Non-invasive coronary angiography using multislice computed tomography

Non-invasive methods for detection of coronary atherosclerosis have been limited to indirect markers, such as myocardial perfusion or wall motion during exercise or pharmacological stress. However, advances in multislice computed tomography (MSCT) not allow sufficient spatial resolution for direct non-invasive imaging of the coronary arteries. This review focuses on imaging techniques and clinical applications of MSCT in human studies. Published studies of the diagnostic accuracy of MSCT in native coronary arteries and bypass grafts indicate excellent sensitivity and specificity for detection of 50% diameter stenosis. MSCT is particularly good for evaluating the origin and course of anomalous coronary arteries. MSCT offers the ability to visualise both the lumen and wall of artery, as well as to quantify coronary classification. Further technical developments promise to render MSCT the ideal non-invasive tool for direct visualisation of the coronary arteries.     

Spiral multislice computed tomography coronary angiography: a current status report

Multislice computed tomography coronary angiography (MSCT-CA) has emerged as a powerful noninvasive diagnostic modality to visualize the coronary arteries and to detect significant coronary stenoses. The latest generation 64-slice computed tomography (CT) scanners is a robust technique which allows high-resolution, isotropic, nearly motion-free coronary imaging. Coronary stenoses are detected with high sensitivity and a normal scan accurately rules out the presence of a coronary stenosis. With the introduction of further novel concepts in CT-technology one may expect that MSCT-CA will become a clinically used diagnostic tool.     

多层螺旋计算机断层扫描血管造影对冠状动脉易损斑块的检测作用

目的 评价多层螺旋计算机断层扫描（computed tomography,CT）血管造影（multislice computed tomography angiography,MSCTA）检测冠状动脉易损斑块的可靠性,建立急性冠脉综合征积分（score system of acute coronary syndromes,SACS）,用于评估冠状动脉粥样硬化性心脏病（冠心病）患者危险分层.方法 研究20例非急性冠脉综合征及41例急性冠脉综合征且冠状动脉MSCTA发现斑块的患者,比较两组斑块CT值、重构指数（RI）等指标,进而构建急性冠脉综合征发病风险预测模型.结果 两组病变血管99支,可分析斑块1 17个,非急性冠脉综合征组36个,以钙化斑块为主（88.9％,32/36）;急性冠脉综合征组81个,以脂质斑块为主（37.0％,30/81）.两组正性重构比例比较,差异有统计学意义（61.1％ vs.32.1％,P＜0.01）;负性重构比例比较,差异有统计学意义（25.0％vs.19.8％,P＜0.01）.由RI建立SACS,所得模型为：SACS=0.003PA＋2.255RI-4.22,预测准确率为76.9％（P＜0.01）,受试者工作曲线下面积为0.815（P＜0.01）.结论 急性冠脉综合征患者冠状动脉斑块多为脂质斑块,以正性重构为主,SACS对急性冠脉综合征发病具有较高的预测价值,有助于临床指导冠心病危险分层及早期干预.     

Standard versus user-interactive assessment of significant coronary stenoses with multislice computed tomography coronary angiography

Forty-four patients in sinus rhythm with suspected coronary artery disease underwent 16-row multislice computed tomography coronary angiography and conventional coronary angiography. Two protocols for image analysis were applied to the multislice computed tomographic images: standard projections versus interactive postprocessing. The diagnostic accuracy of both methods for the detection of significant lesions (>50% lumen reduction) was compared with quantitative coronary angiography. Sensitivity and specificity were 58% and 96% and 96% and 97%, for standard projections and interactive postprocessing protocol, respectively.     

The chance finding at multislice computed tomography coronary angiography of myocardial bridging

Myocardial bridging is present when a segment of a major epicardial coronary artery, the ‘tunnelled artery’, runs intramurally through the myocardium. With each systole, the coronary artery is compressed. The pathophysiology of myocardial bridging is incompletely understood. With each systole, the coronary artery is compressed. Moreover, intravascular ultrasound analysis revealed a delayed relaxation after systolic compression, which may extend significantly into diastole. This explains both the impaired coronary flow reserve and ischemia. Evidence indicates that the intima beneath the bridge is protected from atherosclerosis, and the proximal segment is more susceptible to the development of atherosclerotic lesions because of haemodynamic disturbances. Myocardial bridging is sometimes associated with overt pathology, as well as it can just be an incidental finding without any significance. Myocardial bridging may cause angina pectoris, myocardial infarction, life threatening arrhythmias and even sudden cardiac death but most of them are harmless. Furthermore depressed left ventricular function, myocardial stunning, early death after cardiac transplantation has been also reported. Although the exact management is not well known, beta blockers seem to be the first choice. Stenting is controversial and one must think “twice” before stenting the bridged coronary artery. We report a case of chance finding at multislice computed tomography coronary angiography of two myocardial bridging. Also this case focuses attention on myocardial bridging and it confirms that multislice computed tomography coronary angiography technology represents a useful, noninvasive imaging method of its assessment.     

Comparison of radiation doses from multislice computed tomography coronary angiography and conventional diagnostic angiography.

OBJECTIVES: The aim of this study was to quantify and compare effective doses from conventional angiography and multislice computed tomography (MSCT) coronary angiography using a 16-slice scanner. BACKGROUND: Multislice computed tomography is now a viable modality for cardiac imaging. However, for any diagnostic use of ionizing radiation, the risk to the patient must be considered and justified. METHODS: Multislice computed tomography angiography and conventional angiography were used to assess 180 patients with suspected coronary artery disease. Estimates of effective dose were derived from exposure data recorded for each patient examination. For each modality, a comparable calculation technique was used, based on Monte Carlo modeling of the standard Cristy phantom. RESULTS: In a subset of 91 directly comparable patients the mean effective dose for MSCT coronary angiography was 14.7 mSv (SD 2.2) and that for conventional angiography was 5.6 mSv (SD 3.6). A significant difference in effective dose was seen between the two protocols. CONCLUSIONS: The mean effective dose for MSCT coronary angiography was significantly higher than that for conventional angiography. As MSCT cardiac scanners become increasingly available, operators must be aware of the radiation dose and the factors that affect it.     

Application of multislice computed tomography coronary angiography for the diagnostic work-up of acute coronary syndromes

No previous study has examined the association of clinical variables and QTc interval dispersion in patients with Chagas-Hypertensive cardiomyopathy. Sixty-four patients with Chagas-Hypertensive cardiomyopathy were entered for the study. Seventy-one chronic Chagas' disease heart failure patients and 68 patients with Hypertensive cardiomyopathy heart failure were used in the comparison of QTc interval dispersion. The QTc interval dispersion was defined as the difference between maximum and minimum QTc. Median QTc interval dispersion was 75 (55) ms in patients with Chagas' cardiomyopathy, (56) 73 ms in patients with Hypertensive cardiomyopathy, and (87.3) 98 ms in patients with Chagas-Hypertensive cardiomyopathy (p>0.05). In patients with Chagas-Hypertensive cardiomyopathy, median QTc interval was (134) 100 ms in survivors and (87) 96 ms in nonsurvivors (p>0.05). Thus, QTc interval dispersion values in patients with Chagas-Hypertensive cardiomyopathy are not associated with mortality and similar to those found in patients with Chagas' cardiomyopathy and in patients with Hypertensive cardiomyopathy.     

Non-invasive multislice computed tomography coronary angiography for imaging coronary arteries, stents and bypass grafts

Abstract Multislice computed tomography (MSCT) is evolving rapidly and available data suggest that MSCT coronary angiography may be a reliable and accurate non-invasive imaging modality of coronary arteries. Current generations of MSCT scanners have high sensitivity and specificity for diagnosing native coronary artery disease and coronary bypass graft occlusion. The performance of MSCT in the evaluation of stent patency is still being assessed. In comparison with conventional selective coronary angiography (SCA), MSCT is non-invasive, cheaper and it has the advantages of imaging plaque compositions as well as assessment of luminal patency. Nevertheless, the role of MSCT in the management of coronary artery disease is yet to be fully defined.     

A unique case of anomalous coronary origin detected by 64-row multislice computed tomography coronary angiography

The anomalous origin of the left coronary artery from the right sinus of valsalva is an anatomical abnormality that is usually associated with myocardial ischaemia and sudden death. We report on a case in which three different diagnostic techniques were used to find the cause of the ischaemic symptoms in a patient whose left coronary artery originated anomalously in the right sinus of valsalva and followed a course between the aorta and the pulmonary trunk. The techniques were treadmill exercise test for ischaemia, conventional angiography, which was used for the initial diagnosis, and 64-row multislice computerised tomography, used to determine the anomalous course of the artery.