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X-ray coronary angiography is a primary imaging technique for diagnosing coronary diseases. Although quantitative coronary angiography (QCA) provides morphological information of coronary arteries with objective quantitative measures, considerable training is required to identify the target vessels and understand the tree structure of coronary arteries. Despite the use of computer-aided tools, such as the edge-detection method, manual correction is necessary for accurate segmentation of coronary vessels. In the present study, we proposed a robust method for major vessel segmentation using deep learning models with fully convolutional networks. When angiographic images of 3302 diseased major vessels from 2042 patients were tested, deep learning networks accurately identified and segmented the major vessels in X-ray coronary angiography. The average F1 score reached 0.917, and 93.7% of the images exhibited a high F1 score > 0.8. The most narrowed region at the stenosis was distinctly captured with high connectivity. Robust predictability was validated for the external dataset with different image characteristics. For major vessel segmentation, our approach demonstrated that prediction could be completed in real time with minimal image preprocessing. By applying deep learning segmentation, QCA analysis could be further automated, thereby facilitating the use of QCA-based diagnostic methods.

Objectives: The application of SYNTAX score II based on coronary CT angiography (CCTA) for selecting further treatment options has not been studied. This study aimed to investigate the diagnostic performance of CCTA combined with SYNTAX score II for selecting the revascularization method compared with invasive coronary angiography (ICA) based on 2014 European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) guidelines., Methods: From January-May 2011, 160 patients who underwent both CCTA and ICA within 30 interval days were included. The diagnostic performance of CCTA, CCTA plus CT-SYNTAX score I and CT-SYNTAX score II was analysed using ICA counterparts as references., Results: Overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CCTA plus CT-SYNTAX I for selecting coronary artery bypass grafting (CABG) candidates using ICA plus ICA-SYNTAX I as reference, were 70.6 %, 95.8 %, 66.7 %, 96.5 % and 93.1 %, respectively. The diagnostic performance of CCTA plus CT-SYNTAX II showed improvement with values of 83.3 %, 97.3 %, 71.4 %, 98.6 % and 96.3 %, respectively, using ICA plus ICA-SYNTAX II as reference., Conclusions: CCTA combined with CT-SYNTAX score II is an accurate method for selecting CABG surgery candidates compared with ICA-SYNTAX score II., Key Points: • SYNTAX plus CCTA can be highly specific for selecting the revascularization method. • SYNTAX II was complemented by including clinical considerations to SYNTAX I. • CCTA plus CT-SYNTAX II is an accurate method for selecting CABG candidates.

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.

This study was designed to determine the prognostic value of coronary computed tomography angiography (CCTA) in ischemic stroke patients and to identify any incremental risk stratification benefits of CCTA findings compared with coronary artery calcium scoring (CACS) and traditional Framingham risk scores (FRS) in ischemic stroke patients without chest pain. IMPACTS is a prospective, multicenter, observational cohort study in which at least seven centers in Korea will participate. All participants will be enrolled in this study after providing informed consent. Nine hundred total ischemic stroke patients without chest pain will be enrolled and will undergo CACS and CCTA. All participants will be followed-up for a minimum of 24 months to determine the endpoints. The primary endpoint will be occurrence of major adverse cardiovascular events (MACEs), defined as all-cause mortality, cardiovascular death, myocardial infarction, or cardiovascular events requiring hospitalization and revascularization either by percutaneous coronary intervention or by coronary artery bypass graft after 90 days of index testing during the follow-up period. Patient enrollment should be completed within 2.5 years. We plan to analyze and identify the CCTA predictors of MACEs. In addition, we will compare several models used to assess independent relationships between the variables and MACEs using a shared frailty model and therefore determine the incremental prognostic value of CCTA findings compared with either the CACS or FRS. The results of IMPACTS will provide valuable information for risk stratification with CCTA in ischemic stroke patients without chest pain.

Purpose: To investigate the diagnostic performance of coronary computed tomographic (CT) angiography for selecting candidates for coronary artery bypass graft (CABG) surgery according to the 2011 American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) guidelines for CABG surgery and determine the added value of SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) scoring for selecting CABG surgery candidates., Materials and Methods: Approval was obtained from the Institutional Review Board, and informed consent was waived for this retrospective study. A total of 399 patients (mean age, 63.8 years; 244 men and 155 women) who underwent both coronary CT angiography and invasive coronary angiography were included. Eligible criteria for CABG surgery were established on the basis of the 2011 ACCF/AHA guidelines., Results: from coronary CT angiography and invasive coronary angiography were retrospectively reviewed, and SYNTAX scores were determined. The diagnostic performance of coronary CT angiography for selecting CABG surgery candidates was calculated with invasive coronary angiography as the reference method. The diagnostic performance of coronary CT angiography alone, the CT-based SYNTAX score, and the combined coronary CT angiography with CT-based SYNTAX score were assessed by using a combination of invasive coronary angiography and invasive coronary angiography-based SYNTAX scores as a reference method. Statistical analyses were performed by using the generalized estimating equation, independent t test, Mann-Whitney U test, Wilcoxon signed rank test, Fisher exact test, and χ(2) statistics., Results: The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value of coronary CT angiography for selecting CABG surgery candidates were 96.5%, 96.5%, 88.3%, and 99.0%, respectively. When a combination of invasive coronary angiography with an invasive coronary angiography-based SYNTAX score was used as a standard reference, combined coronary CT angiography with a CT-based SYNTAX score had higher specificity and PPV (98.3% and 86.0%, respectively) than did coronary CT angiography alone (84.5% and 40.4%, respectively; P < .0001)., Conclusion: Coronary CT angiography had diagnostic accuracy comparable to that of invasive coronary angiography for selecting CABG surgery candidates, and combining a CT-based SYNTAX score with coronary CT angiography can be a highly specific method for selecting CABG surgery candidates., ((©) RSNA, 2015.)

Objective: The predictive value of coronary computed tomography angiography (CCTA) in stroke patients has not yet been established. We investigated the prognostic value of coronary artery disease (CAD) detection by CCTA, and determined the incremental risk stratification benefit of CCTA findings as compared to coronary artery calcium scores (CACS) in ischemic stroke patients without chest pain., Methods: Among 914 consecutive ischemic stroke patients, 317 (68.5% were male with a mean age of 64 years) who had at least one clinical risk factor for CAD without chest pain were prospectively enrolled to undergo CCTA. CT images were assessed for CAC, presence of CAD and extent of CAD. The primary endpoint was major adverse cardiac events (MACEs) defined as cardiac death, non-fatal myocardial infarction, unstable angina requiring hospitalization, or revascularization after 90 days from index CCTA., Results: The prevalence of CAC ≥1 was 73.1% (232/317) and the average CACS was 346.6 ± 693.5 (Agatston unit). During the median follow-up period of 409 days, there were a total of 26 MACEs. Both CACS [CAC (101-400, and >400)] and CCTA findings [presence of obstructive CAD, 1-vessel disease (VD), 2-VD, and 3-VD] independently stratified risk of future MACEs (all p < 0.05). The time-dependent receiver operating characteristic curve analysis revealed that CAD findings (presence of obstructive CAD and number of involved vessels) based on CCTA improved risk stratification beyond clinical risk factors and CACS (iAUC: 0.863 vs 0.752, p < 0.05)., Conclusion: In ischemic stroke patients without chest pain, CCTA findings of CAD provide additional risk-discrimination over CACS., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

There is little data regarding coronary artery disease (CAD) and/or atherosclerotic plaques on coronary computed tomographic angiography (CCTA) among the elderly and its outcome, especially in asymptomatic patients. Using CCTA, we evaluated the prevalence and extent of CAD and/or atherosclerosis and related outcomes in asymptomatic elderly patients as compared with symptomatic elderly patients. The study included 1,196 consecutive patients aged 70 years or older who underwent CCTA over a 2-year period. Data were retrospectively evaluated for clinical cardiovascular risk factors with co-morbidities, and CCTA findings, including calcium scores, atherosclerotic plaques (number, plaque-segment score, plaque-extent score, and plaque-significant score) and presence of significant CAD. Follow-up data for active management and all-cause mortality after CCTA were collected for 2 years. Two-sided Student's t test for independent samples, Chi square contingency tables, and Kaplan-Meier survival curves were used for statistical analysis. Data for 454 asymptomatic and 742 symptomatic elderly patients were analyzed. The prevalence of significant CAD and the extent of atherosclerotic plaques did not differ between the two groups (all P > 0.05). Asymptomatic patients with significant CAD on CCTA, were less likely to receive active management (P < 0.001), which may be related to the higher death rate in this group (P = 0.012) than in the symptomatic patients with significant CAD. Overall, symptoms were not related to the presence of significant CAD or to the extent of atherosclerosis in these elderly patients. However, all-cause mortality was higher in the asymptomatic patients with significant CAD than in the symptomatic ones.

Purpose: To analyze the effect of automatic tube potential selection with tube current modulation (APSCM) and iterative reconstruction on image quality, diagnostic accuracy, and radiation dose at computed tomographic (CT) angiography and compare it with APSCM-only and body mass index (BMI)-based examination protocols., Materials and Methods: This study was approved by the institutional review board, and informed consent was obtained from all patients. Images from 185 patients who underwent a BMI-based protocol and 197 patients who underwent an APSCM protocol with filtered back projection (FBP) and an APSCM protocol with sinogram-affirmed iterative reconstruction (SAFIRE) were retrospectively evaluated. Diagnostic performance was compared with that of conventional coronary angiography in a subgroup of 51 patients. Statistical analysis was performed by using the independent or paired t test, Mann-Whitney U test, Wilcoxon signed rank test, χ(2) statistics, linear weighted κ statistics, and generalized estimating equation., Results: The APSCM group with SAFIRE had a significant reduction in image noise and a significant increase in CT number, contrast enhancement, signal-to-noise ratio, and contrast-to-noise ratio compared with the APSCM group with FBP (P < .0001) and the BMI-based group (P < .001, except P = .002 for image noise). Image quality and diagnostic accuracy showed no significant difference between the three groups. The use of APSCM resulted in a significant reduction in radiation dose compared with the BMI-based protocol., Conclusion: The combination of SAFIRE and APSCM at coronary CT angiography significantly improves objective image quality while maintaining diagnostic accuracy and reduced radiation dose. Online supplemental material is available for this article., (© RSNA, 2013.)

Background: There have been limited reports on the diagnostic performance and prognostic value of coronary computed tomography angiography (CCTA) for selecting coronary artery bypass graft (CABG) candidates., Methods: There were 1,018 patients with suspected coronary artery disease who underwent 64-slice multidetector CCTA between July 2009 and January 2010. Of them, we excluded 324 patients who denied further treatment (n=7), who were lost for unidentified reasons (n=107), or who were transferred to local clinics (n=210). The total analysis cohort consisted of 694 patients. We established eligible CABG criteria defined as three-vessel disease, left main coronary disease, and left main coronary artery equivalent disease. Diagnostic performance was determined using conventional coronary angiography as the reference standard. For assessment of the prognostic utility of CCTA, electronic medical records were reviewed to screen for the occurrence of a major adverse cardiac event, defined as cardiac death, nonfatal myocardial infarction, or revascularization., Results: The overall sensitivity, specificity, positive predictive value, and negative predictive value of CCTA for the selection of CABG candidates were 83.3%, 96.2%, 90.9%, and 92.7%, respectively. The presence of CABG criteria on CCTA was an independent prognostic factor for predicting a major adverse cardiac event (hazard ratio, 12.508; 95% confidence interval, 7.353 to 21.278; p<0.0001)., Conclusions: We found CCTA had a high diagnostic performance for selecting CABG candidates and predicted major adverse cardiac events in CABG candidates referred for CCTA owing to suspected coronary artery disease., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

To determine the feasibility of dual-source coronary CT angiography (CTA) using a prospectively electrocardiogram (ECG)-triggered axial mode to target end-systole in patients with high heart rates (HR) as compared with the retrospective mode. One hundred fifty consecutive patients with regular HR > 75 bpm who underwent coronary CTA were enrolled; 75 patients underwent prospectively ECG-triggered coronary CTA targeting only end-systole (Prospective Axial Group) and 75 patients underwent retrospectively ECG-gated coronary CTA (Retrospective Helical Group). The image quality of multiple coronary artery segments was evaluated and radiation doses were recorded. The diagnostic performance of coronary CTA was compared to the reference standard of invasive coronary angiography in 52 patients (35 %) (28 patients in Prospective Axial Group and 24 patients in Retrospective Helical Group). Image quality was not significantly different between the 2 groups (P = 0.784). In subgroup analysis, segment-based sensitivity, specificity, and positive and negative predictive values of coronary CTA were 98, 96, 88 and 99 %, respectively, in the Prospective Axial Group and were 97, 95, 82, and 99 %, respectively, in the Retrospective Helical Group. Mean radiation dose was significantly lower for the Prospective Axial Group than for the Retrospective Helical Group (2.9 ± 1.4 vs. 7.4 ± 3.3 mSv; P < 0.0001). Dual source coronary CTA with a prospective ECG-triggered axial mode targeting end-systole is feasible in patients with regular high HRs for evaluation of coronary artery disease. It provides comparable image quality and diagnostic value with substantially lower radiation exposure as compared to the retrospective ECG-gated helical technique.

Aims: The clinical implication of a zero coronary calcium score (CCS) in patients with chest pain syndrome has been under debate. This study was undertaken to determine the meaning of a CCS of zero in a large sample of symptomatic patients referred for coronary computed tomographic (CT) angiography., Methods and Results: We consecutively enrolled 2088 patients (age 58 ± 10 years, 1028 men) who had undergone 64-slice cardiac CT due to chest pain syndrome. A CCS of zero was detected in 1114 patients (471 men and 643 women). Of these 1114 patients, obstructive coronary artery disease (CAD) was found in a total of 48 patients (4.3%); 35 men (7.4%) and 13 women (2.0%). Among the zero CCS patients with obstructive CAD, men had a higher prevalence of both premature CAD (49 vs. 0%) and multivessel disease (20 vs. 8%) than women. During the follow-up period (1033 ± 136 days), early revascularization was done in 25 patients (2.2%, 18 men and 7 women) and there were 14 major adverse cardiac events (1.3%, 8 men and 7 women) among the zero CCS patients. CAD severity was a strong prognostic indicator in the zero CCS patients., Conclusion: A CCS of zero cannot be used by itself to exclude obstructive CAD in symptomatic patients referred for coronary CT angiography (CCTA). The prevalence of obstructive CAD and adverse cardiac events are not negligible in symptomatic patients with a CCS of zero, and CAD severity by CCTA is associated with higher rates of adverse cardiac event.

Background: The use of Automatic Tube Potential Selection with Tube Current Modulation (APSCM) may lower radiation dose, but it is unknown whether image quality is maintained., Objective: The aim of this study was to evaluate the radiation dose and image quality of APSCM application compared with conventional body mass index (BMI)-based examination protocol for coronary computed tomography angiography (CTA)., Methods: Consecutive patients (n = 487) were retrospectively enrolled: 239 patients who underwent coronary CTA with APSCM (APSCM group) and 248 patients who underwent coronary CTA with a BMI-based tube potential (in kV) and tube current-time product (in mAs) protocol (BMI-based group). Comparison of quantitative and qualitative image quality and radiation dose was performed., Results: The use of APSCM found significant reduction in radiation dose compared with the BMI-based protocol, with a significantly more frequent use of 80 kV (P < 0.0001). Diagnostic image quality was maintained, with no significant difference between the 2 groups (P = 0.887)., Conclusion: The use of APSCM for coronary CTA significantly reduced radiation dose while maintaining image quality; therefore, it is feasible in daily practice which covers patients with various BMI values., (Copyright © 2012 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of our study was to investigate the diagnostic accuracy of computed tomographic coronary angiography for the selection of candidates for coronary artery bypass graft surgery., Methods: Institutional review board approval was obtained. We included 172 patients (mean age, 63 years; 127 men and 45 women) with a suspicion of coronary artery disease who underwent both computed tomographic coronary angiography and conventional coronary angiography. We established eligible criteria for coronary artery bypass graft surgery based on American College of Cardiology/American Heart Association practice guidelines: 3-vessel disease, left main coronary artery disease, and left main coronary artery equivalent disease. Results of computed tomographic coronary angiography and conventional coronary angiography were reviewed retrospectively by 2 radiologists and 2 cardiologists who were unaware of the other examiners' findings. Diagnostic performances of computed tomographic coronary angiography were calculated, with conventional coronary angiography as the reference standard., Results: The overall sensitivity, specificity, positive predictive value, and negative predictive value of computed tomographic coronary angiography for the selection of coronary artery bypass graft surgery candidates were 85.9%, 96.0%, 93.8%, and 90.7%, respectively. We also obtained high diagnostic performances for 3-vessel disease (sensitivity, 83.1%; specificity, 96.5%; positive predictive value, 92.5%; negative predictive value, 91.6%), left main coronary artery disease (sensitivity, 94.7%; specificity, 96.7%; positive predictive value, 78.3%; negative predictive value, 99.3%), and left main coronary artery equivalent disease (sensitivity, 100%; specificity, 100%; positive predictive value, 100%; negative predictive value, 100%)., Conclusions: Patients selected as candidates for coronary artery bypass graft surgery with conventional coronary angiography can also be relatively accurately classified by using computed tomographic coronary angiography with 64-slice multidetector computed tomography., (Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: The objective of this study was to evaluate the accuracy of coronary artery calcium scanning in identifying coronary anomalies and potentially high-risk interarterial courses., Materials and Methods: Ninety-five consecutive patients who were diagnosed with a coronary anomaly on CT coronary angiography were enrolled, and 95 age- and sex-matched individuals in whom any coronary anomalies were excluded on CT coronary angiography were used as control subjects (total, 190 patients; 106 men and 84 women; mean age, 58 +/- 12 years). The coronary artery calcium scan for each patient was retrospectively evaluated by three radiologists for the presence of coronary anomalies and the presence of an interarterial course in cases of suspected anomaly. Interobserver agreement was assessed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a coronary artery calcium scan for coronary anomalies and their interarterial courses were calculated, with CT coronary angiography as the reference standard., Results: Almost perfect interobserver agreement was achieved in evaluating coronary anomalies and interarterial courses (kappa = 0.81 and 0.92, respectively). We achieved a high grade of diagnostic performance of coronary artery calcium scanning in detecting coronary anomalies (sensitivity, 79-80%; specificity, 95-98%; PPV, 94-97%; and NPV, 82-83%) and interarterial courses (sensitivity, 88-91%; specificity, 95-97%; PPV, 84-91%; and NPV, 97%)., Conclusion: Coronary anomalies and interarterial courses were detected with great accuracy on coronary artery calcium scans.

Background: The ability of 64-slice computed tomography (CT) angiography to differentiate plaque types remains unclear. We evaluated whether the density of noncalcified coronary plaques by 64-slice CT angiography correlates with plaque components assessed by integrated backscatter intravascular ultrasound (IB-IVUS)., Methods: Eighty-six patients [stable angina/acute coronary syndrome (ACS) 67/19, mean age 62+/-11 years] who showed significant coronary artery stenosis (> or =50% diameter stenosis) by 64-slice CT angiography underwent coronary angiography and were evaluated using IB-IVUS., Results: A total of 92 noncalcified coronary plaques on CT angiography were evaluated with IB-IVUS. There was a positive correlation between CT density and calcified tissue content (r=0.41, P<0.001). However, the CT density of plaques did not correlate with other tissue components. Patients with ACS showed more lipid (43.1+/-13.2 vs. 35.8+/-13.5, P=0.03) and less soft fibrous tissue (50.5+/-11.7 vs. 56.5+/-12.0, P=0.05) by IB-IVUS than those with stable angina. However, the mean CT density of plaques in ACS was not different from that in stable angina (140.6+/-88.5 vs. 113.1+/-80.9, P=0.19)., Conclusion: Except for calcified tissue, CT angiography failed to differentiate plaque types of noncalcified tissue. Therefore, the role of 64-slice CT angiography in identifying lipid-rich plaques remains limited.

Purpose: To determine factors affecting the ability of 64-multislice computed tomography (MSCT) to detect, assess, and accurately diagnose significant coronary arterial in-stent restenosis (ISR)., Materials and Methods: The institutional review board approved this study and waived informed consent. Sixty patients underwent CT coronary angiography using 64-MSCT, after implantation of coronary artery stents (n=91). We assessed diagnostic accuracy for ISR with CT in comparison with conventional coronary angiography as the gold standard, visually and with measurement of in-stent coronary lumen density. Possible factors that influenced the diagnostic performance of CT were evaluated, which included image quality (IQ), stent characteristics, and location., Results: Sixty-nine stents (75.8%) were assessable. Low IQ, location in the left circumflex coronary artery, and narrow stent diameter were associated with poor assessment (P<0.05). In stents that could be assessed, sensitivity, specificity, positive predictive value, and negative predictive value of 64-MSCT were 90.0%, 73.5%, 58.1%, and 94.7%, respectively, for significant ISR. The diagnostic accuracy in assessable stents showed a significant increase with better IQ, thinner strut thickness, and nondrug eluting stent. False-positive diagnoses of ISR by CT were explained by coronary lumen density measurements., Conclusions: Evaluation of stents by 64-MSCT is not recommended in stents with diameters of < or = 2.75 mm or stents located at the left circumflex coronary artery. The diagnostic accuracy of 64-MSCT is affected by IQ and strut thickness in assessable stents. Significant ISR can be excluded with high reliability in selected patients.

Purpose: The aim of this study was to determine the diagnostic accuracy of 64-slice computed tomography (CT) coronary angiography in the quantification and characterization of obstructive coronary plaques in comparison with intravascular ultrasound (IVUS)., Materials and Methods: Thirty-nine patients were selected who underwent both CT coronary angiography (CTCA) and IVUS. For each stenotic site (n = 61), the maximum vessel cross-sectional area, lumen cross-sectional area, plaque area, and percentage of luminal obstruction were measured. Plaque composition was analyzed according to IVUS (plaque echogenicity and classified into several types: calcified, mixed, fibrous, and soft plaques) and CTCA criteria (Hounsfield units [HU]). The correlation between CTCA and IVUS measurements was determined using Pearson correlation coefficient. The statistical significance of differences in the CT densities of plaques among plaque types determined by IVUS was assessed using the Scheffe method., Results: The correlation coefficients for the measurements of the lumen, vessel, plaque area, and percentage of luminal obstruction were r = 0.712, r = 0.654, r = 0.753, and r = 0.799, respectively. The mean CT density values for soft (n = 10), fibrous (n = 11), mixed (n = 31), and calcified plaques (n = 9) were 54 +/- 13 HU, 82 +/- 17 HU, 162 +/- 57 HU, and 392 +/- 155 HU, respectively. Computed tomography density measurements were not significantly different between soft and fibrous plaques (P = 0.224)., Conclusions: Sixty-four-slice CTCA is a noninvasive modality that allows quantification of coronary artery plaques. However, reliable classification of noncalcified plaques as vulnerable or stable plaques based on CT density measurements is currently limited.

Objective: We sought to systemically analyze the characteristics of fat accumulation in patients with myocardial infarction (MI) relative to various clinical parameters., Materials and Methods: We included 161 patients (129 men, 32 women; mean age, 60.7 years) who had previously been diagnosed with MI and had undergone CT coronary angiography between February 2003 and April 2005. We analyzed the characteristics of myocardial fat, if present, and compared the clinical parameters of the patients with and those without myocardial fat., Results: Myocardial fat was found in the subendocardial region in 36 (22.4%) patients with MI. In all cases, the myocardial fat was located in the subendocardial region and was typically detected in the left anterior descending artery territory (75%, n = 27). The mean attenuation value of myocardial fat was -29.6 HU on unenhanced CT. Myocardial fat was more frequently associated with a greater infarct age, milder coronary artery stenosis, and fewer number of diseased vessels. Patients with myocardial fat had more severe regional wall motion abnormalities on follow-up echocardiography. Age, sex, the presence of ST elevation or Q wave, elevated levels of cardiac enzymes, ejection fraction, and end-diastolic left ventricular dimension on follow-up echocardiography, as well as the presence of arrhythmia, were not significantly different between the two groups., Conclusion: Myocardial fat was detected in 22.4% of MI patients and was more frequently associated with a longer postinfarct period, milder coronary artery stenosis, fewer number of diseased vessels, and more severe regional wall motion abnormalities.

Purpose: To assess the diagnostic performance of 64-section cardiac computed tomographic (CT) angiography for detection of left atrial appendage (LAA) thrombi in stroke patients by using transesophageal echocardiography (TEE) as the reference standard., Materials and Methods: This study was approved by the institutional review board. Records were reviewed from 101 consecutive patients who had experienced a recent stroke (onset within the previous 1 month) from a suspected cardioembolic source and who had undergone both 64-section cardiac CT angiography and TEE within 1 week. The numbers of thrombi in the LAA detected with cardiac CT angiography and with TEE were recorded, and the agreement between thrombus detection with CT and with TEE was assessed by using kappa statistics., Results: Eight thrombi in the LAA were detected with TEE, and 12 were detected with cardiac CT angiography. With TEE used as the reference standard, the overall sensitivity, specificity, and accuracy of 64-section cardiac CT angiography for detecting thrombi were 100% (95% confidence interval [CI]): 63%, 100%), 95% (95% CI: 90%, 99%), and 96% (95% CI: 92%, 100%), respectively. The concordance between LAA thrombus detection with 64-section cardiac CT angiography and with TEE was high: 89 patients with no thrombus at CT or TEE; eight patients with thrombus at both CT and TEE; and four patients with thrombus at CT but not at TEE (overall kappa = 0.779 [95% CI: 0.571, 0.987])., Conclusion: Sixty-four-section cardiac CT angiography is a noninvasive and sensitive modality for detecting thrombi in the LAA of stroke patients. Although TEE is currently considered the reference standard modality for detecting LAA thrombi, 64-section cardiac CT angiography has the potential to become a useful modality for detection of intracardiac thrombus., ((c) RSNA, 2008.)

Objective: To determine differential findings of patent foramen ovales (PFOs) and atrial septal defects (ASDs) demonstrating interatrial shunting on coronary computed tomography (CT) angiography., Methods: We retrospectively analyzed 15 cases of patients demonstrating a contrast jet from the left to the right atrium on CT and interatrial shunting on echocardiography. According to the echocardiography results, patients were divided into PFO (n = 10) or ASD (n = 5) groups. The contrast jet direction and atrial septum appearance on CT were compared between the 2 groups., Results: The PFO group had a contrast jet flowing toward the inferior vena cava, and the atrial septum appeared channel-like. The ASD group had a contrast jet flowing perpendicular to the atrial septum in all but one of the patients, and the atrial septum appeared as a membrane with a hole., Conclusions: Atrial septal defects and PFOs can be differentiated using the characteristic direction of the contrast jet from the left to right atrium and the appearance of the atrial septum on coronary CT angiography.

We present a case of an anomalous origin of the left circumflex coronary artery from the right coronary sinus passing between the pulmonary artery and the aorta (interarterial course) diagnosed by multidetector row computed tomography.

To determine if cytomegalovirus (CMV) infection is a risk factor for primary coronary artery disease (CAD), the association between CMV infection and CAD (>50% blockage in any coronary artery) was investigated in nearly 900 successive nontransplant patients undergoing coronary angiography. By use of logistic regression, older age (P <.001), white race (P <.001), gender (P <.001), hypercholesterolemia (P = .04), and other established cardiovascular risk factors (P = .003) were identified as significantly associated with CAD, but CMV seropositivity (P = .462), the level of IgG antibodies to CMV whole cell antigen (P = .98), or the levels of IgG antibodies to CMV glycoprotein B (P = .67) were not. These data suggest that CMV infection is not a major risk factor for the development of primary CAD in adults.