Achenbach Stephan, Daniel Werner G
Department of Medicine 2, University Hospital Erlangen, Germany.
Herz. 2007 Mar;32(2):97-107. doi: 10.1007/s00059-007-2961-8.
The introduction of recent generations of multidetector computed tomography scanners has brought about substantial improvements in spatial and especially temporal resolution which have made imaging of the heart and, under certain conditions, visualization of the coronary arteries possible. Non-enhanced scans allow visualization of cardiac and coronary artery calcification. After intravenous injection of contrast agent, it is possible to visualize cardiac chambers and to analyze the coronary artery lumen. Morphological imaging of the heart, for example in the context of congenital heart disease, is possible by computed tomography (CT) and can, in some very selected cases, be clinically useful as an adjunct to echocardiography or magnetic resonance imaging. Functional imaging allows to analyze left and right ventricular function by CT.CT plays a more prominent clinical role in the context of coronary artery visualization. Coronary calcifications are indicative of coronary atherosclerosis and the presence and amount of coronary artery calcium have a strong predictive value concerning future cardiovascular events, even in asymptomatic individuals. It can potentially be used for refined risk stratification. Contrast-enhanced "CT coronary angiography" has become quite reliable under certain conditions (e.g., a low heart rate). The negative predictive value to rule out coronary artery stenoses has been found to be high in several studies. Therefore, clinical utility to rule out significant coronary artery stenoses in patients who are symptomatic, but have a low to intermediate pretest likelihood of disease is assumed. Ideally, "negative" coronary angiograms would be avoided by using coronary CT angiography. Large-scale trials that would pinpoint specific patient groups to benefit from "CT coronary angiography" are currently lacking.
近年来多排螺旋计算机断层扫描（CT）扫描仪的引入，在空间分辨率尤其是时间分辨率方面带来了显著提升，这使得心脏成像以及在某些情况下冠状动脉可视化成为可能。非增强扫描可显示心脏和冠状动脉钙化。静脉注射造影剂后，能够显示心脏腔室并分析冠状动脉管腔。通过计算机断层扫描（CT）可以对心脏进行形态学成像，例如在先天性心脏病的情况下，并且在一些非常特定的病例中，作为超声心动图或磁共振成像的辅助手段，在临床上可能有用。功能成像可通过CT分析左右心室功能。CT在冠状动脉可视化方面发挥着更为突出的临床作用。冠状动脉钙化表明存在冠状动脉粥样硬化，冠状动脉钙化的存在和数量对未来心血管事件具有很强的预测价值，即使在无症状个体中也是如此。它有可能用于精细的风险分层。在某些条件下（例如心率较低），对比增强的“CT冠状动脉造影”已变得相当可靠。多项研究发现，排除冠状动脉狭窄的阴性预测价值很高。因此，对于有症状但疾病预检可能性低至中等的患者，排除显著冠状动脉狭窄具有临床实用性。理想情况下，通过使用冠状动脉CT造影可以避免“阴性”冠状动脉造影。目前缺乏能够明确哪些特定患者群体将从“CT冠状动脉造影”中获益的大规模试验。
