reduction of iodine contrast material.

Time-Resolved C-Arm Computed Tomographic Angiography Derived From Computed Tomographic Perfusion Acquisition: New Capability for One-Stop-Shop Acute Ischemic Stroke Treatment in the Angiosuite.

PubMed

Yang, Pengfei; Niu, Kai; Wu, Yijing; Struffert, Tobias; Dorfler, Arnd; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

2015-12-01

Multimodal imaging using cone beam C-arm computed tomography (CT) may shorten the delay from ictus to revascularization for acute ischemic stroke patients with a large vessel occlusion. Largely because of limited temporal resolution, reconstruction of time-resolved CT angiography (CTA) from these systems has not yielded satisfactory results. We evaluated the image quality and diagnostic value of time-resolved C-arm CTA reconstructed using novel image processing algorithms. Studies were done under an Institutional Review Board approved protocol. Postprocessing of data from 21 C-arm CT dynamic perfusion acquisitions from 17 patients with acute ischemic stroke were done to derive time-resolved C-arm CTA images. Two observers independently evaluated image quality and diagnostic content for each case. ICC and receiver-operating characteristic analysis were performed to evaluate interobserver agreement and diagnostic value of this novel imaging modality. Time-resolved C-arm CTA images were successfully generated from 20 data sets (95.2%, 20/21). Two observers agreed well that the image quality for large cerebral arteries was good but was more limited for small cerebral arteries (distal to M1, A1, and P1). receiver-operating characteristic curves demonstrated excellent diagnostic value for detecting large vessel occlusions (area under the curve=0.987-1). Time-resolved CTAs derived from C-arm CT perfusion acquisitions provide high quality images that allowed accurate diagnosis of large vessel occlusions. Although image quality of smaller arteries in this study was not optimal ongoing modifications of the postprocessing algorithm will likely remove this limitation. Adding time-resolved C-arm CTAs to the capabilities of the angiography suite further enhances its suitability as a one-stop shop for care for patients with acute ischemic stroke. © 2015 American Heart Association, Inc.

Literature Review of the Role of Ultrasound, Computed Tomography, and Transcatheter Arterial Embolization for the Treatment of Traumatic Splenic Injuries

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

Vlies, Cornelis H. van der, E-mail: c.h.vandervlies@amc.n; Delden, Otto M. van, E-mail: o.m.vandelden@amc.n; Punt, Bastiaan J., E-mail: b.j.punt@asz.n

IntroductionThe spleen is the second most frequently injured organ following blunt abdominal trauma. Trends in management have changed over the years. Traditionally, laparotomy and splenectomy was the standard management. Presently, nonoperative management (NOM) of splenic injury is the most common management strategy in hemodynamically stable patients. Splenic injuries can be managed via simple observation (OBS) or with angiography and embolization (AE). Angio-embolization has shown to be a valuable alternative to observational management and has increased the success rate of nonoperative management in many series.DiagnosticsImproved imaging techniques and advances in interventional radiology have led to a better selection of patients whomore » are amenable to nonoperative management. Despite this, there is still a lot of debate about which patients are prone to NOM.Angiography and EmbolizationThe optimal patient selection is still a matter of debate and the role of CT and angio-embolization has not yet fully evolved. We discuss the role of sonography and CT features, such as contrast extravasation, pseudoaneurysms, arteriovenous fistulas, or hemoperitoneum, to determine the optimal patient selection for angiography and embolization. We also review the efficiency, technical considerations (proximal or selective embolization), logistics, and complication rates of AE for blunt traumatic splenic injuries.« less

Literature Review of the Role of Ultrasound, Computed Tomography, and Transcatheter Arterial Embolization for the Treatment of Traumatic Splenic Injuries

PubMed Central

van Delden, Otto M.; Punt, Bastiaan J.; Ponsen, Kees J.; Reekers, Jim A.; Goslings, J. Carel

2010-01-01

Introduction The spleen is the second most frequently injured organ following blunt abdominal trauma. Trends in management have changed over the years. Traditionally, laparotomy and splenectomy was the standard management. Presently, nonoperative management (NOM) of splenic injury is the most common management strategy in hemodynamically stable patients. Splenic injuries can be managed via simple observation (OBS) or with angiography and embolization (AE). Angio-embolization has shown to be a valuable alternative to observational management and has increased the success rate of nonoperative management in many series. Diagnostics Improved imaging techniques and advances in interventional radiology have led to a better selection of patients who are amenable to nonoperative management. Despite this, there is still a lot of debate about which patients are prone to NOM. Angiography and Embolization The optimal patient selection is still a matter of debate and the role of CT and angio-embolization has not yet fully evolved. We discuss the role of sonography and CT features, such as contrast extravasation, pseudoaneurysms, arteriovenous fistulas, or hemoperitoneum, to determine the optimal patient selection for angiography and embolization. We also review the efficiency, technical considerations (proximal or selective embolization), logistics, and complication rates of AE for blunt traumatic splenic injuries. PMID:20668852

Telestroke Imaging: A Review.

PubMed

Laghari, Fahad J; Hammer, Maxim D

2017-01-01

The use of telecommunications technology to provide the healthcare services, telemedicine, has been in use since the 1860s. The use of technology has ranged from providing medical care to far-off places during wartimes to monitoring physiological measurements of astronauts in space. Since the 1990s, reports have been published on diagnoses of neurological diseases with the use of video links. Studies confirm that the neurological examinations, including the National Institutes of Health Stroke Scale, performed during teleneurology are dependable. The transfer of stroke patients in rural hospitals to bigger medical centers delays treatment while there exists current and projected shortage of neurologists. Telestroke provides the solution. Patients suspected of acute stroke need a noncontrast computerized tomography (CT) scan for tissue plasminogen activator administration. Vascular imaging such as CT angiography, magnetic resonance angiography, and digital subtraction angiography can help show large-vessel occlusion or critical stenosis responsive to endovascular therapy. A standard protocol can be followed to decide a vascular modality of choice, considering advantages and disadvantages of each imaging modality. Telestroke solves the problems of distance and of shortage of neurologists. Neuroimaging plays a vital role in the delivery of telestroke, and the telestroke doctor should be comfortable with making a decision on selecting an appropriate vascular imaging modality. Copyright © 2016 by the American Society of Neuroimaging.

Comparison of radiological and morphologic assessments of myocardial bridges.

PubMed

Ercakmak, Burcu; Bulut, Elif; Hayran, Mutlu; Kaymaz, Figen; Bilgin, Selma; Hazirolan, Tuncay; Bayramoglu, Alp; Erbil, Mine

2015-09-01

In this study we aimed to compare the findings of coronary dual-source computed tomography angiography of myocardial bridges with cadaveric dissections. Forty-one isolated, non-damaged fresh sheep hearts were used in this study. Myocardial bridges of the anterior interventricular branch of the left coronary artery were demonstrated and analyzed by a coronary dual-source computed tomography angiography. Dissections along the left anterior interventricular branch of the left coronary artery were performed by using Zeiss OPMI pico microscope and the length of the bridges were measured. The depths of the myocardial bridges were measured from the stained sections by using the light microscope (Leica DM 6000B). MBs were found in all 41 hearts (100%) during dissections. Dual-source computed tomography angiography successfully detected 87.8% (36 of the 41 hearts) of the myocardial bridges measured on left anterior interventricular branch of left coronary artery. The lengths of the myocardial bridges were found 5-40 and 8-50 mm with dissection and dual-source computed tomography angiography, respectively. And the depths were found 0.7-4.5 mm by dual-source computed tomography angiography and 0.745-4.632 mm morphologically. Comparison of the mean values of the lengths showed statistically significantly higher values (22.0 ± 8.5, 17.7 ± 7.7 mm, p = 0.003) for the dissections. Radiological assessment also effectively discriminated complete bridges from incomplete ones. Our study showed that coronary computed tomography angiography is reliable in evaluating the presence and depth of myocardial bridges.

Occult Mediastinal Great Vessel Trauma: The Value of Aortography Performed During Angiographic Screening for Blunt Cervical Vascular Trauma

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

Ray, Charles E.; Bauer, Jason R.; Cothren, C. Clay

2005-05-15

Purpose. To determine the value of aortography in the assessment of occult aortic and great vessel injuries when routinely performed during screening angiography for blunt cerebrovascular injury (BCVI). Methods. One hundred and one consecutive patients who received both aortography and screening four-vessel angiography over 4 years were identified retrospectively. Angiograms for these patients were evaluated, and the incidence of occult mediastinal vascular injury was determined. Results. Of the 101 patients, 6 (6%) had angiographically documented traumatic aortic injuries. Of these 6 patients, one injury (17%) was unsuspected prior to angiography. Four of the 6 (67%) also had BCVI. One additionalmore » patient also had an injury to a branch of the subclavian artery. Conclusion. Routine aortography during screening angiography for BCVI is not warranted due to the low incidence (1%) of occult mediastinal arterial injury. However, in the setting of a BCVI screening study and no CT scan of the chest, aortography may be advantageous.« less

Cost-effectiveness of 64-slice CT angiography compared to conventional coronary angiography based on a coverage with evidence development study in Ontario.

PubMed

Goeree, Ron; Blackhouse, Gord; Bowen, James M; O'Reilly, Daria; Sutherland, Simone; Hopkins, Robert; Chow, Benjamin; Freeman, Michael; Provost, Yves; Dennie, Carole; Cohen, Eric; Marcuzzi, Dan; Iwanochko, Robert; Moody, Alan; Paul, Narinder; Parker, John D

2013-10-01

Conventional coronary angiography (CCA) is the standard diagnostic for coronary artery disease (CAD), but multi-detector computed tomography coronary angiography (CTCA) is a non-invasive alternative. A multi-center coverage with evidence development study was undertaken and combined with an economic model to estimate the cost-effectiveness of CTCA followed by CCA vs CCA alone. Alternative assumptions were tested in patient scenario and sensitivity analyses. CCA was found to dominate CTCA, however, CTCA was relatively more cost-effective in females, in advancing age, in patients with lower pre-test probabilities of CAD, the higher the sensitivity of CTCA and the lower the probability of undergoing a confirmatory CCA following a positive CTCA. RESULTS were very sensitive to alternative patient populations and modeling assumptions. Careful consideration of patient characteristics, procedures to improve the diagnostic yield of CTCA and selective use of CCA following CTCA will impact whether CTCA is cost-effective or dominates CCA.

Characterization of normal feline renal vascular anatomy with dual-phase CT angiography.

PubMed

Cáceres, Ana V; Zwingenberger, Allison L; Aronson, Lillian R; Mai, Wilfried

2008-01-01

Helical computed tomography angiography was used to evaluate the renal vascular anatomy of potential feline renal donors. One hundred and fourteen computed tomography angiograms were reviewed. The vessels were characterized as single without bifurcation, single with bifurcation, double, or triple. Multiplicity was most commonly seen for the right renal vein (45/114 vs. 3/114 multiple left renal veins, 0/114 multiple right renal arteries, and 8/114 multiple left renal arteries). The right kidney was 13.3 times more likely than the left to have multiple renal veins. Additional vascular variants included double caudal vena cava and an accessory renal artery. For the left kidney, surgery and computed tomography angiography findings were in agreement in 92% of 74 cats. For the right kidney, surgery and computed tomography angiography findings were in agreement in 6/6 cats. Our findings of renal vascular anatomy variations in cats were similar to previous reports in humans. Identifying and recognizing the pattern of distribution of these vessels is important when performing renal transplantation.

Flat panel angiography images in the post-operative follow-up of surgically clipped intracranial aneurysms.

PubMed

Budai, Caterina; Cirillo, Luigi; Patruno, Francesco; Dall'olio, Massimo; Princiotta, Ciro; Leonardi, Marco

2014-04-01

Cerebral aneurysms must be monitored for varying periods after surgical and/or endovascular treatment and the duration of follow-up will depend on the type of therapy and the immediate post-operative outcome. Surgical clipping for intracranial aneurysms is a valid treatment but the metal clips generate artefacts so that follow-up monitoring still relies on catheter angiography. This study reports our preliminary experience with volumetric angiography using a Philips Allura Xper FD biplane system in the post-operative monitoring of aneurysm residues or major vascular changes following the surgical clipping of intracranial aneurysms. Volumetric angiography yields not only volume-rendered (VR) images, but a volume CT can also be reconstructed at high spatial and contrast resolution from a single acquisition, significantly enhancing the technique's diagnostic power. Between August 2012 and April 2013, we studied 19 patients with a total of 26 aneurysms treated by surgical clipping alone or in combination with endovascular treatment. All patients underwent standard post-operative angiographic follow-up including a rotational volumetric acquisition. Follow-up monitoring disclosed eight aneurysm residues whose assessment was optimal after surgical clipping both in patients with one metal clip and in those with two or more clips. In addition, small residues (1.3 mm) could be monitored together with any change in the calibre or course of vessels located adjacent to the clips. In conclusion, flat panel volume CT is much more reliable than the old 3D acquisitions that yielded only VR images. This is particularly true in patients with small aneurysm residues or lesions with multiple metal clips.

Variations in Branching Pattern of Renal Artery in Kidney Donors Using CT Angiography.

PubMed

Munnusamy, Kumaresan; Kasirajan, Sankaran Ponnusamy; Gurusamy, Karthikeyan; Raghunath, Gunapriya; Bolshetty, Shilpakala Leshappa; Chakrabarti, Sudakshina; Annadurai, Priyadarshini; Miyajan, Zareena Begum

2016-03-01

Each kidney is supplied by a single renal artery originating from abdominal aorta. Since there are lots of renal surgeries happening now-a-days, it becomes mandatory for the surgeons to understand the abnormality and variations in the renal vasculature. To study the variations in the branching pattern of renal artery for the presence of early division and accessory renal artery in Indian kidney donors using CT angiography. The CT angiogram images of 100 normal individuals willing for kidney donation were analysed for early divisions and occurrence of accessory renal artery. A 51% of kidney donors showed variation in the renal artery. Out of 51% variations 38 individuals had accessory renal artery and 13 individuals had early division of renal artery. The distribution of accessory renal artery was equal on both sides (13% on right and left) and 12% of individuals had accessory renal artery on both sides. Out of 13% earlier divisions, 5% was on right side, 7% was on left side and 1% was on both sides. This study concludes that 51% of kidney donors had renal artery variations. Hence, awareness of variations by evaluating the donors is a must before renal transplantation, urological procedures and angiographic interventions.

Successful Embolization of a Renal Artery Pseudoaneurysm with Arteriovenous Fistula and Extravasations Using Onyx After Partial Nephrectomy for Renal Cell Carcinoma

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

Zelenak, Kamil, E-mail: zelenak@mfn.s; Sopilko, Igor; Svihra, Jan

2009-01-15

Partial nephrectomy can be associated with vascular complications. Computed tomography (CT) with CT angiography is ideal for noninvasive imaging of this process. The treatment of choice is selective embolization. Successful transcatheter embolization of right renal subsegmental artery pseudoaneurysm with arteriovenous fistula and extravasations using Onyx was performed in a 66-year-old woman with macrohematuria 12 days after partial nephrectomy for renal cell carcinoma.

Prospective randomized comparison of rotational angiography with three-dimensional reconstruction and computed tomography merged with electro-anatomical mapping: a two center atrial fibrillation ablation study.

PubMed

Anand, Rishi; Gorev, Maxim V; Poghosyan, Hermine; Pothier, Lindsay; Matkins, John; Kotler, Gregory; Moroz, Sarah; Armstrong, James; Nemtsov, Sergei V; Orlov, Michael V

2016-08-01

To compare the efficacy and accuracy of rotational angiography with three-dimensional reconstruction (3DATG) image merged with electro-anatomical mapping (EAM) vs. CT-EAM. A prospective, randomized, parallel, two-center study conducted in 36 patients (25 men, age 65 ± 10 years) undergoing AF ablation (33 % paroxysmal, 67 % persistent) guided by 3DATG (group 1) vs. CT (group 2) image fusion with EAM. 3DATG was performed on the Philips Allura Xper FD 10 system. Procedural characteristics including time, radiation exposure, outcome, and navigation accuracy were compared between two groups. There was no significant difference between the groups in total procedure duration or time spent for various procedural steps. Minor differences in procedural characteristics were present between two centers. Segmentation and fusion time for 3DATG or CT-EAM was short and similar between both centers. Accuracy of navigation guided by either method was high and did not depend on left atrial size. Maintenance of sinus rhythm between the two groups was no different up to 24 months of follow-up. This study did not find superiority of 3DATG-EAM image merge to guide AF ablation when compared to CT-EAM fusion. Both merging techniques result in similar navigation accuracy.

Dose profiles for lung and breast regions at prospective and retrospective CT coronary angiography using optically stimulated luminescence dosimeters on a 64-detector CT scanner.

PubMed

Funama, Yoshinori; Taguchi, Katsuyuki; Utsunomiya, Daisuke; Oda, Seitaro; Murasaki, Hiroo; Yamashita, Yasuyuki; Awai, Kazuo

2012-01-01

The purpose of our study was to acquire dose profiles at critical organs of lung and breast regions using optically stimulated luminescence (OSL) dosimeters; assess the actual radiation dose delivered at retrospective and prospective computed tomography coronary angiography (CTCA). Using a chest CT phantom we applied a prospectively-gated step-and-shoot- and a retrospectively-gated helical mode on a 64-detector row CT scanner. Retrospective scan mode was used with and without electrocardiogram (ECG) based tube current modulation. OSL dosimeters were used to measure dose profiles. In the both scan modes we acquired dose profiles and determined the mean and maximum dose in left lung and in left breast regions. In prospective mode, the mean dose was 21.53 mGy in left lung- and 23.59 mGy in left breast region. With respect to the retrospective mode, the mean dose with tube current modulation was 38.63 mGy for left lung- and 46.02 mGy for left breast region, i.e. 0.56 and 0.55 times lower than the mean dose without modulation. The OSL dosimeter is useful for measurement of the actual radiation dose along z-axis at lung and breast regions in the prospective and the retrospective CTCA. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Systematic review of the accuracy of dual-source cardiac CT for detection of arterial stenosis in difficult to image patient groups.

PubMed

Westwood, Marie E; Raatz, Heike D I; Misso, Kate; Burgers, Laura; Redekop, Ken; Lhachimi, Stefan K; Armstrong, Nigel; Kleijnen, Jos

2013-05-01

To assess the diagnostic performance of dual-source cardiac (DSC) computed tomography (CT) newer-generation CT instruments for identifying anatomically significant coronary artery disease (CAD) in patients who are difficult to image by using 64-section CT. A literature search comprised bibliographic databases (January 1, 2000, to March 22, 2011, with a pragmatic update on September 6, 2012), trial registries, and conference proceedings. Only studies using invasive coronary angiography as reference standard were included. Risk of bias was assessed (QUADAS-2). Results were stratified according to patient group on the basis of clinical characteristics. Summary estimates of sensitivity and specificity of DSC CT for detecting 50% or greater arterial stenosis were calculated by using a bivariate summary receiver operating characteristic or random-effects model. Twenty-five studies reported accuracy of DSC CT for diagnosing CAD in difficult to image patients; in 22 studies, one of two CT units of the same manufacturer (Somatom Definition or Somatom Definition Flash) was used, and in the remaining three, a different CT unit of another manufacturer (Aquilion One) was used. The pooled, per-patient estimates of sensitivity were 97.7% (95% confidence interval [CI]: 88.0%, 99.9%) and 97.7% (95% CI: 93.2%, 99.3%) for patients with arrhythmias and high heart rates, respectively. The corresponding pooled estimates of specificity were 81.7% (95% CI: 71.6%, 89.4%) and 86.3% (95% CI: 80.2%, 90.7%), respectively. All data were acquired by using Somatom Definition. In two studies with Somatom and one study with Aquilion One, sensitivity estimates of 90% or greater were reported in patients with previous stent implantations; specificities were 81.7% and 89.5% for Somatom and 81.0% for Aquilion One. In patients with high coronary calcium scores, previous bypass grafts, or obesity, only per-segment or per-artery data were available. Sensitivity estimates remained high (>90% in all but one study), and specificities ranged from 79.1% to 100%. All data were acquired by using Somatom Definition. DSC CT may be sufficiently accurate to diagnose clinically significant CAD in some or all difficult to image patients. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121136/-/DC1. © RSNA, 2013.

Noninvasive physiologic assessment of coronary stenoses using cardiac CT.

PubMed

Xu, Lei; Sun, Zhonghua; Fan, Zhanming

2015-01-01

Coronary CT angiography (CCTA) has become an important noninvasive imaging modality in the diagnosis of coronary artery disease (CAD). CCTA enables accurate evaluation of coronary artery stenosis. However, CCTA provides limited information on the physiological significance of stenotic lesions. A noninvasive "one-stop-shop" diagnostic test that can provide both anatomical significance and functional significance of stenotic lesions would be beneficial in the diagnosis and management of CAD. Recently, with the introduction of novel techniques, such as myocardial CT perfusion, CT-derived fractional flow reserve (FFRCT), and transluminal attenuation gradient (TAG), CCTA has emerged as a noninvasive method for the assessment of both anatomy of coronary lesions and its physiological consequences during a single study. This review provides an overview of the current status of new CT techniques for the physiologic assessments of CAD.

Submillisievert median radiation dose for coronary angiography with a second-generation 320-detector row CT scanner in 107 consecutive patients.

PubMed

Chen, Marcus Y; Shanbhag, Sujata M; Arai, Andrew E

2013-04-01

To (a) use a new second-generation wide-volume 320-detector row computed tomographic (CT) scanner to explore optimization of radiation exposure in coronary CT angiography in an unselected and consecutive cohort of patients referred for clinical purposes and (b) compare estimated radiation exposure and image quality with that from a cohort of similar patients who underwent imaging with a previous first-generation CT system. The study was approved by the institutional review board, and all subjects provided written consent. Coronary CT angiography was performed in 107 consecutive patients with a new second-generation 320-detector row unit. Estimated radiation exposure and image quality were compared with those from 100 consecutive patients who underwent imaging with a previous first-generation scanner. Effective radiation dose was estimated by multiplying the dose-length product by an effective dose conversion factor of 0.014 mSv/mGy ⋅ cm and reported with size-specific dose estimates (SSDEs). Image quality was evaluated by two independent readers. The mean age of the 107 patients was 55.4 years ± 12.0 (standard deviation); 57 patients (53.3%) were men. The median body mass index was 27.3 kg/m(2) (range, 18.1-47.2 kg/m(2)); however, 71 patients (66.4%) were overweight, obese, or morbidly obese. A tube potential of 100 kV was used in 97 patients (90.6%), single-volume acquisition was used in 104 (97.2%), and prospective electrocardiographic gating was used in 106 (99.1%). The mean heart rate was 57.1 beats per minute ± 11.2 (range, 34-96 beats per minute), which enabled single-heartbeat scans in 100 patients (93.4%). The median radiation dose was 0.93 mSv (interquartile range [IQR], 0.58-1.74 mSv) with the second-generation unit and 2.67 mSv (IQR, 1.68-4.00 mSv) with the first-generation unit (P < .0001). The median SSDE was 6.0 mGy (IQR, 4.1-10.0 mGy) with the second-generation unit and 13.2 mGy (IQR, 10.2-18.6 mGy) with the first-generation unit (P < .0001). Overall, the radiation dose was less than 0.5 mSv for 23 of the 107 CT angiography examinations (21.5%), less than 1 mSv for 58 (54.2%), and less than 4 mSv for 103 (96.3%). All studies were of diagnostic quality, with most having excellent image quality. Three of four image quality indexes were significantly better with the second-generation unit compared with the first-generation unit. The combination of a gantry rotation time of 275 msec, wide volume coverage, iterative reconstruction, automated exposure control, and larger x-ray power generator of the second-generation CT scanner provides excellent image quality over a wide range of body sizes and heart rates at low radiation doses. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122621/-/DC1. RSNA, 2013

Multislice CT Angiography in Renal Artery Stent Evaluation: Prospective Comparison with Intra-Arterial Digital Subtraction Angiography

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

Raza, Syed A.; Chughtai, Aamer R.; Wahba, Mona

2004-01-15

Purpose: To assess the role of multislice computed tomography angiography (MCTA) in the evaluation of renal artery stents, using intra-arterial digital subtraction angiography (DSA) as the gold standard. Methods: Twenty consecutive patients (15 men, 5 women) with 23 renal artery stents prospectively underwent both MCTA and DSA. Axial images, multiplanar reconstructions and maximum intensity projection images were used for diagnosis. The MCTA and DSA images were each interpreted without reference to the result of the other investigation. Results:The three cases of restenosis on DSA were detected correctly by MCTA; in 19 cases where MCTA showed a fully patent stent, themore » DSA was also negative. Sensitivity and negative predictive value (NPV) of MCTA were therefore 100%. In four cases, MCTA showed apparently minimal disease which was not shown on DSA. These cases are taken as false positive giving a specificity of 80% and a positive predictive value of 43%. Conclusion: The high sensitivity and NPV suggest MCTA may be useful as a noninvasive screen for renal artery stentrestenosis. MCTA detected mild disease in a few patients which was not confirmed on angiography.« less

WE-G-207-07: Iterative CT Shading Correction Method with No Prior Information

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

Wu, P; Mao, T; Niu, T

2015-06-15

Purpose: Shading artifacts are caused by scatter contamination, beam hardening effects and other non-ideal imaging condition. Our Purpose is to propose a novel and general correction framework to eliminate low-frequency shading artifacts in CT imaging (e.g., cone-beam CT, low-kVp CT) without relying on prior information. Methods: Our method applies general knowledge of the relatively uniform CT number distribution in one tissue component. Image segmentation is applied to construct template image where each structure is filled with the same CT number of that specific tissue. By subtracting the ideal template from CT image, the residual from various error sources are generated.more » Since the forward projection is an integration process, the non-continuous low-frequency shading artifacts in the image become continuous and low-frequency signals in the line integral. Residual image is thus forward projected and its line integral is filtered using Savitzky-Golay filter to estimate the error. A compensation map is reconstructed on the error using standard FDK algorithm and added to the original image to obtain the shading corrected one. Since the segmentation is not accurate on shaded CT image, the proposed scheme is iterated until the variation of residual image is minimized. Results: The proposed method is evaluated on a Catphan600 phantom, a pelvic patient and a CT angiography scan for carotid artery assessment. Compared to the one without correction, our method reduces the overall CT number error from >200 HU to be <35 HU and increases the spatial uniformity by a factor of 1.4. Conclusion: We propose an effective iterative algorithm for shading correction in CT imaging. Being different from existing algorithms, our method is only assisted by general anatomical and physical information in CT imaging without relying on prior knowledge. Our method is thus practical and attractive as a general solution to CT shading correction. This work is supported by the National Science Foundation of China (NSFC Grant No. 81201091), National High Technology Research and Development Program of China (863 program, Grant No. 2015AA020917), and Fund Project for Excellent Abroad Scholar Personnel in Science and Technology.« less

Prediction model to estimate presence of coronary artery disease: retrospective pooled analysis of existing cohorts

PubMed Central

Genders, Tessa S S; Steyerberg, Ewout W; Nieman, Koen; Galema, Tjebbe W; Mollet, Nico R; de Feyter, Pim J; Krestin, Gabriel P; Alkadhi, Hatem; Leschka, Sebastian; Desbiolles, Lotus; Meijs, Matthijs F L; Cramer, Maarten J; Knuuti, Juhani; Kajander, Sami; Bogaert, Jan; Goetschalckx, Kaatje; Cademartiri, Filippo; Maffei, Erica; Martini, Chiara; Seitun, Sara; Aldrovandi, Annachiara; Wildermuth, Simon; Stinn, Björn; Fornaro, Jürgen; Feuchtner, Gudrun; De Zordo, Tobias; Auer, Thomas; Plank, Fabian; Friedrich, Guy; Pugliese, Francesca; Petersen, Steffen E; Davies, L Ceri; Schoepf, U Joseph; Rowe, Garrett W; van Mieghem, Carlos A G; van Driessche, Luc; Sinitsyn, Valentin; Gopalan, Deepa; Nikolaou, Konstantin; Bamberg, Fabian; Cury, Ricardo C; Battle, Juan; Maurovich-Horvat, Pál; Bartykowszki, Andrea; Merkely, Bela; Becker, Dávid; Hadamitzky, Martin; Hausleiter, Jörg; Dewey, Marc; Zimmermann, Elke; Laule, Michael

2012-01-01

Objectives To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations. Design Retrospective pooled analysis of individual patient data. Setting 18 hospitals in Europe and the United States. Participants Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively). Main outcome measures Obstructive coronary artery disease (≥50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model factors and use of the CT based coronary calcium score). We assessed discrimination (c statistic), calibration, and continuous net reclassification improvement by cross validation for the four largest low prevalence datasets separately and the smaller remaining low prevalence datasets combined. Results We included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended model was a major predictor (0.79 to 0.88, 102%). Calibration for low prevalence datasets was satisfactory. Conclusions Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates. PMID:22692650

Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections.

PubMed

Jones, Ryan M; O'Reilly, Meaghan A; Hynynen, Kullervo

2015-07-01

Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981-5005 (2013)]. A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11-0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors' previous experimental measurements using source-based skull corrections O'Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285-1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood-brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography.

Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections

PubMed Central

Jones, Ryan M.; O’Reilly, Meaghan A.; Hynynen, Kullervo

2015-01-01

Purpose: Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981–5005 (2013)]. Methods: A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11–0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. Results: For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors’ previous experimental measurements using source-based skull corrections O’Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285–1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood–brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Conclusions: Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography. PMID:26133635

ART 3.5D: an algorithm to label arteries and veins from three-dimensional angiography.

PubMed

Barra, Beatrice; De Momi, Elena; Ferrigno, Giancarlo; Pero, Guglielmo; Cardinale, Francesco; Baselli, Giuseppe

2016-10-01

Preoperative three-dimensional (3-D) visualization of brain vasculature by digital subtraction angiography from computerized tomography (CT) in neurosurgery is gaining more and more importance, since vessels are the primary landmarks both for organs at risk and for navigation. Surgical embolization of cerebral aneurysms and arteriovenous malformations, epilepsy surgery, and stereoelectroencephalography are a few examples. Contrast-enhanced cone-beam computed tomography (CE-CBCT) represents a powerful facility, since it is capable of acquiring images in the operation room, shortly before surgery. However, standard 3-D reconstructions do not provide a direct distinction between arteries and veins, which is of utmost importance and is left to the surgeon's inference so far. Pioneering attempts by true four-dimensional (4-D) CT perfusion scans were already described, though at the expense of longer acquisition protocols, higher dosages, and sensible resolution losses. Hence, space is open to approaches attempting to recover the contrast dynamics from standard CE-CBCT, on the basis of anomalies overlooked in the standard 3-D approach. This paper aims at presenting algebraic reconstruction technique (ART) 3.5D, a method that overcomes the clinical limitations of 4-D CT, from standard 3-D CE-CBCT scans. The strategy works on the 3-D angiography, previously segmented in the standard way, and reprocesses the dynamics hidden in the raw data to recover an approximate dynamics in each segmented voxel. Next, a classification algorithm labels the angiographic voxels and artery or vein. Numerical simulations were performed on a digital phantom of a simplified 3-D vasculature with contrast transit. CE-CBCT projections were simulated and used for ART 3.5D testing. We achieved up to 90% classification accuracy in simulations, proving the feasibility of the presented approach for dynamic information recovery for arteries and veins segmentation.

CT Coronary Angiography vs. Coronary Artery Calcium Scoring for the Occupational Assessment of Military Aircrew.

PubMed

Parsons, Iain; Pavitt, Chris; Chamley, Rebecca; d'Arcy, Jo; Nicol, Ed

2017-02-01

To ensure flight safety military aircrew undergo regular clinical and occupational assessment. Coronary artery calcium scoring (CACS) has been established as an imaging modality to noninvasively assess coronary artery disease (CAD). CT coronary angiography (CTCA) potentially offers a more accurate assessment of CAD, but has not been formally assessed in military aircrew. This retrospective cohort study is designed to compare the theoretical differences in downstream investigations and occupational outcomes in aircrew with suspected CAD comparing CTCA with existing CACS pathways. A 2-yr retrospective cohort study of consecutive UK military patients who underwent a CTCA and CACS was undertaken. Patient demographics, CTCA and CACS results, and initial and final occupational restrictions were analyzed comparing current UK, Canadian, and U.S. pathways. There were 44 patients who underwent CACS and CTCA. The commonest indication for a CTCA was a positive exercise ECG. Increasing CACS, stenosis severity, and stenosis burden were associated with significantly greater likelihood of occupational restriction (P = < 0.01). Following CTCA, 26/44 (59%) patients were found to have evidence of CAD, with 13/44 (30%) having at least a single vessel stenosis ≥50%. All of these patients had subsequent occupational restrictions. Two patients with a calcium score ≤10 had at least 1 single vessel stenosis ≥50%. A CTCA pathway is potentially a better discriminator of CAD burden in aircrew when compared with CACS and may reduce downstream testing, allowing a more efficacious approach to CAD assessment in military aircrew.Parsons I, Pavitt C, Chamley R, d'Arcy J, Nicol E. CT coronary angiography vs. coronary artery calcium scoring for the occupational assessment of military aircrew. Aerosp Med Hum Perform. 2017; 88(2):76-81.

Deformable known component model-based reconstruction for coronary CT angiography

NASA Astrophysics Data System (ADS)

Zhang, X.; Tilley, S.; Xu, S.; Mathews, A.; McVeigh, E. R.; Stayman, J. W.

2017-03-01

Purpose: Atherosclerosis detection remains challenging in coronary CT angiography for patients with cardiac implants. Pacing electrodes of a pacemaker or lead components of a defibrillator can create substantial blooming and streak artifacts in the heart region, severely hindering the visualization of a plaque of interest. We present a novel reconstruction method that incorporates a deformable model for metal leads to eliminate metal artifacts and improve anatomy visualization even near the boundary of the component. Methods: The proposed reconstruction method, referred as STF-dKCR, includes a novel parameterization of the component that integrates deformation, a 3D-2D preregistration process that estimates component shape and position, and a polyenergetic forward model for x-ray propagation through the component where the spectral properties are jointly estimated. The methodology was tested on physical data of a cardiac phantom acquired on a CBCT testbench. The phantom included a simulated vessel, a metal wire emulating a pacing lead, and a small Teflon sphere attached to the vessel wall, mimicking a calcified plaque. The proposed method was also compared to the traditional FBP reconstruction and an interpolation-based metal correction method (FBP-MAR). Results: Metal artifacts presented in standard FBP reconstruction were significantly reduced in both FBP-MAR and STF- dKCR, yet only the STF-dKCR approach significantly improved the visibility of the small Teflon target (within 2 mm of the metal wire). The attenuation of the Teflon bead improved to 0.0481 mm-1 with STF-dKCR from 0.0166 mm-1 with FBP and from 0.0301 mm-1 with FBP-MAR - much closer to the expected 0.0414 mm-1. Conclusion: The proposed method has the potential to improve plaque visualization in coronary CT angiography in the presence of wire-shaped metal components.

Cost-effectiveness of coronary CT angiography in patients with chest pain: Comparison with myocardial single photon emission tomography.

PubMed

Lee, Seung-Pyo; Jang, Eun Jin; Kim, Yong-Jin; Cha, Myung-Jin; Park, Sun-Young; Song, Hyun Jin; Choi, Ji Eun; Shim, Jung-Im; Ahn, Jeonghoon; Lee, Hyun Joo

2015-01-01

Coronary CT angiography (CCTA) has been proven accurate and is incorporated in clinical recommendations for coronary artery disease (CAD) diagnosis workup, but cost-effectiveness data, especially in comparison to other methods such as myocardial single photon emission CT (SPECT) are insufficient. To compare the cost-effectiveness of CCTA and myocardial SPECT in a real-world setting. We performed a retrospective cohort study on consecutive patients with suspected CAD and a pretest probability between 10% and 90%. Test accuracy was compared by correcting referral bias to coronary angiography depending on noninvasive test results based on the Bayes' theorem and also by incorporating 1-year follow-up results. Cost-effectiveness was analyzed using test accuracy and quality-adjusted life year (QALY). The model using diagnostic accuracy used the number of patients accurately diagnosed among 1000 persons as the effect and contained only expenses for diagnostic testing as the cost. In the model using QALY, a decision tree was developed, and the time horizon was 1 year. CCTA was performed in 635 patients and SPECT in 997 patients. An accurate diagnosis per 1000 patients was achieved in 725 patients by CCTA vs 661 patients by SPECT. In the model using diagnostic accuracy, CCTA was more effective and less expensive than SPECT ($725.38 for CCTA vs $661.46 for SPECT). In the model using QALY, CCTA was generally more effective in terms of life quality (0.00221 QALY) and cost ($513) than SPECT. However, cost utility varied among subgroups, with SPECT outperforming CCTA in patients with a pretest probability of 30% to 60% (0.01890 QALY; $113). These results suggest that CCTA may be more cost-effective than myocardial SPECT. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Central Core Laboratory versus Site Interpretation of Coronary CT Angiography: Agreement and Association with Cardiovascular Events in the PROMISE Trial.

PubMed

Lu, Michael T; Meyersohn, Nandini M; Mayrhofer, Thomas; Bittner, Daniel O; Emami, Hamed; Puchner, Stefan B; Foldyna, Borek; Mueller, Martin E; Hearne, Steven; Yang, Clifford; Achenbach, Stephan; Truong, Quynh A; Ghoshhajra, Brian B; Patel, Manesh R; Ferencik, Maros; Douglas, Pamela S; Hoffmann, Udo

2018-04-01

Purpose To assess concordance and relative prognostic utility between central core laboratory and local site interpretation for significant coronary artery disease (CAD) and cardiovascular events. Materials and Methods In the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial, readers at 193 North American sites interpreted coronary computed tomographic (CT) angiography as part of the clinical evaluation of stable chest pain. Readers at a central core laboratory also interpreted CT angiography blinded to clinical data, site interpretation, and outcomes. Significant CAD was defined as stenosis greater than or equal to 50%; cardiovascular events were defined as a composite of cardiovascular death or myocardial infarction. Results In 4347 patients (51.8% women; mean age ± standard deviation, 60.4 years ± 8.2), core laboratory and site interpretations were discordant in 16% (683 of 4347), most commonly because of a finding of significant CAD by site but not by core laboratory interpretation (80%, 544 of 683). Overall, core laboratory interpretation resulted in 41% fewer patients being reported as having significant CAD (14%, 595 of 4347 vs 23%, 1000 of 4347; P < .001). Over a median follow-up period of 25 months, 1.3% (57 of 4347) sustained myocardial infarction or cardiovascular death. The C statistic for future myocardial infarction or cardiovascular death was 0.61 (95% confidence interval [CI]: 0.54, 0.68) for the core laboratory and 0.63 (95% CI: 0.56, 0.70) for the sites. Conclusion Compared with interpretation by readers at 193 North American sites, standardized core laboratory interpretation classified 41% fewer patients as having significant CAD. © RSNA, 2017 Online supplemental material is available for this article. Clinical trial registration no. NCT01174550.

Contrast agent comparison for three-dimensional micro-CT angiography: A cadaveric study.

PubMed

Kingston, Mitchell J; Perriman, Diana M; Neeman, Teresa; Smith, Paul N; Webb, Alexandra L

2016-07-01

Barium sulfate and lead oxide contrast media are frequently used for cadaver-based angiography studies. These contrast media have not previously been compared to determine which is optimal for the visualisation and measurement of blood vessels. In this study, the lower limb vessels of 16 embalmed Wistar rats, and four sets of cannulae of known diameter, were injected with one of three different contrast agents (barium sulfate and resin, barium sulfate and gelatin, and lead oxide combined with milk powder). All were then scanned using micro-computed tomography (CT) angiography and 3-D reconstructions generated. The number of branching generations of the rat lower limb vessels were counted and compared between the contrast agents using ANOVA. The diameter of the contrast-filled cannulae, were measured and used to calculate the accuracy of the measurements by comparing the bias and variance of the estimates. Intra- and inter-observer reliability were calculated using intra-class correlation coefficients. There was no significant difference (mean difference [MD] 0.05; MD 95% confidence interval [CI] -0.83 to 0.93) between the number of branching generations for barium sulfate-resin and lead oxide-milk powder. Barium sulfate-resin demonstrated less bias and less variance of the estimates (MD 0.03; standard deviation [SD] 1.96 mm) compared to lead oxide-milk powder (MD 0.11; SD 1.96 mm) for measurements of contrast-filled cannulae scanned at high resolution. Barium sulfate-resin proved to be more accurate than lead oxide-milk powder for high resolution micro-CT scans and is preferred due to its non-toxicity. This technique could be applied to any embalmed specimen model. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Simultaneous extraction of centerlines, stenosis, and thrombus detection in renal CT angiography

NASA Astrophysics Data System (ADS)

Subramanyan, Krishna; Durgan, Jacob; Hodgkiss, Thomas D.; Chandra, Shalabh

2004-05-01

The Renal Artery Stenosis (RAS) is the major cause of renovascular hypertension and CT angiography has shown tremendous promise as a noninvasive method for reliably detecting renal artery stenosis. The purpose of this study was to validate the semi-automated methods to assist in extraction of renal branches and characterizing the associated renal artery stenosis. Automatically computed diagnostic images such as straight MIP, curved MPR, cross-sections, and diameters from multi-slice CT are presented and evaluated for its acceptance. We used vessel-tracking image processing methods to extract the aortic-renal vessel tree in a CT data in axial slice images. Next, from the topology and anatomy of the aortic vessel tree, the stenosis, and thrombus section and branching of the renal arteries are extracted. The results are presented in curved MPR and continuously variable MIP images. In this study, 15 patients were scanned with contrast on Mx8000 CT scanner (Philips Medical Systems), with 1.0 mm thickness, 0.5mm slice spacing, and 120kVp and a stack of 512x512x150 volume sets were reconstructed. The automated image processing took less than 50 seconds to compute the centerline and borders of the aortic/renal vessel tree. The overall assessment of manual and automatically generated stenosis yielded a weighted kappa statistic of 0.97 at right renal arteries, 0.94 at the left renal branches. The thrombus region contoured manually and semi-automatically agreed upon at 0.93. The manual time to process each case is approximately 25 to 30 minutes.

Aortitis in giant cell arteritis: diagnosis with FDG PET/CT and agreement with CT angiography.

PubMed

Hommada, Mona; Mekinian, Arsène; Brillet, Pierre-Yves; Abad, Sébastien; Larroche, Claire; Dhôte, Robin; Fain, Olivier; Soussan, Michael

2017-11-01

To assess the detection rate of aortitis in giant cell arteritis (GCA) with fluorodeoxyglucose positron emission tomography/computed tomography (PET) and to compare the findings with CT angiography (CTA). Fifty-two GCA patients and 27 controls were included. GCA patients had a PET scan at diagnosis (35/52) or during relapse (17/52). Concomitant CTA was performed in 35/52 patients. Aortitis was defined as FDG uptake higher than the liver for PET and wall thickness≥3mm for CTA. Agreement between PET and CTA was evaluated by the kappa coefficient and Spearman correlation coefficient. Aortitis was diagnosed using PET in 40% (14/35) of patients at diagnosis and in 0% of controls (0/27). Agreement was perfect between PET and CT at a patient-based level, and very good at a vascular segment-based level (kappa: 0.72 to 1). PET was positive in 35% (6/17) of patients scanned during GCA relapse, showing aortitis (n=4) and/or articular uptake (n=4). Discrepancies between PET and CT were observed only in relapsing GCA (n=3). Correlation between the maximum standardized uptake value and wall thickness was moderate at diagnosis (r: 0.57 to 0.7) and not statistically significant during relapse. The detection rate of aortitis in GCA patients using PET is 40%, approximately in the range of CTA rates, suggesting that the two techniques have similar sensitivity. PET seems valuable in relapsing GCA, allowing the detection of vascular and articular activities. Copyright © 2017 Elsevier B.V. All rights reserved.

Patient-related factors influencing detectability of coronary arteries in 320-row CT angiography in infants with complex congenital heart disease.

PubMed

Yamasaki, Yuzo; Kawanami, Satoshi; Kamitani, Takeshi; Sagiyama, Koji; Shin, Seitaro; Hino, Takuya; Nagata, Hazumu; Yabuuchi, Hidetake; Nagao, Michinobu; Honda, Hiroshi

2018-05-05

To investigate the performance of second-generation 320-row computed tomographic (CT) angiography (CTA) in detecting coronary arteries and identify factors influencing visibility of the coronary arteries in infants with complex congenital heart disease (CHD). Data of 60 infants (aged 0-2 years, median 2 months) with complex CHD who underwent examination using 320-row CTA with low-dose prospective electrocardiogram-triggered volume target scanning were reviewed. The coronary arteries of each infant were assessed using a 0-4-point scoring system based on the number of coronary segments with a visible course. Clinical parameters, the CT value in the ascending aorta, image noise, and the radiation dose were subjected to univariate and multivariate analyses. The mean coronary score for all examinations was 2.6 ± 1.5 points. The mean attenuation in the ascending aorta was 306.7 ± 66.2 HU and the mean standard deviation was 21.7 ± 4.4. The mean effective radiation dose was 1.27 ± 0.39 mSv. Multivariate regression analysis showed significant correlations between coronary score and body weight (p < 0.05) and between coronary score and the CT value in the ascending aorta (p < 0.02). Second-generation 320-row CTA with prospective electrocardiogram-triggered volume target scanning and hybrid iterative reconstruction allows good visibility of the coronary arteries in infants with complex CHD. Body weight and the CT value in the ascending aorta are important factors influencing the visibility of the coronary arteries in infants.

Prognostic Value of Negative Coronary CT Angiography in Severely Obese Patients Prior to Bariatric Surgery: a Follow-Up After 6 Years.

PubMed

Messerli, Michael; Maywald, Céline; Wälti, Stephan; Warschkow, René; Wildermuth, Simon; Alkadhi, Hatem; Leschka, Sebastian; Schiesser, Marc

2017-08-01

This study aims to determine the long-term prognostic value of coronary CT angiography (CCTA) prior to bariatric surgery in severely obese patients with a body mass index (BMI) ≥35 kg/m 2 . Seventy consecutive patients undergoing cardiac CT for coronary assessment prior to bariatric surgery were prospectively included. Images were analysed for the presence of coronary calcification and for non-obstructive (<50%) or obstructive (>50% stenosis) coronary artery disease (CAD). A median clinical follow-up of 6.1 years in 54 patients was obtained for major adverse cardiovascular events (MACEs), defined as death, non-fatal myocardial infarction or coronary revascularisation. Weight loss and BMI decrease following bariatric surgery were recorded. The median BMI prior to surgery was 46.9 kg/m 2 . The median percentage of excess BMI loss after surgery was 75%. CT showed coronary calcification in 26 (48%) patients, whereas 28 (52%) patients had no calcification. CCTA revealed normal coronaries in 47 (87%) and non-obstructive CAD in 7 (13%) patients. No obstructive CAD was found. All patients successfully underwent bariatric surgery, and no MACE occurred neither perioperatively nor in the follow-up period. The negative predictive value of CCTA was 100% (95% confidence interval of 90.1-100.0%). In severely obese patients, the absence of obstructive CAD in cardiac CT prior to bariatric surgery with subsequently marked weight reduction has strong long-term prognostic implications for ruling out major adverse cardiac events in the postoperative period.

Phantom-based standardization of CT angiography images for spot sign detection.

PubMed

Morotti, Andrea; Romero, Javier M; Jessel, Michael J; Hernandez, Andrew M; Vashkevich, Anastasia; Schwab, Kristin; Burns, Joseph D; Shah, Qaisar A; Bergman, Thomas A; Suri, M Fareed K; Ezzeddine, Mustapha; Kirmani, Jawad F; Agarwal, Sachin; Shapshak, Angela Hays; Messe, Steven R; Venkatasubramanian, Chitra; Palmieri, Katherine; Lewandowski, Christopher; Chang, Tiffany R; Chang, Ira; Rose, David Z; Smith, Wade; Hsu, Chung Y; Liu, Chun-Lin; Lien, Li-Ming; Hsiao, Chen-Yu; Iwama, Toru; Afzal, Mohammad Rauf; Cassarly, Christy; Greenberg, Steven M; Martin, Renee' Hebert; Qureshi, Adnan I; Rosand, Jonathan; Boone, John M; Goldstein, Joshua N

2017-09-01

The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

Motion correction for improving the accuracy of dual-energy myocardial perfusion CT imaging

NASA Astrophysics Data System (ADS)

Pack, Jed D.; Yin, Zhye; Xiong, Guanglei; Mittal, Priya; Dunham, Simon; Elmore, Kimberly; Edic, Peter M.; Min, James K.

2016-03-01

Coronary Artery Disease (CAD) is the leading cause of death globally [1]. Modern cardiac computed tomography angiography (CCTA) is highly effective at identifying and assessing coronary blockages associated with CAD. The diagnostic value of this anatomical information can be substantially increased in combination with a non-invasive, low-dose, correlative, quantitative measure of blood supply to the myocardium. While CT perfusion has shown promise of providing such indications of ischemia, artifacts due to motion, beam hardening, and other factors confound clinical findings and can limit quantitative accuracy. In this paper, we investigate the impact of applying a novel motion correction algorithm to correct for motion in the myocardium. This motion compensation algorithm (originally designed to correct for the motion of the coronary arteries in order to improve CCTA images) has been shown to provide substantial improvements in both overall image quality and diagnostic accuracy of CCTA. We have adapted this technique for application beyond the coronary arteries and present an assessment of its impact on image quality and quantitative accuracy within the context of dual-energy CT perfusion imaging. We conclude that motion correction is a promising technique that can help foster the routine clinical use of dual-energy CT perfusion. When combined, the anatomical information of CCTA and the hemodynamic information from dual-energy CT perfusion should facilitate better clinical decisions about which patients would benefit from treatments such as stent placement, drug therapy, or surgery and help other patients avoid the risks and costs associated with unnecessary, invasive, diagnostic coronary angiography procedures.

Residual aneurysm after metal coils treatment detected by spectral CT

PubMed Central

Wang, Yang; Gao, Xiaolei; Lu, Aixun; Zhou, Zhengyang; Li, Baoxin

2012-01-01

Digital subtraction angiography (DSA) is currently the gold standard for diagnosing the residue or recurrence of aneurysm after treatment, especially in the presence of metal coils. However, DSA is an invasive procedure which may cause additional trauma and economic burden to patients. Spectral CT imaging, as a newly introduced CT imaging mode, produces monochromatic image sets that is able to reduce beam-hardening and other metal-related artifacts, and has found its use in several clinical applications including brain imaging to reduce beam-hardening artifacts. In this study, we describe a case of spectral CT imaging in follow-up of the metal coils treatment and detection of a small leaf of residual aneurysm after metal coils treatment. PMID:23256074

Exponentially Decelerated Contrast Media Injection Rate Combined With a Novel Patient-Specific Contrast Formula Reduces Contrast Volume Administration and Radiation Dose During Computed Tomography Pulmonary Angiography.

PubMed

Saade, Charbel; Mayat, Ahmad; El-Merhi, Fadi

2016-01-01

Matching contrast injection timing with vessel dynamics significantly improves vessel opacification and reduces contrast dose in the assessment of pulmonary embolism during computed tomography (CT) pulmonary angiography. The aim of this study was to investigate opacification of the pulmonary vasculature (PV) during CT pulmonary angiography using a patient-specific contrast formula (PSCF) and exponentially decelerated contrast media (EDCM) injection rate. Institutional review board approved this retrospective study. Computed tomography pulmonary angiography was performed on 200 patients with suspected pulmonary embolism using a 64-channel CT scanner. Patient demographics were equally distributed. Patients were randomly assigned to 2 equal protocol groups: protocol A used a PSCF, and protocol B involved the use of a PSCF combined with EDCM. The mean cross-sectional opacification profile of 8 central and 11 peripheral PVs were measured for each patient, and arteriovenous contrast ratio was calculated. Protocols were compared using Mann-Whitney U nonparametric statistics. Jackknife alternative free-response receiver operating characteristic analyses were used to assess diagnostic efficacy. Interobserver variations were investigated using kappa methods. A number of pulmonary arteries demonstrated increases in opacification (P < 0.02) for protocol B compared with A, whereas opacification in all veins was reduced in protocol B (P < 0.03). Subsequently, increased arteriovenous contrast ratio in protocol B compared with A was observed at all anatomic locations (P < 0.0002). An increase in jackknife alternative free-response receiver operating characteristic figure of merit (P < 0.0002) and interobserver variation was observed with protocol B compared with protocol A (κ = 0.3-0.73). Mean contrast volume was reduced in protocol B (29 [4] mL) compared with protocol A (33 [9] mL). Mean effective radiation dose in protocol B (1.2 [0.4] mSv) was reduced by 14% compared with protocol A (1.4 [0.6] mSv). Significant improvements in visualization of the PV can be achieved with a low contrast volume using an EDCM and PSCF. The reduced risk of cancer induction is highlighted.

Coronary vasodilation by the use of sublingual nitroglycerin using 64-slice dual-source coronary computed tomography angiography.

PubMed

Okada, Munemasa; Nakashima, Yoshiteru; Nomura, Takafumi; Miura, Toshiro; Nao, Tomoko; Yoshimura, Masayuki; Sano, Yuichi; Matsunaga, Naofumi

2015-03-01

Sublingual nitroglycerin capsules or spray is routinely used to treat anginal attacks and to maximally dilate the epicardial coronary arteries during coronary angiography. These dilated coronary vessels have an advantage, but increased heart rates were disadvantageous for coronary computed tomography angiography (CTA). The influence of applying nitroglycerin was analyzed regarding the coronary diameter, coronary luminal attenuation, evaluable number of coronary segments, heart rate (HR), HR variability, the optimal reconstruction phase, and image scoring of CTA in the same patients using a 64-slice dual-source CT. Fifty-two patients with atypical chest pain underwent coronary CTA before and after the administration of sublingual nitroglycerin without heart rate control. The coronary diameter and luminal attenuation were measured on short-axial images in each coronary segment. The coronary vasodilation ratios (VRs) were calculated from the coronary diameters at the same location before and after the use of nitroglycerin. The local institutional review board approved this study and written informed consent was obtained from all the patients. No significant differences were noted in the HR variability or optimal reconstruction phase, despite an increase in HR after the use of nitroglycerin. Nitroglycerin significantly enlarged the coronary artery diameter, and VRs of each coronary segment ranged from 7.54% to 22.26%. As compared with baseline coronary diameter, VRs of minor segments (16.91%) were significantly larger than those of major segments (11.35%), and the magnitude of VR correlated with the baseline coronary diameter (r=-0.48, p<0.001). Coronary luminal attenuation significantly increased due to additional administration of contrast material after the use of nitroglycerin (p<0.01), but no significant difference was noted in the image quality after the use of nitroglycerin. Sublingual nitroglycerin significantly enlarged the coronary diameters, especially in peripheral small coronary arteries, and increased the evaluable number of coronary segments on coronary CTA. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Scatter correction using a primary modulator on a clinical angiography C-arm CT system.

PubMed

Bier, Bastian; Berger, Martin; Maier, Andreas; Kachelrieß, Marc; Ritschl, Ludwig; Müller, Kerstin; Choi, Jang-Hwan; Fahrig, Rebecca

2017-09-01

Cone beam computed tomography (CBCT) suffers from a large amount of scatter, resulting in severe scatter artifacts in the reconstructions. Recently, a new scatter correction approach, called improved primary modulator scatter estimation (iPMSE), was introduced. That approach utilizes a primary modulator that is inserted between the X-ray source and the object. This modulation enables estimation of the scatter in the projection domain by optimizing an objective function with respect to the scatter estimate. Up to now the approach has not been implemented on a clinical angiography C-arm CT system. In our work, the iPMSE method is transferred to a clinical C-arm CBCT. Additional processing steps are added in order to compensate for the C-arm scanner motion and the automatic X-ray tube current modulation. These challenges were overcome by establishing a reference modulator database and a block-matching algorithm. Experiments with phantom and experimental in vivo data were performed to evaluate the method. We show that scatter correction using primary modulation is possible on a clinical C-arm CBCT. Scatter artifacts in the reconstructions are reduced with the newly extended method. Compared to a scan with a narrow collimation, our approach showed superior results with an improvement of the contrast and the contrast-to-noise ratio for the phantom experiments. In vivo data are evaluated by comparing the results with a scan with a narrow collimation and with a constant scatter correction approach. Scatter correction using primary modulation is possible on a clinical CBCT by compensating for the scanner motion and the tube current modulation. Scatter artifacts could be reduced in the reconstructions of phantom scans and in experimental in vivo data. © 2017 American Association of Physicists in Medicine.

Impact of metal artifact reduction software on image quality of gemstone spectral imaging dual-energy cerebral CT angiography after intracranial aneurysm clipping.

PubMed

Dunet, Vincent; Bernasconi, Martine; Hajdu, Steven David; Meuli, Reto Antoine; Daniel, Roy Thomas; Zerlauth, Jean-Baptiste

2017-09-01

We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after intracranial aneurysm clipping. This retrospective study was approved by the institutional review board, which waived patient written consent. From January 2013 to September 2016, single source DE cerebral CTA were performed in 45 patients (mean age: 60 ± 9 years, male 9) after intracranial aneurysm clipping and reconstructed with and without MARs. Signal-to-noise (SNR), contrast-to-noise (CNR), and relative CNR (rCNR) ratios were calculated from attenuation values measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Volume of clip and artifacts and relative clip blurring reduction (rCBR) ratios were also measured at each energy level with/without MARs. Variables were compared between GSI and GSI-MARs using the paired Wilcoxon signed-rank test. MARs significantly reduced metal artifacts at all energy levels but 130 and 140 keV, regardless of clips' location and number. The optimal rCBR was obtained at 110 and 80 keV, respectively, on GSI and GSI-MARs images, with up to 96% rCNR increase on GSI-MARs images. The best compromise between metal artifact reduction and rCNR was obtained at 70-75 and 65-70 keV for GSI and GSI-MARs images, respectively, with up to 15% rCBR and rCNR increase on GSI-MARs images. MARs significantly reduces metal artifacts on DE cerebral CTA after intracranial aneurysm clipping regardless of clips' location and number. It may be used to reduce radiation dose while increasing CNR.

Anatomy and function: PET-CT.

PubMed

Kajander, Sami; Saraste, Antti; Ukkonen, Heikki; Knuuti, Juhani

2010-05-01

CT coronary angiography and perfusion PET form an attractive combination to study coronary artery lesions and their consequences in patients with coronary artery disease. Whereas CT provides non-invasive assessment of coronary lumen and wall, PET perfusion is a reliable method for the evaluation of myocardial flow. CT, although very capable of ruling out significant coronary artery disease, is less than satisfactory in assessing the actual significance of the detected lesions. PET imaging, despite its excellent sensitivity, fails to describe the exact anatomy of the epicardial vessels. By fusing image data from these two modalities, lesions can be accurately correlated with their physiological or anatomical counterparts. Hybrid PET-CT devices, now in wide clinical use, allow such fusion in a one-stop-shop study. Although still seeking its place in clinical scenarios, growing evidence suggests that hybrid PET-CT imaging of coronary anatomy and myocardial perfusion can accurately - and non-invasively - assess the existence and degree of coronary artery disease.

Life-threatening gastrointestinal system bleeding in Hodgkin disease: multidetector CT findings and review of the literature.

PubMed

Akpinar, Erhan; Türkbey, Bariş; Cil, Barbaros Erhan; Canyiğit, Murat; Dündar, Ziya; Balkanci, Ferhun

2007-06-01

Acute lower gastrointestinal system (GIS) bleeding is a life-threatening condition. Immediate determination of the origin of the bleeding is crucial, since hemostatic management must be initiated as rapidly as possible. Colonoscopy, radionuclide studies, and conventional angiography are considered the most important methods for assessing the origin of the bleeding. There are few published reports about the feasibility of computed tomography (CT) in acute GIS bleeding. We present multidetector CT (MDCT) findings in a case of Hodgkin disease status one month post-chemotherapy (CHOP protocol; cyclophosphamide, doxorubicin, vincristine, prednisone) that presented with acute lower GIS bleeding.

Hematoma Expansion Following Acute Intracerebral Hemorrhage

PubMed Central

Brouwers, H. Bart; Greenberg, Steven M.

2013-01-01

Intracerebral hemorrhage, the most devastating form of stroke, has no specific therapy proven to improve outcome by randomized controlled trial. Location and baseline hematoma volume are strong predictors of mortality, but are non-modifiable by the time of diagnosis. Expansion of the initial hematoma is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for hematoma expansion have been identified, including baseline ICH volume, early presentation after symptom onset, anticoagulation, and the CT angiography spot sign. Although the biological mechanisms of hematoma expansion remain unclear, accumulating evidence supports a model of ongoing secondary bleeding from ruptured adjacent vessels surrounding the initial bleeding site. Several large clinical trials testing therapies aimed at preventing hematoma expansion are in progress, including aggressive blood pressure reduction, treatment with recombinant factor VIIa guided by CT angiography findings, and surgical intervention for superficial hematomas without intraventricular extension. Hematoma expansion is so far the only marker of outcome that is amenable to treatment and thus a potentially important therapeutic target. PMID:23466430

Comparative effectiveness of coronary CT angiography vs stress cardiac imaging in patients following hospital admission for chest pain work-up: The Prospective First Evaluation in Chest Pain (PERFECT) Trial.

PubMed

Uretsky, Seth; Argulian, Edgar; Supariwala, Azhar; Agarwal, Shiv K; El-Hayek, Georges; Chavez, Patricia; Awan, Hira; Jagarlamudi, Ashadevi; Puppala, Siva P; Cohen, Randy; Rozanski, Alan

2017-08-01

Because the frequency of cardiac event rates is low among chest pain patients following either performance of coronary CT angiography (CCTA) or stress testing, there is a need to better assess how these tests influence the central management decisions that follow from cardiac testing. The present study was performed to assess the relative impact of CCTA vs stress testing on medical therapies and downstream resource utilization among patients admitted for the work-up of chest pain. The admitted patients were randomized in a 1:1 ratio to either cardiac imaging stress test or CCTA. Primary outcomes were time to discharge, change in medication usage, and frequency of downstream testing, cardiac interventions, and cardiovascular re-hospitalizations. We randomized 411 patients, 205 to stress testing, and 206 to CCTA. There were no differences in time to discharge or initiation of new cardiac medications at discharge. At 1 year follow-up, there was no difference in the number of patients who underwent cardiovascular downstream tests in the CCTA vs stress test patients (21% vs 15%, P = .1) or cardiovascular hospitalizations (14% vs 16%, P = .5). However, there was a higher frequency of invasive angiography in the CCTA group (11% vs 2%, P = .001) and percutaneous coronary interventions (6% vs 0%, P < .001). Randomization of hospitalized patients admitted for chest pain work-up to either CCTA or to stress testing resulted in similar discharge times, change in medical therapies at discharge, frequency of downstream noninvasive testing, and repeat hospitalizations. However, a higher frequency of invasive coronary angiography and revascularization procedures were performed in the CCTA arm. (ClinicalTrials.gov number, NCT01604655.).

Cost-effectiveness of angiographic imaging in isolated perimesencephalic subarachnoid hemorrhage.

PubMed

Kalra, Vivek B; Wu, Xiao; Forman, Howard P; Malhotra, Ajay

2014-12-01

The purpose of this study is to perform a comprehensive cost-effectiveness analysis of all possible permutations of computed tomographic angiography (CTA) and digital subtraction angiography imaging strategies for both initial diagnosis and follow-up imaging in patients with perimesencephalic subarachnoid hemorrhage on noncontrast CT. Each possible imaging strategy was evaluated in a decision tree created with TreeAge Pro Suite 2014, with parameters derived from a meta-analysis of 40 studies and literature values. Base case and sensitivity analyses were performed to assess the cost-effectiveness of each strategy. A Monte Carlo simulation was conducted with distributional variables to evaluate the robustness of the optimal strategy. The base case scenario showed performing initial CTA with no follow-up angiographic studies in patients with perimesencephalic subarachnoid hemorrhage to be the most cost-effective strategy ($5422/quality adjusted life year). Using a willingness-to-pay threshold of $50 000/quality adjusted life year, the most cost-effective strategy based on net monetary benefit is CTA with no follow-up when the sensitivity of initial CTA is >97.9%, and CTA with CTA follow-up otherwise. The Monte Carlo simulation reported CTA with no follow-up to be the optimal strategy at willingness-to-pay of $50 000 in 99.99% of the iterations. Digital subtraction angiography, whether at initial diagnosis or as part of follow-up imaging, is never the optimal strategy in our model. CTA without follow-up imaging is the optimal strategy for evaluation of patients with perimesencephalic subarachnoid hemorrhage when modern CT scanners and a strict definition of perimesencephalic subarachnoid hemorrhage are used. Digital subtraction angiography and follow-up imaging are not optimal as they carry complications and associated costs. © 2014 American Heart Association, Inc.

IntAct: Intraoperative Fluorescence Angiography (IFA) to Prevent Anastomotic Leak in Rectal Cancer Surgery: A Randomised Controlled Trial.

PubMed

Armstrong, G; Croft, J; Corrigan, N; Brown, J M; Goh, V; Quirke, P; Hulme, C; Tolan, D; Kirby, A; Cahill, R; O'Connell, R; Miskovic, D; Coleman, M; Jayne, D G

2018-05-11

Anastomotic leak (AL) is a major complication of rectal cancer surgery. Despite advances in surgical practice, rates of AL have remained static at around 10-15%. The aetiology of AL is multifactorial, but one of the most crucial risk factors, which is mostly under the control of the surgeon, is blood supply to the anastomosis. The MRC/NIHR IntAct study will determine whether assessment of anastomotic perfusion using a fluorescent dye (Indocyanine Green) and near-infrared laparoscopy can minimise the rate of anastomotic leak as compared to conventional white light laparoscopy. Two mechanistic sub-studies will explore the role of the rectal microbiome in AL and the predictive value of CT angiography/perfusion studies. IntAct is a prospective, unblinded, parallel group, multicentre, European, randomised controlled trial comparing surgery with intraoperative fluorescence angiography (IFA) against standard care (surgery with no IFA). The primary end-point is rate of clinical anastomotic leak at 90-days following surgery. Secondary endpoints include all AL (clinical and radiological), change in planned anastomosis, complications and re-interventions, use of stoma, cost effectiveness of the intervention and quality of life. Patients should have a diagnosis of adenocarcinoma of the rectum suitable for potentially curative surgery by anterior resection. Over three years, 880 patients from 25 European centres will be recruited and followed up for 90 days. IntAct will rigorously evaluate the use of IFA in rectal cancer surgery and explore the role of the microbiome in AL and the predictive value of preoperative CT angiography/perfusion scanning. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Three-dimensional rotational micro-angiography

NASA Astrophysics Data System (ADS)

Patel, Vikas

Computed tomography (CT) is state-of-the-art for 3D imaging in which images are acquired about the patient and are used to reconstruct the data. But the commercial CT systems suffer from low spatial resolution (0.5-2 lp/mm). Micro-CT (microCT) systems have high resolution 3D reconstruction (>10 lp/mm), but are currently limited to small objects, e.g., small animals. To achieve artifact free reconstructions, geometric calibration of the rotating-object cone-beam microCT (CBmicroCT) system is performed using new techniques that use only the projection images of the object, i.e., no calibration objects are required. Translations (up to 0.2 mm) occurring during the acquisition in the horizontal direction are detected, quantified, and corrected based on sinogram analysis. The parameters describing the physical axis of rotation determined using our image-based method (aligning anti-posed images) agree well (within 0.1 mm and 0.3 degrees) with those determined using other techniques that use calibration objects. Geometric calibrations of the rotational angiography (RA) systems (clinical cone-beam CT systems with fluoroscopic capabilities provided by flat-panel detectors (FPD)) are performed using a simple single projection technique (SPT), which aligns a known 3D model of a calibration phantom with the projection data. The calibration parameters obtained by the SPT are found to be reproducible (angles within 0.2° and x- and y-translations less than 2 mm) for over 7 months. The spatial resolution of the RA systems is found to be virtually unaffected by such small geometric variations. Finally, using our understanding of the geometric calibrations, we have developed methods to combine relatively low-resolution RA acquisitions (2-3 lp/mm) with high resolution microCT acquisitions (using a high-resolution micro-angiographic fluoroscope (MAF) attached to the RA gantry) to produce the first-ever 3D rotational micro-angiography (3D-RmicroA) system on a clinical gantry. Images of a rabbit with a coronary stent placed in an artery were obtained and reconstructed. To eliminate artifacts due to image truncation, lower-dose (compared to the MAF acquisition) full-FOV (FFOV) FPD RA sequences are also obtained. To ensure high-quality high-resolution reconstruction, the high-resolution images from the MAF are aligned spatially with the lower-dose FPD images (average correlation coefficient before and after alignment: 0.65 and 0.97 respectively), and the pixel values in the FPD image data are scaled (using linear regression) to match those of the MAF. Greater details without any visible truncation artifacts are seen in 3D RmicroA (MAF-FPD) images than in those of the FPD alone. The FWHM of line profiles of stent struts (100 micron diameter) are approximately 192 +/- 21 and 313 +/- 38 microns for the 3D RmicroA and FPD data, respectively. Thus, with the RmicroA system, we have essentially developed a high resolution CBmicroCT system for clinical use.

Computed tomography hepatic arteriography has a hepatic falciform artery detection rate that is much higher than that of digital subtraction angiography and 99mTc-MAA SPECT/CT: implications for planning 90Y radioembolization?

PubMed

Burgmans, M C; Too, C W; Kao, Y H; Goh, A S W; Chow, P K H; Tan, B S; Tay, K H; Lo, R H G

2012-12-01

To compare the hepatic falciform artery (HFA) detection rates of digital subtraction angiography (DSA), computed tomography hepatic arteriography (CTHA) and 99mTc-macroaggregated albumin (99mTc-MAA) single photon emission computed tomography with integrated CT (SPECT/CT) and to correlate HFA patency with complication rates of yttrium-90 (90Y) radioembolization. From August 2008 to November 2010, 79 patients (range 23-83 years, mean 62.3 years; 67 male) underwent pre-treatment DSA, CTHA and 99mTc-MAA scintigraphy (planar/SPECT/CT) to assess suitability for radioembolization with 90Y resin microspheres. Thirty-seven patients were excluded from the study, because CTHA was performed with a catheter position that did not result in opacification of the liver parenchyma adjacent to the falciform ligament. DSA, CTHA and 99mTc-MAA SPECT/CT images and medical records were retrospectively reviewed. A patent HFA was detected in 22 of 42 patients (52.3%). The HFA detection rates of DSA, CTHA and 99mTc-MAA SPECT/CT were 11.9%, 52.3% and 13.3%, respectively (p<0.0001). An origin from the segment 4 artery was seen in 51.7% of HFAs. Prophylactic HFA coil-embolization prior to 90Y microspheres infusion was performed in 2 patients. Of the patients who underwent radioembolization with a patent HFA, none developed supra-umbilical radiation dermatitis. One patient experienced epigastric pain attributed to post-embolization syndrome and was managed conservatively. The HFA detection rate of CTHA is superior to that of DSA and 99mTc-MAA SPECT/CT. Complications related to non-target radiation of the HFA vascular territory rarely occur, even in patients undergoing radioembolization with a patent HFA. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A Case of Pulmonary Hypertension Due to Fistulas Between Multiple Systemic Arteries and the Right Pulmonary Artery in an Adult Discovered for Occulted Dyspnoea.

PubMed

Li, Ji-Feng; Zhai, Zhen-Guo; Kuang, Tu-Guang; Liu, Min; Ma, Zhan-Hong; Li, Yi-Dan; Yang, Yuan-Hua

2017-08-01

Pulmonary hypertension (PH) can be caused by a fistula between the systemic and pulmonary arteries. Here, we report a case of PH due to multiple fistulas between systemic arteries and the right pulmonary artery where the ventilation/perfusion scan showed no perfusion in the right lung. A 32-year-old male patient was hospitalised for community-acquired pneumonia. After treatment with antibiotics, the pneumonia was alleviated but dyspnoea persisted. Pulmonary hypertension was diagnosed using right heart catheterisation, which detected the mean pulmonary artery pressure as 37mmHg. The anomalies were confirmed by contrast-enhanced CT scan (CT pulmonary angiography), systemic arterial angiography and pulmonary angiography. Following embolisation of the largest fistula, the haemodynamics and oxygen dynamics did not improve, and even worsened to some extent. After supportive therapy including diuretics and oxygen, the patient's dyspnoea, WHO function class and right heart function by transthoracic echocardiography all improved during follow-up. Pulmonary hypertension can be present even when the right lung perfusion is lost. Closure of fistulas by embolisation, when those fistulas act as the proliferating vessels, may be harmful. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Automatic tube potential selection with tube current modulation in coronary CT angiography: Can it achieve consistent image quality among various individuals?

PubMed

Wang, Xiao-Ping; Zhu, Xiao-Mei; Zhu, Yin-Su; Liu, Wang-Yan; Yang, Xiao-Han; Huang, Wei-Wei; Xu, Yi; Tang, Li-Jun

2018-07-01

The present study included a total of 111 consecutive patients who had undergone coronary computed tomography (CT) angiography, using a first-generation dual-source CT with automatic tube potential selection and tube current modulation. Body weight (BW) and body mass index (BMI) were recorded prior to CT examinations. Image noise and attenuation of the proximal ascending aorta (AA) and descending aorta (DA) at the middle level of the left ventricle were measured. Correlations between BW, BMI and objective image quality were evaluated using linear regression. In addition, two subgroups based on BMI (BMI ≤25 and >25 kg/m 2 ) were analyzed. Subjective image quality, image noise, the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were all compared between those. The image noise of the AA increased with the BW and BMI (BW: r=0.453, P<0.001; BMI: r=0.545, P<0.001). The CNR and SNR of the AA were inversely correlated with BW and BMI, respectively. The image noise of the DA and the CNR and SNR of the DA exhibited a similar association to those with the BW or BMI. The BMI >25 kg/m 2 group had a significant increase in image noise (33.1±6.9 vs. 27.8±4.0 HU, P<0.05) and a significant reduction in CNR and SNR, when compared with those in the BMI ≤25 kg/m 2 group (CNR: 18.9±4.3 vs. 16.1±3.7, P<0.05; SNR: 16.0±3.8 vs. 13.6±3.2, P<0.05). Patients with a BMI of ≤25 kg/m 2 had more coronary artery segments scored as excellent, compared with patients with a BMI of >25 kg/m 2 (P=0.02). In conclusion, this method is not able to achieve a consistent objective image quality across the entire patient population. The impact of BW and BMI on objective image quality was not completely eliminated. BMI-based adjustment of the tube potential may achieve a more consistent image quality compared to automatic tube potential selection, particularly in patients with a larger body habitus.

Evaluation of radiation dose of triple rule-out coronary angiography protocols with different scan length using 256-slice CT

NASA Astrophysics Data System (ADS)

Tsai, Chia-Jung; Lee, Jason J. S.; Chen, Liang-Kuang; Mok, Greta S. P.; Hsu, Shih-Ming; Wu, Tung-Hsin

2011-10-01

Triple rule-out coronary CT angiography (TRO-CTA) is a new approach for providing noninvasive visualization of coronary arteries with simultaneous evaluation of pulmonary arteries, thoracic aorta and other intrathoracic structures. The increasing use of TRO-CTA examination with longer scan length is associated with the concerns about radiation dose and their corresponding cancer risk. The purpose of this study is to evaluate organ dose and effective dose for the TRO-CTA examination with 2 scan lengths: TRO std and TRO ext, using 256-slice CT. TRO-CTA examinations were performed on a 256-slice CT scanner without ECG-based tube current modulation. Absorbed organ doses were measured using an anthropomorphic phantom and thermal-luminance dosimeters (TLDs). Effective dose was determined by taking a sum of the measured absorbed organ doses multiplied with the tissue weighting factor based on ICRP-103, and compared to that calculated using the dose-length product (DLP) method. We obtained high organ doses in the thyroid, esophagus, breast, heart and lung in both TRO-CTA protocols. Effective doses of the TRO std and TRO ext protocols with the phantom method were 26.37 and 42.49 mSv, while those with the DLP method were 19.68 and 38.96 mSv, respectively. Our quantitative dose information establishes a relationship between radiation dose and scanning length, and can provide a practical guidance to best clinical practice.

Aneurysmal rupture of the costo-cervical trunk in a patient with neurofibromatosis type 1: A case report☆

PubMed Central

Hoonjan, Bhupinder; Thayur, Nagendra; Abu-Own, Abdusalam

2013-01-01

INTRODUCTION Rupture of blood vessels associated with neurofibromatosis type 1 (NF-1) is a rare but life threatening complication. We report the first case of an aneurysmal rupture from the costocervical trunk in a NF-1 patient treated by endovascular embolisation. PRESENTATION OF CASE A 43 year-old gentleman with a past medical history of NF-1 presented with sudden onset left sided neck swelling. A computed tomography (CT) revealed a large cervical haematoma, which was causing airway compromise, requiring the patient to be intubated. Percutaneous embolisation of the bleeding vessel from the costo-cervical trunk was performed with successful haemostasis and no immediate complications. A repeat CT scan showed a reduction in the original cervical haematoma. However, six days post embolisation, the patient arrested with complete whiteout of the left hemithorax. DISCUSSION CT angiography is the gold standard for diagnosis of an aneurysmal rupture in NF-1 patients, and percutaneous embolisation is the preferred modality in patients who are haemodynamically stable due to arterial fragility and high intra operative mortality rates. The increasing haemothorax could be explained by the original cervical haematoma draining down into the pleural space, or the possibility of a new second bleed. CONCLUSION This is the first reported episode of bleeding from the costocervical trunk in NF-1 patients. Ruptured aneurysms require urgent CT angiography, if haemodynamically stable, and further input from the vascular surgeons and vascular radiologists. PMID:24463561

Aneurysmal rupture of the costo-cervical trunk in a patient with neurofibromatosis type 1: A case report.

PubMed

Hoonjan, Bhupinder; Thayur, Nagendra; Abu-Own, Abdusalam

2014-01-01

Rupture of blood vessels associated with neurofibromatosis type 1 (NF-1) is a rare but life threatening complication. We report the first case of an aneurysmal rupture from the costocervical trunk in a NF-1 patient treated by endovascular embolisation. A 43 year-old gentleman with a past medical history of NF-1 presented with sudden onset left sided neck swelling. A computed tomography (CT) revealed a large cervical haematoma, which was causing airway compromise, requiring the patient to be intubated. Percutaneous embolisation of the bleeding vessel from the costo-cervical trunk was performed with successful haemostasis and no immediate complications. A repeat CT scan showed a reduction in the original cervical haematoma. However, six days post embolisation, the patient arrested with complete whiteout of the left hemithorax. CT angiography is the gold standard for diagnosis of an aneurysmal rupture in NF-1 patients, and percutaneous embolisation is the preferred modality in patients who are haemodynamically stable due to arterial fragility and high intra operative mortality rates. The increasing haemothorax could be explained by the original cervical haematoma draining down into the pleural space, or the possibility of a new second bleed. This is the first reported episode of bleeding from the costocervical trunk in NF-1 patients. Ruptured aneurysms require urgent CT angiography, if haemodynamically stable, and further input from the vascular surgeons and vascular radiologists. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Variations in Branching Pattern of Renal Artery in Kidney Donors Using CT Angiography

PubMed Central

Munnusamy, Kumaresan; Gurusamy, Karthikeyan; Raghunath, Gunapriya; Bolshetty, Shilpakala Leshappa; Chakrabarti, Sudakshina; Annadurai, Priyadarshini; Miyajan, Zareena Begum

2016-01-01

Introduction Each kidney is supplied by a single renal artery originating from abdominal aorta. Since there are lots of renal surgeries happening now-a-days, it becomes mandatory for the surgeons to understand the abnormality and variations in the renal vasculature. Aim To study the variations in the branching pattern of renal artery for the presence of early division and accessory renal artery in Indian kidney donors using CT angiography. Materials and Methods The CT angiogram images of 100 normal individuals willing for kidney donation were analysed for early divisions and occurrence of accessory renal artery. Results A 51% of kidney donors showed variation in the renal artery. Out of 51% variations 38 individuals had accessory renal artery and 13 individuals had early division of renal artery. The distribution of accessory renal artery was equal on both sides (13% on right and left) and 12% of individuals had accessory renal artery on both sides. Out of 13% earlier divisions, 5% was on right side, 7% was on left side and 1% was on both sides. Conclusion This study concludes that 51% of kidney donors had renal artery variations. Hence, awareness of variations by evaluating the donors is a must before renal transplantation, urological procedures and angiographic interventions. PMID:27134847

The success of opening single chronic total occlusion lesions to improve myocardialviabilitytrial (SOS-COMEDY)

PubMed Central

Huang, Rongchong; Song, Xiantao; Zhang, Haishan; Tian, Wen; Huang, Zheng; Zhang, Xingwei; Yang, Junqing; Zhang, Dongfeng; Wu, Jian; Zhong, Lei; Ting, Henry H.

2018-01-01

Abstract Aims: Success of opening single (SOS)-comedy is a prospective multicenter study to compare the improvement in the decrease of myocardial viability by percutaneous coronary intervention (PCI) with that by optimal medical therapy (OMT) alone in patients with chronic total occlusion (CTO) of a single coronary artery. Methods and results: The risks and the benefits of both options (PCI and OMT) were listed in a CTO decision aid (DA). Eligible participants detected by invasive coronary angiography (ICA) or coronary computed tomography angiography (CCTA) were divided into PCI or OMT groups according to patients’ choice after shared-decision making process with DA. Participants will undergo positron emission tomography/computed tomography (PET/CT), cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE), and proceed to ICA and revascularization if possible. Blinded core laboratory interpretation will be performed for ICA, CCTA, PET/CT, CMR, and TTE. All participants will be followed up for 12 months. The primary endpoint is the improvement to the decrease of myocardial viability from baseline assessed with the use of PET/CT after 12-month follow-up. Conclusions: All of the patients are appropriately consented before enrolling in this study, which has been approved by the Ethics Committee. Results of SOS-COMEDY will be helpful to develop a strategy for single CTO patients. PMID:29668609

The success of opening single chronic total occlusion lesions to improve myocardialviabilitytrial (SOS-COMEDY): Study protocol of a prospective multicenter study.

PubMed

Huang, Rongchong; Song, Xiantao; Zhang, Haishan; Tian, Wen; Huang, Zheng; Zhang, Xingwei; Yang, Junqing; Zhang, Dongfeng; Wu, Jian; Zhong, Lei; Ting, Henry H

2018-04-01

Success of opening single (SOS)-comedy is a prospective multicenter study to compare the improvement in the decrease of myocardial viability by percutaneous coronary intervention (PCI) with that by optimal medical therapy (OMT) alone in patients with chronic total occlusion (CTO) of a single coronary artery. The risks and the benefits of both options (PCI and OMT) were listed in a CTO decision aid (DA). Eligible participants detected by invasive coronary angiography (ICA) or coronary computed tomography angiography (CCTA) were divided into PCI or OMT groups according to patients' choice after shared-decision making process with DA. Participants will undergo positron emission tomography/computed tomography (PET/CT), cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE), and proceed to ICA and revascularization if possible. Blinded core laboratory interpretation will be performed for ICA, CCTA, PET/CT, CMR, and TTE. All participants will be followed up for 12 months. The primary endpoint is the improvement to the decrease of myocardial viability from baseline assessed with the use of PET/CT after 12-month follow-up. All of the patients are appropriately consented before enrolling in this study, which has been approved by the Ethics Committee. Results of SOS-COMEDY will be helpful to develop a strategy for single CTO patients.

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

Li Xiao; Zhou Xiangping, E-mail: xiangpingzhou46@163.com; Guan Yongsong

Experimental research involving animal models plays a critical role in the development and improvement of minimally invasive therapies for hepatocellular carcinoma (HCC). As a large animal, the pig is commonly used for surgery and interventional radiology research. In this study, liver multicentric HCC with cirrhosis was induced in six China Taihu pigs by intraperitoneal injection of 10 mg/kg of N-nitrosodiethylamine once a week for 3 months, followed by a period of 10-12 months without N-nitrosodiethylamine treatment. All pigs were in generally good health until the end of the study. The tumor nodules appeared hyperattenuating in the arterial phase of amore » dynamic computed tomography (CT) scan. Digital subtraction angiography (DSA) and CT angiography demonstrated that the tumors derived their blood supply mainly from the hepatic artery system. Lipiodol-CT showed Lipiodol retention in tumor areas. The histology and electron microscopic ultrastructure of the chemically induced liver HCC in this study resembled human HCC with a cirrhosis background. An immunohistochemistry study confirmed that the tumors were of hepatocyte origin. All highly, moderately, and poorly differentiated HCC tumors were identified in this study. Cholangiocarcinoma was not seen in any of the animals. Due to its comparable size to human anatomy, the pig liver HCC model would give a better scope for interventional and surgical manipulations than small animal models.« less

Use of the 2.8 French Progreat microcatheter in diagnostic cerebral angiography.

PubMed

Griauzde, Julius; Gemmete, Joseph J; Shastri, Ravi; Pandey, Aditya S; Chaudhary, Neeraj

2017-01-01

Tortuous vascular anatomy poses a significant challenge to performing diagnostic cerebral angiography. To report a new cerebral angiography technique for overcoming tortuous aortic and supra-aortic anatomy using a 2.8 French (F) Progreat microcatheter (0.028 inch (internal diameter) (Terumo; Somerset, New Jersey, USA) to obtain a diagnostic cerebral angiogram. A retrospective analysis of consecutive cases undergoing diagnostic cerebral angiography at our institution between 1 January 2013 and 30 November 2015 in which a 2.8F Progreat microcatheter was used. Clinical and operative notes were reviewed and correlated with imaging. Radiologic imaging, including CT, MRI, and digital subtraction angiography, was reviewed. Neurologic, systemic, and local complications were recorded on the basis of clinical follow-up results after each angiographic examination. Events that occurred within 24 h of the angiography were considered to be complications of the procedure. Initial attempts at catheterization of the target vessel with various 4F and 5F catheters were unsuccessful owing to tortuosity, atherosclerotic disease, or occlusion of the catheter in the target vessel. Microcatheterization of the target vessel was successful in 59/62 (95%) target vessels. A diagnostic cerebral angiogram with a power injection was obtained in 59 (100%) of the successfully catheterized vessels. In one case, angiography proceeded to aneurysm coiling after over-the-wire exchange. In two cases, angiography proceeded to mechanical thrombectomy after over-the-wire exchange. No procedural complications were seen. The 2.8F Progreat microcatheter can be used to obtain a diagnostic cerebral angiogram in patients with anatomic challenges limiting catheterization by standard techniques. 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/.

Tailoring protocols for chest CT applications: when and how?

PubMed Central

Iezzi, Roberto; Larici, Anna Rita; Franchi, Paola; Marano, Riccardo; Magarelli, Nicola; Posa, Alessandro; Merlino, Biagio; Manfredi, Riccardo; Colosimo, Cesare

2017-01-01

In the medical era of early detection of diseases and tailored therapies, an accurate characterization and staging of the disease is pivotal for treatment planning. The widespread use of computed tomography (CT)—often with the use of contrast material (CM)—probably represents the most important advance in diagnostic radiology. The result is a marked increase in radiation exposure of the population for medical purposes, with its intrinsic carcinogenic potential, and CM affecting kidney function. The radiologists should aim to minimize patient’s risk by reducing radiation exposure and CM amount, while maintaining the highest image quality. To achieve this goal, it is necessary to perform “patient-centric imaging”. The purpose of this review is to provide radiologists with “tips and tricks” to control radiation dose at CT, summarizing technical artifices in order to reduce image noise and increase image contrast. Also chest CT tailored protocols are supplied, with particular attention to three most common thoracic CT protocols: aortic/cardiac CT angiography (CTA), pulmonary CTA, and routine chest CT. PMID:29097345

Pioglitazone decreases coronary artery inflammation in impaired glucose tolerance and diabetes mellitus: evaluation by FDG-PET/CT imaging.

PubMed

Nitta, Yoshikazu; Tahara, Nobuhiro; Tahara, Atsuko; Honda, Akihiro; Kodama, Norihiro; Mizoguchi, Minori; Kaida, Hayato; Ishibashi, Masatoshi; Hayabuchi, Naofumi; Ikeda, Hisao; Yamagishi, Sho-ichi; Imaizumi, Tsutomu

2013-11-01

The aim of this study was to compare the effect of pioglitazone with glimepiride on coronary arterial inflammation with serial (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) combined with computed tomography (CT) angiography. Recent studies have shown that FDG-PET combined with CT is a reliable tool to visualize and quantify vascular inflammation. Although pioglitazone significantly prevented the progression of coronary atherosclerosis and reduced the recurrence of myocardial infarction in patients with type 2 diabetes mellitus (DM), it remains unclear whether pioglitazone could attenuate coronary artery inflammation. Fifty atherosclerotic patients with impaired glucose tolerance or type 2 DM underwent determination of blood chemistries, anthropometric and inflammatory variables, and FDG-PET/CT angiography, and then were randomized to receive either pioglitazone or glimepiride for 16 weeks. Effects of the treatments on vascular inflammation of the left main trunk were evaluated by FDG-PET/CT angiography at baseline and end of the study. Vascular inflammation of the left main trunk was measured by blood-normalized standardized uptake value, known as a target-to-background ratio. Three patients dropped out of the study during the assessment or treatment. Finally, 25 pioglitazone-treated patients and 22 glimepiride-treated patients (37 men; mean age: 68.1 ± 8.3 years; glycosylated hemoglobin: 6.72 ± 0.70%) completed the study. After 16-week treatments, fasting plasma glucose and glycosylated hemoglobin values were comparably reduced in both groups. Changes in target-to-background ratio values from baseline were significantly greater in the pioglitazone group than in the glimepiride group (-0.12 ± 0.06 vs. 0.09 ± 0.07, p = 0.032), as well as changes in high-sensitivity C-reactive protein (pioglitazone vs. glimepiride group: median: -0.24 [interquartile range (IQR): -1.58 to -0.04] mg/l vs. 0.08 [IQR: -0.07 to 0.79] mg/l, p = 0.031). Our study indicated that pioglitazone attenuated left main trunk inflammation in patients with impaired glucose tolerance or DM in a glucose-lowering independent manner, suggesting that pioglitazone may protect against cardiac events in patients with impaired glucose tolerance or DM by suppressing coronary inflammation. (Anti-Inflammatory Effects of Pioglitazone; NCT00722631). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

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

PubMed

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

2011-01-01

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

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

PubMed

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

2013-01-01

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

DETECTION OF TREATMENT-NAIVE CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION BY SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PubMed

Ahmed, Daniel; Stattin, Martin; Graf, Alexandra; Forster, Julia; Glittenberg, Carl; Krebs, Ilse; Ansari-Shahrezaei, Siamak

2017-09-04

To compare the detection rate of choroidal neovascularization (CNV) in treatment-naive neovascular age-related macular degeneration by swept source optical coherence tomography angiography (SS-OCTA, Topcon's DRI Triton) working at 1,050 nm wavelength versus fluorescence angiography. Cross-sectional analysis of 156 eyes (107 neovascular age-related macular degeneration and 49 dry AMD) in 98 patients, previously diagnosed by multimodal imaging using fluorescein (FA) and indocyanine green angiography (Heidelberg's Spectralis) in a tertiary retina center, evaluated by SS-OCTA 4.5 mm × 4.5 mm and 6 mm × 6 mm macular cubes. Main outcome measures were sensitivity and specificity of SS-OCTA in AMD. Potential factors influencing CNV detection rate were analyzed. Swept source optical coherence tomography angiography detected CNV in 81 of 107 eyes, resulting in a sensitivity of 75.7%. In 49 eyes with dry AMD, no CNV could be identified (specificity 100%). A statistical significance was calculated for nondetection of treatment-naive CNV by SS-OCTA in pigment epithelial detachment over 400 μm (P = 0.0238). Topcon's SS-OCTA was not able to detect all CNV lesions. Large pigment epithelial detachments were associated with signal loss. Fluorescence angiography still remains the gold standard, but the tested SS-OCTA device can be considered as a feasible additional diagnostic tool in AMD.

New stroboscopic light source and technique for intraoperative retinal fluorescein angiography during penetrating keratoplasty

NASA Astrophysics Data System (ADS)

Krueger, Ronald R.; Morales, Ronald B.; Chong, Lawrence P.; Smith, Ronald E.

1994-06-01

We report the development of a new stroboscopic light source system and technique for performing intraoperative fluorescein angiography during penetrating keratoplasty for aphakic or pseudophakic bullous keratopathy. A controllable pulse xenon light source system with a fiber optic endoilluminator probe is used to perform high-quality intraoperative fluorescein angiography during penetrating keratoplasty in pigmented rabbits and human subjects. Following corneal trephination and extraction of the intraocular lens, a temporary Cobo keratoprosthesis is secured while a 20-gauge endoilluminator is inserted into the vitreous cavity through a limbal incision. The endoilluminator is advanced to a retinal illumination area of approximately 3 DD and 10% fluorescein is injected intravenously. A microscope camera coupled to a 50:50 beamsplitter photographs the passage of fluorescein dye while the surgeon maintains an unaltered view through the operating microscope. Angiograms through a keratoprosthesis show excellent contrast and resolution, comparable to standard fluorescein angiography. Fine peripapillary vessels are seen reproducibly and with great detail in the rabbits. All the phases of retinal angiography can be seen, including arteriolar constriction and capillary nonperfusion in one of four human subjects examined. High quality intraoperative fluorescein angiography can be performed in patients undergoing penetrating keratoplasty for aphakic/ pseudophakic bullous keratopathy. With this technology, preexisting retinal disorders such as cystoid macular edema might be identified in the perioperative setting allowing for important management decisions to be made intraoperatively.

[Study of CT Automatic Exposure Control System (CT-AEC) Optimization in CT Angiography of Lower Extremity Artery by Considering Contrast-to-Noise Ratio].

PubMed

Inada, Satoshi; Masuda, Takanori; Maruyama, Naoya; Yamashita, Yukari; Sato, Tomoyasu; Imada, Naoyuki

2016-01-01

To evaluate the image quality and effect of radiation dose reduction by setting for computed tomography automatic exposure control system (CT-AEC) in computed tomographic angiography (CTA) of lower extremity artery. Two methods of setting were compared for CT-AEC [conventional and contrast-to-noise ratio (CNR) methods]. Conventional method was set noise index (NI): 14and tube current threshold: 10-750 mA. CNR method was set NI: 18, minimum tube current: (X+Y)/2 mA (X, Y: maximum X (Y)-axis tube current value of leg in NI: 14), and maximum tube current: 750 mA. The image quality was evaluated by CNR, and radiation dose reduction was evaluated by dose-length-product (DLP). In conventional method, mean CNRs for pelvis, femur, and leg were 19.9±4.8, 20.4±5.4, and 16.2±4.3, respectively. There was a significant difference between the CNRs of pelvis and leg (P<0.001), and between femur and leg (P<0.001). In CNR method, mean CNRs for pelvis, femur, and leg were 15.2±3.3, 15.3±3.2, and 15.3±3.1, respectively; no significant difference between pelvis, femur, and leg (P=0.973) in CNR method was observed. Mean DLPs were 1457±434 mGy⋅cm in conventional method, and 1049±434 mGy·cm in CNR method. There was a significant difference in the DLPs of conventional method and CNR method (P<0.001). CNR method gave equal CNRs for pelvis, femur, and leg, and was beneficial for radiation dose reduction in CTA of lower extremity artery.

Micro-CT Based Experimental Liver Imaging Using a Nanoparticulate Contrast Agent: A Longitudinal Study in Mice

PubMed Central

Boll, Hanne; Nittka, Stefanie; Doyon, Fabian; Neumaier, Michael; Marx, Alexander; Kramer, Martin; Groden, Christoph; Brockmann, Marc A.

2011-01-01

Background Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging. Methodology ExiTron nano 6000 and ExiTron nano 12000, formulated for liver/spleen imaging and angiography, respectively, were intravenously injected in C57BL/6J-mice. The distribution and time course of contrast enhancement were analysed by repeated micro-CT up to 6 months. Finally, mice developing liver metastases after intrasplenic injection of colon carcinoma cells underwent longitudinal micro-CT imaging after a single injection of ExiTron nano. Principal Findings After a single injection of ExiTron nano the contrast of liver and spleen peaked after 4–8 hours, lasted up to several months and was tolerated well by all mice. In addition, strong contrast enhancement of abdominal and mediastinal lymph nodes and the adrenal glands was observed. Within the first two hours after injection, particularly ExiTron nano 12000 provided pronounced contrast for imaging of vascular structures. ExiTron nano facilitated detection of liver metastases and provided sufficient contrast for longitudinal observation of tumor development over weeks. Conclusions The nanoparticulate contrast agents ExiTron nano 6000 and 12000 provide strong contrast of the liver, spleen, lymph nodes and adrenal glands up to weeks, hereby allowing longitudinal monitoring of pathological processes of these organs in small animals, with ExiTron nano 12000 being particularly optimized for angiography due to its very high initial vessel contrast. PMID:21984939

Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

PubMed

Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

2018-02-01

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm 3 , 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

Comparison of image quality and radiation dose between fixed tube current and combined automatic tube current modulation in craniocervical CT angiography.

PubMed

Lee, E J; Lee, S K; Agid, R; Howard, P; Bae, J M; terBrugge, K

2009-10-01

The combined automatic tube current modulation (ATCM) technique adapts and modulates the x-ray tube current in the x-y-z axis according to the patient's individual anatomy. We compared image quality and radiation dose of the combined ATCM technique with those of a fixed tube current (FTC) technique in craniocervical CT angiography performed with a 64-section multidetector row CT (MDCT) system. A retrospective review of craniocervical CT angiograms (CTAs) by using combined ATCM (n = 25) and FTC techniques (n = 25) was performed. Other CTA parameters, such as kilovolt (peak), matrix size, FOV, section thickness, pitch, contrast agent, and contrast injection techniques, were held constant. We recorded objective image noise in the muscles at 2 anatomic levels: radiation exposure doses (CT dose index volume and dose-length product); and subjective image quality parameters, such as vascular delineation of various arterial vessels, visibility of small arterial detail, image artifacts, and certainty of diagnosis. The Mann-Whitney U test was used for statistical analysis. No significant difference was detected in subjective image quality parameters between the FTC and combined ATCM techniques. Most subjects in both study groups (49/50, 98%) had acceptable subjective artifacts. The objective image noise values at shoulder level did not show a significant difference, but the noise value at the upper neck was higher with the combined ATCM (P < .05) technique. Significant reduction in radiation dose (18% reduction) was noted with the combined ATCM technique (P < .05). The combined ATCM technique for craniocervical CTA performed at 64-section MDCT substantially reduced radiation exposure dose but maintained diagnostic image quality.

Multislice CT imaging of ruptured left sinus of Valsalva aneurysm with fistulous track between left sinus and right atrium.

PubMed

Pampapati, Praveenkumar; Rao, Hejmadi Tati Gururaj; Radhesh, Srinivasan; Anand, Hejjaji Krishnamurthy; Praveen, Lokkur Srinivasamurthy

2011-01-01

Sinus of valsalva aneurysm is a rare condition arising from any of the three aortic sinuses. Among them, an aneurysm arising from the left coronary sinus is the rarest. Most of these cases were earlier diagnosed using echocardiography and conventional angiography. But with the availability of advanced imaging modalities like 64 slice cardiac CT and MR modalities, this condition can be accurately assessed noninvasively. We report a case of ruptured aneurysm originating from the left coronary sinus with a long windsock type of fistulous track between the aneurysm and right atrium evaluated by 64 slice cardiac CT imaging. This was later confirmed perioperatively.

Verbesserte Visualisierung der Koronararterien in MSCT-Daten mit direkter Vergleichbarkeit zur Angiographie

NASA Astrophysics Data System (ADS)

Lacalli, Christina; Jähne, Marion; Wesarg, Stefan

In diesem Beitrag stellen wir neue, automatisierte Verfahren zur Visualisierung der Koronararterien einerseits und für eine direkte Vergleichbarkeit mit konventionellen Angiogrammen andererseits vor. Unser Ansatz umfasst Methoden für die automatische Extraktion des Herzens aus kontrastverstärkten CT-Daten, sowie für die Maskierung grosser kontrastmittelgefüllter Kavitäten des Herzens, um die Sichtbarkeit der Koronararterien bei der Darstellung mittels Volumenrendering zu verbessern. Zum direkten Vergleich mit konventionellen Angiographien wurde ein Verfahren zur automatischen Generierung von Projektionsansichten aus den CT-Daten entwickelt.

Hafnium-Based Contrast Agents for X-ray Computed Tomography.

PubMed

Berger, Markus; Bauser, Marcus; Frenzel, Thomas; Hilger, Christoph Stephan; Jost, Gregor; Lauria, Silvia; Morgenstern, Bernd; Neis, Christian; Pietsch, Hubertus; Sülzle, Detlev; Hegetschweiler, Kaspar

2017-05-15

Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry. The superior properties of this asymmetrically substituted hafnium CA were demonstrated by a CT angiography study in rabbits that revealed excellent signal contrast enhancement.

Reference ranges for LVEF and LV volumes from electrocardiographically gated 82Rb cardiac PET/CT using commercially available software.

PubMed

Bravo, Paco E; Chien, David; Javadi, Mehrbod; Merrill, Jennifer; Bengel, Frank M

2010-06-01

Electrocardiographic gating is increasingly used for (82)Rb cardiac PET/CT, but reference ranges for global functional parameters are not well defined. We sought to establish reference values for left ventricular ejection fraction (LVEF), end systolic volume (ESV), and end diastolic volume (EDV) using 4 different commercial software packages. Additionally, we compared 2 different approaches for the definition of a healthy individual. Sixty-two subjects (mean age +/- SD, 49 +/- 9 y; 85% women; mean body mass index +/- SD, 34 +/- 10 kg/m(2)) who underwent (82)Rb-gated myocardial perfusion PET/CT were evaluated. All subjects had normal myocardial perfusion and no history of coronary artery disease (CAD) or cardiomyopathy. Subgroup 1 consisted of 34 individuals with low pretest probability of CAD (<10%), and subgroup 2 comprised 28 subjects who had no atherosclerosis on a coronary CT angiogram obtained concurrently during the PET/CT session. LVEF, ESV, and EDV were calculated at rest and during dipyridamole-induced stress, using CardIQ Physio (a dedicated PET software) and the 3 major SPECT software packages (Emory Cardiac Toolbox, Quantitative Gated SPECT, and 4DM-SPECT). Mean LVEF was significantly different among all 4 software packages. LVEF was most comparable between CardIQ Physio (62% +/- 6% and 54% +/- 7% at stress and rest, respectively) and 4DM-SPECT (64% +/- 7% and 56% +/- 8%, respectively), whereas Emory Cardiac Toolbox yielded higher values (71% +/- 6% and 65% +/- 6%, respectively, P < 0.001) and Quantitated Gated SPECT lower values (56% +/- 8% and 50% +/- 8%, respectively, P < 0.001). Subgroup 1 (low likelihood) demonstrated higher LVEF values than did subgroup 2 (normal CT angiography findings), using all software packages (P < 0.05). However, mean ESV and EDV at stress and rest were comparable between both subgroups (p = NS). Intra- and interobserver agreement were excellent for all methods. The reference range of LVEF and LV volumes from gated (82)Rb PET/CT varies significantly among available software programs and therefore cannot be used interchangeably. LVEF results were higher when healthy subjects were defined by a low pretest probability of CAD than by normal CT angiography results.

Acute Renal Infarction Secondary to Calcific Embolus from Mitral Annular Calcification

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

Bande, Dinesh; Abbara, Suhny; Kalva, Sanjeeva P., E-mail: skalva@partners.org

2011-06-15

We report a case of a 62-year-old man who presented with right groin pain who subsequently was found to have a renal infarct secondary to calcific embolus from mitral annular calcification on CT and angiography. We briefly review the literature and discuss the importance of this entity in clinical practice.

Asymptomatic young man with an incidental murmur.

PubMed

Shojaeifard, Maryam; Pouraliakbar, Hamid Reza; Houshmand, Golnaz

2018-05-31

A 32-year old man was referred to our institution for transthoracic echocardiography (TTE) following detection of an incidental murmur on physical examination before blood donation. He was asymptomatic with no significant medical history. Physical examination revealed dual heart sounds with a grade II/VI systolic murmur heard in the left sternal border. An ECG was in normal sinus rhythm. TTE was performed (figure 1A-C, online supplementary videos 1-4) followed by cardiac CT angiography (CTA) (figure 1D,E).heartjnl;heartjnl-2018-313223v1/F1F1F1Figure 1(A) Transthoracic echocardiography, parasternal left ventricular long axis view. (B) Colour Doppler of modified short axis in the mid-left ventricular level. (C) Doppler flow velocity profile. (D) Cardiac CT angiography (CTA) sagittal reconstruction. (E) Three-dimensional CTA reconstruction of the heart. What is the diagnosis?Pericardial cyst.Ventricular septal defect.Kawasaki.Anomalous left coronary artery from pulmonary artery (ALCAPA). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Double aortic arch presenting with a foreign object in the oesophagus: a case report and imaging diagnosis.

PubMed

Yang, Xiuzhen; Ye, Jingjing; Gao, Zhan

2017-10-01

In this article, we report a rare case of double aortic arch. The case presented initially with a foreign object in the oesophagus. The patient was a 2-year-old boy, who was referred with primary symptoms of tussis (15 days) and emesis (2 days). He had a history of ingesting a coin. Routine chest X-ray indicated a rounded, metal foreign object in the upper oesophagus. A half-Yuan coin was removed by gastroduodenoscopy. Echocardiographic imaging suggested that the patient had double aortic arch, which was subsequently diagnosed by CT angiography with three-dimensional reconstruction. The right subclavian artery arose from the right loop of the double aortic arch. The left subclavian artery as well as left and right common carotid arteries had distinct origins from the left aortic arch. Imaging also indicated atresia of the distal left arch. The patient underwent corrective surgery and made a full recovery. Despite the rarity, double aortic arch should be considered when patients present with a foreign object in the oesophagus. Echocardiography and CT angiography can inform the diagnosis.

Structured Head and Neck CT Angiography Reporting Reduces Resident Revision Rates.

PubMed

Johnson, Tucker F; Brinjikji, Waleed; Doolittle, Derrick A; Nagelschneider, Alex A; Welch, Brian T; Kotsenas, Amy L

2018-04-12

This resident-driven quality improvement project was undertaken to assess the effectiveness of structured reporting to reduce revision rates for afterhours reports dictated by residents. The first part of the study assessed baseline revision rates for head and neck CT angiography (CTA) examinations dictated by residents during afterhours call. A structured report was subsequently created based on templates on the RSNA informatics reporting website and critical findings that should be assessed for on all CTA examinations. The template was made available to residents through the speech recognition software for all head and neck CTA examinations for a duration of 2 months. Report revision rates were then compared with and without use of the structured template. The structured template was found to reduce revision rates by approximately 50% with 10/41 unstructured reports revised and 2/17 structured reports revised. We believe that structured reporting can help reduce reporting errors, particularly in term of typographical errors, train residents to evaluate complex examinations in a systematic fashion, and assist them in recalling critical findings on these examinations. Copyright © 2018 Elsevier Inc. All rights reserved.

Tradeoff between noise reduction and inartificial visualization in a model-based iterative reconstruction algorithm on coronary computed tomography angiography.

PubMed

Hirata, Kenichiro; Utsunomiya, Daisuke; Kidoh, Masafumi; Funama, Yoshinori; Oda, Seitaro; Yuki, Hideaki; Nagayama, Yasunori; Iyama, Yuji; Nakaura, Takeshi; Sakabe, Daisuke; Tsujita, Kenichi; Yamashita, Yasuyuki

2018-05-01

We aimed to evaluate the image quality performance of coronary CT angiography (CTA) under the different settings of forward-projected model-based iterative reconstruction solutions (FIRST).Thirty patients undergoing coronary CTA were included. Each image was reconstructed using filtered back projection (FBP), adaptive iterative dose reduction 3D (AIDR-3D), and 2 model-based iterative reconstructions including FIRST-body and FIRST-cardiac sharp (CS). CT number and noise were measured in the coronary vessels and plaque. Subjective image-quality scores were obtained for noise and structure visibility.In the objective image analysis, FIRST-body produced the significantly highest contrast-to-noise ratio. Regarding subjective image quality, FIRST-CS had the highest score for structure visibility, although the image noise score was inferior to that of FIRST-body.In conclusion, FIRST provides significant improvements in objective and subjective image quality compared with FBP and AIDR-3D. FIRST-body effectively reduces image noise, but the structure visibility with FIRST-CS was superior to FIRST-body.

Evaluation of hepatic arterial anatomy by multidetector computed tomographic angiography in living donor liver transplantation.

PubMed

Keles, Papatya; Yuce, Ihsan; Keles, Sait; Kantarci, Mecit

2016-06-01

The aim of this study was to define the different courses and percentages of hepatic artery that were detected during preoperative evaluation of living liver donors by multidetector computed tomographic angiography (MDCTA). We evaluated 150 donors before hepatic transplantation. All of the donors were evaluated by multislice CT scan with 256 detectors. For each patient, arterial, portal and venous phase images were obtained. The hepatic arterial variations were evaluated by the same radiologist according to Michels' classification. Common hepatic arterial anatomy (type I) was observed in 95 donors (63.3%). Other arterial variations were determined in the remaining 55 donors (36.6%). The second common variation was type XI which did not match with the description of Michels' classification variation in 15 donors (10%). The remaining variations described in Michels' classification were seen at lower rates. Type VII or X variation was not seen. MDCTA is a useful method to identify the blood supply of the liver before the liver transplantations, and surgeons can make their plan on the basis of CT data.

In Vivo Small Animal Imaging using Micro-CT and Digital Subtraction Angiography

PubMed Central

Badea, C.T.; Drangova, M.; Holdsworth, D.W.; Johnson, G.A.

2009-01-01

Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review in vivo X-ray based small animal imaging, with a focus on in vivo micro-computed tomography (micro-CT) and digital subtraction angiography (DSA). We present the principles, technologies, image quality parameters and types of applications. We show that both methods can be used not only to provide morphological, but also functional information, such as cardiac function estimation or perfusion. Compared to other modalities, x-ray based imaging is usually regarded as being able to provide higher throughput at lower cost and adequate resolution. The limitations are usually associated with the relatively poor contrast mechanisms and potential radiation damage due to ionizing radiation, although the use of contrast agents and careful design of studies can address these limitations. We hope that the information will effectively address how x-ray based imaging can be exploited for successful in vivo preclinical imaging. PMID:18758005

Association of brain abscess with a mycotic aneurysm of the contralateral internal carotid artery in a patient of cyanotic heart disease

PubMed Central

Bansal, Sumit; Borkar, Sachin A.; Mahapatra, Ashok K.

2017-01-01

Congenital cyanotic heart disease can lead to intra-cranial involvement. Authors report a very rare case of right intra-cerebral abscess diagnosed on computerized tomography (CT) scan and simultaneous presence of an aneurysm of the left internal carotid artery diagnosed on CT angiogram in a 15-year-old child with congenital cyanotic heart disease with recent onset left hemiparesis. Right cerebral abscess was tapped and left internal carotid aneurysm was planned to be followed up by giving antibiotics and serial angiograms, but he could not survive and died due to non-cranial cause. We conclude that cerebral angiography is necessary to diagnose cerebro-vascular complications, including infectious aneurysms, in cases presenting with unusual findings on neuroimaging study. Patient must undergo serial angiography while being on intravenous antibiotics. Intervention (either surgical or endovascular) should be considered if there are no signs of regression of size of aneurysm or in the presence of aneurysm rupture. We have not been able to find a similar case in the English literature. PMID:28484536

Neuroimaging in adult penetrating brain injury: a guide for radiographers

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

Temple, Nikki; Donald, Cortny; Skora, Amanda

Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Basedmore » on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.« less

Anatomical variations of hepatic arterial system, coeliac trunk and renal arteries: an analysis with multidetector CT angiography.

PubMed

Ugurel, M S; Battal, B; Bozlar, U; Nural, M S; Tasar, M; Ors, F; Saglam, M; Karademir, I

2010-08-01

The purpose of our investigation was to determine the anatomical variations in the coeliac trunk-hepatic arterial system and the renal arteries in patients who underwent multidetector CT (MDCT) angiography of the abdominal aorta for various reasons. A total of 100 patients were analysed retrospectively. The coeliac trunk, hepatic arterial system and renal arteries were analysed individually and anatomical variations were recorded. Statistical analysis of the relationship between hepatocoeliac variations and renal artery variations was performed using a chi(2) test. There was a coeliac trunk trifurcation in 89% and bifurcation in 8% of the cases. Coeliac trunk was absent in 1%, a hepatosplenomesenteric trunk was seen in 1% and a splenomesenteric trunk was present in 1%. Hepatic artery variation was present in 48% of patients. Coeliac trunk and/or hepatic arterial variation was present in 23 (39.7%) of the 58 patients with normal renal arteries, and in 27 (64.3%) of the 42 patients with accessory renal arteries. There was a statistically significant correlation between renal artery variations and coeliac trunk-hepatic arterial system variations (p = 0.015). MDCT angiography permits a correct and detailed evaluation of hepatic and renal vascular anatomy. The prevalence of variations in the coeliac trunk and/or hepatic arteries is increased in people with accessory renal arteries. For that reason, when undertaking angiographic examinations directed towards any single organ, the possibility of variations in the vascular structure of other organs should be kept in mind.

The treatment of pseudoaneurysms with flow diverters after malignant otitis externa.

PubMed

Németh, Tamás; Szakács, László; Bella, Zsolt; Majoros, Valéria; Barzó, Pál; Vörös, Erika

2017-12-01

Background We report a case of bilateral malignant otitis externa complicated with bilateral petrous internal carotid artery pseudoaneurysms and their successful treatment with a flow diverter. Case report A 68-year-old woman with serious complications of type II diabetes mellitus had malignant otitis externa on the right side. She was treated with combined antibiotic therapy and underwent mastoidectomy for mastoiditis. She presented at our hospital with acute hemorrhage from the right external auditory canal. The emergency computed tomography (CT) angiography revealed a multiobulated pseudoaneurysm at the petrous segment of the right internal carotid artery. The pseudoaneurysm was treated with a 5 × 40-mm Surpass flow diverter. Three months later, she developed a malignant external otitis on the left side. As the infection progressed, a left-sided mastoiditis, a brain abscess, and a pseudoaneurysm at the petrous segment of the left internal carotid artery developed. The pseudoaneurysm caused bleeding from the left ear, and was treated with a 5 × 50-mm Surpass flow diverter. No recurrent bleeding was observed. Four months later, a follow-up angiography showed complete occlusion of the pseudoaneurysm on the left side, but a residual aneurysm could be detected on the right side. One year after the first intervention, the follow-up CT and magnetic resonance angiography revealed the complete occlusion of the aneurysms bilaterally. Conclusion The use of a flow diverter appears to be an efficient and safe method to occlude carotid pseudoaneurysms even in an inflammatory milieu.

CT features and common causes of arc of Riolan expansion: an analysis with 64-detector-row computed tomographic angiography

PubMed Central

Xie, Yuanliang; Jin, Chaolin; Zhang, Shutong; Wang, Xiang; Jiang, Yanping

2015-01-01

Objective: To study the manifestations of arc of Riolan expansion (ARE) using multi-detector computed tomography angiography (MDCTA). Materials and methods: The manifestations and clinical data of 626 consecutive mesentery CTA images were retrospectively analyzed. The 47 cases with ARE and 47 patients without expansion were involved. The average diameter of arc of Riolan was measured. Two radiologists after reaching consensus analyzed the shapes of mesenteric artery, CT findings and the occurrence and causes of ARE. Results: The mean diameter of arc of Riolan was 1.2 mm, 4.6 mm, 2.5 mm, 2.3 mm, 1.9 mm, 2.5 mm, and 2.0 mm at baseline and following obstruction of superior mesenteric artery (SMA), stenosis of SMA, obstruction of inferior mesenteric artery (IMA), stenosis of IMA, colon cancer, and active ulcerative colitis, respectively. The expansion of arc of Riolan was the most significant following obstruction of SMA. The diameters of arc of Riolan were significantly different between the upward flow group and the downward or the two-way flow groups, and between the colon tumor group and the active ulcerative colitis group. CT findings such as bowel wall thickening, contrast enhancement, intestinal obstruction, marginal artery expansion, lymph node enlargement varied and were help to identify the cause of ARE. Conclusions: ARE often suggests the occurrence of obstructed intestinal feeding artery or intestinal lesions. MDCTA can clearly display the situation of arc of Riolan and collateral circulation, and together with CT symptoms, can guide the selection of diagnosis and treatment schemes in clinic. PMID:26064208

Computed Tomography Cisternography for Evaluation of Trigeminal Neuralgia When Magnetic Resonance Imaging Is Contraindicated: Case Report and Review of the Literature.

PubMed

Gospodarev, Vadim; Chakravarthy, Vikram; Harms, Casey; Myers, Hannah; Kaplan, Brett; Kim, Esther; Pond, Matthew; De Los Reyes, Kenneth

2018-05-01

Trigeminal neuralgia (TGN) causes severe unilateral facial pain. The etiology is hypothesized to be segmental demyelination of the trigeminal nerve root via compression by the superior cerebellar artery (SCA). Microvascular decompression (MVD) allows immediate and long-term pain relief. Preoperative evaluation includes magnetic resonance imaging (MRI) and/or magnetic resonance angiography of the brain. Having a pacemaker is a contraindication for MRI. There have been isolated reports of using computed tomography (CT) cisternography scans for radiation planning for TGN. A 75-year-old male with a permanent pacemaker who had refractory TGN in the V2 (maxillary) distribution of the trigeminal nerve underwent CT cisternography to prepare for MVD. CT angiography with Isovue 370 intravenous contrast injection and 0.625-mm axial images were obtained from the skull base across the posterior fossa. An intrathecal injection of Isovue 180 was performed at the L2/3 level. Imaging revealed the right SCA abutting the medial margin of the proximal right trigeminal nerve. In surgery (K.D.), a standard retrosigmoid suboccipital craniotomy was performed to access the cerebellopontine angle and separate the abutting SCA and trigeminal nerve. The patient had immediate pain relief. MRI is the preferred method of evaluating for TGN because it offers excellent visualization of vasculature in relation to the trigeminal nerve without accompanying radiation exposure. However, for patients who have contraindications to MRI, CT cisternography is shown to also be an effective method for visualizing the trigeminal root entry zone and nearby vasculature in preparation for MVD of the trigeminal nerve. Published by Elsevier Inc.

Floating arterial thrombus related stroke treated by intravenous thrombolysis.

PubMed

Vanacker, P; Cordier, M; Janbieh, J; Federau, C; Michel, P

2014-01-01

The effects of intravenous thrombolysis on floating thrombi in cervical and intracranial arteries of acute ischemic stroke patients are unknown. Similarly, the best prevention methods of early recurrences remain controversial. This study aimed to describe the clinical and radiological outcome of thrombolyzed strokes with floating thrombi. We retrospectively analyzed all thrombolyzed stroke patients in our institution between 2003 and 2010 with floating thrombi on acute CT-angiography before the intravenous thrombolysis. The floating thrombus was diagnosed if an elongated thrombus of at least 5 mm length, completely surrounded by contrast on supra-aortic neck or intracerebral arteries, was present on CT-angiography. Demographics, vascular risk factors, and comorbidities were recorded and stroke etiology was determined after a standardized workup. Repeat arterial imaging was performed by CTA at 24 h or before if clinical worsening was noted and then by Doppler and MRA during the first week and at four months. Of 409 thrombolyzed stroke patients undergoing acute CT Angiography, seven (1.7%) had a floating thrombus; of these seven, six had it in the anterior circulation. Demographics, risk factors and stroke severity of these patients were comparable to the other thrombolyzed patients. After intravenous thrombolysis, the floating thrombi resolved completely at 24 h in four of the patients, whereas one had an early recurrent stroke and one developed progressive worsening. One patient developed early occlusion of the carotid artery with floating thrombus and subsequently a TIA. The two patients with a stable floating thrombus had no clinical recurrences. In the literature, only one of four reported cases were found to have a thrombolysis-related early recurrence. Long-term outcome seemed similar in thrombolyzed patients with floating thrombus, despite a possible increase of very early recurrence. It remains to be established whether acute mechanical thrombectomy could be a safer and more effective treatment to prevent early recurrence. However, intravenous thrombolysis should not be withheld in eligible stroke patients. © 2014 S. Karger AG, Basel.

Diagnostic Performance of a Novel Coronary CT Angiography Algorithm: Prospective Multicenter Validation of an Intracycle CT Motion Correction Algorithm for Diagnostic Accuracy.

PubMed

Andreini, Daniele; Lin, Fay Y; Rizvi, Asim; Cho, Iksung; Heo, Ran; Pontone, Gianluca; Bartorelli, Antonio L; Mushtaq, Saima; Villines, Todd C; Carrascosa, Patricia; Choi, Byoung Wook; Bloom, Stephen; Wei, Han; Xing, Yan; Gebow, Dan; Gransar, Heidi; Chang, Hyuk-Jae; Leipsic, Jonathon; Min, James K

2018-06-01

Motion artifact can reduce the diagnostic accuracy of coronary CT angiography (CCTA) for coronary artery disease (CAD). The purpose of this study was to compare the diagnostic performance of an algorithm dedicated to correcting coronary motion artifact with the performance of standard reconstruction methods in a prospective international multicenter study. Patients referred for clinically indicated invasive coronary angiography (ICA) for suspected CAD prospectively underwent an investigational CCTA examination free from heart rate-lowering medications before they underwent ICA. Blinded core laboratory interpretations of motion-corrected and standard reconstructions for obstructive CAD (≥ 50% stenosis) were compared with ICA findings. Segments unevaluable owing to artifact were considered obstructive. The primary endpoint was per-subject diagnostic accuracy of the intracycle motion correction algorithm for obstructive CAD found at ICA. Among 230 patients who underwent CCTA with the motion correction algorithm and standard reconstruction, 92 (40.0%) had obstructive CAD on the basis of ICA findings. At a mean heart rate of 68.0 ± 11.7 beats/min, the motion correction algorithm reduced the number of nondiagnostic scans compared with standard reconstruction (20.4% vs 34.8%; p < 0.001). Diagnostic accuracy for obstructive CAD with the motion correction algorithm (62%; 95% CI, 56-68%) was not significantly different from that of standard reconstruction on a per-subject basis (59%; 95% CI, 53-66%; p = 0.28) but was superior on a per-vessel basis: 77% (95% CI, 74-80%) versus 72% (95% CI, 69-75%) (p = 0.02). The motion correction algorithm was superior in subgroups of patients with severely obstructive (≥ 70%) stenosis, heart rate ≥ 70 beats/min, and vessels in the atrioventricular groove. The motion correction algorithm studied reduces artifacts and improves diagnostic performance for obstructive CAD on a per-vessel basis and in selected subgroups on a per-subject basis.

Feasibility Study of a Novel Thoraco-abdominal Aortic Hybrid Device (SPIDER-graft) in a Translational Pig Model.

PubMed

Debus, Eike S; Kölbel, Tilo; Duprée, Anna; Daum, Günter; Sandhu, Harleen K; Manzoni, Daniel; Wipper, Sabine H

2018-02-01

The hybrid SPIDER-graft consists of a proximal descending aortic stent graft and a conventional six branched Dacron graft for open abdominal aortic repair. Technical feasibility with regard to avoiding thoracotomy and extracorporeal circulation (ECC) during thoraco-abdominal aortic hybrid repair and peri-procedural safety of this novel device are unknown. This was a feasibility and safety study in domestic pigs (75-85 kg). The abdominal aorta including iliac bifurcation, left renal artery, and visceral arteries were exposed via retroperitoneal access. The right iliac branch was first temporarily anastomosed end to side to the distal aorta via partial clamping. During inflow reduction and infra-coeliac cross-clamping, the coeliac trunk (CT) was divided and the proximal stent graft portion of the SPIDER-graft was deployed into the descending aorta via the CT ostium. Retrograde visceral and antegrade aorto-iliac blood flow was maintained via the iliac side branch. The visceral, renal, and iliac arteries were sequentially anastomosed, finally replacing the first iliac end to side anastomosis. Technical success, blood flow, periods of ischaemia, and peri-procedural complications were evaluated after intra-operative completion angiography and post-operative computed tomography angiography. Six animals underwent successful thoracic stent graft deployment and distal open reconstruction without peri-operative death. The median thoracic graft implantation time was 4.5 min, and the median ischaemia times before reperfusion were 10 min for the CT, 8 min for the superior mesenteric artery, 13 min for the right renal artery, and 22 min for the left renal artery. Angiography demonstrated appropriate graft implantation and blood flow measurements confirmed sufficient blood flow through all side branches. In this translational pig model, thoraco-abdominal hybrid repair using the novel SPIDER-graft was successful in avoiding thoracotomy and ECC. Technical feasibility and safety appear promising, but need to be reassessed in humans. Copyright © 2017. Published by Elsevier Ltd.

Removal of bone in CT angiography by multiscale matched mask bone elimination.

PubMed

Gratama van Andel, H A F; Venema, H W; Streekstra, G J; van Straten, M; Majoie, C B L M; den Heeten, G J; Grimbergen, C A

2007-10-01

For clear visualization of vessels in CT angiography (CTA) images of the head and neck using maximum intensity projection (MIP) or volume rendering (VR) bone has to be removed. In the past we presented a fully automatic method to mask the bone [matched mask bone elimination (MMBE)] for this purpose. A drawback is that vessels adjacent to bone may be partly masked as well. We propose a modification, multiscale MMBE, which reduces this problem by using images at two scales: a higher resolution than usual for image processing and a lower resolution to which the processed images are transformed for use in the diagnostic process. A higher in-plane resolution is obtained by the use of a sharper reconstruction kernel. The out-of-plane resolution is improved by deconvolution or by scanning with narrower collimation. The quality of the mask that is used to remove bone is improved by using images at both scales. After masking, the desired resolution for the normal clinical use of the images is obtained by blurring with Gaussian kernels of appropriate widths. Both methods (multiscale and original) were compared in a phantom study and with clinical CTA data sets. With the multiscale approach the width of the strip of soft tissue adjacent to the bone that is masked can be reduced from 1.0 to 0.2 mm without reducing the quality of the bone removal. The clinical examples show that vessels adjacent to bone are less affected and therefore better visible. Images processed with multiscale MMBE have a slightly higher noise level or slightly reduced resolution compared with images processed by the original method and the reconstruction and processing time is also somewhat increased. Nevertheless, multiscale MMBE offers a way to remove bone automatically from CT angiography images without affecting the integrity of the blood vessels. The overall image quality of MIP or VR images is substantially improved relative to images processed with the original MMBE method.

Length of occlusion predicts recanalization and outcome after intravenous thrombolysis in middle cerebral artery stroke.

PubMed

Rohan, Vladimir; Baxa, Jan; Tupy, Radek; Cerna, Lenka; Sevcik, Petr; Friesl, Michal; Polivka, Jiri; Polivka, Jiri; Ferda, Jiri

2014-07-01

The length of large vessel occlusion is considered a major factor for therapy in patients with ischemic stroke. We used 4D-CT angiography evaluation of middle cerebral artery occlusion in prediction of recanalization and favorable clinical outcome and after intravenous thrombolysis (IV-tPA). In 80 patients treated with IV-tPA for acute complete middle cerebral artery/M1 occlusion determined using CT angiography and temporal maximum intensity projection, calculated from 4D-CT angiography, the length of middle cerebral artery proximal stump, occlusion in M1 or M1 and M2 segment were measured. Univariate and multivariate analyses were performed to define independent predictors of successful recanalization after 24 hours and favorable outcome after 3 months. The length of occlusion was measureable in all patients using temporal maximum intensity projection. Recanalization thrombolysis in myocardial infarction 2 to 3 was achieved in 37 individuals (46%). The extension to M2 segment as a category (odds ratio, 4.58; 95% confidence interval, 1.39-15.05; P=0.012) and the length of M1 segment occlusion (odds ratio, 0.82; 95% confidence interval, 0.73-0.92; P=0.0007) with an optimal cutoff value of 12 mm (sensitivity 0.67; specificity 0.71) were significant independent predictors of recanalization. Favorable outcome (modified Rankin scale 0-2) was achieved in 25 patients (31%), baseline National Institutes of Health Stroke Scale (odds ratio, 0.82; 95% confidence interval, 0.72-0.93; P=0.003) and the length of occlusion M1 in segment (odds ratio, 0.79; 95% confidence interval, 0.69-0.91; P=0.0008) with an optimal cutoff value of 11 mm (sensitivity 0.74; specificity 0.76) were significant independent predictors of favorable outcome. The length of middle cerebral artery occlusion is an independent predictor of successful IV-tPA treatment. © 2014 American Heart Association, Inc.

Feasibility of three-dimensional magnetic resonance angiography-fluoroscopy image fusion technique in guiding complex endovascular aortic procedures in patients with renal insufficiency.

PubMed

Schwein, Adeline; Chinnadurai, Ponraj; Shah, Dipan J; Lumsden, Alan B; Bechara, Carlos F; Bismuth, Jean

2017-05-01

Three-dimensional image fusion of preoperative computed tomography (CT) angiography with fluoroscopy using intraoperative noncontrast cone-beam CT (CBCT) has been shown to improve endovascular procedures by reducing procedure length, radiation dose, and contrast media volume. However, patients with a contraindication to CT angiography (renal insufficiency, iodinated contrast allergy) may not benefit from this image fusion technique. The primary objective of this study was to evaluate the feasibility of magnetic resonance angiography (MRA) and fluoroscopy image fusion using noncontrast CBCT as a guidance tool during complex endovascular aortic procedures, especially in patients with renal insufficiency. All endovascular aortic procedures done under MRA image fusion guidance at a single-center were retrospectively reviewed. The patients had moderate to severe renal insufficiency and underwent diagnostic contrast-enhanced magnetic resonance imaging after gadolinium or ferumoxytol injection. Relevant vascular landmarks electronically marked in MRA images were overlaid on real-time two-dimensional fluoroscopy for image guidance, after image fusion with noncontrast intraoperative CBCT. Technical success, time for image registration, procedure time, fluoroscopy time, number of digital subtraction angiography (DSA) acquisitions before stent deployment or vessel catheterization, and renal function before and after the procedure were recorded. The image fusion accuracy was qualitatively evaluated on a binary scale by three physicians after review of image data showing virtual landmarks from MRA on fluoroscopy. Between November 2012 and March 2016, 10 patients underwent endovascular procedures for aortoiliac aneurysmal disease or aortic dissection using MRA image fusion guidance. All procedures were technically successful. A paired t-test analysis showed no difference between preimaging and postoperative renal function (P = .6). The mean time required for MRA-CBCT image fusion was 4:09 ± 01:31 min:sec. Total fluoroscopy time was 20.1 ± 6.9 minutes. Five of 10 patients (50%) underwent stent graft deployment without any predeployment DSA acquisition. Three of six vessels (50%) were cannulated under image fusion guidance without any precannulation DSA runs, and the remaining vessels were cannulated after one planning DSA acquisition. Qualitative evaluation showed 14 of 22 virtual landmarks (63.6%) from MRA overlaid on fluoroscopy were completely accurate, without the need for adjustment. Five of eight incorrect virtual landmarks (iliac and visceral arteries) resulted from vessel deformation caused by endovascular devices. Ferumoxytol or gadolinium-enhanced MRA imaging and image fusion with fluoroscopy using noncontrast CBCT is feasible and allows patients with renal insufficiency to benefit from optimal guidance during complex endovascular aortic procedures, while preserving their residual renal function. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study.

PubMed

Morawiec, Beata; Fournier, Stephane; Tapponnier, Maxime; Prior, John O; Monney, Pierre; Dunet, Vincent; Lauriers, Nathalie; Recordon, Frederique; Trana, Catalina; Iglesias, Juan-Fernando; Kawecki, Damian; Boulat, Olivier; Bardy, Daniel; Lamsidri, Sabine; Eeckhout, Eric; Hugli, Olivier; Muller, Olivier

2017-07-10

Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay's performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented. To assess hs-TnT assay's performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain. Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography. Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively. Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value. ClinicalTrials.gov Identifier: NCT01374607. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

TU-H-CAMPUS-IeP1-04: Combined Organ Dose for Digital Subtraction Angiography and Computed Tomography Using Monte Carlo Simulation

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

Sakabe, D; Ohno, T; Araki, F

Purpose: The purpose of this study was to evaluate the combined organ dose of digital subtraction angiography (DSA) and computed tomography (CT) using a Monte Carlo (MC) simulation on the abdominal intervention. Methods: The organ doses for DSA and CT were obtained with MC simulation and actual measurements using fluorescent-glass dosimeters at 7 abdominal portions in an Alderson-Rando phantom. DSA was performed from three directions: posterior anterior (PA), right anterior oblique (RAO), and left anterior oblique (LAO). The organ dose with MC simulation was compared with actual radiation dose measurements. Calculations for the MC simulation were carried out with themore » GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. Finally, the combined organ dose for DSA and CT was calculated from the MC simulation using the X-ray conditions of a patient with a diagnosis of hepatocellular carcinoma. Results: For DSA from the PA direction, the organ doses for the actual measurements and MC simulation were 2.2 and 2.4 mGy/100 mAs at the liver, respectively, and 3.0 and 3.1 mGy/100 mAs at the spinal cord, while for CT, the organ doses were 15.2 and 15.1 mGy/100 mAs at the liver, and 14.6 and 13.5 mGy/100 mAs at the spinal cord. The maximum difference in organ dose between the actual measurements and the MC simulation was 11.0% of the spleen at PA, 8.2% of the spinal cord at RAO, and 6.1% of left kidney at LAO with DSA and 9.3% of the stomach with CT. The combined organ dose (4 DSAs and 6 CT scans) with the use of actual patient conditions was found to be 197.4 mGy for the liver and 205.1 mGy for the spinal cord. Conclusion: Our method makes it possible to accurately assess the organ dose to patients for abdominal intervention with combined DSA and CT.« less

SU-E-I-31: Differences Observed in Radiation Doses Across 2 Similar CT Scanners From Adult Brain-Neck CT Angiography

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

Fujii, K; UCLA School of Medicine, Los Angeles, CA; McMillan, K

2015-06-15

Purpose: The aim of this study is to evaluate the difference in radiation doses from adult Brain-Neck CT angiography (CTA) between two CT scanners. Methods: We collected CT dose index data (CTDIvol, DLP) from adult Brain-Neck CTA performed with two CT scanners (Sensation 64 (S64) and Definition AS (AS), Siemens Healthcare) performed at two of our facilities from Jan 1st to Dec 31th, 2014. X-ray dose management software (Radmetrics, Bayer Healthcare) was used to mine these data. All exams were performed with Tube Current Modulation (Care Dose 4D), tube voltage of 120 kVp, quality reference mAs of 300, beam collimationmore » of 64*0.6 mm. The rotation time was set to 0.5 sec for S64 and 1.0 sec for AS. We also scanned an anthropomorphic skull and chest phantom under routine Brain-Neck CTA protocol with the two scanners and extracted the tube current values from the raw projection data. Results: The mean CTDIvol and DLP in Brain-Neck CTA was 72 mGy and 2554 mGy*cm for AS, which was substantially larger than the mean values of 46 mGy and 1699 mGy*cm for S64. The maximum tube current was 583 mA for most cases on the S64 while the maximum was 666 mA for AS even though the rotation time set for AS was 1.0 sec. Measurements obtained with the anthropomorphic phantom showed that the tube current reached 583 mA at the shoulder region for S64 while it reached to 666 mA for AS. Conclusion: The results of this study showed that substantially different CT doses can Result from Brain-Neck CTA protocols even when similar scanners and similar settings are used. Though both scanners have a similar maximum mA rating, differences in mA were observed through the shoulders, resulting in substantially different CTDIvol values.« less

Subarachnoid Hemorrhage Mimicking Leakage of Contrast Media After Coronary Angiography

PubMed Central

Oh, Min Seok; Kwon, Jee Eun; Kim, Kyung Jun; Jo, Joon Hwan; Min, Yun Ju; Byun, Jun Soo; Kim, Kyung Tae; Kim, Sang Wook

2012-01-01

We report a patient who developed subarachnoid hemorrhage (SAH) just after coronary angiography (CAG) with non-ionic contrast media (CM) and minimal dose of heparin. The 55-year-old man had a history of acute ST elevation myocardial infarction that had been treated with primary percutaneous coronary intervention and was admitted for a follow-up CAG. The CAG was performed by the transradial approach, using 1000 U of unfractionated heparin for the luminal coating and 70 mL of iodixanol. At the end of CAG, he complained of nausea and rapidly became stuporous. Brain CT showed a diffusely increased Hounsfield unit (HU) in the cisternal space, similar to leakage of CM. The maximal HU was 65 in the cisternal space. No vascular malformations were detected on cerebral angiography. The patient partially recovered his mental status and motor weakness after 2 days. Two weeks later, subacute SAH was evident on magnetic resonance imaging. The patient was discharged after 28 days. PMID:22493615

Gadopentetate dimeglumine is potentially an alternative contrast agent for three-dimensional computed tomography angiography with multidetector-row helical scanning.

PubMed

Gupta, Atul K; Alberico, Ronald A; Litwin, Alan; Kanter, Peter; Grossman, Zachary D

2002-01-01

To demonstrate that gadopentetate dimeglumine is potentially an alternative contrast medium for computed tomographic angiography (CTA). One 12.2-kg Beagle dog was studied as proof of principle; the cervical vessels of three adult human patients were imaged for presurgical planning of the neck. Gadopentetate dimeglumine, 0.5 mol/l (Berlex Laboratories, Wayne, NJ, U.S.A.), a LightSpeed QX/i CT (General Electric Medical Systems, Milwaukee, WI, U.S.A.), and an Ultra Sparc II (SUN Microsystems, Santa Clara, CA, U.S.A.) running Advantage Windows 3.1 (General Electric Medical Systems) were used. Sufficient enhancement for CTA of the thoracic aorta, cervical vessels, and abdominal vessels was produced in the experimental dog, and the cervical vessels were clearly defined in all three patients. In that subset of patients with contraindications to iodinated contrast medium and for whom magnetic resonance angiography is inappropriate, gadopentetate dimeglumine may be an alternative contrast medium for CTA.

[Middle aortic syndrome: a report of three pediatric cases].

PubMed

Martínez León, M I; Alcaide Martín, D; García-Herrera Taillefer, P; Ramos Rodríguez, R

2013-09-01

The middle aortic syndrome (MAS) is caused by stenosis of the abdominal aorta, often accompanied by concomitant stenosis of the renal or visceral arteries. Although MAS is uncommon (0.5-2%), it is an important cause of hypertension in children and adolescents. It is thought to originate in a failure of the two dorsal aortas to fuse during embryological development, and a high percentage of cases are idiopathic. MAS affects the segment of the aorta between the renal arteries in 54% of cases. Clinically, it courses with symptomatic or asymptomatic arterial hypertension. On physical examination, findings include an abdominal bruit, diminished or absent femoral pulses, and a difference between the arterial pressure of the upper and lower limbs. Angiography is the technique of choice, although noninvasive MR angiography and CT angiography have similar diagnostic accuracy. Ultrasonography is the primary screening technique. Medical treatment consists of a combination of different antihypertensives. Surgical treatment can be curative. Copyright © 2010 SERAM. Published by Elsevier Espana. All rights reserved.

Rotational Angiography Based Three-Dimensional Left Atrial Reconstruction: A New Approach for Transseptal Puncture.

PubMed

Koektuerk, Buelent; Yorgun, Hikmet; Koektuerk, Oezlem; Turan, Cem H; Gorr, Eduard; Horlitz, Marc; Turan, Ramazan G

2016-02-01

Rotational angiography is a well-known method for the three-dimensional (3-D) reconstruction of left atrium and pulmonary veins during left-sided atrial arrhythmia ablation procedures. In our study, we aimed to review our experience in transseptal puncture (TSP) using 3-D rotational angiography. We included a total of 271 patients who underwent atrial fibrillation ablation using cryoballoon. Rotational angiography was performed to get the three-dimensional left atrial and pulmonary vein reconstructions using cardiac C-arm computed tomography. The image reconstruction was made using the DynaCT Cardiac software (Siemens, Erlangen, Germany). The mean age of the study population was 61 ± 10 years. The indications for left atrial arrhythmia ablation were paroxysmal AF in 140 patients (52%) and persistent AF patients in 131 (48%) patients. The success rate of TSP using only rotational guidance was (264/271 patients, 97.4%). In the remaining seven patients, transesophageal guidance was used after the initial attempt due to thick interatrial septum in five patients and difficult TSP due to abnormal anatomy and mild pericardial effusion in the remaining two patients. Mean fluoroscopy dosage of the rotational angiography was 4896.4 ± 825.3 μGym(2). The mean time beginning from femoral vein puncture to TSP was 12.3 ± 5.5 min. TSP guided by rotational angiography is a safe and effective method. Our results indicate that integration of rotational angiographic images into the real-time fluoroscopy can guide the TSP during the procedure. © 2015 John Wiley & Sons Ltd.

Absent right common carotid artery associated with aberrant right subclavian artery.

PubMed

Uchino, Akira; Uwabe, Kazuhiko; Osawa, Iichiro

2018-06-01

Rarely, the external and internal carotid arteries arise separately from the brachiocephalic trunk and right subclavian artery (SA) or the aortic arch and reflect the absence of a common carotid artery (CCA). We report a 45-year-old man with absent right CCA associated with aberrant right SA, an extremely rare combination, diagnosed by computed tomography (CT) angiography during follow-up for postoperative aortic dissection. Retrospective careful observation of preoperative postcontrast CT revealed the absent right CCA. Previously reported arch variations associated with absent CCA include cervical aortic arch, double aortic arch, and right aortic arch.

Angiographic findings and clinical outcomes in asymptomatic patients with severe obstructive atherosclerosis on computed tomography angiography.

PubMed

Kornowski, Ran; Bachar, Gil N; Dvir, Danny; Fuchs, Shmuel; Atar, Eli

2008-01-01

Cardiac computed tomography angiography is a relatively new imaging modality to detect coronary atherosclerosis. To explore the diagnostic value of CTA in assessing coronary artery disease among asymptomatic patients. In this retrospective single-centered analysis, 622 consecutive patients underwent CTA of coronary arteries between November 2004 and May 2006 at the Mor Institute for Cardiovascular Imaging in Bnei Brak, Israel. All patients were asymptomatic but had at least one risk factor for atherosclerotic CAD. The initial 244 patients were examined with the 16-slice Brilliance CT scanner (Philips, Cleveland, OH, U.S.A.), and in the remaining 378 patients the 64-slice scanner (GE Healthcare, The Netherlands) with dedicated cardiac reconstruction software and electrocardiography triggering was used. Scanning was performed in the cranio-caudal direction. Images reconstructed in different phases of the cardiac cycle using a retrospective ECG-gated reconstruction algorithm were transferred to a dedicated workstation for review by experienced CT radiologists and cardiologists. Of 622 patients, 52 (8.4%) had severe obstructive atherosclerosis (suspected > or = 75% stenosis) according to CTA interpretation. Invasive coronary angiography was performed in 48 patients while 4 patients had no further procedure. A non-significant CAD (e.g., diameter stenosis < 70%) was identified in 6 of 48 patients (12%) by selective coronary angiography. Forty-two patients showed severe CAD with at least one lesion of 70% stenosis. Percutaneous coronary intervention was performed in 35 patients and coronary artery bypass grafting surgery in the other 4 patients. Angioplasty procedures were successful in all 35 patients and stents were utilized in all cases without complications. No further complications occurred among the study cohort undergoing either PCI or surgery. The 6 month survival rate in these patients was 100%. Non-invasive coronary CTA appears to be a reliable technique, with reasonably high accuracy, to detect obstructive atherosclerosis in asymptomatic high risk patients for atherosclerotic CAD.

Diagnostic Value of Transthoracic Echocardiography in Patients With Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery

PubMed Central

Li, Rong-Juan; Sun, Zhonghua; Yang, Jiao; Yang, Ya; Li, Yi-Jia; Leng, Zhao-Ting; Liu, Guo-Wen; Pu, Li-Hong

2016-01-01

Abstract Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary abnormality associated with early infant mortality and sudden death in adults. Transthoracic echocardiography (TTE) plays an important role in early detection and diagnosis of ALCAPA as a noninvasive modality. However, its diagnostic value is not well studied. The purpose of this study is to determine the performance of TTE in the diagnostic assessment of ALCAPA as compared with coronary CT and invasive coronary angiography. A total of 22 patients (13 women and 9 men, mean age, 12.9 ± 19.5 years) with ALCAPA who underwent echocardiographic examination for clinical diagnosis were retrospectively reviewed and analyzed. Transthoracic echocardiographic features of ALCAPA were analyzed and its diagnostic value was compared with invasive coronary angiography and coronary CT angiography (CTA) with surgical findings serving as the gold standard. Surgery was performed in all of the patients to establish the dual coronary artery system. Five underwent the Takeuchi procedure and 17 had re-implantation of the anomalous left coronary artery. Of 20 patients, echocardiographic diagnoses were in good agreement with findings at surgery, resulting in the diagnostic accuracy of 90.9%. Two cases were misdiagnosed—one as the right coronary artery to pulmonary artery fistula and the other as rheumatic heart disease. The echocardiographic features of these patients with ALCAPA included: abnormal left coronary ostium arising from the pulmonary trunk with retrograde coronary artery flow in 20 patients; enlargement of the right coronary artery in 17 patients; abundant intercoronary septal collaterals in 17 patients; and moderate and significant mitral regurgitation in 14 patients. The diagnostic accuracy of invasive coronary angiography (in 17 patients) and coronary CTA (in 9 patients) was 100%. This study shows that TTE is an accurate, noninvasive imaging modality for displaying the origin of coronary arteries and demonstrating the coronary courses as well as other associated abnormalities in patients with ALCAPA. PMID:27082616

Which test for CAD should be used in patients with left bundle branch block?

PubMed

Xu, Bo; Cremer, Paul; Jaber, Wael; Moir, Stuart; Harb, Serge C; Rodriguez, L Leonardo

2018-03-01

Exercise stress electrocardiography is unreliable as a test for obstructive coronary artery disease (CAD) if the patient has left bundle branch block. The authors provide an algorithm for using alternative tests: exercise stress echocardiography, dobutamine echocardiography, computed tomographic (CT) angiography, and nuclear myocardial perfusion imaging. Copyright © 2018 Cleveland Clinic.

Pre-procedural assessment of aortic annulus dimensions for transcatheter aortic valve replacement: comparison of a non-contrast 3D MRA protocol with contrast-enhanced cardiac dual-source CT angiography.

PubMed

Ruile, Philipp; Blanke, Philipp; Krauss, Tobias; Dorfs, Stephan; Jung, Bernd; Jander, Nikolaus; Leipsic, Jonathon; Langer, Mathias; Neumann, Franz-Josef; Pache, Gregor

2016-04-01

To evaluate the feasibility of a non-contrast three-dimensional (3D)-FLASH magnetic resonance angiography (MRA) protocol for pre-procedural aortic annulus assessment for transcatheter aortic valve replacement (TAVR) in comparison with cardiac dual-source computed tomography angiography (CTA). In this prospective study, 69 of 104 consecutive patients (mean age 81.8 ± 5.4 years, 37.7% arrhythmic) with severe aortic stenosis who had undergone pre-TAVR cardiac CTA received a respiratory and ECG-triggered, non-contrast 3D-FLASH MRA at 3 T. Annular area measurements were obtained at mid-diastole for both modalities whereas maximum systolic area was assessed by CTA only. Systolic MRA dimensions were modelled, by adding the relative difference of systolic and diastolic CTA area dimensions as a corrective factor. Hypothetical prosthesis sizing was performed based on systolic CTA, diastolic, and modelled systolic MRA area measurements. MR image quality and degree of annular calcifications were evaluated using 4-point-grading scales. The mean acquisition time was 14 ± 4.2 min. The mean image quality was 3.1 ± 0.9 with only two examinations rated non-diagnostic. The mean degree of calcifications was equal. As assessed by Bland-Altman analysis, there was no relevant systematic difference between area measurements for modelled systolic MRA and systolic CTA [the mean difference -3.1 mm(2) (limits of agreement -44.4 mm(2); 38.2 mm(2))]. Agreement for hypothetical prosthesis sizing was found in 63 of 67 (94%) patients for systolic CTA and modelled systolic MRA. The employed non-contrast 3D-FLASH MRA protocol allows for reliable assessment of aortic annulus dimensions and calcifications even in the presence of arrhythmias in an all-comers pre-TAVR population. Implementation of this technique appears legitimate in patients at an increased risk for contrast-induced nephropathy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Subpial Hematoma and Extravasation in the Interhemispheric Fissure with Subarachnoid Hemorrhage

PubMed Central

Matsuoka, Go; Abe, Kayoko; Okada, Yoshikazu; Sakai, Shuji

2015-01-01

A recent report on computed tomography (CT) findings of contrast extravasation in subarachnoid hemorrhage (SAH) with Sylvian hematoma suggests that the occurrence of the hematoma is secondary to bleeding in the subpial space. Our patient was in his sixties and was admitted to the hospital because of loss of consciousness (Glasgow Coma Scale E4V1M4). SAH was diagnosed in plain head CT, and growing hematomas were observed in the Sylvian and interhemispheric fissures following a subarachnoid hemorrhage. CT angiography (CTA) using a dual-phase scan protocol revealed contrast extravasation in both the fissures in the latter phase, and hematoma in the interhemispheric fissure contained multiple bleeding points. This case indicates that the occurrence of subpial hematoma such as Sylvian hematoma can be a secondary event following subpial bleeding from damaged small vessels elsewhere in the cranium. Instead of four-dimensional (4D) CT, the dual-phase CTA technique may help detect minor extravasations with usual helical CT scanner. PMID:25963159

Subtraction CT angiography in head and neck with low radiation and contrast dose dual-energy spectral CT using rapid kV-switching technique.

PubMed

Ma, Guangming; Yu, Yong; Duan, Haifeng; Dou, Yuequn; Jia, Yongjun; Zhang, Xirong; Yang, Chuangbo; Chen, Xiaoxia; Han, Dong; Guo, Changyi; He, Taiping

2018-06-01

To investigate the application of low radiation and contrast dose spectral CT angiology using rapid kV-switching technique in the head and neck with subtraction method for bone removal. This prospective study was approved by the local ethics committee. 64 cases for head and neck CT angiology were randomly divided into Groups A (n = 32) and B (n = 32). Group A underwent unenhanced CT with 100 kVp, 200 mA and contrast-enhanced CT with spectral CT mode with body mass index-dependent low dose protocols. Group B used conventional helical scanning with 120 kVp, auto mA for noise index of 12 HU (Hounsfield unit) for both the unenhanced and contrast-enhanced CT. Subtraction images were formed by subtracting the unenhanced images from enhanced images (with the 65 keV-enhanced spectral CT image in Group A). CT numbers and their standard deviations in aortic arch, carotid arteries, middle cerebral artery and air were measured in the subtraction images. The signal-to-noise ratio and contrast-to-noise ratio for the common and internal carotid arteries and middle cerebral artery were calculated. Image quality in terms of bone removal effect was evaluated by two experienced radiologists independently and blindly using a 4-point system. Radiation dose and total iodine load were recorded. Measurements were statistically compared between the two groups. The two groups had same demographic results. There was no difference in the CT number, signal-to-noise and contrast-to-noise ratio values for carotid arteries and middle cerebral artery in the subtraction images between the two groups (p > 0.05). However, the bone removal effect score [median (min-max)] in Group A [4 (3-4)] was rated better than in Group B [3 (2-4)] (p < 0.001), with excellent agreement between the two observers (κ > 0.80). The radiation dose in Group A (average of 2.64 mSv) was 57% lower than the 6.18 mSv in Group B (p < 0.001). The total iodine intake in Group A was 13.5g, 36% lower than the 21g in Group B. Spectral CT imaging with rapid kV-switching in the subtraction angiography in head and neck provides better bone removal with significantly reduced radiation and contrast dose compared with conventional subtraction method. Advances in knowledge: This novel method provides better bone removal with significant radiation and contrast dose reduction compared with the conventional subtraction CT, and maybe used clinically to protect the thyroid gland and ocular lenses from unnecessary high radiation.

Risks and benefits of CT angiography in spontaneous intracerebral hemorrhage.

PubMed

Hotta, Kazuko; Sorimachi, Takatoshi; Osada, Takahiro; Baba, Tanefumi; Inoue, Go; Atsumi, Hideki; Ishizaka, Hideo; Matsuda, Minako; Hayashi, Naokazu; Matsumae, Mitsunori

2014-05-01

Few studies have examined the risk of computed tomography angiography (CTA) during the acute phase of spontaneous intracerebral hemorrhage (ICH), while the benefits of CTA in ICH have been well-documented. The present study investigated both the benefits of identifying spot signs, which are supposed to indicate hematoma enlargement after admission, and risks of CTA performed during the acute phase of ICH. We retrospectively assessed 323 consecutive patients with spontaneous ICHs admitted to our hospital between April 2009 and March 2012 and who underwent CTA on admission. In 80 patients (24.7 %), spot signs were demonstrated on CTA source images. Multivariate analysis revealed two independent factors correlated with presence of the spot sign: age and hematoma volume (p < 0.05 each). The presence of spot sign was associated with unfavorable outcomes at discharge and hematoma growth after admission (p < 0.05 each). Adverse events related to CTA occurred in 17 patients (5.2 %), including transient renal dysfunction in 16 patients and allergy to contrast medium in one patient. All adverse events completely resolved within 1 week. Presence of the spot sign indicated the possibility of hematoma growth and unfavorable outcomes. A small number of adverse events occurred in association with CTA, but without any permanent deficits. Given the potential benefits and risks, we believe that CTA performed at admission in all patients with ICH is beneficial to improve the outcomes.

Visualization of Middle Ear Ossicles in Elder Subjects with Ultra-short Echo Time MR Imaging.

PubMed

Naganawa, Shinji; Nakane, Toshiki; Kawai, Hisashi; Taoka, Toshiaki; Suzuki, Kojiro; Iwano, Shingo; Satake, Hiroko; Grodzki, David

2017-04-10

To evaluate the visualization of middle ear ossicles by ultra-short echo time magnetic resonance (MR) imaging at 3T in subjects over 50 years old. Sixty ears from 30 elder patients that underwent surgical or interventional treatment for neurovascular diseases were included (ages: 50-82, median age: 65; 10 men, 20 women). Patients received follow-up MR imaging including routine T 1 - and T 2 -weighted images, time-of-flight MR angiography, and ultra-short echo time imaging (PETRA, pointwise encoding time reduction with radial acquisition). All patients underwent computed tomography (CT) angiography before treatment. Thin-section source CT images were correlated with PETRA images. Scan parameters for PETRA were: TR 3.13, TE 0.07, flip angle 6 degrees, 0.83 × 0.83 × 0.83 mm resolution, 3 min 43 s scan time. Two radiologists retrospectively evaluated the visibility of each ossicular structure as positive or negative using PETRA images. The structures evaluated included the head of the malleus, manubrium of the malleus, body of the incus, long process of the incus, and the stapes. Signal intensity of the ossicles was classified as: between labyrinthine fluid and air, similar to labyrinthine fluid, between labyrinthine fluid and cerebellar parenchyma, or higher than cerebellar parenchyma. In all ears, the body of the incus was visible. The head of the malleus was visualized in 36/60 ears. The manubrium of the malleus and long process of the incus was visualized in 1/60 and 4/60 ears, respectively. The stapes were not visualized in any ear. Signal intensity of the visible structures was between labyrinthine fluid and air in all ears. The body of the incus was consistently visualized with intensity between air and labyrinthine fluid on PETRA images in aged subjects. Poor visualization of the manubrium of the malleus, long process of the incus, and the stapes limits clinical significance of middle ear imaging with current PETRA methods.

Safety of Landiolol Hydrochloride as a Premedication for Producing an Appropriate Heart Rate for Multidetector-Row Computed Tomography Coronary Angiography.

PubMed

Koyoshi, Rie; Shiga, Yuhei; Idemoto, Yoshiaki; Ueda, Yoko; Tashiro, Kohei; Kuwano, Takashi; Kitajima, Ken; Fujimi, Kanta; Kawamura, Akira; Ogawa, Masahiro; Miura, Shin-Ichiro

2018-01-01

We evaluated the safety of a bolus injection of landiolol hydrochloride, an ultrashort-acting β1-selective antagonist, as a premedication prior to multidetector-row computed tomography coronary angiography (CTA). The subjects consisted of 176 patients (M/F = 64:112, 67 ± 11 years) who had heart rate (HR) at rest ≥ 70 beats/min (bpm) and underwent CTA. Systolic/diastolic blood pressure (SBP/DBP) and HR were measured before and after the administration of landiolol. SBP/DBP and HR upon entry to the CT room were 136 ± 17/80 ± 11 mm Hg and 83 ± 10 bpm, respectively. HR was significantly reduced at the time of CTA scan (62 ± 7 bpm). Next, we divided the patients into three groups according to HR upon entry to the CT room: 70 - 79 bpm (n = 76), 80 - 89 bpm (n = 60) and ≥ 90 bpm (n = 40). HR at the time of CTA scan was significantly lower than that upon entry to the CT room in all three groups: 70 - 79 bpm (74 ± 3 bpm upon entry to the CT room to 61 ± 6 bpm at the time of CAT scan), 80 - 89 bpm (84 ± 3 to 63 ± 7 bpm) and ≥ 90 bpm (98 ± 6 to 65 ± 7 bpm). Although SBP/DBP was significantly decreased after the CTA scan (123 ± 18/72 ± 12 mm Hg), landiolol had no severe adverse events throughout CTA. In conclusion, a bolus injection of landiolol reduced HR by about 20 bpm without any severe adverse effects. Thus, a bolus injection of landiolol hydrochloride may be a suitable pretreatment for controlling HR in CTA.

3D CT cerebral angiography technique using a 320-detector machine with a time-density curve and low contrast medium volume: comparison with fixed time delay technique.

PubMed

Das, K; Biswas, S; Roughley, S; Bhojak, M; Niven, S

2014-03-01

To describe a cerebral computed tomography angiography (CTA) technique using a 320-detector CT machine and a small contrast medium volume (35 ml, 15 ml for test bolus). Also, to compare the quality of these images with that of the images acquired using a larger contrast medium volume (90 or 120 ml) and a fixed time delay (FTD) of 18 s using a 16-detector CT machine. Cerebral CTA images were acquired using a 320-detector machine by synchronizing the scanning time with the time of peak enhancement as determined from the time-density curve (TDC) using a test bolus dose. The quality of CTA images acquired using this technique was compared with that obtained using a FTD of 18 s (by 16-detector CT), retrospectively. Average densities in four different intracranial arteries, overall opacification of arteries, and the degree of venous contamination were graded and compared. Thirty-eight patients were scanned using the TDC technique and 40 patients using the FTD technique. The arterial densities achieved by the TDC technique were higher (significant for supraclinoid and basilar arteries, p < 0.05). The proportion of images deemed as having "good" arterial opacification was 95% for TDC and 90% for FTD. The degree of venous contamination was significantly higher in images produced by the FTD technique (p < 0.001%). Good diagnostic quality CTA images with significant reduction of venous contamination can be achieved with a low contrast medium dose using a 320-detector machine by coupling the time of data acquisition with the time of peak enhancement. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Correlation between carotid bifurcation calcium burden on non-enhanced CT and percentage stenosis, as confirmed by digital subtraction angiography

PubMed Central

Sarikaya, B; Lohman, B; Mckinney, A M; Gadani, S; Irfan, M; Lucato, L

2012-01-01

Objectives Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA). Methods 50 patients (aged 41–82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered “significant”. Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm3 were utilised and Pearson'S correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis. Results Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate–strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm3 was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses. Conclusion This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a “score” that could predict high grade stenosis. PMID:21896662

Improved Outcome Prediction Using CT Angiography in Addition to Standard Ischemic Stroke Assessment: Results from the STOPStroke Study

PubMed Central

González, R. Gilberto; Lev, Michael H.; Goldmacher, Gregory V.; Smith, Wade S.; Payabvash, Seyedmehdi; Harris, Gordon J.; Halpern, Elkan F.; Koroshetz, Walter J.; Camargo, Erica C. S.; Dillon, William P.; Furie, Karen L.

2012-01-01

Purpose To improve ischemic stroke outcome prediction using imaging information from a prospective cohort who received admission CT angiography (CTA). Methods In a prospectively designed study, 649 stroke patients diagnosed with acute ischemic stroke had admission NIH stroke scale scores, noncontrast CT (NCCT), CTA, and 6-month outcome assessed using the modified Rankin scale (mRS) scores. Poor outcome was defined as mRS>2. Strokes were classified as “major” by the (1) Alberta Stroke Program Early CT Score (ASPECTS+) if NCCT ASPECTS was≤7; (2) Boston Acute Stroke Imaging Scale (BASIS+) if they were ASPECTS+ or CTA showed occlusion of the distal internal carotid, proximal middle cerebral, or basilar arteries; and (3) NIHSS for scores>10. Results Of 649 patients, 253 (39.0%) had poor outcomes. NIHSS, BASIS, and age, but not ASPECTS, were independent predictors of outcome. BASIS and NIHSS had similar sensitivities, both superior to ASPECTS (p<0.0001). Combining NIHSS with BASIS was highly predictive: 77.6% (114/147) classified as NIHSS>10/BASIS+ had poor outcomes, versus 21.5% (77/358) with NIHSS≤10/BASIS− (p<0.0001), regardless of treatment. The odds ratios for poor outcome is 12.6 (95% CI: 7.9 to 20.0) in patients who are NIHSS>10/BASIS+ compared to patients who are NIHSS≤10/BASIS−; the odds ratio is 5.4 (95% CI: 3.5 to 8.5) when compared to patients who are only NIHSS>10 or BASIS+. Conclusions BASIS and NIHSS are independent outcome predictors. Their combination is stronger than either instrument alone in predicting outcomes. The findings suggest that CTA is a significant clinical tool in routine acute stroke assessment. PMID:22276182

Change in Imaging Findings on Angiography-Assisted CT During Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma

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

Yoshimatsu, Rika; Yamagami, Takuji, E-mail: yamagami@kochi-u.ac.jp; Ishikawa, Masaki

2016-06-15

PurposeTo evaluate changes in imaging findings on CT during hepatic arteriography (CTHA) and CT during arterial portography (CTAP) by balloon occlusion of the treated artery and their relationship with iodized oil accumulation in the tumor during balloon-occluded transcatheter arterial chemoembolization (B-TACE).MethodsBoth B-TACE and angiography-assisted CT were performed for 27 hepatocellular carcinomas. Tumor enhancement on selective CTHA with/without balloon occlusion and iodized oil accumulation after B-TACE were evaluated. Tumorous portal perfusion defect size on CTAP was compared with/without balloon occlusion. Factors influencing discrepancies between selective CTHA with/without balloon occlusion and the degree of iodized oil accumulation were investigated.ResultsAmong 27 tumors, tumormore » enhancement on selective CTHA changed after balloon occlusion in 14 (decreased, 11; increased, 3). In 18 tumors, there was a discrepancy between tumor enhancement on selective CTHA with balloon occlusion and the degree of accumulated iodized oil, which was higher than the tumor enhancement grade in all 18. The tumorous portal perfusion defect on CTAP significantly decreased after balloon occlusion in 18 of 20 tumors (mean decrease from 21.9 to 19.1 mm in diameter; p = 0.0001). No significant factors influenced discrepancies between selective CTHA with/without balloon occlusion. Central area tumor location, poor tumor enhancement on selective CTHA with balloon occlusion, and no decrease in the tumorous portal perfusion defect area on CTAP after balloon occlusion significantly influenced poor iodized oil accumulation in the tumor.ConclusionsTumor enhancement on selective CTHA frequently changed after balloon occlusion, which did not correspond to accumulated iodized oil in most cases.« less

Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit.

PubMed

Pedicelli, Alessandro; Verdolotti, Tommaso; Pompucci, Angelo; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo

2011-12-01

The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180° and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of "CT-like" MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room.

Radiation dose to patients and image quality evaluation from coronary 256-slice computed tomographic angiography

NASA Astrophysics Data System (ADS)

Chen, Liang-Kuang; Wu, Tung-Hsin; Yang, Ching-Ching; Tsai, Chia-Jung; Lee, Jason J. S.

2010-07-01

The aim of this study is to assess radiation dose and the corresponding image quality from suggested CT protocols which depends on different mean heart rate and high heart rate variability by using 256-slice CT. Fifty consecutive patients referred for a cardiac CT examination were included in this study. All coronary computed tomographic angiography (CCTA) examinations were performed on a 256-slice CT scanner with one of five different protocols: retrospective ECG-gating (RGH) with full dose exposure in all R-R intervals (protocol A), RGH of 30-80% pulsing window with tube current modulation (B), RGH of 78±5% pulsing window with tube current modulation (C), prospective ECG-triggering (PGT) of 78% R-R interval with 5% padding window (D) and PGT of 78% R-R interval without padding window (E). Radiation dose parameters and image quality scoring were determined and compared. In this study, no significant differences were found in comparison on image quality of the five different protocols. Protocol A obtained the highest radiation dose comparing with those of protocols B, C, D and E by a factor of 1.6, 2.4, 2.5 and 4.3, respectively ( p<0.001), which were ranged between 2.7 and 11.8 mSv. The PGT could significantly reduce radiation dose delivered to patients, as compared to the RGH. However, the use of PGT has limitations and is only good in assessing cases with lower mean heart rate and stable heart rate variability. With higher mean heart rate and high heart rate variability circumstances, the RGH within 30-80% of R-R interval pulsing window is suggested as a feasible technique for assessing diagnostic performance.

Long-term Results of Endovascular Stent Graft Placement of Ureteroarterial Fistula

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

Okada, Takuya, E-mail: okabone@gmail.com; Yamaguchi, Masato, E-mail: masato03310402@yahoo.co.jp; Muradi, Akhmadu, E-mail: muradiakhmadu@gmail.com

2013-08-01

PurposeTo evaluate the safety, efficacy, and long-term results of endovascular stent graft placement for ureteroarterial fistula (UAF).MethodsWe retrospectively analyzed stent graft placement for UAF performed at our institution from 2004 to 2012. Fistula location was assessed by contrast-enhanced computed tomography (CT) and angiography, and freedom from hematuria recurrence and mortality rates were estimated.ResultsStent graft placement for 11 UAFs was performed (4 men, mean age 72.8 {+-} 11.6 years). Some risk factors were present, including long-term ureteral stenting in 10 (91 %), pelvic surgery in 8 (73 %), and pelvic radiation in 5 (45 %). Contrast-enhanced CT and/or angiography revealed fistulamore » or encasement of the artery in 6 cases (55 %). In the remaining 5 (45 %), angiography revealed no abnormality, and the suspected fistula site was at the crossing area between urinary tract and artery. All procedures were successful. However, one patient died of urosepsis 37 days after the procedure. At a mean follow-up of 548 (range 35-1,386) days, 4 patients (36 %) had recurrent hematuria, and two of them underwent additional treatment with secondary stent graft placement and surgical reconstruction. The hematuria recurrence-free rates at 1 and 2 years were 76.2 and 40.6 %, respectively. The freedom from UAF-related and overall mortality rates at 2 years were 85.7 and 54.9 %, respectively.ConclusionEndovascular stent graft placement for UAF is a safe and effective method to manage acute events. However, the hematuria recurrence rate remains high. A further study of long-term results in larger number of patients is necessary.« less

The role of angiography in the congruence of cardiovascular measurements between autopsy and postmortem imaging.

PubMed

Troxler, Renaud; Minoiu, Costin; Vaucher, Paul; Michaud, Katarzyna; Doenz, Francesco; Ducrot, Kewin; Grabherr, Silke

2018-01-01

Postmortem CT angiography is the method of choice for the postmortem imaging investigations of the cardiovascular (CV) system. However, autopsy still remains the gold standard for CV measurement. Nevertheless, there are not any studies on CV measurements on the multi-phase postmortem angiography (MPMCTA) which includes comparisons with autopsy. Therefore, the aim of this study is to compare CV measurements between the native CT scan and the three phases of the MPMCTA to find out which of these modalities correlate the best with autopsy measurements. For this study, we selected retrospectively 50 postmortem cases that underwent both MPMCTA and autopsy. A comparison was carried out between the CV measurements obtained with imaging (aorta; heart cavities and cardiac wall thicknesses; maximum cardiac diameter and cardiothoracic ratio) and at the autopsy (aorta; cardiac valves, ventricular thicknesses, and weight). Our results show that the dynamic phase displays an advantage for the measurement of the aortas. However, the MPMCTA is not accurate to measure the cardiac wall thicknesses. The measurements of the heart cavities show no correlation with the heart valves. The cardiothoracic ratio measured by the MPMCTA shows no correlation with the heart weight. Nevertheless, the maximum cardiac diameter exhibits a correlation with the latter on the venous and dynamic phase. These results show that only few CV parameters measured with imaging correlate with measurement obtained at the autopsy. These results indicate that in order to better estimate values obtained at the autopsy, we need to define new reference values for the CV measurement on MPMCTA.

Mesenteric ischemia: Pathogenesis and challenging diagnostic and therapeutic modalities.

PubMed

Mastoraki, Aikaterini; Mastoraki, Sotiria; Tziava, Evgenia; Touloumi, Stavroula; Krinos, Nikolaos; Danias, Nikolaos; Lazaris, Andreas; Arkadopoulos, Nikolaos

2016-02-15

Mesenteric ischemia (MI) is an uncommon medical condition with high mortality rates. ΜΙ includes inadequate blood supply, inflammatory injury and eventually necrosis of the bowel wall. The disease can be divided into acute and chronic MI (CMI), with the first being subdivided into four categories. Therefore, acute MI (AMI) can occur as a result of arterial embolism, arterial thrombosis, mesenteric venous thrombosis and non-occlusive causes. Bowel damage is in proportion to the mesenteric blood flow decrease and may vary from minimum lesions, due to reversible ischemia, to transmural injury, with subsequent necrosis and perforation. CMI is associated to diffuse atherosclerotic disease in more than 95% of cases, with all major mesenteric arteries presenting stenosis or occlusion. Because of a lack of specific signs or due to its sometime quiet presentation, this condition is frequently diagnosed only at an advanced stage. Computed tomography (CT) imaging and CT angiography contribute to differential diagnosis and management of AMI. Angiography is also the criterion standard for CMI, with mesenteric duplex ultrasonography and magnetic resonance angiography also being of great importance. Therapeutic approach of MI includes both medical and surgical treatment. Surgical procedures include restoration of the blood flow with arteriotomy, endarterectomy or anterograde bypass, while resection of necrotic bowel is always implemented. The aim of this review was to evaluate the results of surgical treatment for MI and to present the recent literature in order to provide an update on the current concepts of surgical management of the disease. Mesh words selected include MI, diagnostic approach and therapeutic management.

Flat-Panel Cone-Beam Ct-Guided Radiofrequency Ablation of Very Small (≤1.5 cm) Liver Tumors: Technical Note on a Preliminary Experience

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

Cazzato, Roberto Luigi, E-mail: r.cazzato@unicampus.it; Buy, Xavier, E-mail: x.buy@bordeaux.unicancer.fr; Alberti, Nicolas, E-mail: nicoalbertibdx@gmail.com

2015-02-15

PurposeThe aim of the present study was to investigate the technical feasibility of flat-panel cone-beam CT (CBCT)-guided radiofrequency ablation (RFA) of very small (<1.5 cm) liver tumors.Materials and MethodsPatients included were candidates for hepatic percutaneous RFA as they had single biopsy-proven hepatic tumors sized ≤1.5 cm and poorly defined on ultrasonography. Following apnea induction, unenhanced CBCT scans were acquired and used to deploy the RF electrode with the aid of a virtual navigation system. If the tumor was not clearly identified on the unenhanced CBCT scan, a right retrograde arterial femoral access was established to carry out hepatic angiography and localize themore » tumor. Patients’ lesions and procedural variables were recorded and analyzed.ResultsThree patients (2 male and 1 female), aged 68, 76, and 87 years were included; 3 lesions (2 hepato-cellular carcinoma and 1 metastasis from colorectal cancer) were treated. One patient required hepatic angiography. Cycles of apnea used to acquire CBCT images and to deploy the electrode lasted <120 s. Mean fluoroscopic time needed to deploy the electrode was 36.6 ± 5.7 min. Mean overall procedural time was 66.0 ± 22.9 min. No peri- or post-procedural complications were noted. No cases of incomplete ablation were noted at 1-month follow-up.ConclusionPercutaneous CBCT-guided liver RFA with or without arterial hepatic angiography is technically feasible.« less

A unifying hypothesis for a patient with superficial siderosis, low-pressure headache, intraspinal cyst, back pain, and prominent vascularity.

PubMed

Kumar, Neeraj; Miller, Gary M; Piepgras, David G; Mokri, Bahram

2010-07-01

A source of bleeding is often not evident during the evaluation of patients with superficial siderosis of the CNS despite extensive imaging. An intraspinal fluid-filled collection of variable dimensions is frequently observed on spine MR imaging in patients with idiopathic superficial siderosis. A similar finding has also been reported in patients with idiopathic intracranial hypotension. The authors report on a patient with superficial siderosis and a longitudinally extensive intraspinal fluid-filled collection secondary to a dural tear. The patient had a history of low-pressure headaches. His spine MR imaging and spine CT suggested the possibility of an underlying vascular malformation, but none was found on angiography. Repair of the dural tear resulted in resolution of the intraspinal fluid collection and CSF abnormalities. The significance of the association between superficial siderosis and idiopathic intracranial hypotension, and potential therapeutic and pathophysiological implications, are the subject of this report.

Perfusion defects in pulmonary perfusion iodine maps: causes and semiology.

PubMed

Bustos Fiore, A; González Vázquez, M; Trinidad López, C; Mera Fernández, D; Costas Álvarez, M

2017-12-14

to describe the usefulness of dual-energy CT for obtaining pulmonary perfusion maps to provide morphological and functional information in patients with pulmonary embolisms. To review the semiology of perfusion defects due to pulmonary embolism so they can be differentiated from perfusion defects due to other causes: alterations outside the range used in the iodine map caused by other diseases of the lung parenchyma or artifacts. CT angiography of the pulmonary arteries is the technique of choice for the diagnosis of pulmonary embolisms. New dual-energy CT scanners are useful for detecting perfusion defects secondary to complete or partial obstruction of pulmonary arteries and is most useful for detecting pulmonary embolisms in subsegmental branches. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

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 metal artifacts. Recent introduction of iterative reconstruction techniques can increase the use of DECT techniques; the use of dual energy in patients with a high BMI is limited due to noise and the radiation dose. DECT may be a good alternative to PET-CT. Iodine map images can quantify iodine uptake, and this approach may be more effective than obtaining non-contrast and post-contrast images for the diagnosis of a solid mass. Thus, computer-aided detection may be used more effectively in CT applications. DECT is a promising technique with potential clinical applications.

Efficacy of Lens Protection Systems: Dependency on Different Cranial CT Scans in The Acute Stroke Setting.

PubMed

Guberina, Nika; Forsting, Michael; Ringelstein, Adrian

2017-06-15

To evaluate the dose-reduction potential with different lens protectors for patients undergoing cranial computed tomography (CT) scans. Eye lens dose was assessed in vitro (α-Al2O3:C thermoluminescence dosemeters) using an Alderson-Rando phantom® in cranial CT protocols at different CT scanners (SOMATOM-Definition-AS+®(CT1) and SOMATOM-Definition-Flash® (CT2)) using two different lens-protection systems (Somatex® (SOM) and Medical Imaging Systems® (MIS)). Summarised percentage of the transmitted photons: (1) CT1 (a) unenhanced CT (nCT) with gantry angulation: SOM = 103%, MIS = 111%; (2) CT2 (a) nCT without gantry angulation: SOM = 81%, MIS = 91%; (b) CT angiography (CTA) with automatic dose-modulation technique: SOM = 39%, MIS = 74%; (c) CTA without dose-modulation technique: SOM = 22%, MIS = 48%; (d) CT perfusion: SOM = 44%, MIS = 69%. SOM showed a higher dose-reduction potential than MIS maintaining equal image quality. Lens-protection systems are most effective in CTA protocols without dose-reduction techniques. Lens-protection systems lower the average eye lens dose during CT scans up to 1/3 (MIS) and 2/3 (SOM), respectively, if the eye lens is exposed to the direct beam of radiation. Considering both the CT protocol and the material of lens protectors, they seem to be mandatory for reducing the radiation exposure of the eye lens. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

Provenzale, J.M.; Morgenlander, J.C.; Gress, D.

The purpose of this study was to determine if typical clinical and neuroradiologic patterns exist in patients with spontaneous vertebral artery (VA) dissection. The medical records and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to exclude patients with a history of trauma and to record evidence of a nontratimatic precipitating event ({open_quotes}trivial trauma{close_quotes}) and presence of possible risk factors such as hypertension. All patients under-went conventional angiography, 13 either CT or MRI (II both CT and MRI), and 3 MRA. Conventional arteriograrris were evaluated for dissection site, evidence of fibromuscular dysplasia,more » luminal stenosis or occlusion, and pseudoaneurysm formation, CT examinations for the presence of infarction or subarachnoid hemorrhage, MR examinations for the presence of infarction or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column. Seven patients had precipitating events within 24 h of onset of symptoms that may have been causative of dissection and five had hypertension. At catheter angiography, two patients had dissections in two arteries (both VAs in one patient, VA and internal carotid artery in one patient), giving a total of 15 VAs with dissection. Dissection sites included V1 in four patients, V2 in one patient, V3 in three patients, V4 in six patients, and both V3 and V4 in one patient. Luminal stenosis was present in 13 VAs, occlusion in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia in 1. Posterior circulation infarcts were found on CT or MR in five patients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination in one.« less

Implantation of personalized, biocompatible mitral annuloplasty rings: feasibility study in an animal model

PubMed Central

Sündermann, Simon H.; Gessat, Michael; Cesarovic, Nikola; Frauenfelder, Thomas; Biaggi, Patric; Bettex, Dominique; Falk, Volkmar; Jacobs, Stephan

2013-01-01

OBJECTIVES Implantation of an annuloplasty ring is an essential component of a durable mitral valve repair. Currently available off-the-shelf rings still do not cover all the variations in mitral annulus anatomy and pathology from subject to subject. Computed tomography (CT) and echo imaging allow for 3-D segmentation of the mitral valve and mitral annulus. The concept of tailored annuloplasty rings has been proposed although, to date, no surgically applicable implementation of patient-specific annuloplasty rings has been seen. The objective of this trial was to prove the concept of surgical implantation of a model-guided, personalized mitral annuloplasty ring, manufactured based on individual CT-scan models. METHODS ECG-gated CT angiography was performed in six healthy pigs under general anaesthesia. Based on the individual shape of the mitral annulus in systole, a customized solid ring with integrated suturing holes was designed and manufactured from a biocompatible titanium alloy by a rapid process using laser melting. The ring was implanted three days later and valve function was assessed by intraoperative echocardiography. The macroscopic annulus–annuloplasty match was assessed after heart explantation. RESULTS CT angiography provided good enough image quality in all animals to allow for segmentation of the mitral annulus. The individually tailored mitral rings were manufactured and successfully implanted in all pigs. In 50%, a perfect matching of the implanted ring and the mitral annulus was achieved. In one animal, a slight deviation of the ring shape from the circumference was seen postoperatively. The rings implanted in the first two animals were significantly oversized but the deviation did not affect valve competence. CONCLUSIONS CT image quality and accuracy of the dimensions of the mitral annulus were sufficient for digital modelling and rapid manufacturing of mitral rings. Implantation of individually tailored annuloplasty rings is feasible. PMID:23287589

CT Angiography of Peripheral Arterial Disease by 256-Slice Scanner: Accuracy, Advantages and Disadvantages Compared to Digital Subtraction Angiography.

PubMed

Mishra, Atul; Jain, Narendra; Bhagwat, Anand

2017-07-01

Peripheral arterial occlusive disease (PAOD) may cause disabling claudication or critical limb ischemia. Multidetector computed tomography (CT) technology has evolved to the level of 256-slice CT scanners which has significantly improved the spatial and temporal resolution of the images. This has provided the capability of chasing the contrast bolus at a fast speed enabling angiographic imaging of long segments of the body. These images can be reconstructed in various planes and various modes for detailed analysis of the peripheral vascular diseases which helps in making treatment decision. The aim of this retrospective study was to compare the CT angiograms (CTAs) of all cases of PAOD done by 256-slice CT scanner at a tertiary care vascular center and comparing these images with the digital subtraction angiograms (DSAs) of these patients. The retrospective study included 53 patients who underwent both CTA and DSA at our center over a period of 3 years from March 2013 to March 2016. The CTA showed high sensitivity (93%) and specificity (92.7%) for overall assessment of degree of stenosis in a vascular segment in cases of aortic and lower limb occlusive disease. The assessment of lesions of infrapopliteal segment was comparatively inferior (sensitivity 91.6%, accuracy 73.3%, and positive predictive value 78.5%), more so in the presence of significant calcification. The advantages of CTA were its noninvasive nature, ability to image large area of body, almost no adverse effects to the patients, and better assessment of vessel wall disease. However, the CTA assessment of collaterals was inferior with a sensitivity of only 62.7% as compared to DSA. Overall, 256-slice CTA provides fast and accurate imaging of vascular tree which can restrict DSA only in few selected cases as a problem-solving tool where clinico-radiological mismatch is present.

Determination of Stent Frame Displacement After Endovascular Aneurysm Sealing.

PubMed

van Veen, Ruben; van Noort, Kim; Schuurmann, Richte C L; Wille, Jan; Slump, Cornelis H; de Vries, Jean-Paul P M

2018-02-01

To describe and validate a new methodology for visualizing and quantifying 3-dimensional (3D) displacement of the stent frames of the Nellix endosystem after endovascular aneurysm sealing (EVAS). The 3D positions of the stent frames were registered to 5 fixed anatomical landmarks on the post-EVAS computed tomography (CT) scans, facilitating comparison of the position and shape of the stent frames between consecutive follow-up scans. Displacement of the proximal and distal ends of the stent frames, the entire stent frame trajectories, as well as changes in distance between the stent frames were determined for 6 patients with >5-mm displacement and 6 patients with <5-mm displacement at 1-year follow-up. The measurements were performed by 2 independent observers; the intraclass correlation coefficient (ICC) was used to determine interobserver variability. Three types of displacement were identified: displacement of the proximal and/or distal end of the stent frames, lateral displacement of one or both stent frames, and stent frame buckling. The ICC ranged from good (0.750) to excellent (0.958). No endoleak or migration was detected in the 12 patients on conventional CT angiography at 1 year. However, of the 6 patients with >5-mm displacement on the 1-year CT as determined by the new methodology, 2 went on to develop a type Ia endoleak in longer follow-up, and displacement progressed to >15 mm for 2 other patients. No endoleak or progressive displacement was appreciated for the patients with <5-mm displacement. The sac anchoring principle of the Nellix endosystem may result in several types of displacement that have not been observed during surveillance of regular endovascular aneurysm repairs. The presented methodology allows precise 3D determination of the Nellix endosystems and can detect subtle displacement better than standard CT angiography. Displacement >5 mm on the 1-year CT scans reconstructed with the new methodology may forecast impaired sealing and anchoring of the Nellix endosystem.

Pancreatic abscess caused by Corynebacterium coyleae mimicking malignant neoplasm.

PubMed

Taguchi, Masashi; Nishikawa, Shoichiro; Matsuoka, Hidehiko; Narita, Ryoichi; Abe, Shintaro; Fukuda, Kazumasa; Miyamoto, Hiroshi; Taniguchi, Hatsumi; Otsuki, Makoto

2006-11-01

A 50-year-old female was referred to our hospital because of postprandial epigastric pain and pancreatic head mass. On admission, an elastic hard mass with tenderness was palpable in the epigastric region. Laboratory findings showed no abnormalities, except for a slightly elevated C-reactive protein value and iron deficiency anemia. Serum levels of pancreatic enzymes and tumor markers were also within the reference range. Computed tomography (CT) demonstrated a 5-cm heterogenous mass at the head of the pancreas. Angiography showed that gastroduodenal artery was transformed and narrowed by the mass. Smooth stenosis of portal vein was also observed. Fusion CT-positron emission tomography with 2-deoxy-2-[F]fluoro-D-glucose demonstrated a focus of increased uptake in the pancreatic head mass. We suspected the mass of malignancy but, surprisingly, tumor size was gradually decreased without any therapies. Biopsy specimens from the mass of the pancreas showed marked inflammatory cell infiltration and marked interstitial fibrosis without malignant cells. Thereafter, we could isolate Corynebacterium coyleae from the biopsy specimen. We diagnosed the mass as a pancreatic abscess caused by C. coyleae and started with the intravenous antibiotics therapy. Subsequent follow-up CT and ultrasonography showed dramatic improvement in pancreatic mass. We present here a case of pancreatic abscess which was difficult to differentiate from malignant lesion by various imaging studies. Moreover, we could culture and identify C. coyleae which had never been reported to be the source of pancreatic abscess.

Management of Patients with Acute Lower Gastrointestinal Bleeding

PubMed Central

Strate, Lisa L.; Gralnek, Ian M.

2016-01-01

This guideline provides recommendations for the management of patients with acute overt lower gastrointestinal hemorrhage. Hemodynamic status should be initially assessed with intravascular volume resuscitation started as needed. Risk stratification based upon clinical parameters should be performed to help distinguish patients at high and low-risk of adverse outcomes. Hematochezia associated with hemodynamic instability may be indicative of an upper GI bleeding source and thus warrants an upper endoscopy. In the majority of patients, colonoscopy should be the initial diagnostic procedure and should be performed within 24 hours of patient presentation after adequate colon preparation. Endoscopic hemostasis therapy should be provided to patients with high risk endoscopic stigmata of bleeding including active bleeding, non-bleeding visible vessel, or adherent clot. The endoscopic hemostasis modality used (mechanical, thermal, injection or combination) is most often guided by the etiology of bleeding, access to the bleeding site, and endoscopist experience with the various hemostasis modalities. Repeat colonoscopy, with endoscopic hemostasis performed if indicated, should be considered for patients with evidence of recurrent bleeding. Radiographic interventions (tagged red blood cell scintigraphy, CT angiography, angiography) should be considered in high-risk patients with ongoing bleeding who do not respond adequately to resuscitation, and who are unlikely to tolerate bowel preparation and colonoscopy. Strategies to prevent recurrent bleeding should be considered. NSAID use should be avoided in patients with a history of acute lower GI bleeding particularly if secondary to diverticulosis or angioectasia. In patients with established cardiovascular disease who require aspirin (secondary prophylaxis), aspirin should not be discontinued. The exact timing depends on the severity of bleeding, perceived adequacy of hemostasis and the risk of a thromboembolic event. Surgery for the prevention of recurrent lower gastrointestinal bleeding should be individualized and the source of bleeding should be carefully localized prior to resection. PMID:26925883

Investigating pulmonary embolism in the emergency department with lower limb plethysmography: the Manchester Investigation of Pulmonary Embolism Diagnosis (MIOPED) study

PubMed Central

Hogg, K; Dawson, D; Mackway‐Jones, K

2006-01-01

Objectives To measure the diagnostic accuracy of computerised strain gauge plethysmography in the diagnosis of pulmonary embolism (PE). Methods Two researchers prospectively recruited 425 patients with pleuritic chest pain presenting to the emergency department (ED). Lower limb computerised strain gauge plethysmography was performed in the ED. All patients underwent an independent reference standard diagnostic algorithm to establish the presence or absence of PE. A low modified Wells' clinical probability combined with a normal D‐dimer excluded PE. All others required diagnostic imaging with PIOPED interpreted ventilation perfusion scanning and/or computerised tomography (CT) pulmonary angiography. Patients with a nondiagnostic CT had digital subtraction pulmonary angiography. All patients were followed up clinically for 3 months. Results The sensitivity of computerised strain gauge plethysmography was 33.3% (95% confidence interval (CI) 16.3 to 56.2%) and specificity 64.1% (95% CI 59.0 to 68.8%). The negative likelihood ratio was 1.04 (95% CI 0.68 to 1.33) and positive likelihood ratio 0.93 (95% CI 0.45 to 1.60). Conclusions Lower limb computerised strain gauge plethysmography does not aid in the diagnosis of PE. PMID:16439734

Contrast-Enhanced Abdominal Angiographic CT for Intra-abdominal Tumor Embolization: A New Tool for Vessel and Soft Tissue Visualization

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

Meyer, Bernhard Christian, E-mail: bernhard.meyer@charite.de; Frericks, Bernd Benedikt; Albrecht, Thomas

2007-07-15

C-Arm cone-beam computed tomography (CACT), is a relatively new technique that uses data acquired with a flat-panel detector C-arm angiography system during an interventional procedure to reconstruct CT-like images. The purpose of this Technical Note is to present the technique, feasibility, and added value of CACT in five patients who underwent abdominal transarterial chemoembolization procedures. Target organs for the chemoembolizations were kidney, liver, and pancreas and a liposarcoma infiltrating the duodenum. The time for patient positioning, C-arm and system preparation, CACT raw data acquisition, and data reconstruction for a single CACT study ranged from 6 to 12 min. The volumemore » data set produced by the workstation was interactively reformatted using maximum intensity projections and multiplanar reconstructions. As part of an angiography system CACT provided essential information on vascular anatomy, therapy endpoints, and immediate follow-up during and immediately after the abdominal interventions without patient transfer. The quality of CACT images was sufficient to influence the course of treatment. This technology has the potential to expedite any interventional procedure that requires three-dimensional information and navigation.« less

[Diamond-Forrester and cardiac CT : Is there a need to redefine the pretest probability of coronary artery disease?].

PubMed

Schuhbäck, A; Kolwelter, J; Achenbach, S

2016-08-01

Apart from the Diamond-Forrester classification, which is widely used particularly in the USA for the pretest probability of coronary artery disease, other scores also exist, such as an updated version of the classification table by Genders et al., the Morise score and the Duke clinical risk score. These scores estimate the probability of coronary artery disease, defined as the presence of at least one high-grade stenosis, based on symptom characteristics, age, gender and other parameters. All of the scores were derived from patient cohorts in which invasive coronary angiography had been performed for clinical reasons. It has subsequently been shown that these scores, especially those developed several decades ago, substantially overestimate the pretest probability of coronary artery disease. When these risk scores are applied to patients for whom a non-invasive work-up of suspected coronary artery disease is planned, for example by coronary computed tomography (CT) angiography, the expected prevalence of significant coronary stenosis will be overestimated. This, in turn, influences the test characteristics and the significance of the non-invasive examination (positive and negative predictive values) and needs to be taken into account when interpreting test results.

Instant wireless transmission of radiological images using a personal digital assistant phone for emergency teleconsultation.

PubMed

Kim, Dong-Keun; Yoo, Sun K; Kim, Sun H

2005-01-01

The instant transmission of radiological images may be important for making rapid clinical decisions about emergency patients. We have examined an instant image transfer system based on a personal digital assistant (PDA) phone with a built-in camera. Images displayed on a picture archiving and communication systems (PACS) monitor can be captured by the camera in the PDA phone directly. Images can then be transmitted from an emergency centre to a remote physician via a wireless high-bandwidth network (CDMA 1 x EVDO). We reviewed the radiological lesions in 10 normal and 10 abnormal cases produced by modalities such as computerized tomography (CT), magnetic resonance (MR) and digital angiography. The images were of 24-bit depth and 1,144 x 880, 1,120 x 840, 1,024 x 768, 800 x 600, 640 x 480 and 320 x 240 pixels. Three neurosurgeons found that for satisfactory remote consultation a minimum size of 640 x 480 pixels was required for CT and MR images and 1,024 x 768 pixels for angiography images. Although higher resolution produced higher clinical satisfaction, it also required more transmission time. At the limited bandwidth employed, higher resolutions could not be justified.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

PubMed

Lee, Young; Zuckerman, Scott L; Mocco, J

2013-01-01

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Extranasopharyngeal angiofibroma: clinical and radiological presentation.

PubMed

Szymańska, Anna; Szymański, Marcin; Morshed, Kamal; Czekajska-Chehab, Elżbieta; Szczerbo-Trojanowska, Małgorzata

2013-02-01

Nasopharyngeal angiofibroma (NA) is a rare, vascular tumor affecting adolescent males. Due to aggressive local growth, skull base location and risk of profound hemorrhage, NA is a challenge for surgeons. Angiofibromas have been sporadically described in extanasopharyngeal locations. We review ten cases of extranasopharyngeal angiofibroma (ENA) and discuss the incidence, clinical presentation and management of this pathology. The group consisted of 4 males and 5 females aged 8-49. There were 7 patients with nasal angiofibroma, 1 patient with laryngeal angiofibroma, 1 patient with oral angiofibroma and another patient with infratemporal fossa tumor. In patients with nasal angiofibroma most common presenting symptoms were nasal obstruction and epistaxis. Patients with laryngeal angiofibroma suffered from mild dysphagia and patients with the infratemporal fossa tumor had painless cheek swelling. In four patients with nasal tumor computed tomography (CT) demonstrated mass with strong to intermediate contrast enhancement. In one patient with nasal tumor carotid angiography demonstrated pathological vessels without intensive tumor blush. Infratemporal fossa tumor showed intensive contrast enhancement on CT and magnetic resonance imaging (MRI) scans, and abundant vascularity on angiography. Laryngeal and oral angiofibroma required no radiological imaging. Three nasal tumors were evaluated before introduction of CT to clinical practice. All patients underwent surgery. No recurrences developed. ENAs differ significantly from NAs regarding clinical and radiological presentations. They lack typical clinical and radiological features as they develop in all age groups and in females, may be less vascularised, arise from various sites and produce a variety of symptoms.

Time-resolved C-arm cone beam CT angiography (TR-CBCTA) imaging from a single short-scan C-arm cone beam CT acquisition with intra-arterial contrast injection

NASA Astrophysics Data System (ADS)

Li, Yinsheng; Garrett, John W.; Li, Ke; Wu, Yijing; Johnson, Kevin; Schafer, Sebastian; Strother, Charles; Chen, Guang-Hong

2018-04-01

Time-resolved C-arm cone-beam CT (CBCT) angiography (TR-CBCTA) images can be generated from a series of CBCT acquisitions that satisfy data sufficiency condition in analytical image reconstruction theory. In this work, a new technique was developed to generate TR-CBCTA images from a single short-scan CBCT data acquisition with contrast media injection. The reconstruction technique enabling this application is a previously developed image reconstruction technique, synchronized multi-artifact reduction with tomographic reconstruction (SMART-RECON). In this new application, the acquired short-scan CBCT projection data were sorted into a union of several sub-sectors of view angles and each sub-sector of view angles corresponds to an individual image volume to be reconstructed. The SMART-RECON method was then used to jointly reconstruct all of these individual image volumes under two constraints: (1) each individual image volume is maximally consistent with the measured cone-beam projection data within the corresponding view angle sector and (2) the nuclear norm of the image matrix is minimized. The difference between these reconstructed individual image volumes is used to generated the desired subtracted angiograms. To validate the technique, numerical simulation data generated from a fractal tree angiogram phantom were used to quantitatively study the accuracy of the proposed method and retrospective in vivo human subject studies were used to demonstrate the feasibility of generating TR-CBCTA in clinical practice.

Frostbite: Spectrum of Imaging Findings and Guidelines for Management

PubMed Central

Brown, Richard K. J.; Levi, Benjamin; Kraft, Casey T.; Jacobson, Jon A.; Gross, Milton D.; Wong, Ka Kit

2016-01-01

Frostbite is a localized cold thermal injury that results from tissue freezing. Frostbite injuries can have a substantial effect on long-term limb function and mobility if not promptly evaluated and treated. Imaging plays a critical role in initial evaluation of frostbite injuries and in monitoring response to treatment. A multimodality approach involving radiography, digital subtraction angiography (DSA), and/or multiphase bone scintigraphy with hybrid single photon emission computed tomography (SPECT)/computed tomography (CT) is often necessary for optimal guidance of frostbite care. Radiographs serve as an initial survey of the affected limb and may demonstrate characteristic findings, depending on the time course and severity of injury. DSA is used to evaluate perfusion of affected soft tissues and identify potential targets for therapeutic intervention. Angiography-directed thrombolysis plays an essential role in tissue preservation and salvage in deep frostbite injuries. Multiphase bone scintigraphy with technetium 99m–labeled diphosphonate provides valuable information regarding the status of tissue viability after initial treatment. The addition of SPECT/CT to multiphase bone scintigraphy enables precise anatomic localization of the level and depth of tissue necrosis before its appearance at physical examination and can help uncover subtle findings that may remain occult at scintigraphy alone. Multiphase bone scintigraphy with SPECT/CT is the modality of choice for prognostication and planning of definitive surgical care of affected limbs. Appropriate use of imaging to direct frostbite care can help limit the effects that these injuries have on limb function and mobility. ©RSNA, 2016 PMID:27494386

Coronary Events and Anatomy After Arterial Switch Operation for Transposition of the Great Arteries: Detection by 16-Row Multislice Computed Tomography Angiography in Pediatric Patients

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

Oztunc, Funda, E-mail: foztunc@yahoo.com; Baris, Safa, E-mail: safabaris@hotmail.co; Adaletli, Ibrahim, E-mail: iadaletli@yahoo.com

2009-03-15

The purpose of this study was to evaluate the feasibility of multislice computed tomographic (MSCT) angiography as a noninvasive method for detecting ostial, proximal, and middle segment coronary stenosis or occlusion and anatomy in patients with transposition of the great arteries who had undergone arterial switch operation (ASO). Sixteen-detector-row MSCT angiography was performed in 16 patients treated with ASO for transposition of the great arteries. The median age was 10.3 years (range, 6.2-16.3 years). Sixteen-detector-row MSCT angiography was performed in 16 patients who had undergone ASO. CT imaging was performed in the craniocaudal direction from 2 cm above the carinamore » up to the heart basis. Noninvasive assessment of coronary artery stenosis and anatomy were investigated by MSCT angiography. Two patients were excluded from the study because of artifacts. Of 14 evaluated patients, 1 patient had ostial stenosis (7.1%). A coronary artery anatomy variant was present in six patients: left main artery (LMA) and right coronary artery (RCA) originating from the right sinus as a single orifice (n = 2); left circumflex artery (LCX) originating from the RCA (n = 1); LMA and RCA, after branching to the LCX, originating separately from the right sinus (n = 1); and LMA (n = 1) and left anterior descending artery (LADA; n = 1) originating directly from the right sinus. Intramural bridging in the LAD (n = 2) was detected. Five patients were normal. In conclusion, MSCT angiography, as a noninvasive, feasible technique for assessing coronary stenosis or occlusion and anatomy, can be used in the follow-up of patients who have undergone ASO.« less

Interventricular membranous septal aneurysm: CT and MR manifestations.

PubMed

Carcano, Carolina; Kanne, Jeffrey P; Kirsch, Jacobo

2016-02-01

Advanced cardiac imaging is a valuable method to investigate cardiac malformations. The detection of the interventricular membranous septum has clinical significance due to thrombogenic and arrythmogenic predisposition, as well as a role in obstructing the pulmonary flow. This review describes six clinical presentations in which advanced cardiac imaging has been the tool for evaluation, with special emphasis in CT angiography and cardiac MRI sequences. Teaching Points • The interventricular membranous septum can predispose patients to thrombogenic and arrythmogenic events. • Subpulmonic stenosis relates to the protrusion of the aneurysm into the right ventricle • During surgery, ventricular pressures of the opened heart become balanced, making the aneurysm less evident.

Multiple congenital PSS in a dog: case report and literature review.

PubMed

Leeman, Jessica J; Kim, Stanley E; Reese, David J; Risselada, Marije; Ellison, Gary W

2013-01-01

A 4 yr old spayed female mixed-breed dog presented with a 2 yr history of recurring increases in liver enzymes. Two congenital portosystemic shunts (PSSs) were identified using computed tomography (CT) angiography, which included a portoazygous and portorenal extrahepatic shunt. Double right renal veins were also identified. The shunts were successfully identified and attenuated with cellophane banding. Multiple congenital PSS is a rare phenomenon, but should be considered during exploratory laparotomy for PSS and in dogs with poor response to surgical attenuation of a single PSS. CT proved to be a crucial part of accurate diagnosis and surgical planning for this dog with multiple congenital PSS.

CT myocardial perfusion imaging: current status and future perspectives.

PubMed

Yang, Dong Hyun; Kim, Young-Hak

2017-07-01

Computed tomography myocardial perfusion (CTP) combined with coronary computed tomography angiography (CCTA) may constitute a "1-stop shop" for the noninvasive diagnosis of hemodynamically significant coronary stenosis during a single CT examination. CTP shows high diagnostic performance and provides incremental value over CCTA for the detection of hemodynamically significant coronary stenosis in patients with a high Agatston calcium score or coronary artery stents. Future studies should determine the optimal protocol and clinical value of CTP for guiding revascularization strategy and prognostication. In this article, we review the current status and future perspectives of CTP, focusing on technical considerations, clinical applications, and future research topics.

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 patients with PFO. (c) RSNA, 2008.

Intraoperative computed tomography with integrated navigation system in a multidisciplinary operating suite.

PubMed

Uhl, Eberhard; Zausinger, Stefan; Morhard, Dominik; Heigl, Thomas; Scheder, Benjamin; Rachinger, Walter; Schichor, Christian; Tonn, Jörg-Christian

2009-05-01

We report our preliminary experience in a prospective series of patients with regard to feasibility, work flow, and image quality using a multislice computed tomographic (CT) scanner combined with a frameless neuronavigation system (NNS). A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. The scanner was connected to a frameless infrared-based NNS. Image data was transferred directly from the scanner into the navigation system. This allowed updating of the NNS during surgery by automated image registration based on the position of the gantry. Intraoperative CT angiography was possible. The patient was positioned on a radiolucent operating table that fits within the bore of the gantry. During image acquisition, the gantry moved over the patient. This table allowed all positions and movements like any normal operating table without compromising the positioning of the patient. For cranial surgery, a carbon-made radiolucent head clamp was fixed to the table. Experience with the first 230 patients confirms the feasibility of intraoperative CT scanning (136 patients with intracranial pathology, 94 patients with spinal lesions). After a specific work flow, interruption of surgery for intraoperative scanning can be limited to 10 to 15 minutes in cranial surgery and to 9 minutes in spinal surgery. Intraoperative imaging changed the course of surgery in 16 of the 230 cases either because control CT scans showed suboptimal screw position (17 of 307 screws, with 9 in 7 patients requiring correction) or that tumor resection was insufficient (9 cases). Intraoperative CT angiography has been performed in 7 cases so far with good image quality to determine residual flow in an aneurysm. Image quality was excellent in spinal and cranial base surgery. The system can be installed in a preexisting operating environment without the need for special surgical instruments. It increases the safety of the patient and the surgeon without necessitating a change in the existing surgical protocol and work flow. Imaging and updating of the NNS can be performed at any time during surgery with very limited time and modification of the surgical setup. Multidisciplinary use increases utilization of the system and thus improves the cost-efficiency relationship.

Pediatric blunt cerebrovascular injury: the McGovern screening score.

PubMed

Herbert, Joseph P; Venkataraman, Sidish S; Turkmani, Ali H; Zhu, Liang; Kerr, Marcia L; Patel, Rajan P; Ugalde, Irma T; Fletcher, Stephen A; Sandberg, David I; Cox, Charles S; Kitagawa, Ryan S; Day, Arthur L; Shah, Manish N

2018-03-16

OBJECTIVE The objective of this study was to assess the incidence, diagnosis, and treatment of pediatric blunt cerebrovascular injury (BCVI) at a busy Level 1 trauma center and to develop a tool for accurately predicting pediatric BCVI and the need for diagnostic testing. METHODS This is a retrospective cohort study of a prospectively collected database of pediatric patients who had sustained blunt trauma (patient age range 0-15 years) and were treated at a Level 1 trauma center between 2005 and 2015. Digital subtraction angiography, MR angiography, or CT angiography was used to confirm BCVI. Recently, the Utah score has emerged as a screening tool specifically targeted toward evaluating BCVI risk in the pediatric population. Using logistical regression and adding mechanism of injury as a logit, the McGovern score was able to use the Utah score as a starting point to create a more sensitive screening tool to identify which pediatric trauma patients should receive angiographic imaging due to a high risk for BCVI. RESULTS A total of 12,614 patients (mean age 6.6 years) were admitted with blunt trauma and prospectively registered in the trauma database. Of these, 460 (3.6%) patients underwent angiography after blunt trauma: 295 (64.1%), 107 (23.3%), 6 (1.3%), and 52 (11.3%) patients underwent CT angiography, MR angiography, digital subtraction angiography, and a combination of imaging modalities, respectively. The BCVI incidence (n = 21; 0.17%) was lower than that in a comparable adult group (p < 0.05). The mean patient was age 10.4 years with a mean follow-up of 7.5 months. Eleven patients (52.4%) were involved in a motor vehicle collision, with a mean Glasgow Coma Scale score of 8.6. There were 8 patients (38.1%) with carotid canal fracture, 6 patients (28.6%) with petrous bone fracture, and 2 patients (9.5%) with infarction on initial presentation. Eight patients (38.1%) were managed with observation alone. The Denver, modified Memphis, Eastern Association for the Surgery of Trauma (EAST), and Utah scores, which are the currently used screening tools for BCVI, misclassified 6 (28.6%), 6 (28.6%), 7 (33.3%), and 10 (47.6%) patients with BCVI, respectively, as "low risk" and not in need of subsequent angiographic imaging. By incorporating the mechanism of injury into the score, the McGovern score only misclassified 4 (19.0%) children, all of whom were managed conservatively with no treatment or aspirin. CONCLUSIONS With a low incidence of pediatric BCVI and a nonsurgical treatment paradigm, a more conservative approach than the Biffl scale should be adopted. The Denver, modified Memphis, EAST, and Utah scores did not accurately predict BCVI in our equally large cohort. The McGovern score is the first BCVI screening tool to incorporate the mechanism of injury into its screening criteria, thereby potentially allowing physicians to minimize unnecessary radiation and determine which high-risk patients are truly in need of angiographic imaging.

[Reseach development of vascular anatomy and preoperative design technology of anterolateral thigh flap].

PubMed

Duan, Jiazhang; He, Xiaoqing; Xu, Yongqing

2016-07-08

?To summarize the present status and progress of vascular anatomy and preoperative design technology of the anterolateral thigh flap. ?The relative researches focused on vascular anatomy and preoperative design technology of the anterolateral thigh flap were extensively reviewed, analyzed, and summarized. ?Vascular anatomy of the anterolateral thigh flap has been reported by numerous researchers, but perforators' location, origin, course, and the variation of the quantity have been emphasized. Meanwhile, the variation of descending branch, oblique branch, and lateral circumflex femoral artery has also been widely reported. Preoperative design technology of the anterolateral thigh flap includes hand-held Doppler, Color Doppler, CT angiography (CTA), magnetic resonance angiography, digital subtraction angiography, and digital technology, among which the hand-held Doppler is most widely used, and CTA is the most ideal, but each method has its own advantages and disadvantages. ?There is multiple variation of vascular anatomy of the anterolateral thigh flap. Though all kinds of preoperative design technologies can offer strong support to operation of anterolateral thigh flap, a simple, quick, precise, and noninvasive technology is the direction of further research.

Complete resection of hypervascularised extraventricular neurocytoma after preoperative embolisation.

PubMed

Katati, Majed; Ortiz García, Isabel; Chamorro, Clara Isabel; Horcajadas, Ángel; Hurtado, Alicia; Sánchez, Carlos; Iañez, Benjamín; Saura, Enrique; García, Ernesto; Busquier, Heriberto

2018-04-18

A 13-year-old female arrived at the Emergency Department with a two-week history of headache, and bilateral papilloedema on examination. The initial study with CT and MRI showed a large multicystic left frontal mass with calcification surrounded by peripheral oedema, subacute intralesional bleeding and association of multiple large vessels. She was initially operated on in another centre where a subacute haematoma was found, evacuating to multiple vessels and arteriolised veins. Despite the earlier neuroimaging findings, arteriovenous malformation (AVM) was suspected, so she was referred to our centre for further treatment. We performed angiography, MR angiography and MRI with advanced sequences, diagnosing a highly vascularised intra-axial tumour which was embolised. The patient was then definitively operated on, with the resulting finding of extraventricular neurocytoma (EVN). EVN are extremely rare lesions, not previously described in the literature as hypervascularised lesions, which in our case required prior angiography and embolisation for proper diagnosis and adequate management. Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

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

Joja, Ikuo; Asakawa, Mari; Motoyama, Kazumi

Uterine cirsoid aneurysm is uncommon. It is important to make a diagnosis of this disease preoperatively, because repeated curettages may induce life-threatening massive genital bleeding. We present a case of a 51-year-old woman with uterine cirsoid aneurysm in whom MRI and MRA were very useful for the preoperative diagnosis. The radiologic appearances on ultrasonography, CT, conventional SE MRI, MRA, dynamic MRI, and pelvic angiography are presented. Conventional SE T1-weighted and T2-weighted images demonstrated multiple flow voids in the uterus and bilateral adnexal regions. MRA demonstrated a cluster of distinct, tortuous, and coiled vascular channels in the pelvis. MRA could obtainmore » images almost equal to angiography and was considered to be an excellent noninvasive imaging technique for the diagnosis of uterine cirsoid aneurysm. 28 refs., 7 figs« less

Recanalization of Splenic Artery Aneurysm After Transcatheter Arterial Embolization Using N-Butyl Cyanoacrylate

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

Matsumoto, Keiji; Ushijima, Yasuhiro, E-mail: ushijima@radiol.med.kyushu-u.ac.jp; Tajima, Tsuyoshi

2010-02-15

A 65-year-old woman who had been diagnosed as having microscopic polyangiitis developed sudden abdominal pain and entered a state of shock. Abdominal CT showed massive hemoperitoneum, and emergent angiography revealed a ruptured splenic artery aneurysm. After direct catheterization attempts failed due to tortuous vessels and angiospasm, transcatheter arterial embolization using an n-butyl cyanoacrylate (NBCA)-lipiodol mixture was successfully performed. Fifty days later, the patient developed sudden abdominal pain again. Repeated angiography demonstrated recanalization of the splenic artery and splenic artery aneurysm. This time, the recanalized aneurysm was embolized using metallic coils with the isolation method. Physicians should keep in mind thatmore » recanalization can occur after transcatheter arterial embolization using N-butyl cyanoacrylate, which has been used as a permanent embolic agent.« less

Electrocardiographically gated 16-section CT of the thorax: cardiac motion suppression.

PubMed

Hofmann, Lars K; Zou, Kelly H; Costello, Philip; Schoepf, U Joseph

2004-12-01

Thirty patients underwent 16-section multi-detector row computed tomographic (CT) angiography of the thorax with retrospective electrocardiographic gating. Institutional review board approval was obtained for retrospective analysis of CT scan data and records; patient informed consent was not required. Images reconstructed at six different time points (0%, 20%, 40%, 50%, 60%, 80%) within the R-R interval on the electrocardiogram were analyzed by two radiologists for diagnostic quality, to identify suitable reconstruction intervals for optimal suppression of cardiac motion. Five regions of interest (left coronary artery, aortic root, ascending and descending aorta, pulmonary arteries) were evaluated. Best image quality was achieved by referencing image reconstruction to middiastole (50%-60%) for the left coronary artery, aortic root, and ascending aorta. The pulmonary arteries are best displayed during mid- to late diastole (80%). (c) RSNA, 2004

Assessment of cerebral perfusion in childhood strokes

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

Gates, G.F.; Fishman, L.S.; Segall, H.D.

1982-11-01

Thirty-three children who had strokes were studied by dynamic and static scintigraphy, 29 by CT scanning, and 10 by cerebral angiography. The accuracy of dynamic scintigraphy in stroke detection during the first week of clinical symptoms was 94% while CT scanning was 60% accurate and static scintigraphy 11% accurate. During the second week the accuracy of CT scanning increased to 100%, but static scintigraphy improved to only 50%. Fifty percent of scintiangiograms performed during the first week showed either luxuriant perfusion or flip-flop patterns. In some patients these two flow patterns changed to that of cerebral hemispheric ischemia after goingmore » through a phase during which perfusion appeared to be equal in the two hemispheres. Dynamic scintigraphy is believed to be the test of choice for stroke detection in children during the first week.« less

SYNTAX score based on coronary computed tomography angiography may have a prognostic value in patients with complex coronary artery disease: An observational study from a retrospective cohort.

PubMed

Suh, Young Joo; Han, Kyunghwa; Chang, Suyon; Kim, Jin Young; Im, Dong Jin; Hong, Yoo Jin; Lee, Hye-Jeong; Hur, Jin; Kim, Young Jin; Choi, Byoung Wook

2017-09-01

The SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) score is an invasive coronary angiography (ICA)-based score for quantifying the complexity of coronary artery disease (CAD). Although the SYNTAX score was originally developed based on ICA, recent publications have reported that coronary computed tomography angiography (CCTA) is a feasible modality for the estimation of the SYNTAX score.The aim of our study was to investigate the prognostic value of the SYNTAX score, based on CCTA for the prediction of major adverse cardiac and cerebrovascular events (MACCEs) in patients with complex CAD.The current study was approved by the institutional review board of our institution, and informed consent was waived for this retrospective cohort study. We included 251 patients (173 men, mean age 66.0 ± 9.29 years) who had complex CAD [3-vessel disease or left main (LM) disease] on CCTA. SYNTAX score was obtained on the basis of CCTA. Follow-up clinical outcome data regarding composite MACCEs were also obtained. Cox proportional hazards models were developed to predict the risk of MACCEs based on clinical variables, treatment, and computed tomography (CT)-SYNTAX scores.During the median follow-up period of 1517 days, there were 48 MACCEs. Univariate Cox hazards models demonstrated that MACCEs were associated with advanced age, low body mass index (BMI), and dyslipidemia (P < .2). In patients with LM disease, MACCEs were associated with a higher SYNTAX score. In patients with CT-SYNTAX score ≥23, patients who underwent coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention had significantly lower hazard ratios than patients who were treated with medication alone. In multivariate Cox hazards model, advanced age, low BMI, and higher SYNTAX score showed an increased hazard ratio for MACCE, while treatment with CABG showed a lower hazard ratio (P < .2).On the basis of our results, CT-SYNTAX score can be a useful method for noninvasively predicting MACCEs in patients with complex CAD, especially in patients with LM disease.

SU-E-I-25: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Simulation Study

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

Johnson, T; Ding, H; Lipinski, J

2015-06-15

Purpose: To develop a physics-based model for accurate quantification of the cross-sectional area (CSA) of coronary arteries in CT angiography by measuring the integrated density to account for the partial volume effect. Methods: In this technique the integrated density of the object as compared with its local background is measured to account for the partial volume effect. Normal vessels were simulated as circles with diameters in the range of 0.1–3mm. Diseased vessels were simulated as 2, 3, and 4mm diameter vessels with 10–90% area stenosis, created by inserting circular plaques. A simplified two material model was used with the lumenmore » as 8mg/ml Iodine and background as lipid. The contrast-to-noise ratio between lumen and background was approximately 26. Linear fits to the known CSA were calculated. The precision and accuracy of the measurement were quantified using the root-mean-square fit deviations (RMSD) and errors to the known CSA (RMSE). Results compared to manual segmentation of the vessel lumen. To assess the impact of random variations, coefficients of variation (CV) from 10 simulations for each vessel were computed to determine reliability. Measurements with CVs less than 10% were considered reliable. Results: For normal vessels, the precision and accuracy of the integrated density technique were 0.12mm{sup 2} and 0.28mm{sup 2}, respectively. The corresponding results for manual segmentation were 0.27mm{sup 2} and 0.43mm{sup 2}. For diseased vessels, the precision and accuracy of the integrated density technique were 0.14mm{sup 2} and 0.19mm{sup 2}. Corresponding results for manual segmentation were 0.42mm{sup 2} and 0.71mm{sup 2}. Reliable CSAs were obtained for normal vessels with diameters larger than 1 mm and for diseased vessels with area as low as 1.26mm2. Conclusion: The CSA based on integrated density showed improved precision and accuracy as compared with manual segmentation in simulation. These results indicate the potential of using integrated density to quantify CSA of coronary arteries in CT angiography.« less

[Impact of multi-layer spiral CT angiography of bronchial artery and pulmonary artery in assessment of the main blood supply to the primary lung cancer].

PubMed

Xiao, Xiang-sheng; Yu, Hong; Li, Hui-min; Liu, Shi-yuan; Li, Cheng-zhou; Liu, Jing

2006-04-01

To investigate the blood supply of primary lung cancer (PLC) using CT angiography for bronchial artery (BA) and pulmonary artery (PA). Thin-section enhanced multi-layer spiral CT (MSCT) were carried out in 147 primary lung cancer patients and 46 healthy subjects as control. Three-dimensional images of bronchial artery and pulmonary artery were obtained using volume render (VR) and multi-planar reconstruction (MPR) or maximum intensity projection (MIP) at the workstation, and their morphological findings and relationship with the mass were assessed. 136 primary lung cancer patients and 32 healthy controls were evaluated for at least one bronchial artery displayed clearly in VR. The detective rate of the bronchial artery was 92.5% and 69.6%, respectively. The bronchial artery caliber and the total section area of lesion side in lung cancer patients were significantly larger than that on the contralateral side and that of the control (P < 0.05). Bronchial artery on the lesion side in lung cancer was dilated and tortuous, directly penetrating into the mass with reticularly anastomosed branches. In the PLC patients, all PA were shown clearly with normal morphological image though crossing over the masses in 54 patients; In 25 PLC patients, the PA being essentially intact, was pushed around and surrounded the mass, giving the "hold ball" sign; In 40 other PLC patients, PA being also intact, the mass surrounded and buried the PA from the outside, crushing the PA flat resulting in an eccentric or centrifugal shrinkage, forming the "dead branch" sign; In the rest 28 patients, the PA was surrounded and even compressed, forming the "residual root" sign. Primary lung cancer patient shows dilated bronchial arteries and increased bronchial artery blood flow, whereas pulmonary arteries just pass through the mass or are compressed by the mass. It is further demonstrated that the bronchial artery, instead of the pulmonary artery, is the main vessel of blood supply to the primary lung cancer as shown by MSCT angiography of bronchial artery and pulmonary artery.

Role of time-resolved-CTA in intracranial arteriovenous malformation evaluation at 128-slice CT in comparison with digital subtraction angiography.

PubMed

Singh, Rupinder; Gupta, Vivek; Ahuja, Chirag; Kumar, Ajay; Mukherjee, Kanchan K; Khandelwal, Niranjan

2018-06-01

Introduction The present study aimed to evaluate the accuracy of time-resolved-computed tomographic angiography (TR-CTA) on a 128-slice CT scanner vis-à-vis cerebral digital subtraction angiography (DSA) in defining the morphological and haemodynamic characteristics of cerebral arteriovenous malformation (AVM). Methods Twenty-one patients (age range 10-46, mean 24.8 years) with clinical suspicion of AVM and three patients (age range 23-35, mean 24.3 years) with diagnosed AVM who were on follow-up underwent DSA and TR-CTA, on average 1.5 days apart. Three independent neuroradiologists analysed both studies in a blinded fashion based on the following parameters: AVM location, arterial feeder territories, venous drainage pattern, nidus flow characteristics, venous outflow obstruction, arterial feeder enlargement, external carotid artery feeder, location of aneurysm if any, leptomeningeal and transdural recruitment, neoangiogenesis, and pseudophlebitic pattern. Results The TR-CTA correctly demonstrated AVM in all 21 positive cases. It concordantly detected location (21/21), venous drainage pattern (21/21), nidus flow characteristics (21/21), and the venous outflow obstruction (9/9). However, discordance was seen in the demonstration of the arterial feeder (2/45) ( p = 0.49), arterial enlargement (13/17) ( p = 0.103), external carotid artery feeder (0/1), aneurysmal location (3/5) ( p = 0.40), leptomeningeal recruitment (1/3) ( p = 0.40), neoangiogenesis (0/4) ( p = 0.028) and in the pseudophlebitic pattern (2/5) ( p = 0.167) demonstration. Conclusions The results suggest that TR-CTA can provide the important features of cerebral AVM which are required in patient management.

Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

PubMed

Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

2013-12-01

The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

Observer variability in the assessment of CT coronary angiography and coronary artery calcium score: substudy of the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial

PubMed Central

Williams, Michelle C; Golay, Saroj K; Hunter, Amanda; Weir-McCall, Jonathan R; Mlynska, Lucja; Dweck, Marc R; Uren, Neal G; Reid, John H; Lewis, Steff C; Berry, Colin; van Beek, Edwin J R; Roditi, Giles; Newby, David E; Mirsadraee, Saeed

2015-01-01

Introduction Observer variability can influence the assessment of CT coronary angiography (CTCA) and the subsequent diagnosis of angina pectoris due to coronary heart disease. Methods We assessed 210 CTCAs from the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial for intraobserver and interobserver variability. Calcium score, coronary angiography and image quality were evaluated. Coronary artery disease was defined as none (<10%), mild (10–49%), moderate (50–70%) and severe (>70%) luminal stenosis and classified as no (<10%), non-obstructive (10–70%) or obstructive (>70%) coronary artery disease. Post-CTCA diagnosis of angina pectoris due to coronary heart disease was classified as yes, probable, unlikely or no. Results Patients had a mean body mass index of 29 (28, 30) kg/m2, heart rate of 58 (57, 60)/min and 62% were men. Intraobserver and interobserver agreements for the presence or absence of coronary artery disease were excellent (95% agreement, κ 0.884 (0.817 to 0.951) and good (91%, 0.791 (0.703 to 0.879)). Intraobserver and interobserver agreement for the presence or absence of angina pectoris due to coronary heart disease were excellent (93%, 0.842 (0.918 to 0.755) and good (86%, 0.701 (0.799 to 0.603)), respectively. Observer variability of calcium score was excellent for calcium scores below 1000. More segments were categorised as uninterpretable with 64-multidetector compared to 320-multidetector CTCA (10.1% vs 2.6%, p<0.001) but there was no difference in observer variability. Conclusions Multicentre multidetector CTCA has excellent agreement in patients under investigation for suspected angina due to coronary heart disease. Trial registration number NCT01149590. PMID:26019881

SU-E-P-10: Imaging in the Cardiac Catheterization Lab - Technologies and Clinical Applications

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

Fetterly, K

2014-06-01

Purpose: Diagnosis and treatment of cardiovascular disease in the cardiac catheterization laboratory is often aided by a multitude of imaging technologies. The purpose of this work is to highlight the contributions to patient care offered by the various imaging systems used during cardiovascular interventional procedures. Methods: Imaging technologies used in the cardiac catheterization lab were characterized by their fundamental technology and by the clinical applications for which they are used. Whether the modality is external to the patient, intravascular, or intracavity was specified. Specific clinical procedures for which multiple modalities are routinely used will be highlighted. Results: X-ray imaging modalitiesmore » include fluoroscopy/angiography and angiography CT. Ultrasound imaging is performed with external, trans-esophageal echocardiography (TEE), and intravascular (IVUS) transducers. Intravascular infrared optical coherence tomography (IVOCT) is used to assess vessel endothelium. Relatively large (>0.5 mm) anatomical structures are imaged with x-ray and ultrasound. IVUS and IVOCT provide high resolution images of vessel walls. Cardiac CT and MRI images are used to plan complex cardiovascular interventions. Advanced applications are used to spatially and temporally merge images from different technologies. Diagnosis and treatment of coronary artery disease frequently utilizes angiography and intra-vascular imaging, and treatment of complex structural heart conditions routinely includes use of multiple imaging modalities. Conclusion: There are several imaging modalities which are routinely used in the cardiac catheterization laboratory to diagnose and treat both coronary artery and structural heart disease. Multiple modalities are frequently used to enhance the quality and safety of procedures. The cardiac catheterization laboratory includes many opportunities for medical physicists to contribute substantially toward advancing patient care.« less

Diagnostic Accuracy of CT Coronary Angiography According to Pretest Probability of Coronary Artery Disease and Severity of Coronary Arterial Calcification: The CorE-64 International, Multicenter Study

PubMed Central

Arbab-Zadeh, Armin; Miller, Julie M; Rochitte, Carlos E; Dewey, Marc; Niinuma, Hiroyuki; Gottlieb, Ilan; Paul, Narinder; Clouse, Melvin E.; Shapiro, Edward P.; Hoe, John; Lardo, Albert C.; Bush, David E.; de Roos, Albert; Cox, Christopher; Brinker, Jeffrey; Lima, Joăo A. C.

2012-01-01

Objectives Assess the impact of patient population characteristics on accuracy by CT angiography (CTA) to detect obstructive coronary artery disease (CAD). Background The ability of CTA to exclude obstructive CAD in patients of different pretest probabilities and in presence of coronary calcification remains uncertain. Methods For the CorE-64 study 371 patients underwent CTA and cardiac catheterization for the detection of obstructive CAD defined as 50% or greater luminal stenosis by quantitative coronary angiography (QCA). This analysis includes 80 initially excluded patients with a calcium score ≥ 600. Area under the receiver-operating-characteristics curve (AUC) was used to evaluate CTA diagnostic accuracy compared to QCA in patients according to calcium score and pretest probability of CAD. Results Analysis of patient-based quantitative CTA accuracy revealed an AUC of 0.93 (95% confidence interval [CI] 0.90-0.95). AUC remained 0.93 (0.90-0.96) after excluding patients with known CAD but decreased to 0.81 (0.71-0.89) in patients with calcium score ≥ 600 (p=0.077). While AUC were similar (0.93, 0.92, and 0.93, respectively) for patients with intermediate, high pretest probability for CAD, and known CAD, negative predictive values were different: 0.90, 0.83, and 0.50, respectively. Negative predictive values decreased from 0.93 to 0.75 for patients with calcium score < or ≥ 100, respectively (p= 0.053). Conclusions Both pretest probability for CAD and coronary calcium scoring should be considered before using CTA for excluding obstructive CAD. CTA is less effective for this purpose in patients with calcium score ≥ 600 and in patients with a high pretest probability for obstructive CAD. PMID:22261160

Effects of Multi-Electrode Renal Denervation on Insulin Sensitivity and Glucose Metabolism in a Canine Model of Type 2 Diabetes Mellitus.

PubMed

Pan, Tao; Guo, Jin-He; Ling, Long; Qian, Yue; Dong, Yong-Hua; Yin, Hua-Qing; Zhu, Hai-Dong; Teng, Gao-Jun

2018-05-01

To evaluate the effects of multi-electrode catheter-based renal denervation (RDN) on insulin sensitivity and glucose metabolism in a type 2 diabetes mellitus (T2DM) canine model. Thirty-three dogs were divided equally into 3 groups: bilateral renal denervation (BRDN) group, left renal denervation (LRDN) group, and sham operation (SHAM) group. Body weight and blood biochemistry were measured at baseline, 20 weeks, and 32 weeks, and renal angiography and computerized tomographic (CT) angiography were determined before the procedure and 1 month, 2 months, and 3 months after the procedure. Western blot was used to identify the activities of gluconeogenic enzymes and insulin-signaling proteins. Fasting plasma glucose (9.64 ± 1.57 mmol/L vs 5.12 ± 1.08 mmol/L; P < .0001), fasting insulin (16.19 ± 1.43 mIU/mL vs 5.07 ± 1.13 mIU/mL; P < .0001), and homeostasis-model assessment of insulin resistance (HOMA-IR; 6.95 ± 1.33 vs 1.15 ± 0.33; P < .0001) in the BRDN group had significantly decreased at the 3-month follow-up compared with the SHAM group. Western blot analyses showed that RDN suppressed the gluconeogenetic genes, modulated insulin action, and activated insulin receptors-AKT signaling cascade in the liver. CT angiography and histopathologic analyses did not show any dissection, aneurysm, thrombus, or rupture in any of the renal arteries. These findings identified that multi-electrode catheter-based RDN could effectively decrease gluconeogenesis and glycogenolysis, resulting in improvements in insulin sensitivity and glucose metabolism in a T2DM canine model. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

A novel technique for ventriculoperitoneal shunting by flat panel detector CT-guided real-time fluoroscopy

PubMed Central

Kobayashi, Shinya; Ishikawa, Tatsuya; Mutoh, Tatsushi; Hikichi, Kentaro; Suzuki, Akifumi

2012-01-01

Background: Surgical placement of a ventriculoperitoneal shunt (VPS) is the main strategy to manage hydrocephalus. However, the failure rate associated with placement of ventricular catheters remains high. Methods: A hybrid operating room, equipped with a flat-panel detector digital subtraction angiography system containing C-arm cone-beam computed tomography (CB-CT) imaging, has recently been developed and utilized to assist neurosurgical procedures. We have developed a novel technique using intraoperative fluoroscopy and a C-arm CB-CT system to facilitate accurate placement of a VPS. Results: Using this novel technique, 39 consecutive ventricular catheters were placed accurately, and no ventricular catheter failures were experienced during the follow-up period. Only two patients experienced obstruction of the VPS, both of which occurred in the extracranial portion of the shunt system. Conclusion: Surgical placement of a VPS assisted by flat panel detector CT-guided real-time fluoroscopy enabled accurate placement of ventricular catheters and was associated with a decreased need for shunt revision. PMID:23226605

Planning-free cerebral blood flow territory mapping in patients with intracranial arterial stenosis

PubMed Central

Arteaga, Daniel F; Strother, Megan K; Davis, L Taylor; Fusco, Matthew R; Faraco, Carlos C; Roach, Brent A; Scott, Allison O

2016-01-01

A noninvasive method for quantifying cerebral blood flow and simultaneously visualizing cerebral blood flow territories is vessel-encoded pseudocontinuous arterial spin labeling MRI. However, obstacles to acquiring such information include limited access to the methodology in clinical centers and limited work on how clinically acquired vessel-encoded pseudocontinuous arterial spin labeling data correlate with gold-standard methods. The purpose of this work is to develop and validate a semiautomated pipeline for the online quantification of cerebral blood flow maps and cerebral blood flow territories from planning-free vessel-encoded pseudocontinuous arterial spin labeling MRI with gold-standard digital subtraction angiography. Healthy controls (n = 10) and intracranial atherosclerotic disease patients (n = 34) underwent 3.0 T MRI imaging including vascular (MR angiography) and hemodynamic (cerebral blood flow-weighted arterial spin labeling) MRI. Patients additionally underwent catheter and/or CT angiography. Variations in cross-territorial filling were grouped according to diameters of circle of Willis vessels in controls. In patients, Cohen’s k-statistics were computed to quantify agreement in perfusion patterns between vessel-encoded pseudocontinuous arterial spin labeling and angiography. Cross-territorial filling patterns were consistent with circle of Willis anatomy. The intraobserver Cohen's k-statistics for cerebral blood flow territory and digital subtraction angiography perfusion agreement were 0.730 (95% CI = 0.593–0.867; reader one) and 0.708 (95% CI = 0.561–0.855; reader two). These results support the feasibility of a semiautomated pipeline for evaluating major neurovascular cerebral blood flow territories in patients with intracranial atherosclerotic disease. PMID:27389177

Direct costs and cost-effectiveness of dual-source computed tomography and invasive coronary angiography in patients with an intermediate pretest likelihood for coronary artery disease.

PubMed

Dorenkamp, Marc; Bonaventura, Klaus; Sohns, Christian; Becker, Christoph R; Leber, Alexander W

2012-03-01

The study aims to determine the direct costs and comparative cost-effectiveness of latest-generation dual-source computed tomography (DSCT) and invasive coronary angiography for diagnosing coronary artery disease (CAD) in patients suspected of having this disease. The study was based on a previously elaborated cohort with an intermediate pretest likelihood for CAD and on complementary clinical data. Cost calculations were based on a detailed analysis of direct costs, and generally accepted accounting principles were applied. Based on Bayes' theorem, a mathematical model was used to compare the cost-effectiveness of both diagnostic approaches. Total costs included direct costs, induced costs and costs of complications. Effectiveness was defined as the ability of a diagnostic test to accurately identify a patient with CAD. Direct costs amounted to €98.60 for DSCT and to €317.75 for invasive coronary angiography. Analysis of model calculations indicated that cost-effectiveness grew hyperbolically with increasing prevalence of CAD. Given the prevalence of CAD in the study cohort (24%), DSCT was found to be more cost-effective than invasive coronary angiography (€970 vs €1354 for one patient correctly diagnosed as having CAD). At a disease prevalence of 49%, DSCT and invasive angiography were equally effective with costs of €633. Above a threshold value of disease prevalence of 55%, proceeding directly to invasive coronary angiography was more cost-effective than DSCT. With proper patient selection and consideration of disease prevalence, DSCT coronary angiography is cost-effective for diagnosing CAD in patients with an intermediate pretest likelihood for it. However, the range of eligible patients may be smaller than previously reported.

Intra-operative cone beam computed tomography can help avoid reinterventions and reduce CT follow up after infrarenal EVAR.

PubMed

Törnqvist, P; Dias, N; Sonesson, B; Kristmundsson, T; Resch, T

2015-04-01

Re-interventions after endovascular abdominal aortic aneurysm repair (EVAR) are common and therefore a strict imaging follow up protocol is required. The purpose of this study was to evaluate whether cone beam computed tomography (CBCT) can detect intra-operative complications and to compare this with angiography and the 1 month CT follow up (computed tomography angiography [CTA]). Fifty-one patients (44 men) were enrolled in a prospective trial. Patients underwent completion angiography and CBCT during infrarenal EVAR. Contrast was used except when pre-operative renal insufficiency was present or if the maximum contrast dose threshold was reached. CBCT reconstruction included the top of the stent graft to the iliac bifurcation. Endoleaks, kinks, or compressions were recorded. CBCT was technically successful in all patients. Twelve endoleaks were detected on completion digital subtraction angiography (CA). CBCT detected 4/5 type 1 endoleaks, but only one type 2 endoleak. CTA identified eight type 2 endoleaks and one residual type I endoleak. Two cases of stent compression were seen on CA. CBCT revealed five stent compressions and one kink, which resulted in four intra-operative adjunctive manoeuvres. CTA identified all cases of kinks or compressions that were left untreated. Two of them were corrected later. No additional kinks/compressions were found on CTA. Groin closure consisted of 78 fascia sutures, nine cut downs, and 11 percutaneous sutures. Seven femoral artery pseudoaneurysms (<1 cm) were detected on CTA, but no intervention was needed. CA is better than CBCT in detecting and categorizing endoleaks but CBCT (with or without contrast) is better than CA for detection of kinks or stentgraft compression. CTA plus CBCT identified all significant complications noted on the 1 month follow up CTA. The use of intra-operative CA and CBCT could replace early CTA after standard EVAR thus reducing overall radiation and contrast use. Technical development might further improve the resolution and usefulness of CBCT. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Prognostic and therapeutic implications of statin and aspirin therapy in individuals with nonobstructive coronary artery disease: results from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter registry) registry.

PubMed

Chow, Benjamin J W; Small, Gary; Yam, Yeung; Chen, Li; McPherson, Ruth; Achenbach, Stephan; Al-Mallah, Mouaz; Berman, Daniel S; Budoff, Matthew J; Cademartiri, Filippo; Callister, Tracy Q; Chang, Hyuk-Jae; Cheng, Victor Y; Chinnaiyan, Kavitha; Cury, Ricardo; Delago, Augustin; Dunning, Allison; Feuchtner, Gundrun; Hadamitzky, Martin; Hausleiter, Jörg; Karlsberg, Ronald P; Kaufmann, Philipp A; Kim, Yong-Jin; Leipsic, Jonathon; LaBounty, Troy; Lin, Fay; Maffei, Erica; Raff, Gilbert L; Shaw, Leslee J; Villines, Todd C; Min, James K

2015-04-01

We sought to examine the risk of mortality associated with nonobstructive coronary artery disease (CAD) and to determine the impact of baseline statin and aspirin use on mortality. Coronary computed tomographic angiography permits direct visualization of nonobstructive CAD. To date, the prognostic implications of nonobstructive CAD and the potential benefit of directing therapy based on nonobstructive CAD have not been carefully examined. A total of 27 125 consecutive patients who underwent computed tomographic angiography (12 enrolling centers and 6 countries) were prospectively entered into the COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter (CONFIRM) registry. Patients, without history of previous CAD or obstructive CAD, for whom baseline statin and aspirin use was available were analyzed. Each coronary segment was classified as normal or nonobstructive CAD (1%-49% stenosis). Patients were followed up for a median of 27.2 months for all-cause mortality. The study comprised 10 418 patients (5712 normal and 4706 with nonobstructive CAD). In multivariable analyses, patients with nonobstructive CAD had a 6% (95% confidence interval, 1%-12%) higher risk of mortality for each additional segment with nonobstructive plaque (P=0.021). Baseline statin use was associated with a reduced risk of mortality (hazard ratio, 0.44; 95% confidence interval, 0.28-0.68; P=0.0003), a benefit that was present for individuals with nonobstructive CAD (hazard ratio, 0.32; 95% confidence interval, 0.19-0.55; P<0.001) but not for those without plaque (hazard ratio, 0.66; 95% confidence interval, 0.30-1.43; P=0.287). When stratified by National Cholesterol Education Program/Adult Treatment Program III, no mortality benefit was observed in individuals without plaque. Aspirin use was not associated with mortality benefit, irrespective of the status of plaque. The presence and extent of nonobstructive CAD predicted mortality. Baseline statin therapy was associated with a significant reduction in mortality for individuals with nonobstructive CAD but not for individuals without CAD. URL: http://clinicaltrials.gov/. Unique identifier NCT01443637. © 2015 American Heart Association, Inc.

Consideration of the Protection Curtain's Shielding Ability after Identifying the Source of Scattered Radiation in the Angiography.

PubMed

Sato, Naoki; Fujibuchi, Toshioh; Toyoda, Takatoshi; Ishida, Takato; Ohura, Hiroki; Miyajima, Ryuichi; Orita, Shinichi; Sueyoshi, Tomonari

2017-06-15

To decrease radiation exposure to medical staff performing angiography, the dose distribution in the angiography was calculated in room using the particle and heavy ion transport code system (PHITS), which is based on Monte Carlo code, and the source of scattered radiation was confirmed using a tungsten sheet by considering the difference shielding performance among different sheet placements. Scattered radiation generated from a flat panel detector, X-ray tube and bed was calculated using the PHITS. In this experiment, the source of scattered radiation was identified as the phantom or acrylic window attached to the X-ray tube thus, a protection curtain was placed on the bed to shield against scattered radiation at low positions. There was an average difference of 20% between the measured and calculated values. The H*(10) value decreased after placing the sheet on the right side of the phantom. Thus, the curtain could decrease scattered radiation. © Crown copyright 2016.

ULTRAHIGH SPEED SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF RETINAL AND CHORIOCAPILLARIS ALTERATIONS IN DIABETIC PATIENTS WITH AND WITHOUT RETINOPATHY.

PubMed

Choi, WooJhon; Waheed, Nadia K; Moult, Eric M; Adhi, Mehreen; Lee, ByungKun; De Carlo, Talisa; Jayaraman, Vijaysekhar; Baumal, Caroline R; Duker, Jay S; Fujimoto, James G

2017-01-01

To investigate the utility of ultrahigh speed, swept source optical coherence tomography angiography in visualizing retinal microvascular and choriocapillaris (CC) changes in diabetic patients. The study was prospective and cross-sectional. A 1,050 nm wavelength, 400 kHz A-scan rate swept source optical coherence tomography prototype was used to perform volumetric optical coherence tomography angiography of the retinal and CC vasculatures in diabetic patients and normal subjects. Sixty-three eyes from 32 normal subjects, 9 eyes from 7 patients with proliferative diabetic retinopathy, 29 eyes from 16 patients with nonproliferative diabetic retinopathy, and 51 eyes from 28 diabetic patients without retinopathy were imaged. Retinal and CC microvascular abnormalities were observed in all stages of diabetic retinopathy. In nonproliferative diabetic retinopathy and proliferative diabetic retinopathy, optical coherence tomography angiography visualized a variety of vascular abnormalities, including clustered capillaries, dilated capillary segments, tortuous capillaries, regions of capillary dropout, reduced capillary density, abnormal capillary loops, and foveal avascular zone enlargement. In proliferative diabetic retinopathy, retinal neovascularization above the inner limiting membrane was visualized. Regions of CC flow impairment in patients with proliferative diabetic retinopathy and nonproliferative diabetic retinopathy were also observed. In 18 of the 51 of eyes from diabetic patients without retinopathy, retinal mircrovascular abnormalities were observed and CC flow impairment was found in 24 of the 51 diabetic eyes without retinopathy. The ability of optical coherence tomography angiography to visualize retinal and CC microvascular abnormalities suggests it may be a useful tool for understanding pathogenesis, evaluating treatment response, and earlier detection of vascular abnormalities in patients with diabetes.

Accuracy of MSCT Coronary Angiography with 64 Row CT Scanner—Facing the Facts

PubMed Central

Wehrschuetz, M.; Wehrschuetz, E.; Schuchlenz, H.; Schaffler, G.

2010-01-01

Improvements in multislice computed tomography (MSCT) angiography of the coronary vessels have enabled the minimally invasive detection of coronary artery stenoses, while quantitative coronary angiography (QCA) is the accepted reference standard for evaluation thereof. Sixteen-slice MSCT showed promising diagnostic accuracy in detecting coronary artery stenoses haemodynamically and the subsequent introduction of 64-slice scanners promised excellent and fast results for coronary artery studies. This prompted us to evaluate the diagnostic accuracy, sensitivity, specificity, and the negative und positive predictive value of 64-slice MSCT in the detection of haemodynamically significant coronary artery stenoses. Thirty-seven consecutive subjects with suspected coronary artery disease were evaluated with MSCT angiography and the results compared with QCA. All vessels were considered for the assessment of significant coronary artery stenosis (diameter reduction ≥ 50%). Thirteen patients (35%) were identified as having significant coronary artery stenoses on QCA with 6.3% (35/555) affected segments. None of the coronary segments were excluded from analysis. Overall sensitivity for classifying stenoses of 64-slice MSCT was 69%, specificity was 92%, positive predictive value was 38% and negative predictive value was 98%. The interobserver variability for detection of significant lesions had a k-value of 0.43. Sixty-four-slice MSCT offers the diagnostic potential to detect coronary artery disease, to quantify haemodynamically significant coronary artery stenoses and to avoid unnecessary invasive coronary artery examinations. PMID:20567636

A case of acute subdural hematoma due to ruptured aneurysm detected by postmortem angiography.

PubMed

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

2016-03-01

Acute subdural hematoma (ASDH) is mostly caused by head trauma, but intrinsic causes also exist such as aneurysm rupture. We describe here a case involving a man in his 70s who was found lying on the bedroom floor by his family. CT performed at the hospital showed ASDH and a forensic autopsy was requested. Postmortem cerebral angiography showed dilatation of the bifurcation of the middle cerebral artery, which coincided with the dilated part of the Sylvian fissure. Extravasation of contrast medium into the subdural hematoma from this site was suggestive of a ruptured aneurysm. Autopsy revealed a fleshy hematoma (total weight 110 g) in the right subdural space and findings of brain herniation. As indicated on angiography, a ruptured saccular aneurysm was confirmed at the bifurcation of the middle cerebral artery. Obvious injuries to the head or face could not be detected on either external or internal examination, and intrinsic ASDH due to a ruptured middle cerebral artery aneurysm was determined as the cause of death. One of the key points of forensic diagnosis is the strict differentiation between intrinsic and extrinsic onset for conditions leading to death. Although most subdural hematomas (SDH) are caused by extrinsic factors, forensic pathologists should consider the possibility of intrinsic SDH. In addition, postmortem angiography can be useful for identifying vascular lesions in such cases.

Detection and quantification of large-vessel inflammation with 11C-(R)-PK11195 PET/CT.

PubMed

Lamare, Frederic; Hinz, Rainer; Gaemperli, Oliver; Pugliese, Francesca; Mason, Justin C; Spinks, Terence; Camici, Paolo G; Rimoldi, Ornella E

2011-01-01

We investigated whether PET/CT angiography using 11C-(R)-PK11195, a selective ligand for the translocator protein (18 kDa) expressed in activated macrophages, could allow imaging and quantification of arterial wall inflammation in patients with large-vessel vasculitis. Seven patients with systemic inflammatory disorders (3 symptomatic patients with clinical suspicion of active vasculitis and 4 asymptomatic patients) underwent PET with 11C-(R)-PK11195 and CT angiography to colocalize arterial wall uptake of 11C-(R)-PK11195. Tissue regions of interest were defined in bone marrow, lung parenchyma, wall of the ascending aorta, aortic arch, and descending aorta. Blood-derived and image-derived input functions (IFs) were generated. A reversible 1-tissue compartment with 2 kinetic rate constants and a fractional blood volume term were used to fit the time-activity curves to calculate total volume of distribution (VT). The correlation between VT and standardized uptake values was assessed. VT was significantly higher in symptomatic than in asymptomatic patients using both image-derived total plasma IF (0.55±0.15 vs. 0.27±0.12, P=0.009) and image-derived parent plasma IF (1.40±0.50 vs. 0.58±0.25, P=0.018). A good correlation was observed between VT and standardized uptake value (R=0.79; P=0.03). 11C-(R)-PK11195 imaging allows visualization of macrophage infiltration in inflamed arterial walls. Tracer uptake can be quantified with image-derived IF without the need for metabolite corrections and evaluated semiquantitatively with standardized uptake values.

Rationale, Design, and Methodological Aspects of the BUDAPEST-GLOBAL Study (Burden of Atherosclerotic Plaques Study in Twins-Genetic Loci and the Burden of Atherosclerotic Lesions).

PubMed

Maurovich-Horvat, Pál; Tárnoki, Dávid L; Tárnoki, Ádám D; Horváth, Tamás; Jermendy, Ádám L; Kolossváry, Márton; Szilveszter, Bálint; Voros, Viktor; Kovács, Attila; Molnár, Andrea Á; Littvay, Levente; Lamb, Hildo J; Voros, Szilard; Jermendy, György; Merkely, Béla

2015-12-01

The heritability of coronary atherosclerotic plaque burden, coronary geometry, and phenotypes associated with increased cardiometabolic risk are largely unknown. The primary aim of the Burden of Atherosclerotic Plaques Study in Twins-Genetic Loci and the Burden of Atherosclerotic Lesions (BUDAPEST-GLOBAL) study is to evaluate the influence of genetic and environmental factors on the burden of coronary artery disease. By design this is a prospective, single-center, classical twin study. In total, 202 twins (61 monozygotic pairs, 40 dizygotic same-sex pairs) were enrolled from the Hungarian Twin Registry database. All twins underwent non-contrast-enhanced computed tomography (CT) for the detection and quantification of coronary artery calcium and for the measurement of epicardial fat volumes. In addition, a single non-contrast-enhanced image slice was acquired at the level of L3-L4 to assess abdominal fat distribution. Coronary CT angiography was used for the detection and quantification of plaque, stenosis, and overall coronary artery disease burden. For the primary analysis, we will assess the presence and volume of atherosclerotic plaques. Furthermore, the 3-dimensional coronary geometry will be assessed based on the coronary CT angiography datasets. Additional phenotypic analyses will include per-patient epicardial and abdominal fat quantity measurements. Measurements obtained from monozygotic and dizygotic twin pairs will be compared to evaluate the genetic or environmental effects of the given phenotype. The BUDAPEST-GLOBAL study provides a unique framework to shed some light on the genetic and environmental influences of cardiometabolic disorders. © 2015 Wiley Periodicals, Inc.

Electrocardiogram‐gated coronary CT angiography dose estimates using ImPACT

PubMed Central

Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Koshida, Kichiro; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Toyama, Hiroshi; Kato, Ryoichi

2016-01-01

The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), prospective CTA, continuous CTA/cardiac function analysis (CFA), and CTA/CFA modulation. Accordingly, we clarified the CT dose index (CTDI) to determine the relationship between heart rate (HR) and X‐ray exposure. As a secondary objective, we compared radiation doses using modified ImPACT, a whole‐body dosimetry phantom study, and the k‐factor method to verify the validity of the dose results obtained with modified ImPACT. The effective dose determined for the reference person (4.66 mSv at 60 beats per minute (bpm) and 33.43 mSv at 90 bpm) were approximately 10% less than those determined for the phantom study (5.28 mSv and 36.68 mSv). The effective doses according to the k‐factor (0.014 mSv·mGy−1·cm−1; 2.57 mSv and 17.10 mSv) were significantly lower than those obtained with the other two methods. In the present study, we have shown that ImPACT, when modified for cardiac applications, can assess both absorbed and effective doses. The results of our dose comparison indicate that modified ImPACT dose assessment is a promising and practical method for evaluating coronary CTA. PACS number(s): 87.57.Q‐, 87.59.Dj, 87.57.uq PMID:27455500

Morphologic classification of the right auricule on 256-slice computed tomography.

PubMed

Li, Cai-Ying; Gao, Bu-Lang; Pan, Tong; Xiang, Cheng; Liu, Xiao-Wei; Yang, Hai-Qing; Yi, Lan-Ying; Liao, Qi-Bin

2017-06-01

To investigate the shape of right auricule on 256-slice computed tomography (CT). Five hundred people (250 men, age range 16-84 years) who had cardiac multidetector CT angiography were recruited in this study. All patients had normal sinus rhythm with normal blood pressure (<140/90 mmHg for systolic/diastolic pressure). The morphology of the right auricule was studied and compared after reconstruction of the raw images. All patients successfully had cardiac CT angiography (100%), and the right auricule morphology was divided into five types and nine subtypes, including Type I of triangular shape (Ia and Ib), Type II of M shape (IIa and IIb), Type III of L shape (IIIa and IIIb), Type IV of reverse L shape (IVa and IVb), and Type V of balanced shape. The most common type of right auricule is Type IV (28.4%) followed by Type II (24.0%), whereas the least common is Type V (11.0%). Type Ia was present significantly (P < 0.0001) more frequently in females than in males, whereas Type IIa significantly (P = 0.042) more frequently in males than females. No other significant (P > 0.05) sex difference existed in the constitution ratio of the types. The normal angle was greater in Type Ib than in Ia. The greater the normal angle in Type I, the greater the deviation of the right auricule tip towards the left. A good understanding of the right auricule anatomical morphology can better guide atrial pacing, radiofrequency ablation and other surgical procedures while preventing possible intra-procedural complications.

Pulmonary artery segmentation and quantification in sickle cell associated pulmonary hypertension

NASA Astrophysics Data System (ADS)

Linguraru, Marius George; Mukherjee, Nisha; Van Uitert, Robert L.; Summers, Ronald M.; Gladwin, Mark T.; Machado, Roberto F.; Wood, Bradford J.

2008-03-01

Pulmonary arterial hypertension is a known complication associated with sickle-cell disease; roughly 75% of sickle cell disease-afflicted patients have pulmonary arterial hypertension at the time of death. This prospective study investigates the potential of image analysis to act as a surrogate for presence and extent of disease, and whether the size change of the pulmonary arteries of sickle cell patients could be linked to sickle-cell associated pulmonary hypertension. Pulmonary CT-Angiography scans from sickle-cell patients were obtained and retrospectively analyzed. Randomly selected pulmonary CT-Angiography studies from patients without sickle-cell anemia were used as negative controls. First, images were smoothed using anisotropic diffusion. Then, a combination of fast marching and geodesic active contours level sets were employed to segment the pulmonary artery. An algorithm based on fast marching methods was used to compute the centerline of the segmented arteries. From the centerline, the diameters at the pulmonary trunk and first branch of the pulmonary arteries were measured automatically. Arterial diameters were normalized to the width of the thoracic cavity, patient weight and body surface. Results show that the pulmonary trunk and first right and left pulmonary arterial branches at the pulmonary trunk junction are significantly larger in diameter with increased blood flow in sickle-cell anemia patients as compared to controls (p values of 0.0278 for trunk and 0.0007 for branches). CT with image processing shows great potential as a surrogate indicator of pulmonary hemodynamics or response to therapy, which could be an important tool for drug discovery and noninvasive clinical surveillance.

Combined anatomical and functional imaging using coronary CT angiography and myocardial perfusion SPECT in symptomatic adults with abnormal origin of a coronary artery.

PubMed

Uebleis, C; Groebner, M; von Ziegler, F; Becker, A; Rischpler, C; Tegtmeyer, R; Becker, C; Lehner, S; Haug, A R; Cumming, P; Bartenstein, P; Franz, W M; Hacker, M

2012-10-01

There has been a lack of standardized workup guidelines for patients with congenital abnormal origin of a coronary artery from the opposite sinus (ACAOS). We aimed to evaluate the use of cardiac hybrid imaging using multi-detector row CT (MDCT) for coronary CT angiography (Coronary CTA) and stress-rest myocardial perfusion SPECT (MPS) for comprehensive diagnosis of symptomatic adult patients with ACAOS. Seventeen symptomatic patients (12 men; 54 ± 13 years) presenting with ACAOS underwent coronary CTA and MPS. Imaging data were analyzed by conventional means, and with additional use of 3D image fusion to allocate stress induced perfusion defects (PD) to their supplying coronary arteries. An anomalous RCA arose from the left anterior sinus in eight patients, an abnormal origin from the right sinus was detected in nine patients (5 left coronary arteries, LCA and 4 LCx). Five of the 17 patients (29%) demonstrated a reversible PD in MPS. There was no correlation between the anatomical variants of ACAOS and the presence of myocardial ischemia. Image fusion enabled the allocation of reversible PD to the anomalous vessel in three patients (two cases in the RCA and the other in the LCA territory); PD in two patients were allocated to the territory of artery giving rise to the anomalies, rather than the anomalies themselves. In a small cohort of adult symptomatic patients with ACAOS anomaly there was no relation found between the specific anatomical variant and the appearance of stress induced myocardial ischemia using cardiac hybrid imaging.

Diagnosing Internal Herniation After Roux-en-Y Gastric Bypass Surgery: Literature Overview, Cadaver Study and the Added Value of 3D CT Angiography.

PubMed

Klop, Cornelis; Deden, Laura N; Aarts, Edo O; Janssen, Ignace M C; Pijl, Milan E J; van den Ende, Anneline; Witteman, Bart P L; de Jong, Gabie M; Aufenacker, Theo J; Slump, Cornelis H; Berends, Frits J

2018-02-05

The purposes of the study are to outline the complexity of diagnosing internal herniation after Roux-en-Y gastric bypass (RYGB) surgery and to investigate the added value of computed tomography angiography (CTA) for diagnosing internal herniation. A cadaver study was performed to investigate the manifestations of internal hernias and mesenteric vascularization. Furthermore, a prospective, ethics approved study with retrospective interpretation was conducted. Ten patients, clinically suspected for internal herniation, were prospectively included. After informed consent was obtained, these subjects underwent abdominal CT examination, including additional arterial phase CTA. All subjects underwent diagnostic laparoscopy for suspected internal herniation. The CTA was used to create a 3D reconstruction of the mesenteric arteries and surgical staples (3D CTA). The 3D CTA was interpreted, taking into account the presence and type of internal hernia that was found upon laparoscopy. Cadaveric analysis demonstrated the complexity of internal herniation. It also confirmed the expected changes in vascular structure and surgical staple arrangement in the presence of internal herniation. 3D CTA studies of the subjects with active internal hernias demonstrated remarkable differences when compared to control 3D CTA studies. The blood supply of herniated intestinal limbs in particular showed abnormal trajectories. Additionally, enteroenterostomy staple lines had migrated or altered orientation. 3D CTA is a promising technique for diagnosing active internal hernias. Our findings suggest that for diagnosing internal hernias, focus should probably shift from routine abdominal CT examination towards the 3D assessment of the mesenteric vasculature and surgical staples.

[Selection of patients for transcatheter aortic valve implantation].

PubMed

Tron, Christophe; Godin, Matthieu; Litzler, Pierre-Yves; Bauer, Fabrice; Caudron, Jérome; Dacher, Jean-Nicolas; Borz, Bogdan; Canville, Alexandre; Kurtz, Baptiste; Bessou, Jean-Paul; Cribier, Alain; Eltchaninoff, Hélène

2012-06-01

A good selection of patients is a crucial step before transcatheter aortic valve implantation (TAVI) in order to select the good indications and choose the access route. TAVI should be considered only in patients with symptomatic severe aortic stenosis and either contraindication or high surgical risk. Indication for TAVI should be discussed in a multidisciplinary team meeting. Echocardiography and/or CT scan are mandatory to evaluate the aortic annulus size and select the good prosthesis size. The possibility of transfemoral implantation is evaluated by angiography and CT scan, and based on the arterial diameters, but also on the presence of tortuosities and arterial calcifications. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke.

PubMed

Sporns, Peter; Schmidt, Rene; Minnerup, Jens; Dziewas, Rainer; Kemmling, André; Dittrich, Ralf; Zoubi, Tarek; Heermann, Philipp; Cnyrim, Christian; Schwindt, Wolfram; Heindel, Walter; Niederstadt, Thomas; Hanning, Uta

2016-01-01

Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone. © 2016 S. Karger AG, Basel.

Neuroradiologic characteristics of astroblastoma and systematic review of the literature: 2 new cases and 125 cases reported in 59 publications.

PubMed

Cunningham, Danielle A; Lowe, Lisa H; Shao, Lei; Acosta, Natasha R

2016-08-01

Astroblastoma is a rare tumor of uncertain origin most commonly presenting in the cerebrum of children and young adults. The literature contains only case reports and small series regarding its radiologic features. This systematic review is the largest study of imaging findings of astroblastoma to date and serves to identify features that might differentiate it from other neoplasms. This study describes the imaging features of astroblastoma based on a systematic review of the literature and two new cases. We conducted a PubMed and Google Scholar database search that identified 59 publications containing 125 cases of pathology-confirmed astroblastoma, and we also added two new cases from our own institution. Data collected include patient age, gender, tumor location, morphology, calcifications and calvarial changes. We recorded findings on CT, MRI, diffusion-weighted imaging (DWI), MR spectroscopy, positron emission tomography (PET) and catheter angiography. Age at diagnosis ranged 0-70 years (mean 18 years; median 14 years). Female-to-male ratio was 8:1. Of 127 cases, 66 reported CT, 78 reported MRI and 47 reported both findings. Not all authors reported all features, but the tumor features reported included supratentorial in 96% (122/127), superficial in 72% (48/67), well-demarcated in 96% (79/82), mixed cystic-solid in 93% (79/85), and enhancing in 99% (78/79). On CT, 84% (26/31) of astroblastomas were hyperattenuated, 73% (27/37) had calcifications and 7 cases reported adjacent calvarial erosion. Astroblastomas were hypointense on T1-W in 58% (26/45) and on T2-W in 50% (23/46) of MRI sequences. Peritumoral edema was present in 80% (40/50) of cases but was typically described as slight. Six cases included DWI findings, with 100% showing restricted diffusion. On MR spectroscopy, 100% (5/5) showed nonspecific tumor spectra with elevated choline and decreased N-acetylaspartate (NAA). PET revealed nonspecific reduced uptake of [F-18] 2-fluoro-2-deoxyglucose ((18)F-FDG) and increased uptake of [11C]-Methionine in 100% (3/3) of cases. Catheter angiography findings (n=12) were variable, including hypervascularity in 67%, arteriovenous shunting in 33% and avascular areas in 25%. Astroblastomas occur most often in adolescent girls. Imaging often shows a supratentorial, superficial, well-defined, cystic-solid enhancing mass. On CT, most are hyperattenuated, have calcifications, and may remodel adjacent bone if superficial. MRI characteristically reveals a hypointense mass on T1-W and T2-W sequences with restricted diffusion. MR spectroscopy, PET and catheter angiography findings are nonspecific.

Iatrogenic Aorto-Cisterna Chyli Fistula During Percutaneous Balloon Aortoplasty in a Patient with Takayasu's Arteritis: A Case Report

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

Hwang, Hye Sun; Shin, Sung Wook, E-mail: swshin@smc.samsung.co.kr; Kim, Eun Hui

2007-04-15

We present a case of iatrogenic aorto-cisterna chyli fistula that developed during percutaneous transluminal aortoplasty in a 16-year old girl with Takayasu's arteritis. The aorto-cisterna chyli fistula was angiographically confirmed and treated using a stent-graft, which successfully occluded the fistula. Her claudication then improved, although follow-up CT angiography at 10 months revealed mild recurrent aortic stenosis.

Best-Quality Vessel Identification Using Vessel Quality Measure in Multiple-Phase Coronary CT Angiography.

PubMed

Hadjiiski, Lubomir; Liu, Jordan; Chan, Heang-Ping; Zhou, Chuan; Wei, Jun; Chughtai, Aamer; Kuriakose, Jean; Agarwal, Prachi; Kazerooni, Ella

2016-01-01

The detection of stenotic plaques strongly depends on the quality of the coronary arterial tree imaged with coronary CT angiography (cCTA). However, it is time consuming for the radiologist to select the best-quality vessels from the multiple-phase cCTA for interpretation in clinical practice. We are developing an automated method for selection of the best-quality vessels from coronary arterial trees in multiple-phase cCTA to facilitate radiologist's reading or computerized analysis. Our automated method consists of vessel segmentation, vessel registration, corresponding vessel branch matching, vessel quality measure (VQM) estimation, and automatic selection of best branches based on VQM. For every branch, the VQM was calculated as the average radial gradient. An observer preference study was conducted to visually compare the quality of the selected vessels. 167 corresponding branch pairs were evaluated by two radiologists. The agreement between the first radiologist and the automated selection was 76% with kappa of 0.49. The agreement between the second radiologist and the automated selection was also 76% with kappa of 0.45. The agreement between the two radiologists was 81% with kappa of 0.57. The observer preference study demonstrated the feasibility of the proposed automated method for the selection of the best-quality vessels from multiple cCTA phases.

Fatal carotid dissection after blunt head trauma.

PubMed

Tartara, F; Regolo, P; Servadei, F; Versari, P P; Giovanelli, M

2000-06-01

Occurrence of internal carotid artery injuries associated with skull base fracture has been reported. A. report a case of fatal intracranial carotid dissection related to petrous fracture involving the carotid canal. Identification of carotid lesions may be difficult and generally related to appearance of unexpected neurological deficit. Skull base fractures may be considered an indirect sign for detection of vascular injury. Patterns of the fracture are of paramount importance; routine CT scan may fail to detect basilar fractures and high definition fine-cut CT scan should be executed to carefully identify and evaluate fractures. Temporal and sphenoid bone fractures are common in head trauma and involvement of the course of the carotid artery is frequent. The involvement of the intracranial carotid artery course represents a direct risk factor for lesions of the petrous, lacerum and cavernous segments of the carotid artery. Early diagnosis of post-traumatic vascular injury may lead to prognosis improvement because of effectiveness of heparin anticoagulant therapy. Then vascular screening is recommendable in cases with complex fractures of the skull base and particularly fracturing along the course of the carotid artery. Magnetic resonance angiography may be considered the first line diagnostic tools for vascular screening. Angiography may be reserved for patients with a proven lesion or rapid neurological deterioration taking into account the possibility of interventional treatment.

Correlation between liver volume, portal vascular anatomy, and hepatic perfusion in dogs with congenital portosystemic shunt before and after placement of ameroid constrictors.

PubMed

Zwingenberger, Allison L; Daniel, Leticia; Steffey, Michele A; Mayhew, Philipp D; Mayhew, Kelli N; Culp, William T N; Hunt, Geraldine B

2014-11-01

To correlate changes in hepatic volume, hepatic perfusion, and vascular anatomy of dogs with congenital extrahepatic portosystemic shunts, before and after attenuation with an ameroid constrictor. Prospective study. Dogs (n = 22) with congenital extrahepatic portosystemic shunts. CT angiography and perfusion scans were performed before and after attenuation of a portosystemic shunt with an ameroid constrictor. Changes in hepatic volume, hepatic perfusion, and vascular anatomy were measured. Portal scintigraphy was performed in 8 dogs preoperatively and 22 dogs postoperatively. Dogs with smaller preoperative liver volumes had greater increases in liver volume postoperatively compared with those with larger preoperative liver volumes. Hepatic arterial fraction was increased in dogs preoperatively and returned to normal range after shunt attenuation, and was correlated with increase in liver size and decreased shunt fraction. Three dogs with no visible portal vasculature preoperatively developed portal branches postoperatively. Dogs with smaller preoperative liver volumes had the largest postoperative increase in liver volume. Hepatic arterial perfusion and portal scintigraphy correlate with liver volume and are indicators of successful shunt attenuation. Dogs without visible vasculature on CT angiography had visible portal vasculature postoperatively. © Copyright 2014 by The American College of Veterinary Surgeons.

Document-Level Classification of CT Pulmonary Angiography Reports based on an Extension of the ConText Algorithm

PubMed Central

Chapman, Brian E.; Lee, Sean; Kang, Hyunseok Peter; Chapman, Wendy W.

2011-01-01

In this paper we describe an application called peFinder for document-level classification of CT pulmonary angiography reports. peFinder is based on a generalized version of the ConText algorithm, a simple text processing algorithm for identifying features in clinical report documents. peFinder was used to answer questions about the disease state (pulmonary emboli present or absent), the certainty state of the diagnosis (uncertainty present or absent), the temporal state of an identified pulmonary embolus (acute or chronic), and the technical quality state of the exam (diagnostic or not diagnostic). Gold standard answers for each question were determined from the consensus classifications of three human annotators. peFinder results were compared to naive Bayes’ classifiers using unigrams and bigrams. The sensitivities (and positive predictive values) for peFinder were 0.98(0.83), 0.86(0.96), 0.94(0.93), and 0.60(0.90) for disease state, quality state, certainty state, and temporal state respectively, compared to 0.68(0.77), 0.67(0.87), 0.62(0.82), and 0.04(0.25) for the naive Bayes’ classifier using unigrams, and 0.75(0.79), 0.52(0.69), 0.59(0.84), and 0.04(0.25) for the naive Bayes’ classifier using bigrams. PMID:21459155

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis.

PubMed

Fuchs, Tobias A; Fiechter, Michael; Gebhard, Cathérine; Stehli, Julia; Ghadri, Jelena R; Kazakauskaite, Egle; Herzog, Bernhard A; Husmann, Lars; Gaemperli, Oliver; Kaufmann, Philipp A

2013-03-01

To assess the impact of adaptive statistical iterative reconstruction (ASIR) on coronary plaque volume and composition analysis as well as on stenosis quantification in high definition coronary computed tomography angiography (CCTA). We included 50 plaques in 29 consecutive patients who were referred for the assessment of known or suspected coronary artery disease (CAD) with contrast-enhanced CCTA on a 64-slice high definition CT scanner (Discovery HD 750, GE Healthcare). CCTA scans were reconstructed with standard filtered back projection (FBP) with no ASIR (0 %) or with increasing contributions of ASIR, i.e. 20, 40, 60, 80 and 100 % (no FBP). Plaque analysis (volume, components and stenosis degree) was performed using a previously validated automated software. Mean values for minimal diameter and minimal area as well as degree of stenosis did not change significantly using different ASIR reconstructions. There was virtually no impact of reconstruction algorithms on mean plaque volume or plaque composition (e.g. soft, intermediate and calcified component). However, with increasing ASIR contribution, the percentage of plaque volume component between 401 and 500 HU decreased significantly (p < 0.05). Modern image reconstruction algorithms such as ASIR, which has been developed for noise reduction in latest high resolution CCTA scans, can be used reliably without interfering with the plaque analysis and stenosis severity assessment.

Computer-aided detection of pulmonary embolism at CT pulmonary angiography: can it improve performance of inexperienced readers?

PubMed

Blackmon, Kevin N; Florin, Charles; Bogoni, Luca; McCain, Joshua W; Koonce, James D; Lee, Heon; Bastarrika, Gorka; Thilo, Christian; Costello, Philip; Salganicoff, Marcos; Joseph Schoepf, U

2011-06-01

To evaluate the effect of a computer-aided detection (CAD) algorithm on the performance of novice readers for detection of pulmonary embolism (PE) at CT pulmonary angiography (CTPA). We included CTPA examinations of 79 patients (50 female, 52 ± 18 years). Studies were evaluated by two independent inexperienced readers who marked all vessels containing PE. After 3 months all studies were reevaluated by the same two readers, this time aided by CAD prototype. A consensus read by three expert radiologists served as the reference standard. Statistical analysis used χ(2) and McNemar testing. Expert consensus revealed 119 PEs in 32 studies. For PE detection, the sensitivity of CAD alone was 78%. Inexperienced readers' initial interpretations had an average per-PE sensitivity of 50%, which improved to 71% (p < 0.001) with CAD as a second reader. False positives increased from 0.18 to 0.25 per study (p = 0.03). Per-study, the readers initially detected 27/32 positive studies (84%); with CAD this number increased to 29.5 studies (92%; p = 0.125). Our results suggest that CAD significantly improves the sensitivity of PE detection for inexperienced readers with a small but appreciable increase in the rate of false positives.

[Transcient ischemic attack, a rare manifestation of Eagle syndrome].

PubMed

Usseglio, J; Montoro, F Macian; Martin, S; Lerat, J; Laloze, J; Taibi, A; Brie, J

2016-12-01

Clinical presentation of Eagle syndrome (ES) is very variable and non-specific, making its diagnosis difficult. It is usually limited to pain. Transient neurological manifestations are exceptional. We report one case in which the diagnosis of ES has been made based on neurological events occurring during left anterolateral head bending, without pain. A 47-year-old man presented with transient neurological events progressing since two years, half-right body paresthesia and reduced field of vision on the left side type, triggered by left anterolateral head flexion and regressive in neutral position. Transcranial Doppler and CT angiography of the supra-aortic trunks were performed in neutral position and in right and left head rotation that showed a disruption of the left sylvian flow and an extrinsic compression of the left internal carotid artery, due to a musculoskeletal impediment involving the lower end of the temporal styloid process. Complete recovering was achieved after surgical resection of this process. A control CT angiography confirmed the cessation of the compression. ES has non-specific and highly variable clinical manifestations making diagnosis difficult or leading to misdiagnosis. ES should be considered in any transient neurological deficit, especially when occurring during head rotation. Treatment relies on surgical resection of the excessively long styloid process. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Common celiacomesenteric trunk: a computed tomography radiological study.

PubMed

Özgökçe, Mesut; Ayyıldız, Veysel Atilla; Oğul, Hayri; Arslan, Harun; Batur, Abdussamet; Yavuz, Alpaslan; İnce, Suat; Yüce, Deniz

2018-03-03

There is an increasing trend for administration of invasive radiological interventions, laparoscopic surgery, and transplantation procedures in recent years, and determining the vascular variations prior to these procedures is crucially important. Celiacomesenteric trunk (CMT) is among these variations. This study aimed to retrospectively evaluate this rare anomaly by computed tomography (CT). A total of 1000 CT angiography images were analyzed retrospectively, and the patients with mesenteric and celiac arteries arising from the abdominal aorta with a single root were identified. The level that CMT arose, and its branching patterns were determined individually for all patients. Ten patients (6 males and 4 females) with a mean age of 50.2 years (17-87 years) had CMT in CT images. The knowledge of variations in the CMT prior to vascular or laparoscopic interventions will contribute to early intervention in case of a complication, or to avoid from a potential damage.

[Coronary artery disease and cardiac ischemic disease: two different pathologies with different diagnostic procedures].

PubMed

Vallejo, Enrique

2009-01-01

Coronary artery disease (CAD) remains the leading cause of death in the Western world, and early detection of CAD allows optimal therapeutic management. The gold standard has always been invasive coronary angiography, but over the years various non-invasive techniques have been developed to detect CAD, including cardiac SPECT and cardiac computed tomography (Cardiac CT). Cardiac SPECT permitted visualization of myocardial perfusion and have focused on the assessment of the hemodynamic consequences of obstructive coronary lesions as a marker of CAD. Cardiac CT focuses on the detection of atherosclerosis rather than ischemia, and permit detection of CAD at an earlier stage. Objectives of this manuscript are to discuss the clinical experience with both modalities and to provide a critical review of the strengths and limitations of Cardiac SPECT and Cardiac CT for the diagnostic and management of patients with suspected CAD or cardiac ischemic disease.

Pontine infarction induced by injury of the perforating branch of the basilar artery after blunt head impact: case report.

PubMed

Yanagawa, Youichi; Iwamoto, Shin-ichiro; Nishi, Kouichirou

2008-08-01

A 77-year-old male pedestrian was hit by a car. On admission, he had disturbance of consciousness and left hemiplegia. Computed tomography (CT) indicated only left frontal subcutaneous hematoma and minor hemorrhage in the left frontal lobe, suggesting axonal injury. CT on hospital day 2 revealed a low density area in the right paramedian pons, but CT angiography showed no dissection or occlusion of the vertebrobasilar artery. The diagnosis was pontine infarction resulting from shearing force injury to the paramedian branch of the basilar artery. He was transferred to another hospital for rehabilitation without improvement of symptoms on hospital day 51. Paramedian pontine infarction tends to occur in patients with risk factors for arteriosclerosis, including hypertension, diabetes mellitus, hyperlipidemia, or smoking. The present elderly patient had hypertension and hyperlipidemia, so arteriosclerosis in the paramedian branch may have contributed to his susceptibility to such injury.

Diagnostic performance of a Lattice Boltzmann-based method for CT-based fractional flow reserve.

PubMed

Giannopoulos, Andreas A; Tang, Anji; Ge, Yin; Cheezum, Michael K; Steigner, Michael L; Fujimoto, Shinichiro; Kumamaru, Kanako K; Chiappino, Dante; Della Latta, Daniele; Berti, Sergio; Chiappino, Sara; Rybicki, Frank J; Melchionna, Simone; Mitsouras, Dimitrios

2018-02-20

Fractional flow reserve (FFR) estimated from coronary computed tomography angiography (CT-FFR) offers non-invasive detection of lesion-specific ischaemia. We aimed to develop and validate a fast CT-FFR algorithm utilising the Lattice Boltzmann method for blood flow simulation (LBM CT-FFR). Sixty-four patients with clinically indicated CTA and invasive FFR measurement from three institutions were retrospectively analysed. CT-FFR was performed using an onsite tool interfacing with a commercial Lattice Boltzmann fluid dynamics cloud-based platform. Diagnostic accuracy of LBM CT-FFR ≤0.8 and percent diameter stenosis >50% by CTA to detect invasive FFR ≤0.8 were compared using area under the receiver operating characteristic curve (AUC). Sixty patients successfully underwent LBM CT-FFR analysis; 29 of 73 lesions in 69 vessels had invasive FFR ≤0.8. Total time to perform LBM CT-FFR was 40±10 min. Compared to invasive FFR, LBM CT-FFR had good correlation (r=0.64), small bias (0.009) and good limits of agreement (-0.223 to 0.206). The AUC of LBM CT-FFR (AUC=0.894, 95% confidence interval [CI]: 0.792-0.996) was significantly higher than CTA (AUC=0.685, 95% CI: 0.576-0.794) to detect FFR ≤0.8 (p=0.0021). Per-lesion specificity, sensitivity, and accuracy of LBM CT-FFR were 97.7%, 79.3%, and 90.4%, respectively. LBM CT-FFR has very good diagnostic accuracy to detect lesion-specific ischaemia (FFR ≤0.8) and can be performed in less than one hour.

Thomson scattering laser-electron X-ray source for reduction of patient radiation dose in interventional coronary angiography

NASA Astrophysics Data System (ADS)

Artyukov, I. A.; Dyachkov, N. V.; Feshchenko, R. M.; Polunina, A. V.; Popov, N. L.; Shvedunov, V. I.; Vinogradov, A. V.

2017-05-01

It was medical applications that stimulated F. Carrol in the early 1990s to start the research of on relativistic Thomson scattering X-ray sources, as a part of the infrastructure of the future society. The possibility to use such a source in interventional cardiology is discussed in this paper. The replacement of X-ray tube by relativistic Thomson scattering Xray source is predicted to lower the patient radiation dose by a factor of 3 while image quality remains the same. The required general characteristics of accelerator and laser units are found. They can be reached by existing technology. A semiempirical method for simulation of medical and technical parameters of interventional coronary angiography systems is suggested.

Submillisievert Radiation Dose Coronary CT Angiography: Clinical Impact of the Knowledge-Based Iterative Model Reconstruction.

PubMed

Iyama, Yuji; Nakaura, Takeshi; Kidoh, Masafumi; Oda, Seitaro; Utsunomiya, Daisuke; Sakaino, Naritsugu; Tokuyasu, Shinichi; Osakabe, Hirokazu; Harada, Kazunori; Yamashita, Yasuyuki

2016-11-01

The purpose of this study was to evaluate the noise and image quality of images reconstructed with a knowledge-based iterative model reconstruction (knowledge-based IMR) in ultra-low dose cardiac computed tomography (CT). We performed submillisievert radiation dose coronary CT angiography on 43 patients. We also performed a phantom study to evaluate the influence of object size with the automatic exposure control phantom. We reconstructed clinical and phantom studies with filtered back projection (FBP), hybrid iterative reconstruction (hybrid IR), and knowledge-based IMR. We measured effective dose of patients and compared CT number, image noise, and contrast noise ratio in ascending aorta of each reconstruction technique. We compared the relationship between image noise and body mass index for the clinical study, and object size for phantom study. The mean effective dose was 0.98 ± 0.25 mSv. The image noise of knowledge-based IMR images was significantly lower than those of FBP and hybrid IR images (knowledge-based IMR: 19.4 ± 2.8; FBP: 126.7 ± 35.0; hybrid IR: 48.8 ± 12.8, respectively) (P < .01). The contrast noise ratio of knowledge-based IMR images was significantly higher than those of FBP and hybrid IR images (knowledge-based IMR: 29.1 ± 5.4; FBP: 4.6 ± 1.3; hybrid IR: 13.1 ± 3.5, respectively) (P < .01). There were moderate correlations between image noise and body mass index in FBP (r = 0.57, P < .01) and hybrid IR techniques (r = 0.42, P < .01); however, these correlations were weak in knowledge-based IMR (r = 0.27, P < .01). Compared to FBP and hybrid IR, the knowledge-based IMR offers significant noise reduction and improvement in image quality in submillisievert radiation dose cardiac CT. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Radiation dose reduction and new image modalities development for interventional C-arm imaging system

NASA Astrophysics Data System (ADS)

Niu, Kai

Cardiovascular disease and stroke are the leading health problems and causes of death in the US. Due to the minimally invasive nature of the evolution of image guided techniques, interventional radiological procedures are becoming more common and are preferred in treating many cardiovascular diseases and strokes. In addition, with the recent advances in hardware and device technology, the speed and efficacy of interventional treatment has significantly improved. This implies that more image modalities can be developed based on the current C-arm system and patients treated in interventional suites can potentially experience better health outcomes. However, during the treatment patients are irradiated with substantial amounts of ionizing radiation with a high dose rate (digital subtraction angiography (DSA) with 3muGy/frame and 3D cone beam CT image with 0.36muGy/frame for a Siemens Artis Zee biplane system) and/or a long irradiation time (a roadmapping image sequence can be as long as one hour during aneurysm embolization). As a result, the patient entrance dose is extremely high. Despite the fact that the radiation dose is already substantial, image quality is not always satisfactory. By default a temporal average is used in roadmapping images to overcome poor image quality, but this technique can result in motion blurred images. Therefore, reducing radiation dose while maintaining or even improving the image quality is an important area for continued research. This thesis is focused on improving the clinical applications of C-arm cone beam CT systems in two ways: (1) Improve the performance of current image modalities on the C-arm system. (2) Develop new image modalities based on the current system. To be more specific, the objectives are to reduce radiation dose for current modalities (e.g., DSA, fluoroscopy, roadmapping, and cone beam CT) and enable cone beam CT perfusion and time resolved cone beam CT angiography that can be used to diagnose and triage acute ischemic stroke patients more efficiently compared with the current clinical work-flow. The animal and patient cases presented in this thesis are focused towards but not limited to neurointerventional applications.

Three-dimensional rotational angiography fused with multimodal imaging modalities for targeted endomyocardial injections in the ischaemic heart.

PubMed

Dauwe, Dieter Frans; Nuyens, Dieter; De Buck, Stijn; Claus, Piet; Gheysens, Olivier; Koole, Michel; Coudyzer, Walter; Vanden Driessche, Nina; Janssens, Laurens; Ector, Joris; Dymarkowski, Steven; Bogaert, Jan; Heidbuchel, Hein; Janssens, Stefan

2014-08-01

Biological therapies for ischaemic heart disease require efficient, safe, and affordable intramyocardial delivery. Integration of multiple imaging modalities within the fluoroscopy framework can provide valuable information to guide these procedures. We compared an anatomo-electric method (LARCA) with a non-fluoroscopic electromechanical mapping system (NOGA(®)). LARCA integrates selective three-dimensional-rotational angiograms with biplane fluoroscopy. To identify the infarct region, we studied LARCA-fusion with pre-procedural magnetic resonance imaging (MRI), dedicated CT, or (18)F-FDG-PET/CT. We induced myocardial infarction in 20 pigs by 90-min LAD occlusion. Six weeks later, we compared peri-infarct delivery accuracy of coloured fluospheres using sequential NOGA(®)- and LARCA-MRI-guided vs. LARCA-CT- and LARCA-(18)F-FDG-PET/CT-guided intramyocardial injections. MRI after 6 weeks revealed significant left ventricular (LV) functional impairment and remodelling (LVEF 31 ± 3%, LVEDV 178 ± 15 mL, infarct size 17 ± 2% LV mass). During NOGA(®)-procedures, three of five animals required DC-shock for major ventricular arrhythmias vs. one of ten during LARCA-procedures. Online procedure time was shorter for LARCA than NOGA(®) (77 ± 6 vs. 130 ± 3 min, P < 0.0001). Absolute distance of injection spots to the infarct border was similar for LARCA-MRI (4.8 ± 0.5 mm) and NOGA(®) (5.4 ± 0.5 mm). LARCA-CT-integration allowed closer approximation of the targeted border zone than LARCA-PET (4.0 ± 0.5 mm vs. 6.2 ± 0.6 mm, P < 0.05). Three-dimensional -rotational angiography fused with multimodal imaging offers a new, cost-effective, and safe strategy to guide intramyocardial injections. Endoventricular procedure times and arrhythmias compare favourably to NOGA(®), without compromising injection accuracy. LARCA-based fusion imaging is a promising enabling technology for cardiac biological therapies. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Neurosurgical applications of ion beams

NASA Astrophysics Data System (ADS)

Fabrikant, Jacob I.; Levy, Richard P.; Phillips, Mark H.; Frankel, Kenneth A.; Lyman, John T.

1989-04-01

The program at Donner Pavilion has applied nuclear medicine research to the diagnosis and radiosurgical treatment of life-threatening intracranial vascular disorders that affect more than half a million Americans. Stereotactic heavy-charged-particle Bragg peak radiosurgery, using narrow beams of heavy ions, demonstrates superior biological and physical characteristics in brain over X-and γ-rays, viz., improved dose distribution in the Bragg peak and sharp lateral and distal borders and less scattering of the beam. Examination of CNS tissue response and alteration of cerebral blood-flow dynamics related to heavy-ion Bragg peak radiosurgery is carried out using three-dimensional treatment planning and quantitative imaging utilizing cerebral angiography, computerized tomography (CT), magnetic resonance imaging (MRI), cine-CT, xenon X-ray CT and positron emission tomography (PET). Also under examination are the physical properties of narrow heavy-ion beams for improving methods of dose delivery and dose distribution and for establishing clinical RBE/LET and dose-response relationships for human CNS tissues. Based on the evaluation and treatment with stereotactically directed narrow beams of heavy charged particles of over 300 patients, with cerebral angiography, CT scanning and MRI and PET scanning of selected patients, plus extensive clinical and neuroradiological followup, it appears that Stereotactic charged-particle Bragg peak radiosurgery obliterates intracranial arteriovenous malformations or protects against rebleeding with reduced morbidity and no mortality. Discussion will include the method of evaluation, the clinical research protocol, the Stereotactic neuroradiological preparation, treatment planning, the radiosurgery procedure and the protocol for followup. Emphasis will be placed on the neurological results, including the neuroradiological and clinical response and early and late delayed injury in brain leading to complications (including vasogenic edema, arterial occlusion, venous thrombosis and radiation necrosis). Clinical results in both children and adults will be illustrated and health outcome will be related to the advantages of charged-particle treatment planning, the radiosurgical procedure, dose distribution and dose localization.

High-Pitch Coronary CT Angiography at 70 kVp Adopting a Protocol of Low Injection Speed and Low Volume of Contrast Medium

PubMed Central

Feng, Ruiqi; Tong, Jiajie; Liu, Xiaofei; Zhao, Yu

2017-01-01

Objective To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. Materials and Methods One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m2, sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. Results The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). Conclusion Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min. PMID:28860894

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

PubMed

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

2017-03-01

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

Hybrid operating room concept for combined diagnostics, intervention and surgery in acute type A dissection.

PubMed

Tsagakis, Konstantinos; Konorza, Thomas; Dohle, Daniel Sebastian; Kottenberg, Eva; Buck, Thomas; Thielmann, Matthias; Erbel, Raimund; Jakob, Heinz

2013-02-01

In acute type A dissection (AAAD), it is commonly decided to carry out immediate surgical repair without invasive diagnostics. The hybrid operating room (Hybrid OR) concept encompasses simultaneous haemodynamic control, non-invasive and invasive diagnostics and immediate surgical and/or interventional treatment. Results over a seven-year period are presented here. From March 2004 to March 2011, 1883 cardiological and surgical patients were treated in a Hybrid OR. Of these, 124 patients (age 60 ± 13, 64% male) diagnosed with AAAD were operated upon. External computed tomography (CT) was available for 87% (108/124) of cases and angiography in 15% (19/124). Preoperative transoesophageal echocardiography (TEE) was done in all patients and angiography in 57% (71/124). Surgery was performed without angiography in 27% (34/124), of which 14% (17/124) was due to shock. Postoperative control angiography followed in 18% (22/124) due to suspected ongoing malperfusion. Preoperative angiography was performed in 71 patients, and no angiography related complications were observed during the procedure. A total of 32% (23/71) of these underwent coronary artery bypass graft (CABG)--for newly-diagnosed coronary artery disease in 21% of cases and for coronary malperfusion in 11%. Visceral/peripheral malperfusion syndromes, necessitating primary endovascular intervention, were detected in 23% (16/71). Ascending aorta replacement was performed in 100% (124/124) of patients, arch replacement in 88% (109/124) and descending aorta repair in 35% (44/124). Five postoperative endovascular interventions became necessary due to persistent malperfusion. In-hospital mortality was 13% (12/90) in patients who had undergone preoperative invasive diagnostics and 24% (8/34) in patients who had not. The Hybrid OR concept enables the exact diagnosis of coronary status and downstream malperfusion sites and influences the design of surgical and/or endovascular treatment, without time delay and at negligible risk to the patient.

Volumetric Single-Beat Coronary Computed Tomography Angiography: Relationship of Image Quality, Heart Rate, and Body Mass Index. Initial Patient Experience With a New Computed Tomography Scanner.

PubMed

Latif, Muhammad Aamir; Sanchez, Frank W; Sayegh, Karl; Veledar, Emir; Aziz, Muhammad; Malik, Rehan; Haider, Imran; Agatston, Arthur S; Batlle, Juan C; Janowitz, Warren; Peña, Constantino; Ziffer, Jack A; Nasir, Khurram; Cury, Ricardo C

2016-01-01

Cardiac computed tomography (CT) image quality (IQ) is very important for accurate diagnosis. We propose to evaluate IQ expressed as Likert scale, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) from coronary CT angiography images acquired with a new volumetric single-beat CT scanner on consecutive patients and assess the IQ dependence on heart rate (HR) and body mass index (BMI). We retrospectively analyzed the data of the first 439 consecutive patients (mean age, 55.13 [SD, 12.1] years; 51.47% male), who underwent noninvasive coronary CT angiography in a new single-beat volumetric CT scanner (Revolution CT) to evaluate chest pain at West Kendall Baptist Hospital. Based on patient BMI (mean, 29.43 [SD, 5.81] kg/m), the kVp (kilovolt potential) value and tube current were adjusted within a range of 80 to 140 kVp and 122 to 720 mA, respectively. Each scan was performed in a single-beat acquisition within 1 cardiac cycle, regardless of the HR. Motion correction software (SnapShot Freeze) was used for correcting motion artifacts in patients with higher HRs. Autogating was used to automatically acquire systolic and diastolic phases for higher HRs with electrocardiographic milliampere dose modulation. Image quality was assessed qualitatively by Likert scale and quantitatively by SNR and CNR for the 4 major vessels right coronary, left main, left anterior descending, and left circumflex arteries on axial and multiplanar reformatted images. Values for Likert scale were as follows: 1, nondiagnostic; 2, poor; 3, good; 4, very good; and 5, excellent. Signal-to-noise ratio and CNR were calculated from the average 2 CT attenuation values within regions of interest placed in the proximal left main and proximal right coronary artery. For contrast comparison, a region of interest was selected from left ventricular wall at midcavity level using a dedicated workstation. We divided patients in 2 groups related to the HR: less than or equal to 70 beats/min (bpm) and greater than 70 bpm and also analyzed them in 2 BMI groupings: BMI less than or equal to 30 kg/m and BMI greater than 30 kg/m. Mean SNR was 8.7 (SD, 3.1) (n = 349) for group with HR 70 bpm or less and 7.7 (SD, 2.4) (n = 78) for group with HR greater than 70 bpm (P = 0.008). Mean CNR was 6.9 (SD, 2.7) (n = 349) for group with HR 70 bpm or less and 5.9 (SD, 2.2) (n = 78) for group with HR 70 bpm or greater (P = 0.002). Mean SNR was 8.8 (SD, 3.2) (n = 249) for group with BMI 30 kg/m or less and 8.1 (SD, 2.6) (n = 176) for group with BMI greater than 30 kg/m (P = 0.008). Mean CNR was 7.0 (SD, 2.8) (n = 249) for group with BMI 30 kg/m or less and 6.4 (SD, 2.4) (n = 176) for group with BMI greater than 30 kg/m (P = 0.002). The results for mean Likert scale values were statistically different, reflecting difference in IQ between people with HR 70 bpm or less and greater than 70 bpm, BMI 30 kg/m or less, and BMI greater than 30 kg/m.

Software-based on-site estimation of fractional flow reserve using standard coronary CT angiography data.

PubMed

De Geer, Jakob; Sandstedt, Mårten; Björkholm, Anders; Alfredsson, Joakim; Janzon, Magnus; Engvall, Jan; Persson, Anders

2016-10-01

The significance of a coronary stenosis can be determined by measuring the fractional flow reserve (FFR) during invasive coronary angiography. Recently, methods have been developed which claim to be able to estimate FFR using image data from standard coronary computed tomography angiography (CCTA) exams. To evaluate the accuracy of non-invasively computed fractional flow reserve (cFFR) from CCTA. A total of 23 vessels in 21 patients who had undergone both CCTA and invasive angiography with FFR measurement were evaluated using a cFFR software prototype. The cFFR results were compared to the invasively obtained FFR values. Correlation was calculated using Spearman's rank correlation, and agreement using intraclass correlation coefficient (ICC). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for significant stenosis (defined as both FFR ≤0.80 and FFR ≤0.75) were calculated. The mean cFFR value for the whole group was 0.81 and the corresponding mean invFFR value was 0.84. The cFFR sensitivity for significant stenosis (FFR ≤0.80/0.75) on a per-lesion basis was 0.83/0.80, specificity was 0.76/0.89, and accuracy 0.78/0.87. The positive predictive value was 0.56/0.67 and the negative predictive value was 0.93/0.94. The Spearman rank correlation coefficient was ρ = 0.77 (P < 0.001) and ICC = 0.73 (P < 0.001). This particular CCTA-based cFFR software prototype allows for a rapid, non-invasive on-site evaluation of cFFR. The results are encouraging and cFFR may in the future be of help in the triage to invasive coronary angiography. © The Foundation Acta Radiologica 2015.

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

PubMed

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

2006-06-01

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

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

PubMed

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

2014-01-01

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

Beauty parlor stroke syndrome due to a bone fragment from an osteophyte of the atlas: case report.

PubMed

Kameda, Takuya; Otani, Koji; Tamura, Takamitsu; Konno, Shinichi

2018-04-01

Beauty parlor stroke syndrome (BPSS) is a rare condition characterized by mechanical impingement of a vertebral artery (VA) during neck rotation and/or hyperextension followed by vertebrobasilar insufficiency. However, there have been no reports of BPSS in which the cause of mechanical impingement was identified and no cases for which surgical treatment was reported. The authors report the case of a 56-year-old Japanese man who presented with presyncope that occurred during cervical extension. Given the possibility of vertebrobasilar insufficiency, digital subtraction angiography and CT angiography were performed. These studies revealed that the right VA was hypoplastic and the left VA was dominant. Moreover, in the position of cervical extension, the dominant left VA showed constriction caused by a bone fragment of an osteophyte of the atlas. Removal of the bone fragment was performed. Postoperative left vertebral angiography showed improvement of blood flow in the extended position, and the presyncope completely disappeared. The pathomechanism of this case was a bone fragment compressing the left VA in the C-1 groove during neck extension. In BPSS patients with recurrent transient symptoms, the possibility of this mechanism of VA constriction by a free bone fragment should be considered.

Robotic digital subtraction angiography systems within the hybrid operating room.

PubMed

Murayama, Yuichi; Irie, Koreaki; Saguchi, Takayuki; Ishibashi, Toshihiro; Ebara, Masaki; Nagashima, Hiroyasu; Isoshima, Akira; Arakawa, Hideki; Takao, Hiroyuki; Ohashi, Hiroki; Joki, Tatsuhiro; Kato, Masataka; Tani, Satoshi; Ikeuchi, Satoshi; Abe, Toshiaki

2011-05-01

Fully equipped high-end digital subtraction angiography (DSA) within the operating room (OR) environment has emerged as a new trend in the fields of neurosurgery and vascular surgery. To describe initial clinical experience with a robotic DSA system in the hybrid OR. A newly designed robotic DSA system (Artis zeego; Siemens AG, Forchheim, Germany) was installed in the hybrid OR. The system consists of a multiaxis robotic C arm and surgical OR table. In addition to conventional neuroendovascular procedures, the system was used as an intraoperative imaging tool for various neurosurgical procedures such as aneurysm clipping and spine instrumentation. Five hundred one neurosurgical procedures were successfully conducted in the hybrid OR with the robotic DSA. During surgical procedures such as aneurysm clipping and arteriovenous fistula treatment, intraoperative 2-/3-dimensional angiography and C-arm-based computed tomographic images (DynaCT) were easily performed without moving the OR table. Newly developed virtual navigation software (syngo iGuide; Siemens AG) can be used in frameless navigation and in access to deep-seated intracranial lesions or needle placement. This newly developed robotic DSA system provides safe and precise treatment in the fields of endovascular treatment and neurosurgery.

Diagnosing Early Ischemic Changes with the Latest-Generation Flat Detector CT: A Comparative Study with Multidetector CT.

PubMed

Maier, I L; Leyhe, J R; Tsogkas, I; Behme, D; Schregel, K; Knauth, M; Schnieder, M; Liman, J; Psychogios, M-N

2018-05-01

One-stop management of mechanical thrombectomy-eligible patients with large-vessel occlusion represents an innovative approach in acute stroke treatment. This approach reduces door-to-reperfusion times by omitting multidetector CT, using flat detector CT as pre-mechanical thrombectomy imaging. The purpose of this study was to compare the diagnostic performance of the latest-generation flat detector CT with multidetector CT. Prospectively derived data from patients with ischemic stroke with large-vessel occlusion and mechanical thrombectomy were analyzed in this monocentric study. All included patients underwent multidetector CT before referral to our comprehensive stroke center and flat detector CT in the angiography suite before mechanical thrombectomy. Diagnosis of early ischemic signs, quantified by the ASPECTS, was compared between modalities using cross tables, the Pearson correlation, and Bland-Altman plots. The predictive value of multidetector CT- and flat detector CT-derived ASPECTS for functional outcome was investigated using area under the receiver operating characteristic curve analysis. Of 25 patients, 24 (96%) had flat detector CT with sufficient diagnostic quality. Median multidetector CT and flat detector CT ASPECTSs were 7 (interquartile range, 5.5-9 and 4.25-8, respectively) with a mean period of 143.6 ± 49.5 minutes between both modalities. The overall sensitivity was 85.1% and specificity was 83.1% for flat detector CT ASPECTS compared with multidetector CT ASPECTS as the reference technique. Multidetector CT and flat detector CT ASPECTS were strongly correlated ( r = 0.849, P < .001) and moderately predicted functional outcome (area under the receiver operating characteristic curve, 0.738; P = .007 and .715; P = .069, respectively). Determination of ASPECTS on flat detector CT is feasible, showing no significant difference compared with multidetector CT ASPECTS and a similar predictive value for functional outcome. Our findings support the use of flat detector CT for emergency stroke imaging before mechanical thrombectomy to reduce door-to-groin time. © 2018 by American Journal of Neuroradiology.

Impact of knowledge-based iterative model reconstruction on myocardial late iodine enhancement in computed tomography and comparison with cardiac magnetic resonance.

PubMed

Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Fukuyama, Naoki; Yokoi, Takahiro; Kido, Tomoyuki; Uetani, Teruyoshi; Vembar, Mani; Dhanantwari, Amar; Tokuyasu, Shinichi; Yamashita, Natsumi; Mochizuki, Teruhito

2017-10-01

We evaluated the image quality and diagnostic performance of late iodine enhancement computed tomography (LIE-CT) with knowledge-based iterative model reconstruction (IMR) for the detection of myocardial infarction (MI) in comparison with late gadolinium enhancement magnetic resonance imaging (LGE-MRI). The study investigated 35 patients who underwent a comprehensive cardiac CT protocol and LGE-MRI for the assessment of coronary artery disease. The CT protocol consisted of stress dynamic myocardial CT perfusion, coronary CT angiography (CTA) and LIE-CT using 256-slice CT. LIE-CT scans were acquired 5 min after CTA without additional contrast medium and reconstructed with filtered back projection (FBP), a hybrid iterative reconstruction (HIR), and IMR. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed. Sensitivity and specificity of LIE-CT for detecting MI were assessed according to the 16-segment model. Image quality scores, and diagnostic performance were compared among LIE-CT with FBP, HIR and IMR. Among the 35 patients, 139 of 560 segments showed MI in LGE-MRI. On LIE-CT with FBP, HIR, and IMR, the median SNRs were 2.1, 2.9, and 6.1; and the median CNRs were 1.7, 2.2, and 4.7, respectively. Sensitivity and specificity were 56 and 93% for FBP, 62 and 91% for HIR, and 80 and 91% for IMR. LIE-CT with IMR showed the highest image quality and sensitivity (p < 0.05). The use of IMR enables significant improvement of image quality and diagnostic performance of LIE-CT for detecting MI in comparison with FBP and HIR.

VASCULAR ABNORMALITIES IN DIABETIC RETINOPATHY ASSESSED WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WIDEFIELD IMAGING.

PubMed

Schaal, Karen B; Munk, Marion R; Wyssmueller, Iris; Berger, Lieselotte E; Zinkernagel, Martin S; Wolf, Sebastian

2017-11-10

To detect vascular abnormalities in diabetic retinopathy using swept-source optical coherence tomography angiography (SS-OCTA) widefield images, and to compare the findings with color fundus photographs (CFPs) using Early Treatment Diabetic Retinopathy Study severity grading. 3 mm × 3 mm and 12 mm × 12 mm scans were acquired to cover 70° to 80° of the posterior pole using a 100-kHz SS-OCTA instrument. Two masked graders assessed the presence of vascular abnormalities on SS-OCTA and the Early Treatment Diabetic Retinopathy Study level on CFP. The grading results were then compared. A total of 120 diabetic eyes (60 patients) were imaged with the SS-OCTA instrument. Cohort 1 (91 eyes; SS-OCTA grading only) showed microaneurysms in 91% (n = 83), intraretinal microvascular abnormalities in 79% (n = 72), and neovascularization in 21% (n = 19) of cases. Cohort 2 (52 eyes; CFP grading compared with SS-OCTA) showed microaneurysms on CFP in 90% (n = 47) and on SS-OCTA in 96% (n = 50) of cases. Agreement in intraretinal microvascular abnormality detection was fair (k = 0.2). Swept-source optical coherence tomography angiography detected 50% of intraretinal microvascular abnormality cases (n = 26), which were missed on CFP. Agreement in detecting neovascularization was moderate (k = 0.5). Agreement in detection of diabetic retinopathy features on CFP and SS-OCTA varies depending on the vascular changes examined. Swept-source optical coherence tomography angiography shows a higher detection rate of intraretinal microvascular abnormalities (P = 0.039), compared with Early Treatment Diabetic Retinopathy Study grading.

Chest pain: coronary CT in the ER

PubMed Central

Maffei, Erica; Seitun, Sara; Guaricci, Andrea I

2016-01-01

Cardiac CT has developed into a robust clinical tool during the past 15 years. Of the fields in which the potential of cardiac CT has raised more interest is chest pain in acute settings. In fact, the possibility to exclude with high reliability obstructive coronary artery disease (CAD) in patients at low-to-intermediate risk is of great interest both from the clinical standpoint and from the management standpoint. Several other modalities, with or without imaging, have been used during the past decades in the settings of new onset chest pain or in acute chest pain for both diagnostic and prognostic assessment of CAD. Each one has advantages and disadvantages. Most imaging modalities also focus on inducible ischaemia to guide referral to invasive coronary angiography. The advent of cardiac CT has introduced a new practice diagnostic paradigm, being the most accurate non-invasive method for identification and exclusion of CAD. Furthermore, the detection of subclinical CAD and plaque imaging offer the opportunity to improve risk stratification. Moreover, recent advances of the latest generation CT scanners allow combining both anatomical and functional imaging by stress myocardial perfusion. The role of cardiac CT in acute settings is already important and will become progressively more important in the coming years. PMID:26866681

Diagnostic yield of 90-kVp low-tube-voltage carotid and intracerebral CT-angiography: effects on radiation dose, image quality and diagnostic performance for the detection of carotid stenosis.

PubMed

Leithner, Doris; Wichmann, Julian L; Mahmoudi, Scherwin; Martin, Simon S; Albrecht, Moritz H; Vogl, Thomas J; Scholtz, Jan-Erik

2018-06-01

To investigate the impact of low-tube-voltage 90-kVp acquisition combined with advanced modeled iterative reconstruction algorithm (Admire) on radiation exposure, image quality, artifacts, and assessment of stenosis in carotid and intracranial CT angiography (CTA). Dual-energy CTA studies of 43 patients performed on a third-generation 192-slice dual-source CT were retrospectively evaluated. Intraindividual comparison of 90-kVp and linearly blended 120-kVp equivalent image series (M_0.6, 60% 90-kVp, 40% Sn-150-kVp) was performed. Contrast-to-noise and signal-to-noise ratios of common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery were calculated. Qualitative image analysis included evaluation of artifacts and suitability for angiographical assessment at shoulder level, carotid bifurcation, siphon, and intracranial by three independent radiologists. Detection and quantification of carotid stenosis were performed. Radiation dose was expressed as dose-length product (DLP). Contrast-to-noise values of all arteries were significantly increased in 90-kVp compared to M_0.6 (p < 0.001). Suitability for angiographical evaluation was rated excellent with low artifacts for all levels in both image series. Both 90-kVp and M_0.6 showed excellent accordance for detection and grading of carotid stenosis with almost perfect interobserver agreement (carotid stenoses in 32 of 129 segments; intraclass correlation coefficient, 0.94). dose-length product was reduced by 40.3% in 90-kVp (110.6 ± 32.1 vs 185.4 ± 47.5 mGy·cm, p < 0.001). 90-kVp carotid and intracranial CTA with Admire provides increased quantitative and similarly good qualitative image quality, while reducing radiation exposure substantially compared to M_0.6. Diagnostic performance for arterial stenosis detection and quantification remained excellent. Advances in knowledge: 90-kVp carotid and intracranial CTA with an advanced iterative reconstruction algorithm results in excellent image quality and reduction of radiation exposure without limiting diagnostic performance.

Iterative reconstruction in single source dual-energy CT pulmonary angiography: Is it sufficient to achieve a radiation dose as low as state-of-the-art single-energy CTPA?

PubMed

Ohana, M; Labani, A; Jeung, M Y; El Ghannudi, S; Gaertner, S; Roy, C

2015-11-01

Dual-energy (DE) brings numerous significant improvements in pulmonary CT angiography (CTPA), but is associated with a 15-50% increase in radiation dose that prevents its widespread use. We hypothesize that thanks to iterative reconstruction (IR), single source DE-CTPA acquired at the same radiation dose that a single-energy examination will maintain an equivalent quantitative and qualitative image quality, allowing a more extensive use of the DE technique in the clinical routine. Fifty patients (58% men, mean age 64.8yo ± 16.2, mean BMI 25.6 ± 4.5) were prospectively included and underwent single source DE-CTPA with acquisition parameters (275 mA fixed tube current, 50% IR) tweaked to target a radiation dose similar to a 100 kV single-energy CTPA (SE-CTPA), i.e., a DLP of 260 mGy cm. Thirty patients (47% men, 64.4yo ± 18.6, BMI 26.2 ± 4.6) from a previous prospective study on DE-CTPA (375 mA fixed tube current, reconstruction with filtered-back projection) were used as the reference group. Thirty-five consecutive patients (57% men, 65.8yo ± 15.5, BMI 25.7 ± 4.4) who underwent SE-CTPA on the same scanner (automated tube current modulation, 50% IR) served as a comparison. Subjective image quality was scored by two radiologists using a 5-level scale and compared with a Kruskal-Wallis nonparametric test. Density measurements on the 65 keV monochromatic reconstructions were used to calculate signal-to-noise (SNR) and contrast-to-noise (CNR) ratios that were compared using a Student's t test. Correlations between image quality, SNR, CNR and BMI were sought using a Pearson's test. p<0.05 was considered significant. All examinations were of diagnostic quality (score ≥ 3). In comparison with the reference DE-CTPA and the SE-CTPA protocols, the DE-IR group exhibited a non-inferior image quality (p=0.95 and p=0.21, respectively) and a significantly lower mean image noise (p<0.01 and p=0.01) thus slightly improving the SNR (p=0.09 and p=0.47) and the CNR (p=0.12 and p=0.51). There was a strong negative relationship between BMI and SNR/CNR (ρ=-0.59 and -0.55 respectively), but only a moderate negative relationship between BMI and image quality (ρ=-0.27). With iterative reconstruction, objective and subjective image quality of single source DE-CTPA are preserved even though the radiation dose is lowered to that of a single-energy examination, overcoming a major limitation of the DE technique and allowing a widespread use in the clinical routine. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Physical analysis of breast cancer using dual-source computed tomography

NASA Astrophysics Data System (ADS)

Kim, H. J.; Lee, H. K.; Cho, J. H.

2014-12-01

This study was aimed to analyze various physical characteristics of breast cancer using dual-source computed tomography (CT). A phantom study and a clinical trial were performed in order and a 64-multidetector CT device was used for the examinations. In the phantom study, single-source (SS) CT was set up with a conventional scanning condition that is usually applied for breast CT examination and implementation was done at tube voltage of 120 kVp. Dual-source CT acquired images by irradiating X-ray sources with fast switching between two kilovoltage settings (80 and 140 kVp). After scanning, Hounsfield Unit (HU) values and radiation doses in a region of interest were measured and analyzed. In the clinical trial, the HU values were measured and analyzed after single-source computed tomography (SSCT) and dual-source CT in patients diagnosed with breast cancer. Also, the tumor size measured by dual-source CT was compared with the actual tumor size. The phantom study determined that the tumor region was especially measured by dual-source CT, while nylon fiber and specks region were especially measured by SSCT. The radiation dose was high with dual-source CT. The clinical trial showed a higher HU value of cancerous regions when scanned by dual-source CT compared with SSCT.

Aorta-Left Renal Vein Fistula Complicating an Aortic Aneurysm: Preoperative and Postoperative Multislice CT Findings

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

Barrier, Pierre, E-mail: p.barrier@gmail.com; Otal, Philippe; Garcia, Olivier

Fistulas complicating an abdominal aortic aneurysm (AAA) are rare, and fistulas involving the left renal vein are particularly uncommon. We highlight here a fistula between an infrarenal aortic aneurysm and a retroaortic left renal vein, revealed by left flank pain associated with hematuria and acute renal failure. The multislice CT angiography performed in this 68-year-old patient revealed communication and equal enhancement between the aorta and the left gonadic vein, suggesting the presence of a fistula. The three-dimensional VRT reconstructions presented in this case were of great value in the preoperative planning, enabling immediate visualization of this unusual feature. Alternative diagnosesmore » to consider when encountering this clinical presentation are reviewed.« less

Eccentric apical hypertrophic cardiomyopathy unmasked by multimodality imaging: an uncommon but missed cause of out of hospital cardiac arrest

PubMed Central

Towe, Eric; Sharma, Saurabh; Geske, Jeffrey; Ackerman, Michael J

2015-01-01

A woman in her late 50s experienced a witnessed, sudden out of hospital cardiac arrest. Initial workup included coronary angiography, transthoracic echocardiogram and a CT scan of the chest to rule out pulmonary embolus. She was subsequently discharged home without an implantable cardioverter defibrillator (ICD) or a life vest. On follow-up at another facility, an ICD was placed and a Holter monitor showed no ventricular ectopy. Further transthoracic echocardiographic images were obtained, which were suggestive of apical hypertrophic cardiomyopathy. A limited transthoracic echocardiogram with contrast was performed, which did not elucidate the hypertrophy. However, eccentric left ventricular apical wall hypertrophy was visualised by a coronary CT scan. PMID:26153133

Segmentation of medical images using explicit anatomical knowledge

NASA Astrophysics Data System (ADS)

Wilson, Laurie S.; Brown, Stephen; Brown, Matthew S.; Young, Jeanne; Li, Rongxin; Luo, Suhuai; Brandt, Lee

1999-07-01

Knowledge-based image segmentation is defined in terms of the separation of image analysis procedures and representation of knowledge. Such architecture is particularly suitable for medical image segmentation, because of the large amount of structured domain knowledge. A general methodology for the application of knowledge-based methods to medical image segmentation is described. This includes frames for knowledge representation, fuzzy logic for anatomical variations, and a strategy for determining the order of segmentation from the modal specification. This method has been applied to three separate problems, 3D thoracic CT, chest X-rays and CT angiography. The application of the same methodology to such a range of applications suggests a major role in medical imaging for segmentation methods incorporating representation of anatomical knowledge.

Effectiveness of Adaptive Statistical Iterative Reconstruction for 64-Slice Dual-Energy Computed Tomography Pulmonary Angiography in Patients With a Reduced Iodine Load: Comparison With Standard Computed Tomography Pulmonary Angiography.

PubMed

Lee, Ji Won; Lee, Geewon; Lee, Nam Kyung; Moon, Jin Il; Ju, Yun Hye; Suh, Young Ju; Jeong, Yeon Joo

2016-01-01

The aim of the study was to assess the effectiveness of the adaptive statistical iterative reconstruction (ASIR) for dual-energy computed tomography pulmonary angiography (DE-CTPA) with a reduced iodine load. One hundred forty patients referred for chest CT were randomly divided into a DE-CTPA group with a reduced iodine load or a standard CTPA group. Quantitative and qualitative image qualities of virtual monochromatic spectral (VMS) images with filtered back projection (VMS-FBP) and those with 50% ASIR (VMS-ASIR) in the DE-CTPA group were compared. Image qualities of VMS-ASIR images in the DE-CTPA group and ASIR images in the standard CTPA group were also compared. All quantitative and qualitative indices, except attenuation value of pulmonary artery in the VMS-ASIR subgroup, were superior to those in the VMS-FBP subgroup (all P < 0.001). Noise and signal-to-noise ratio of VMS-ASIR images were superior to those of ASIR images in the standard CTPA group (P < 0.001 and P = 0.007, respectively). Regarding qualitative indices, noise was significantly lower in VMS-ASIR images of the DE-CTPA group than in ASIR images of the standard CTPA group (P = 0.001). The ASIR technique tends to improve the image quality of VMS imaging. Dual-energy computed tomography pulmonary angiography with ASIR can reduce contrast medium volume and produce images of comparable quality with those of standard CTPA.

A predictive software tool for optimal timing in contrast enhanced carotid MR angiography

NASA Astrophysics Data System (ADS)

Moghaddam, Abbas N.; Balawi, Tariq; Habibi, Reza; Panknin, Christoph; Laub, Gerhard; Ruehm, Stefan; Finn, J. Paul

2008-03-01

A clear understanding of the first pass dynamics of contrast agents in the vascular system is crucial in synchronizing data acquisition of 3D MR angiography (MRA) with arrival of the contrast bolus in the vessels of interest. We implemented a computational model to simulate contrast dynamics in the vessels using the theory of linear time-invariant systems. The algorithm calculates a patient-specific impulse response for the contrast concentration from time-resolved images following a small test bolus injection. This is performed for a specific region of interest and through deconvolution of the intensity curve using the long division method. Since high spatial resolution 3D MRA is not time-resolved, the method was validated on time-resolved arterial contrast enhancement in Multi Slice CT angiography. For 20 patients, the timing of the contrast enhancement of the main bolus was predicted by our algorithm from the response to the test bolus, and then for each case the predicted time of maximum intensity was compared to the corresponding time in the actual scan which resulted in an acceptable agreement. Furthermore, as a qualitative validation, the algorithm's predictions of the timing of the carotid MRA in 20 patients with high quality MRA were correlated with the actual timing of those studies. We conclude that the above algorithm can be used as a practical clinical tool to eliminate guesswork and to replace empiric formulae by a priori computation of patient-specific timing of data acquisition for MR angiography.

Diagnostic performance of dual-energy CT stress myocardial perfusion imaging: direct comparison with cardiovascular MRI.

PubMed

Ko, Sung Min; Song, Meong Gun; Chee, Hyun Kun; Hwang, Hweung Kon; Feuchtner, Gudrun Maria; Min, James K

2014-12-01

The purpose of this study was to assess the diagnostic performance of stress perfusion dual-energy CT (DECT) and its incremental value when used with coronary CT angiography (CTA) for identifying hemodynamically significant coronary artery disease. One hundred patients with suspected or known coronary artery disease without chronic myocardial infarction detected with coronary CTA underwent stress perfusion DECT, stress cardiovascular perfusion MRI, and invasive coronary angiography (ICA). Stress perfusion DECT and cardiovascular stress perfusion MR images were used for detecting perfusion defects. Coronary CTA and ICA were evaluated in the detection of ≥50% coronary stenosis. The diagnostic performance of coronary CTA for detecting hemo-dynamically significant stenosis was assessed before and after stress perfusion DECT on a per-vessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. The performance of stress perfusion DECT compared with cardiovascular stress perfusion MRI on a per-vessel basis in the detection of perfusion defects was sensitivity, 89%; specificity, 74%; positive predictive value, 73%; negative predictive value, 90%. Per segment, these values were sensitivity, 76%; specificity, 80%; positive predictive value, 63%; and negative predictive value, 88%. Compared with ICA and cardiovascular stress perfusion MRI per vessel territory the sensitivity, specificity, positive predictive value, and negative predictive value of coronary CTA were 95%, 61%, 61%, and 95%. The values for stress perfusion DECT were 92%, 72%, 68%, and 94%. The values for coronary CTA and stress perfusion DECT were 88%, 79%, 73%, and 91%. The ROC AUC increased from 0.78 to 0.84 (p=0.02) with the use of coronary CTA and stress perfusion DECT compared with coronary CTA alone. Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically significant coronary stenosis.

Prediction of vascular abnormalities on CT angiography in patients with acute headache.

PubMed

Alons, Imanda M E; Goudsmit, Ben F J; Jellema, Korné; van Walderveen, Marianne A A; Wermer, Marieke J H; Algra, Ale

2018-05-09

Patients with acute headache increasingly undergo CT-angiography (CTA) to evaluate underlying vascular causes. The aim of this study is to determine clinical and non-contrast CT (NCCT) criteria to select patients who might benefit from CTA. We retrospectively included patients with acute headache who presented to the emergency department of an academic medical center and large regional teaching hospital and underwent NCCT and CTA. We identified factors that increased the probability of finding a vascular abnormality on CTA, performed multivariable regression analyses and determined discrimination with the c-statistic. A total of 384 patients underwent NCCT and CTA due to acute headache. NCCT was abnormal in 194 patients. Among these, we found abnormalities in 116 cases of which 99 aneurysms. In the remaining 190 with normal NCCT we found abnormalities in 12 cases; four unruptured aneurysms, three cerebral venous thrombosis', two reversible cerebral vasoconstriction syndromes, two cervical arterial dissections and one cerebellar infarction. In multivariable analysis abnormal NCCT, lowered consciousness and presentation within 6 hr of headache onset were independently associated with abnormal CTA. The c-statistic of abnormal NCCT alone was 0.80 (95% CI: 0.75-0.80), that also including the other two variables was 0.84 (95% CI: 0.80-0.88). If NCCT was normal no other factors could help identify patients at risk for abnormalities. In patients with acute headache abnormal NCCT is the strongest predictor of a vascular abnormality on CTA. If NCCT is normal no other predictors increase the probability of finding an abnormality on CTA and diagnostic yield is low. © 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

Technical feasibility and validation of a coronary artery calcium scoring system using CT coronary angiography images.

PubMed

Pavitt, Christopher W; Harron, Katie; Lindsay, Alistair C; Zielke, Sayeh; Ray, Robin; Gordon, Daniel; Rubens, Michael B; Padley, Simon P; Nicol, Edward D

2016-05-01

We validate a novel CT coronary angiography (CCTA) coronary calcium scoring system. Calcium was quantified on CCTA images using a new patient-specific attenuation threshold: mean + 2SD of intra-coronary contrast density (HU). Using 335 patient data sets a conversion factor (CF) for predicting CACS from CCTA scores (CCTAS) was derived and validated in a separate cohort (n = 168). Bland-Altman analysis and weighted kappa for MESA centiles and Agatston risk groupings were calculated. Multivariable linear regression yielded a CF: CACS = (1.185 × CCTAS) + (0.002 × CCTAS × attenuation threshold). When applied to CCTA data sets there was excellent correlation (r = 0.95; p < 0.0001) and agreement (mean difference -10.4 [95% limits of agreement -258.9 to 238.1]) with traditional calcium scores. Agreement was better for calcium scores below 500; however, MESA percentile agreement was better for high risk patients. Risk stratification was excellent (Agatston groups k = 0.88 and MESA centiles k = 0.91). Eliminating the dedicated CACS scan decreased patient radiation exposure by approximately one-third. CCTA calcium scores can accurately predict CACS using a simple, individualized, semiautomated approach reducing acquisition time and radiation exposure when evaluating patients for CAD. This method is not affected by the ROI location, imaging protocol, or tube voltage strengthening its clinical applicability. • Coronary calcium scores can be reliably determined on contrast-enhanced cardiac CT • This score can accurately risk stratify patients • Elimination of a dedicated calcium scan reduces patient radiation by a third.

Good outcome rate of 35% in IV-tPA-treated patients with computed tomography angiography confirmed severe anterior circulation occlusive stroke.

PubMed

González, R Gilberto; Furie, Karen L; Goldmacher, Gregory V; Smith, Wade S; Kamalian, Shervin; Payabvash, Seyedmehdi; Harris, Gordon J; Halpern, Elkan F; Koroshetz, Walter J; Camargo, Erica C S; Dillon, William P; Lev, Michael H

2013-11-01

To determine the effect of intravenous tissue plasminogen activator (IV-tPA) on outcomes in patients with severe major anterior circulation ischemic stroke. Prospectively, 649 patients with acute stroke had admission National Institutes of Health stroke scale (NIHSS) scores, noncontrast computed tomography (CT), CT angiography (CTA), and 6-month outcome assessed using modified Rankin scale. IV-tPA treatment decisions were made before CTA, at the time of noncontrast CT scanning, as per routine clinical protocol. Severe symptoms were defined as NIHSS>10. Poor outcome was defined as modified Rankin scale >2. Major occlusions were identified on CTA. Univariate and multivariate stepwise-forward logistic regression analyses of the full cohort were performed. Of 649 patients, 188 (29%) patients presented with NIHSS>10, and 64 out of 188 (34%) patients received IV-tPA. Admission NIHSS, large artery occlusion, and IV-tPA all independently predicted good outcomes; however, a significant interaction existed between IV-tPA and occlusion (P<0.001). Of the patients who presented with NIHSS>10 with anterior circulation occlusion, twice the percentage had good outcomes if they received IV-tPA (17 out of 49 patients, 35%) than if they did not (13 out of 77 patients, 17%; P=0.031). The number needed to treat was 7 (95% confidence interval, 3-60). IV-tPA treatment resulted in significantly better outcomes in patients with severely symptomatic stroke with major anterior circulation occlusions. The 35% good outcome rate was similar to rates found in endovascular therapy trials. Vascular imaging may help in patient selection and stratification for trials of IV-thrombolytic and endovascular therapies.

Evaluation of dynamic infrared thermography as an alternative to CT angiography for perforator mapping in breast reconstruction: a clinical study.

PubMed

Weum, Sven; Mercer, James B; de Weerd, Louis

2016-07-15

The current gold standard for preoperative perforator mapping in breast reconstruction with a DIEP flap is CT angiography (CTA). Dynamic infrared thermography (DIRT) is an imaging method that does not require ionizing radiation or contrast injection. We evaluated if DIRT could be an alternative to CTA in perforator mapping. Twenty-five patients scheduled for secondary breast reconstruction with a DIEP flap were included. Preoperatively, the lower abdomen was examined with hand-held Doppler, DIRT and CTA. Arterial Doppler sound locations were marked on the skin. DIRT examination involved rewarming of the abdominal skin after a mild cold challenge. The locations of hot spots on DIRT were compared with the arterial Doppler sound locations. The rate and pattern of rewarming of the hot spots were analyzed. Multiplanar CT reconstructions were used to see if hot spots were related to perforators on CTA. All flaps were based on the perforator selected with DIRT and the surgical outcome was analyzed. First appearing hot spots were always associated with arterial Doppler sounds and clearly visible perforators on CTA. The hot spots on DIRT images were always slightly laterally located in relation to the exit points of the associated perforators through the rectus abdominis fascia on CTA. Some periumbilical perforators were not associated with hot spots and showed communication with the superficial inferior epigastric vein on CTA. The selected perforators adequately perfused all flaps. This study confirms that perforators selected with DIRT have arterial Doppler sound, are clearly visible on CTA and provide adequate perfusion for DIEP breast reconstruction. Retrospectively registered at ClinicalTrials.gov with identifier NCT02806518 .

Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT.

PubMed

Ng, Ming Yen; Karimzad, Yasser; Menezes, Ravi J; Wintersperger, Bernd J; Li, Qin; Forero, Julian; Paul, Narinder S; Nguyen, Elsie T

2016-10-01

To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. • Relaxation music does not reduce heart rate in cardiac CT • Relaxation music does not reduce beta-blocker use in cardiac CT • Relaxation music has no effect on cardiac CT image quality • Low levels of anxiety are present in patients prior to cardiac CT • Patients enjoyed the relaxation music and this results in improved patient experience.

Effect of x-ray tube parameters and iodine concentration on image quality and radiation dose in cerebral pediatric and adult CT angiography: a phantom study.

PubMed

Papadakis, Antonios E; Perisinakis, Kostas; Raissaki, Maria; Damilakis, John

2013-04-01

The aim of the present phantom study was to investigate the effect of x-ray tube parameters and iodine concentration on image quality and radiation dose in cerebral computed tomographic (CT) angiographic examinations of pediatric and adult individuals. Four physical anthropomorphic phantoms that represent the average individual as neonate, 1-year-old, 5-year-old, and 10-year-old children and the RANDO phantom that simulates the average adult individual were used. Cylindrical vessels were bored along the brain-equivalent plugs of each physical phantom. To simulate the brain vasculature, vessels of 0.6, 1, 2, and 3 mm in diameter were created. These vessels were filled with contrast medium (CM) solutions at different iodine concentrations, that is, 5.6, 4.2, 2.7, and 1.4 mg I/mL. The phantom heads were scanned at 120, 100, and 80 kV. The applied quality reference tube current-time product values ranged from a minimum of 45 to a maximum of 680. The CT acquisitions were performed on a 16-slice CT scanner using the automatic exposure control system. Image quality was evaluated on the basis of image noise and contrast-to-noise ratio (CNR) between the contrast-enhanced iodinated vessels and the unenhanced regions of interest. Dose reduction was calculated as the percentage difference of the CT dose index value at the quality reference tube current-time product and the CT dose index at the mean modulated tube current-time product. Image noise that was measured using the preset tube current-time product settings varied significantly among the different phantoms (P < 0.0001). Hounsfield unit number of iodinated vessels was linearly related to CM concentration (r² = 0.907) and vessel diameter (r² = 0.918). The Hounsfield unit number of iodinated vessels followed a decreasing trend from the neonate phantom to the adult phantom at all kilovoltage settings. For the same image noise level, a CNR improvement of up to 69% and a dose reduction of up to 61% may be achieved when CT acquisition is performed at 80 kV compared with 120 kV. For the same CNR, a reduction by 25% of the administered CM concentration may be achieved when CT acquisition is performed at 80 kV compared with 120 kV. In cerebral CT angiographic studies, appropriate adjustment of the preset tube current-time product settings is required to achieve the same image noise level among participants of different age. Cerebral CT angiography at 80 kV significantly improves CNR and significantly reduces radiation dose. Moreover, at 80 kV, a considerable reduction of the administered amount of the CM may be reached, thus reducing potential risks for contrast-induced nephropathy.

Calibration free beam hardening correction for cardiac CT perfusion imaging

NASA Astrophysics Data System (ADS)

Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

2016-03-01

Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

Low Contrast Dose Catheter-Directed CT Angiography (CCTA)

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

Formosa, Amanda, E-mail: amandaformosa@yahoo.ca; Santos, Denise May, E-mail: contact@denisemaysantos.com; Marcuzzi, Daniel

2016-04-15

PurposeCatheter-directed computed tomography angiography (CCTA) has been shown to reduce the contrast volumes required in conventional CTA, thus minimizing the risk of contrast-induced nephropathy (CIN).Materials and MethodsA retrospective analysis was performed on cases where CCTA was used to assess access vessels prior to transfemoral aortic valve implantation (TAVI, n = 53), abdominal aortic aneurysm assessment for endovascular aneurysm repair (EVAR, n = 11), and peripheral vascular disease (PVD, n = 24).ResultsWe show that CCTA can image vasculature with adequate diagnostic detail to allow assessment of lower extremity disease, anatomic suitability for EVAR, as well as potential contraindications to TAVI. Average contrast volumes for pre-TAVI, pre-EVAR, andmore » PVD cases were 7, 11, and 28 mL, respectively.ConclusionThis study validates the use of CCTA in obtaining diagnostic images of the abdominal and pelvic vessels and in imaging lower extremity vasculature.« less

Cervical hemorrhage due to spontaneous rupture of the superior thyroid artery: Case report and review of the literature.

PubMed

Stenner, Markus; Helmstaedter, Victor; Spuentrup, Elmar; Quante, Gero; Huettenbrink, Karl-Bernd

2010-09-01

Beneath the different reasons for cervical masses, a spontaneous hemorrhage presents a rare and life-threatening condition. We present the rare case of a 62-year-old man who was presented with a dramatically enlarging cervical mass causing respiratory distress because of upper airway compression. An endotracheal intubation was lifesaving and avoided tracheotomy. A CT scan revealed a hematoma in the region of the left external carotid artery. An emergency angiography embolized a ruptured branch of the superior thyroid artery and surgery evacuated the hematoma. We discuss the rarity of the condition, reasons for a spontaneous rupture of the artery, and the diagnostic and treatment strategy. In addition, we review the literature on spontaneous thyroid artery hemorrhages, which, up to now, have been described only for the inferior thyroid artery. We conclude that the optimal management for cases of cervical hematoma is intubation, diagnosis, and angiography before surgery.

Gadolinium-enhanced computed tomographic angiography: current status.

PubMed

Rosioreanu, Alex; Alberico, Ronald A; Litwin, Alan; Hon, Man; Grossman, Zachary D; Katz, Douglas S

2005-01-01

This article reviews the research to date, as well as our clinical experience from two institutions, on gadolinium-enhanced computed tomographic angiography (gCTA) for imaging the body. gCTA may be an appropriate examination for the small percentage of patients who would benefit from noninvasive vascular imaging, but who have contraindications to both iodinated contrast and magnetic resonance imaging. gCTA is more expensive than CTA with iodinated contrast, due to the dose of gadolinium administered, and gCTA has limitations compared with CTA with iodinated contrast, in that parenchymal organs are not optimally enhanced at doses of 0.5 mmol/kg or lower. However, in our experience, gCTA has been a very useful problem-solving examination in carefully selected patients. With the advent of 16-64 detector CT, in combination with bolus tracking, we believe that the overall dose of gadolinium needed for diagnostic CTA examinations, while relatively high, can be safely administered.

Photodynamic therapy monitoring with optical coherence angiography

NASA Astrophysics Data System (ADS)

Sirotkina, M. A.; Matveev, L. A.; Shirmanova, M. V.; Zaitsev, V. Y.; Buyanova, N. L.; Elagin, V. V.; Gelikonov, G. V.; Kuznetsov, S. S.; Kiseleva, E. B.; Moiseev, A. A.; Gamayunov, S. V.; Zagaynova, E. V.; Feldchtein, F. I.; Vitkin, A.; Gladkova, N. D.

2017-02-01

Photodynamic therapy (PDT) is a promising modern approach for cancer therapy with low normal tissue toxicity. This study was focused on a vascular-targeting Chlorine E6 mediated PDT. A new angiographic imaging approach known as M-mode-like optical coherence angiography (MML-OCA) was able to sensitively detect PDT-induced microvascular alterations in the mouse ear tumour model CT26. Histological analysis showed that the main mechanisms of vascular PDT was thrombosis of blood vessels and hemorrhage, which agrees with angiographic imaging by MML-OCA. Relationship between MML-OCA-detected early microvascular damage post PDT (within 24 hours) and tumour regression/regrowth was confirmed by histology. The advantages of MML-OCA such as direct image acquisition, fast processing, robust and affordable system opto-electronics, and label-free high contrast 3D visualization of the microvasculature suggest attractive possibilities of this method in practical clinical monitoring of cancer therapies with microvascular involvement.

Egas Moniz: 90 Years (1927-2017) from Cerebral Angiography.

PubMed

Artico, Marco; Spoletini, Marialuisa; Fumagalli, Lorenzo; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco; Salvati, Maurizio; Frati, Alessandro; Pastore, Francesco Saverio; Taurone, Samanta

2017-01-01

In June 2017 we celebrate the 90th anniversary of the pioneer discovery of cerebral angiography, the seminal imaging technique used for visualizing cerebral blood vessels and vascular alterations as well as other intracranial disorders. Egas Moniz (1874-1955) was the first to describe the use of this revolutionary technique which, until 1975 (when computed tomography, CT, scan was introduced in the clinical practice), was the sole diagnostic tool to provide an imaging of cerebral vessels and therefore alterations due to intracranial pathology. Moniz introduced in the clinical practice this fundamental and important diagnostic tool. The present contribution wishes to pay a tribute to the Portuguese neurosurgeon, who was also a distinguished neurologist and statesman. Despite his tremendous contribution in modern brain imaging, Egas Moniz was awarded the Nobel Prize in Physiology or Medicine in 1949 for prefrontal leucotomy, the neurosurgical intervention nowadays unacceptable, but should rather be remembered for his key contribution to modern brain imaging.

Endoport-Assisted Microsurgical Treatment of a Ruptured Periventricular Aneurysm

PubMed Central

Chen, Ching-Jen; Caruso, James; Buell, Thomas; Crowley, R. Webster; Liu, Kenneth C.

2016-01-01

Background and Importance. Ruptured periventricular aneurysms in patients with moyamoya disease represent challenging pathologies. The most common methods of treatment include endovascular embolization and microsurgical clipping. However, rare cases arise in which the location and anatomy of the aneurysm make these treatment modalities particularly challenging. Clinical Presentation. We report a case of a 34-year-old female with moyamoya disease who presented with intraventricular hemorrhage. CT angiography and digital subtraction angiography revealed an aneurysm located in the wall of the atrium of the right lateral ventricle. Distal endovascular access was not possible, and embolization risked the sacrifice of arteries supplying critical brain parenchyma. Using the BrainPath endoport system, the aneurysm was able to be accessed. Since the fusiform architecture of the aneurysm prevented clip placement, the aneurysm was ligated with electrocautery. Conclusion. We demonstrate the feasibility of endoport-assisted approach for minimally invasive access and treatment of uncommon, distally located aneurysms. PMID:27195160

Hemodynamic and intravascular ultrasound assessment of myocardial bridging: fractional flow reserve paradox with dobutamine versus adenosine.

PubMed

Hakeem, Abdul; Cilingiroglu, Mehmet; Leesar, Massoud A

2010-02-01

Compared to coronary angiography, both intravascular ultrasound (IVUS) and CT-angiography provide important information with respect to the morphological aspects of myocardial bridging (MB). However, these modalities are limited in defining the hemodynamic and clinical significance of MB. Intracoronary Doppler studies demonstrate a peculiar abnormal Doppler flow profile associated with MB. Fractional flow reserve (FFR) after adenosine infusion has been used to assess the hemodynamic significance of MB, but FFR after adenosine induced hyperemia underestimates the significance of MB. On the other hand, high-dose dobutamine by increasing the contractility of the bridging segment unmasks ischemia induced by MB. This review outlines the role of flow velocity measurement by intracoronary Doppler, FFR, and IVUS for assessment of patients with MB. In addition, we compared FFR measurements after adenosine versus dobutamine infusions for the hemodynamic assessment of MB in two patients.

Coronary CT Angiography Incorporating Doppler-Guided Prospective ECG Gating in Patients with High Heart Rate: Comparison with Results of Traditional Prospective ECG Gating

PubMed Central

Li, Min; Yu, Bing-bing; Wu, Jian-hua; Xu, Lin; Sun, Gang

2013-01-01

Purpose As Doppler ultrasound has been proven to be an effective tool to predict and compress the optimal pulsing windows, we evaluated the effective dose and diagnostic accuracy of coronary CT angiography (CTA) incorporating Doppler-guided prospective electrocardiograph (ECG) gating, which presets pulsing windows according to Doppler analysis, in patients with a heart rate >65 bpm. Materials and Methods 119 patients with a heart rate >65 bpm who were scheduled for invasive coronary angiography were prospectively studied, and patients were randomly divided into traditional prospective (n = 61) and Doppler-guided prospective (n = 58) ECG gating groups. The exposure window of traditional prospective ECG gating was set at 30%–80% of the cardiac cycle. For the Doppler group, the length of diastasis was analyzed by Doppler. For lengths greater than 90 ms, the pulsing window was preset during diastole (during 60%–80%); otherwise, the optimal pulsing intervals were moved from diastole to systole (during 30%–50%). Results The mean heart rates of the traditional ECG and the Doppler-guided group during CT scanning were 75.0±7.7 bpm (range, 66–96 bpm) and 76.5±5.4 bpm (range: 66–105 bpm), respectively. The results indicated that whereas the image quality showed no significant difference between the traditional and Doppler groups (P = 0.42), the radiation dose of the Doppler group was significantly lower than that of the traditional group (5.2±3.4mSv vs. 9.3±4.5mSv, P<0.001). The sensitivities of CTA applying traditional and Doppler-guided prospective ECG gating to diagnose stenosis on a segment level were 95.5% and 94.3%, respectively; specificities 98.0% and 97.1%, respectively; positive predictive values 90.7% and 88.2%, respectively; negative predictive values 99.0% and 98.7%, respectively. There was no statistical difference in concordance between the traditional and Doppler groups (P = 0.22). Conclusion Doppler-guided prospective ECG gating represents an improved method in patients with a high heart rate to reduce effective radiation doses, while maintaining high diagnostic accuracy. PMID:23696793

Patient satisfaction with the consent discussion is not improved by showing patients their computed tomography or angiography images before they undergo vascular surgery.

PubMed

LeBlanc, Dominic; Power, Adam H; DeRose, Guy; Duncan, Audra; Dubois, Luc

2018-05-18

Patient-based decision aids and other multimedia tools have been developed to help enrich the preoperative discussion between surgeon and patient. Use of these tools, however, can be time-consuming and logistically challenging. We investigated whether simply showing patients their images from preoperative computed tomography (CT) or angiography would improve patients' satisfaction with the preoperative discussion. We also examined whether this improved the patient's understanding and trust and whether it contributed to increased preoperative anxiety. Patients undergoing either elective abdominal aortic aneurysm repair or lower limb revascularization were randomly assigned to either standard perioperative discussion or perioperative discussion and review of images (CT image or angiogram). Randomization was concealed and stratified by surgeon. Primary outcome was patient satisfaction with the preoperative discussion as measured by a validated 7-item scale (score, 0-28), with higher scores indicating improved satisfaction. Secondary outcomes included patient understanding, patient anxiety, patient trust, and length of preoperative discussion. Scores were compared using t-test. Overall, 51 patients were randomized, 25 to the intervention arm (discussion and imaging) and 26 to the control arm. Most patients were male (69%), and the average age was 70 years. Forty percent of patients underwent abdominal aortic aneurysm repair, whereas 60% underwent lower limb revascularization. Patient satisfaction with the discussion was generally high, with no added improvement when preoperative images were reviewed (mean score, 24.9 ± 3.02 vs 24.8 ± 2.93; P = .88). Similarly, there was no difference in the patient's anxiety, level of trust, or understanding when the imaging review was compared with standard discussion. There was a trend toward longer preoperative discussions in the group that underwent imaging review (8.18 vs 6.35 minutes; P = .07). Showing patients their CT or angiography images during the preoperative discussion does not improve the patient's satisfaction with the consent discussion. Similarly, there was no effect on the patient's trust, understanding, or anxiety level. Our conclusions are limited by the lack of a standardized measure of patient understanding and not measuring outcomes postoperatively, both of which should be considered in future studies. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Evaluation of a High Concentrated Contrast Media Injection Protocol in Combination with Low Tube Current for Dose Reduction in Coronary Computed Tomography Angiography: A Randomized, Two-center Prospective Study.

PubMed

Sun, Yibo; Hua, Yanqing; Wang, Mingpeng; Mao, Dingbiao; Jin, Xiu; Li, Cheng; Shi, Kailei; Xu, Jianrong

2017-12-01

The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography. Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDI vol ] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale. The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDI vol and dose length product in group B were 58% of those of group A. HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Effect of automated tube voltage selection, integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of 3rd generation dual-source aortic CT angiography: An intra-individual comparison.

PubMed

Mangold, Stefanie; De Cecco, Carlo N; Wichmann, Julian L; Canstein, Christian; Varga-Szemes, Akos; Caruso, Damiano; Fuller, Stephen R; Bamberg, Fabian; Nikolaou, Konstantin; Schoepf, U Joseph

2016-05-01

To compare, on an intra-individual basis, the effect of automated tube voltage selection (ATVS), integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of aortic CTA studies using 2nd and 3rd generation dual-source CT (DSCT). We retrospectively evaluated 32 patients who had undergone CTA of the entire aorta with both 2nd generation DSCT at 120kV using filtered back projection (FBP) (protocol 1) and 3rd generation DSCT using ATVS, an integrated circuit detector and advanced iterative reconstruction (protocol 2). Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using a five-point scale. Radiation dose parameters were recorded. All studies were considered of diagnostic image quality. CNR was significantly higher with protocol 2 (15.0±5.2 vs 11.0±4.2; p<.0001). Subjective image quality analysis revealed no significant differences for evaluation of attenuation (p=0.08501) but image noise was rated significantly lower with protocol 2 (p=0.0005). Mean tube voltage and effective dose were 94.7±14.1kV and 6.7±3.9mSv with protocol 2; 120±0kV and 11.5±5.2mSv with protocol 1 (p<0.0001, respectively). Aortic CTA performed with 3rd generation DSCT, ATVS, integrated circuit detector, and advanced iterative reconstruction allow a substantial reduction of radiation exposure while improving image quality in comparison to 120kV imaging with FBP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Mobile CT: technical aspects of prehospital stroke imaging before intravenous thrombolysis].

PubMed

Gierhake, D; Weber, J E; Villringer, K; Ebinger, M; Audebert, H J; Fiebach, J B

2013-01-01

To reduce the time from symptom onset to treatment with tissue plasminogen activator (tPA) in ischemic stroke, an ambulance was equipped with a CT scanner. We analyzed process and image quality of CT scanning during the pilot study regarding image quality and safety issues. The pilot study of a stroke emergency mobile unit (STEMO) ran over a period of 12 weeks on 5 weekdays from 7a.m. to 6:30 p.m. A teleradiological service for the justifying indication and reporting was established. The radiographer was responsible for the performance of the CT scan on the ambulance. 64 cranial CT scans and 1 intracranial CT angiography were performed. We compared times from ambulance alarm to treatment decision (time of last brain scan) with a cohort of 50 consecutive tPA treatments before implementation of STEMO. 62 (95%) of the 65 scans performed had sufficient quality for reading. Technical quality was not optimal in 45 cases (69%) mainly caused by suboptimal positioning of patient or eye lens protection. Motion artefacts were observed in 8 exams (12%). No safety issues occurred for team or patients. 23 patients were treated with thrombolysis. Time from alarm to last CT scan was 18 minutes shorter than in the tPA cohort before STEMO implementation. A teleradiological support for primary stroke imaging by CT on-site is feasible, quality-wise of diagnostic value and has not raised safety issues. © Georg Thieme Verlag KG Stuttgart · New York.

[Reconstruction of an air-gun injury track in the neck region--a case report].

PubMed

Woźniak, Krzysztof; Nowaczek-Dziocha, Elzbieta; Moskała, Artur; Urbanik, Andrzej; Pohl, Jerzy

2009-01-01

The authors present a case of an air-gun injury of the neck region with a foreign body left in situ. The DICOM files obtained during clinical CT examination (including computed tomography angiography) gave the opportunity for three-dimensional reconstructions of the location of the pellet, neighboring blood vessels and the bullet track--essential for a successful analysis of a possible version according to the testimonies related to the critical event.

[Value of x-ray computed tomography in the study of the inferior vena cava in urologic practice].

PubMed

Barré, C; Vialle, M; Rieux, D; Caron-Poitreau, C; Soret, J Y; Rognon, M

1985-01-01

The CT scan provides a reliable evaluation of the inferior vena cava, especially since the development of second and third generation scanners. It can readily detect congenital malformations and obstructive anomalies complicating renal cancer and it is also able to determine the tumoral or thrombotic nature of the venous obstruction. This excellent definition of the vessel reduces the indications for caval angiography to a few exceptional cases.

Feasibility of low contrast media volume in CT angiography of the aorta.

PubMed

Seehofnerová, Anna; Kok, Madeleine; Mihl, Casper; Douwes, Dave; Sailer, Anni; Nijssen, Estelle; de Haan, Michiel J W; Wildberger, Joachim E; Das, Marco

2015-01-01

Using smaller volumes of contrast media (CM) in CT angiography (CTA) is desirable in terms of cost reduction and prevention of contrast-induced nephropathy (CIN). The purpose was to evaluate the feasibility of low CM volume in CTA of the aorta. 77 patients referred for CTA of the aorta were scanned using a standard MDCT protocol at 100 kV. A bolus of 50 ml CM (Iopromide 300 mg Iodine/ml) at a flow rate of 6 ml/s was applied (Iodine delivery rate IDR = 1.8 g/s; Iodine load 15 g) followed by a saline bolus of 40 ml at the same flow rate. Scan delay was determined by the test bolus method. Subjective image quality was assessed and contrast enhancement was measured at 10 anatomical levels of the aorta. Diagnostic quality images were obtained for all patients, reaching a mean overall contrast enhancement of 324 ± 28 HU. Mean attenuation was 350 ± 60 HU at the thoracic aorta and 315 ± 83 HU at the abdominal aorta. A straightforward low volume CM protocol proved to be technically feasible and led to CTA examinations reaching diagnostic image quality of the aorta at 100 kV. Based on these findings, the use of a relatively small CM bolus can be incorporated into routine clinical imaging.

A fast 3D region growing approach for CT angiography applications

NASA Astrophysics Data System (ADS)

Ye, Zhen; Lin, Zhongmin; Lu, Cheng-chang

2004-05-01

Region growing is one of the most popular methods for low-level image segmentation. Many researches on region growing have focused on the definition of the homogeneity criterion or growing and merging criterion. However, one disadvantage of conventional region growing is redundancy. It requires a large memory usage, and the computation-efficiency is very low especially for 3D images. To overcome this problem, a non-recursive single-pass 3D region growing algorithm named SymRG is implemented and successfully applied to 3D CT angiography (CTA) applications for vessel segmentation and bone removal. The method consists of three steps: segmenting one-dimensional regions of each row; doing region merging to adjacent rows to obtain the region segmentation of each slice; and doing region merging to adjacent slices to obtain the final region segmentation of 3D images. To improve the segmentation speed for very large volume 3D CTA images, this algorithm is applied repeatedly to newly updated local cubes. The next new cube can be estimated by checking isolated segmented regions on all 6 faces of the current local cube. This local non-recursive 3D region-growing algorithm is memory-efficient and computation-efficient. Clinical testings of this algorithm on Brain CTA show this technique could effectively remove whole skull, most of the bones on the skull base, and reveal the cerebral vascular structures clearly.

Document-level classification of CT pulmonary angiography reports based on an extension of the ConText algorithm.

PubMed

Chapman, Brian E; Lee, Sean; Kang, Hyunseok Peter; Chapman, Wendy W

2011-10-01

In this paper we describe an application called peFinder for document-level classification of CT pulmonary angiography reports. peFinder is based on a generalized version of the ConText algorithm, a simple text processing algorithm for identifying features in clinical report documents. peFinder was used to answer questions about the disease state (pulmonary emboli present or absent), the certainty state of the diagnosis (uncertainty present or absent), the temporal state of an identified pulmonary embolus (acute or chronic), and the technical quality state of the exam (diagnostic or not diagnostic). Gold standard answers for each question were determined from the consensus classifications of three human annotators. peFinder results were compared to naive Bayes' classifiers using unigrams and bigrams. The sensitivities (and positive predictive values) for peFinder were 0.98(0.83), 0.86(0.96), 0.94(0.93), and 0.60(0.90) for disease state, quality state, certainty state, and temporal state respectively, compared to 0.68(0.77), 0.67(0.87), 0.62(0.82), and 0.04(0.25) for the naive Bayes' classifier using unigrams, and 0.75(0.79), 0.52(0.69), 0.59(0.84), and 0.04(0.25) for the naive Bayes' classifier using bigrams. Copyright © 2011 Elsevier Inc. All rights reserved.

Can value for money be improved by changing the sequence of our donor work-up in the living kidney donor programme?

PubMed

Larsen, Jesper; Sørensen, Søren Schwartz; Feldt-Rasmussen, Bo

2009-08-01

The aim of the study was to identify procedures of maximum importance for acceptance or rejection of kidney donation from a living donor as well as making the process more cost-effective. We identified all potential living related donors who were examined during the period between January 2002 and December 2006 at our department. The cost in euro (euro) for the programme was estimated using the Danish diagnosis-related group-system (DRG). The donor work-up programme was described. One hundred and thirty-three potential donors were identified; 66 male- and 67 female subjects, median age of 52 years (range 22-69). Sixty-four participants were rejected as donors. Abdominal CT-scan with angiography and urography ruled out 22 of the above 64 potential organ donors; thus, 48% of the volunteers for living kidney donation were unsuited for donation. Abdominal CT-scan with angiography and urography was the procedure identifying most subjects who were unsuited for kidney donation. A rearrangement of the present donor work-up programme could potentially reduce the costs from euro6911 to euro5292 per donor--saving 23% of the costs. By changing the sequence of examinations, it might be possible to cut down on time spent and number of tests needed for approving or rejecting subjects for living kidney donation.

Relative cerebral blood volume is associated with collateral status and infarct growth in stroke patients in SWIFT PRIME.

PubMed

Arenillas, Juan F; Cortijo, Elisa; García-Bermejo, Pablo; Levy, Elad I; Jahan, Reza; Goyal, Mayank; Saver, Jeffrey L; Albers, Gregory W

2017-01-01

We aimed to evaluate how predefined candidate cerebral perfusion parameters correlate with collateral circulation status and to assess their capacity to predict infarct growth in patients with acute ischemic stroke (AIS) eligible for endovascular therapy. Patients enrolled in the SWIFT PRIME trial with baseline computed tomography perfusion (CTP) scans were included. RAPID software was used to calculate mean relative cerebral blood volume (rCBV) in hypoperfused regions, and hypoperfusion index ratio (HIR). Blind assessments of collaterals were performed using CT angiography in the whole sample and cerebral angiogram in the endovascular group. Reperfusion was assessed on 27-h CTP; infarct volume was assessed on 27-h magnetic resonance imaging/CT scans. Logistic and rank linear regression models were conducted. We included 158 patients. High rCBV ( p = 0.03) and low HIR ( p = 0.03) were associated with good collaterals. A positive association was found between rCBV and better collateral grades on cerebral angiography ( p = 0.01). Baseline and 27-h follow-up CTP were available for 115 patients, of whom 74 (64%) achieved successful reperfusion. Lower rCBV predicted a higher infarct growth in successfully reperfused patients ( p = 0.038) and in the endovascular treatment group ( p = 0.049). Finally, rCBV and HIR may serve as markers of collateral circulation in AIS patients prior to endovascular therapy. Unique identifier: NCT0165746.

Transcatheter Arterial Embolization with N-Butyl-2-Cyanoacrylate in the Management of Spontaneous Hematomas.

PubMed

Ozyer, Umut

2017-01-01

Spontaneous hematoma refractory to conservative management is a potentially serious condition that requires prompt diagnosis and intervention. The purpose of this study was to evaluate the performance of computed tomography (CT) in the treatment planning and to report the effectiveness of transcatheter embolization with N-butyl-2-cyanoacrylate (NBCA). Forty-one interventions in 38 patients within a 12-year period were evaluated. CT and angiograms were reviewed for the location of the hematoma, the presence of extravasation, and the correlation of CT and angiography findings. Arterial extravasation was present on 34/39 CT scans. Angiograms confirmed the CT scans in 29 cases. Angiograms revealed extravasation in four cases which CT showed venous bleeding (n = 2) or no bleeding (n = 2). Five patients with arterial and 1 patient with venous extravasation on CT images had no extravasation on angiograms. Embolization was performed to all arteries with extravasation on angiograms. Empiric embolization of the corresponding artery on the CT was performed when there was no extravasation on angiograms. Embolization procedures were performed with 15 % NBCA diluted with iodized oil. Technical success was achieved in 40/41 (97.6 %) interventions. Clinical success was achieved in 35 patients with a single, in 1 patient with 2, and in 1 patient with 3 interventions. No complications related to embolization procedure occurred. None of the patients died due to a progression of the hematoma. NBCA is an effective and safe embolic agent to treat hematoma refractory to conservative management. Contrast-enhanced CT may provide faster and more effective intervention. Retrospective.

Coronary artery disease reporting and data system (CAD-RADSTM): Inter-observer agreement for assessment categories and modifiers.

PubMed

Maroules, Christopher D; Hamilton-Craig, Christian; Branch, Kelley; Lee, James; Cury, Roberto C; Maurovich-Horvat, Pál; Rubinshtein, Ronen; Thomas, Dustin; Williams, Michelle; Guo, Yanshu; Cury, Ricardo C

The Coronary Artery Disease Reporting and Data System (CAD-RADS) provides a lexicon and standardized reporting system for coronary CT angiography. To evaluate inter-observer agreement of the CAD-RADS among an panel of early career and expert readers. Four early career and four expert cardiac imaging readers prospectively and independently evaluated 50 coronary CT angiography cases using the CAD-RADS lexicon. All readers assessed image quality using a five-point Likert scale, with mean Likert score ≥4 designating high image quality, and <4 designating moderate/low image quality. All readers were blinded to medical history and invasive coronary angiography findings. Inter-observer agreement for CAD-RADS assessment categories and modifiers were assessed using intra-class correlation (ICC) and Fleiss' Kappa (κ).The impact of reader experience and image quality on inter-observer agreement was also examined. Inter-observer agreement for CAD-RADS assessment categories was excellent (ICC 0.958, 95% CI 0.938-0.974, p < 0.0001). Agreement among expert readers (ICC 0.925, 95% CI 0.884-0.954) was marginally stronger than for early career readers (ICC 0.904, 95% CI 0.852-0.941), both p < 0.0001. High image quality was associated with stronger agreement than moderate image quality (ICC 0.944, 95% CI 0.886-0.974 vs. ICC 0.887, 95% CI 0.775-0.95, both p < 0.0001). While excellent inter-observer agreement was observed for modifiers S (stent) and G (bypass graft) (both κ = 1.0), only fair agreement (κ = 0.40) was observed for modifier V (high risk plaque). Inter-observer reproducibility of CAD-RADS assessment categories and modifiers is excellent, except for high-risk plaque (modifier V) which demonstrates fair agreement. These results suggest CAD-RADS is feasible for clinical implementation. Copyright © 2017. Published by Elsevier Inc.