Dual-energy computed tomography for detection of coronary artery disease

Recent technological advances in computed tomography (CT) technology have fulfilled the prerequisites for the cardiac application of dual-energy CT (DECT) imaging. By exploiting the unique characteristics of materials when exposed to two different x-ray energies, DECT holds great promise for the diagnosis and management of coronary artery disease. It allows for the assessment of myocardial perfusion to discern the hemodynamic significance of coronary disease and possesses high accuracy for the detection and characterization of coronary plaques, while facilitating reductions in radiation dose. As such, DECT enabled cardiac CT to advance beyond the mere detection of coronary stenosis expanding its role in the evaluation and management of coronary atherosclerosis.     

Quantitative analysis of coronary artery calcinosis: comparative informative value of multispiral computed tomography and electron-beam tomography

AIM: To compare informative value (IV) of electron-beam tomography (EBT) and multispiral computed tomography (MSCT) in the assay of coronary artery calcinosis with participation of one group of patients. MATERIAL AND METHODS: EBT and MSCT were conducted in 210 patients whose mean age was 60.6+/-7.7years (67% males, mean age 60.2+/-7.6 years; 33% females, mean age 61.5+/-8.3 years) with a verified diagnosis of ischemic heart disease (IHD). RESULTS: 185 patients had calcium index (CI) from 21 to 2636 units. EBT and MSCT have not detected coronary artery calcinates in 34 patients. In one patient CI was 2 units by EBT and 0 units by MSCT. Mean CI by EBT was 499.4+/-598.2 units, by MSCT--533.7 +/-594.9 units (p = 0.8). The correlation coefficient between IV of the two methods was 0.976 (p < 0.0001). Mean difference between CI by both methods was 34.3 +/-133.6, variation coefficient 22%. There were differences between compatibility of CI in groups of patients with different CI, correlation and variation coefficients in dividing the patients into the subgroups depending on CI. In CI equal to 0-99 units EBT and MSCT correlation coefficient made up 0. 72, coefficient of variation 66%, in CI being 100-399 units these were 0.81 and 27%, in CI of 400-1000 units--0.85 and 16%, in CI exceeding 1000 units--0.95 and 0.4%, respectively. CONCLUSION. High IV correlation was found of MSCT and EBT for coronary artery calcinosis assay. Compatability of the MSCT and EBT data depends on CI     

Toward the automatic detection of coronary artery calcification in non-contrast computed tomography data

Measurements related to coronary artery calcification (CAC) offer significant predictive value for coronary artery disease (CAD). In current medical practice CAC scoring is a labor-intensive task. The objective of this paper is the development and evaluation of a family of coronary artery region (CAR) models applied to the detection of CACs in coronary artery zones and sections. Thirty patients underwent non-contrast electron-beam computed tomography scanning. Coronary artery trajectory points as presented in the University of Houston heart-centered coordinate system were utilized to construct the CAR models which automatically detect coronary artery zones and sections. On a per-patient and per-zone basis the proposed CAR models detected CACs with a sensitivity, specificity and accuracy of 85.56 (±15.80)%, 93.54 (±1.98)%, and 85.27 (±14.67)%, respectively while the corresponding values in the zones and segments based case were 77.94 (±7.78)%, 96.57 (±4.90)%, and 73.58 (±8.96)%, respectively. The results of this study suggest that the family of CAR models provide an effective method to detect different regions of the coronaries. Further, the CAR classifiers are able to detect CACs with a mean sensitivity and specificity of 86.33 and 93.78%, respectively.     

冠状动脉计算机断层扫描血管造影价值的认识

自1995年首次报道用增强计算机断层扫描血管造影(CTA)进行无创性冠状动脉(冠脉)病变检测以来,CTA已成为诊断冠心病常用的无创性方法[1]。近年来,随着心电图门控多排螺旋CTA的广泛应用,特别是64排或以上的CT硬件系统发     

Efficacy of computer aided analysis in detection of significant coronary artery stenosis in cardiac using dual source computed tomography

Objective To analyze the diagnostic efficacy of computer aided analysis of relevant coronary artery stenosis using dual source computed tomography (DSCT). Methods In a larger scale study patients scheduled for conventional coronary angiography (CA) were additionally examined with DSCT. Based on a 13-segment model 30 CT scans of this study population were analyzed for significant stenosis using conventional 3D charts (3D) as well as a specialized cardiac analysis tool (CAT). Diagnostic accuracy and time to diagnosis was recorded for each vessel separately as well as the three readers’ confidence. Results With severe coronary artery calcifications, 53 false interpretations of segments were found for the total of 390 coronary segments analyzed. 3D and CAT analysis showed a Sensitivity, Specificity, PPV and NPV of 0.59, 0.91, 0.57, 0.92 and 0.57, 0.92, 0.56, 0.92, respectively. No significant differences in diagnostic accuracy could be found between 3D and CAT (P = 0.1667). 3D took a mean of 5.2 min (3–10 min). With CAT a mean time of 8.2 min (4–12 min) was needed. No significant inter-reader time differences (P = 0.4954) and no significant confidence level differences were found between readers and analyzes. Conclusion CAT of the coronary tree shows comparable accuracy to manual 3D analysis but needs improvements concerning coronary tree segmentation times.     

Comparison of planar imaging and single-photon emission computed tomography for the detection and localization of coronary artery disease

Although single photon emission computed tomography (SPECT) has become widely utilized, the superiority of this technique compared to planar conventional imaging remains controversial. In order to compare these two techniques, we retrospectively analysed the results obtained in 70 patients who performed a thallium-201 exercise scintigraphy with a double acquisition during the same test, and who also underwent coronary and ventricular angiography. Overall, SPECT imaging yielded a higher sensitivity (93% vs 82% for SPECT and planar imaging respectively, p<0.05), especially in the inferior and anterior regions. SPECT was also more sensitive for the detection of a single-vessel disease (90% vs 74% for SPECT and planar imaging respectively, p<0.01). The specificity was assessed for both techniques with the help of circumferential computerized analysis, avoiding known causes of false positive scintigrams. We found a high specificity for both SPECT and planar imaging, without any significant difference between the two methods (87% vs 91% for the overall specificity of SPECT and planar imaging respectively, p=NS). Therefore, SPECT imaging analysed with discrimination shows an enhanced reliability over planar imaging for the detection and the localization of coronary artery disease, without increasing the risk of false positive tests.     

Cost-effective applications of cardiac computed tomography in coronary artery disease

Computed tomography has been introduced as a noninvasive imaging modality used for coronary artery calcium scoring in asymptomatic individuals and contrast-enhanced coronary angiography in symptomatic individuals. As the rising costs of healthcare reflect, in part, the development of these types of new expensive technologies for cardiac diagnosis, the economic considerations that surround them should be of interest to clinicians and payers alike. In this review, we discuss basic principles underlying economic efficiency analyses of medical products, using computed tomography in coronary artery disease as a case in point.     

The role of 64-slice multi-detector computed tomography in the detection of subclinical atherosclerosis of the coronary artery

Multi-detector computed tomography (MDCT) has been used for detecting or excluding coronary atherosclerotic stenosis in symptomatic patients. However, the role of MDCT for routine medical examination in asymptomatic, high-risk patients has not been established. We therefore conducted the present study to test the hypothesis that MDCT could be a valuable method for detecting subclinical coronary artery stenosis in asymptomatic patients. An observational, retrospective, single-centre study was conducted with a cohort of 1,529 patients (mean age, 56.4 ± 8.3 years; 1,353 males) who had undergone MDCT as part of their general medical checkups from November 2005 to April 2008. The patients who had a past history of coronary artery disease, typical chest pain, or evidence of myocardial ischemia were excluded. During clinical follow up of these patients, the incidence of subclinical coronary stenosis and the usefulness of MDCT for routine medical examination in asymptomatic patients were investigated. Of the 1,529 enrolled patients, 42.3% had hypertension, 13.5% had diabetes mellitus, 7.7% had hyperlipidemia, and 40.4% were current smokers. Abnormal MDCT findings were noted in 560 (36.6%) patients, who were classified into two groups. One group had the presence coronary calcium with a luminal diameter stenosis of the coronary artery of <50% (n = 508, 33.2%). These patients were treated with medication or clinical follow-up. The other group had a luminal diameter stenosis of the coronary artery of ≥50% with the presence or absence of coronary calcium (n = 52, 3.4%). These patients underwent a conventional coronary angiogram and intravascular ultrasound. A total of 29 of the 1,529 patients (1.9%) presented with insignificant stenosis or myocardial bridge, and 23 patients (1.5%) presented with significant stenosis. The patients with significant stenosis underwent percutaneous coronary intervention (PCI) with stent implantation. Major adverse cardiac events occurred in only 2 patients who had been treated with PCI during a mean follow-up period of 387 ± 253 days. The incidence of significant subclinical coronary stenosis as detected by MDCT in a general medical check-up was 3.4%, and the false-positive rate of MDCT for detecting significant coronary artery stenosis was 55.8% (29/52). 64-Slice MDCT can be a useful tool for noninvasive evaluation of coronary arteries in asymptomatic patients. Further study is needed to clarify the clinical implications of MDCT in general medical check-ups.     

64层螺旋CT对冠状动脉狭窄的评价

目的评价64层多层螺旋CT(MSCT)对冠状动脉狭窄显示的准确性、可靠性。方法收集32例临床怀疑冠心病的患者行64层MSCT冠状动脉成像检查,同期行冠状动脉血管造影(CAG),对两种方法评价的结果进行对照研究。结果 64层MSCT可评估率为91.53%。与SCA对照分析,评价冠状动脉狭窄的敏感性、特异性、阳性预测值以及阴性预测值分别为98.94%、98.59%、95.88%、99.64%。结论 64层MSCT对诊断冠状动脉狭窄的具有很高的应用价值,可无创性的评估冠脉血管状况。     

Functional assessment of coronary artery disease by cardiac computed tomography

Introduction: Rapid technological advances in computed tomography (CT) have allowed CT coronary angiography (CTCA) to be delivered at low radiation dose and high diagnostic accuracy. Due to its high negative predictive value for coronary artery disease, it has become a gatekeeper for the assessment of patients with chest pain of recent onset. Second line functional assessment of a detected coronary stenosis relies mostly on other imaging modalities. Functional assessment of coronary artery disease by CT is therefore an attractive addition to CTCA.

Areas covered: This review will discuss the current evidence base and future development for CT perfusion imaging. Furthermore, this review will discuss CT-derived fractional flow reserve and CT coronary plaque characteristics as alternative approaches for functional evaluation of coronary artery disease. Finally, combining coronary anatomy and functional assessment of coronary flow with myocardial tissue characterization by CT may be attractive allowing triple assessment by CT.

Expert commentary: The combined use of CTCA and functional assessment of coronary artery stenosis by CT perfusion or CT-derived fractional flow reserve is an attractive diagnostic pathway that requires further evaluation.     

多层螺旋CT冠状动脉成像的临床应用

近年，随着多层螺旋CT(muhislice spiral computed tomography，MSCT)的问世，尤其16层螺旋CT冠状动脉(冠脉)成像技术在临床上的应用，已可逐渐替代传统的插管法冠脉造影以诊断冠脉病变。     

多层螺旋CT血管成像诊断冠状动脉瘘

目的 评价冠状动脉瘘(CAF)的多层螺旋CT血管造影(MDCTA)特点及其诊断价值。方法 回顾性分析21例接受回顾性心电门控冠状动脉MDCTA的CAF患者影像资料,经VR、MPR、MIP、CPR后确定诊断。结果 ①瘘支动脉中,单一瘘管12例,其中起自右冠状动脉4例、左冠状动脉8例;多发瘘管9例;16例瘘口引流至肺动脉、2例至右心房,2例至左心室、1例至左心房;②瘘支动脉表现为扩张、纡曲或仅为血管丛状,2例合并动脉瘤,合并心包积液、左心室室壁瘤各1例,均未合并心内畸形;③3例失访,1例死亡,17例经超声心动图检查,5例漏诊;17例经冠状动脉造影证实,7例接受手术治疗。结论 MDCTA可无创而准确地显示CAF 起源、行程、引流部位及合并异常。     

冠状动脉CT血管造影对先天性右冠状动脉缺如的评价价值

目的总结先天性右冠状动脉缺如患者的临床和冠状动脉CT血管造影（CCTA）影像表现。方法回顾性分析2014年1月~2019年6月于本院行CCTA检查并经选择性冠状动脉造影（SCA）确诊的13例先天性右冠状动脉缺如患者的临床资料和CCTA影像表现。结果13例先天性右冠状动脉缺如患者的临床表现缺乏特异性,大多表现为心血管疾病的临床症状。CCTA平扫显示左主干、左前降支和（或）左回旋支走行区内数量不等、形态各异的高密度钙化斑块形成;增强扫描显示左主干、左前降支和（或）左回旋支不同程度变窄,升主动脉和右冠状窦区均未见右冠状动脉发出,左主干、左前降支和左回旋支均不同程度增粗,并左回旋支延伸至右心室背面,进而发出分支供应右心房和右心室。CCTA与SCA表现基本一致。结论先天性右冠状动脉缺如罕见,其临床表现缺乏特异性,仅凭临床表现往往难以诊断,CCTA联合SCA检查常可用于确诊。     

多层螺旋CT冠状动脉成像在急性冠脉综合征的应用价值

目的 评价多层螺旋CT(MSCT)冠状动脉成像在急性冠脉综合征的应用价值.方法 对40例临床诊断为ACS患者行MSCT 冠状动脉成像.结果 MSCT 冠状动脉成像能清楚显示冠状动脉斑块形成及血管狭窄.结论 MSCT冠状动脉成像能较好的评价冠状动脉病变血管的狭窄程度以及斑块的性质,并可作为冠脉病变介入治疗的筛选.     

Multislice computed tomography for determination of coronary artery disease in a symptomatic patient population

Background Multislice computed tomography (MSCT) has started to replace Electron beam CT for quantitation of coronary artery calcium. However no study has evaluated the diagnostic accuracy of MSCT for prediction of coronary artery disease (CAD) in a symptomatic patient population using the volume score. Methods and Results 1347 symptomatic subjects (male = 803, mean age = 62 years) with suspected CAD underwent MSCT studies 1 ± 2 days before the coronary angiogram. The Agatston (ACS) and Volumetric calcium score (VCS) were calculated using a proprietary workstation. Statistical analyses included the Pearson’s correlation coefficient and the nonparametric Mann–Whitney U-test to compare the calcium score in different age groups and between men and women. Sensitivity, specificity and predictive accuracy were calculated for different calcium thresholds for prediction of CAD. ROC curve analyses were used to establish relations between the coronary calcium score and presence or absence of CAD. In 720 (53%) subjects (male = 419) angiography revealed a minimal lumen diameter stenosis greater than 50%. Patients with significant CAD had significantly higher total calcium score values than patients without CAD (P = 0.001). ACS and VCS demonstrate a close correlation for the whole study group, r = 0.99. The overall sensitivity of any calcium to predict stenosis was 99%, specificity = 32%. Exclusion of calcium was highly accurate for exclusion of CAD in subjects older than 50 years (predictive accuracy = 98%). An absolute cutoff >100 and an age and sex specific threshold (score over 75th percentile) were identified as the cutoff levels with the highest sensitivities (86–89%) and lowest false positive rates (20–22%). ROC analyses revealed MSCT calcium scanning as a good clinical test which can be performed with similar accuracy in all age groups with an area under the curve of 0.84. Conclusion Determination of coronary calcium with MSCT is an accurate imaging modality for prediction of significant CAD in a patient population with intermediate likelihood of CAD. Exclusion of any calcium provided strong evidence that patients older than 50 years did not have obstructive CAD. ACS and VCS show an equivalent diagnostic accuracy.     

Value of coronary artery calcium scanning by computed tomography for predicting coronary heart disease in diabetic subjects

OBJECTIVE: The South Bay Heart Watch is a cohort study designed to determine the significance of coronary calcium in high-risk asymptomatic patients. This is a report of the relative risk (RR) for outcomes of coronary artery calcium in diabetic and nondiabetic subjects. RESEARCH DESIGN AND METHODS: A total of 1312 diabetic and nondiabetic subjects underwent risk factor screening and computed tomography testing for coronary calcium at baseline and were followed clinically for 6.3 +/- 1.4 years. End points were either 1). hard events of nonfatal myocardial infarction (MI) or coronary death or 2). any cardiovascular event (nonfatal MI, coronary death, coronary revascularization, or stroke). RESULTS: The incidence rates of a hard event and any cardiovascular event for diabetic and nondiabetic subjects were 14.5 and 6.1% and 23.8 and 12.2%, respectively (P < 0.001). Cox regression analyses of the combined risk relationship of diabetes status and calcium score demonstrated that relative to nondiabetic subjects with low calcium scores (<2.8), diabetic subjects with calcium scores >or=2.8 exhibited at least a fourfold increase in the risk of either a hard or any cardiovascular event (P < 0.001). Cox regression analyses conducted separately for nondiabetic and diabetic subjects revealed that coronary calcium score risk groups were significantly associated with events in nondiabetic subjects (RR >or= 2.6, P 0.05). CONCLUSIONS: The risk of coronary heart disease increases with increasing calcium scores and diabetes status. Calcium scores have less prognostic value in diabetic subjects.