Boxt Lawrence M, Lipton Martin J, Kwong Raymond Y, Rybicki Frank, Clouse Melvin E
Division of Cardiovascular Imaging, Beth Israel Medical Center, 1st Avenue at 16th St., New York, NY 10003, USA.
Cardiol Clin. 2003 Nov;21(4):561-85. doi: 10.1016/s0733-8651(03)00093-6.
The focus to date of MDCT has been primarily on CT applications for evaluating the coronary arteries, notably the measurement of coronary artery calcification, plaque characterization, and atherosclerotic lumen stenosis. This is because of the limited temporal resolution of CT, and the recent rapid improvements in MRI for cardiac applications. However, if the temporal resolution of MDCT can be improved, there will be a compelling argument for undertaking further CT validation studies. Feasibility of CT has already been established by EBT for general cardiac diagnosis. Modifications for MDCT include improved software methods for post processing ECG-gated scan data or higher speed CT hardware for faster image acquisition, both of which are being developed at this time. EBT is also evolving and continuously being refined so that the new generation of scanners have exposure times of 50 msec or less. There are many considerations in comparing the pros and cons of competing cardiac imaging modalities. Published diagnostic validations studies, convenience, procedure time, the comfort level (of patients and physicians), availability, and cost are all critical. The level of acceptance and the accuracy with which specific patient management questions can be appropriately answered are crucial issues in determining which diagnostic procedure to perform. However, the jury is still out regarding the ultimate role of CT in the diagnosis of heart disease; certainly the great potential of cardiac CT has not yet been fully realized.
迄今为止,多层螺旋CT(MDCT)的重点主要在于用于评估冠状动脉的CT应用,尤其是冠状动脉钙化的测量、斑块特征分析以及动脉粥样硬化管腔狭窄情况。这是由于CT的时间分辨率有限,以及近期心脏应用领域磁共振成像(MRI)的快速发展。然而,如果MDCT的时间分辨率能够提高,那么开展进一步的CT验证研究将具有令人信服的理由。电子束CT(EBT)已证实CT用于一般心脏诊断的可行性。MDCT的改进包括用于后处理心电图门控扫描数据的改进软件方法,或用于更快图像采集的更高速度CT硬件,目前这两者都在研发中。EBT也在不断发展和完善,新一代扫描仪的曝光时间已达到或低于50毫秒。在比较相互竞争的心脏成像模式的优缺点时,有许多需要考虑的因素。已发表的诊断验证研究、便利性、检查时间、(患者和医生的)舒适度、可及性和成本都是至关重要的。在确定进行何种诊断程序时,接受程度以及能否恰当回答特定患者管理问题的准确性是关键问题。然而,关于CT在心脏病诊断中的最终作用尚无定论;心脏CT的巨大潜力肯定尚未完全实现。