Klinik für Herz- und Kreislauferkrankungen, Deutsches Herzzentrum München, Lazarettstrasse 36, 80636 Munich, Germany.
J Cardiovasc Comput Tomogr. 2009 Nov-Dec;3 Suppl 2:S65-73. doi: 10.1016/j.jcct.2009.11.003. Epub 2009 Nov 15.
With the introduction of modern multislice scanner generations, computed tomography (CT) has emerged as a useful tool for evaluation of the coronary arteries. A common application of coronary CT angiography (CCTA) is the examination of patients with intermediate pretest probability for obstructive coronary artery disease. Despite the widespread use of cardiac CT examinations in clinical practice, concern remains about the exposure to ionizing radiation and its potential hazards. Therefore, radiation dose and strategies for dose reduction have become an important focus of interest. Several smaller analyses have shown an effective radiation dose between 6.4 and 27.8 mSv for spiral CCTA image acquisition. The international Prospective Multicenter Study On RadiaTion Dose Estimates Of Cardiac CT AngIOgraphy I (PROTECTION I) study, the largest observational study on radiation dose estimates of cardiac CT so far, determined radiation dose estimates of CCTA, as well as the effect of different strategies to reduce dose in clinical practice. The median dose-length-product of 1965 CCTA examinations was 885 mGy x cm, which corresponds to a median estimated effective radiation dose of 12 mSv. However, a large variation in dose between study sites was observed, indicating a large potential to reduce dose for individual sites. Several dose-saving scanning techniques and algorithms have been developed. This article discusses these strategies as well as their effect on radiation dose and image quality. Because the contrast-enhanced CT angiography is the largest part of the total study dose, the following described strategies focus on radiation dose reduction for CCTA image acquisition.
随着现代多层螺旋 CT 扫描仪的问世，计算机断层扫描（CT）已成为评估冠状动脉的有用工具。冠状动脉 CT 血管造影（CCTA）的一个常见应用是检查具有中度阻塞性冠状动脉疾病预测值的患者。尽管心脏 CT 检查在临床实践中得到广泛应用，但仍存在对电离辐射及其潜在危害的担忧。因此，辐射剂量和降低剂量的策略已成为一个重要的关注焦点。几项较小的分析表明，螺旋 CCTA 图像采集的有效辐射剂量在 6.4 至 27.8 mSv 之间。国际前瞻性多中心心脏 CT 血管造影辐射剂量估计研究（PROTECTION I）是迄今为止关于心脏 CT 辐射剂量估计的最大观察性研究，该研究确定了 CCTA 的辐射剂量估计值，以及在临床实践中降低剂量的不同策略的效果。1965 次 CCTA 检查的剂量长度乘积中位数为 885 mGy x cm，这对应于 12 mSv 的中位数估计有效辐射剂量。然而，研究地点之间的剂量差异很大，表明个别地点有很大的降低剂量的潜力。已经开发了几种节省剂量的扫描技术和算法。本文讨论了这些策略及其对辐射剂量和图像质量的影响。由于增强 CT 血管造影是总研究剂量的最大部分，因此以下描述的策略侧重于降低 CCTA 图像采集的辐射剂量。
