Advances in cardiac imaging with 16-section CT systems
Advances in cardiac imaging with 16-section CT systems
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DOI：
10.1016/s1076-6332(03)80027-2
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发表时间：
2003-04-01
影响因子：
4.8
通讯作者：
Ohnesorge, BM
中科院分区：
文献类型：
--
作者：
Flohr, TG;Schoepf, UJ;Ohnesorge, BM
理由和目标。作者介绍了最近引进的16层计算机断层扫描（CT）设备在心电图（ECG）门控心脏螺旋扫描方面的进展。作者讨论了心电门控心脏扫描的技术原理。它们给出了系统特性和检测器设计的概述。他们描述了ECG门控扫描和图像重建技术以及ECG控制的剂量调制（“ECG脉冲”），以减少患者剂量。他们讨论了图像质量的关键参数，并提供了模拟和体模研究，他们给出了患者剂量的初步值。ECG门控螺旋CT自适应心脏容积重建的扩展可为多达16个切片提供足够的图像质量。利用最小的重建截面宽度（约0.83 mm）和重叠图像重建，直径为0.6-0.7 mm的圆柱形孔可以在与心率无关的横向分辨率体模中分辨。对于冠状动脉CT血管造影术，横向分辨率的影响对于相对于扫描平面仅略微倾斜的冠状动脉节段最为显著。在这种情况下，使用1.0 mm或更小的切片宽度，支架和斑块的可视化得到了显著改善。对于0.42秒的机架旋转时间，时间分辨率在每分钟81次心跳的心率下达到其最佳值（105 msec）。制造商推荐的标准方案的有效患者剂量范围从ECG触发钙评分的0.45 mSv（男性）到高分辨率ECG门控冠状动脉CT血管造影的7.1 mSv（男性）。随着心电图脉冲，剂量减少了30%-50%，这取决于患者的心率。临床经验将需要充分评估的潜力，16节技术的心脏成像。
Rationale and Objectives. The authors present advances in electrocardiographically (ECG) gated cardiac spiral scanning with recently introduced 16-section computed tomographic (CT) equipment.Materials and Methods. The authors discuss the technical principles of ECG-gated cardiac scanning. They give an overview on system properties and on the detector design. They describe ECG-gated scan- and image-reconstruction techniques and ECG-controlled dose modulation ("ECG pulsing") for a reduction of the patient dose. They discuss key parameters for image quality and present simulation and phantom studies and they give preliminary values for the patient dose.Results. An extension of the adaptive cardiac volume reconstruction for ECG-gated spiral CT provides adequate image quality for up to 16 sections. With the smallest reconstructed section width (about 0.83 mm) and overlapping image reconstruction, cylindrical holes 0.6-0.7 mm in diameter can be resolved in a transverse resolution phantom independent of the heart rate. For coronary CT angiography, the influence of transverse resolution is most pronounced for coronary segments that are only slightly tilted relative to the scan plane. In this case, visualization of stents and plaques is considerably improved with 1.0-mm or smaller section width. For 0.42-second gantry rotation time, temporal resolution reaches its optimum (105 msec) at a heart rate of 81 beats per minute. Effective patient dose for the standard protocols recommended by the manufacturer ranges from 0.45 mSv (male) for ECG-triggered calcium scoring to 7.1 mSv (male) for high-resolution ECG-gated coronary CT angiography. With ECG pulsing, the dose is reduced by 30%-50% depending on the patient's heart rate.Conclusion. Clinical experience will be needed to evaluate fully the potential of 16-section technology for cardiac imaging.