Siemens Healthcare, Computed Tomography Division, Forchheim, Germany.
J Thorac Imaging. 2010 May;25(2):100-11. doi: 10.1097/RTI.0b013e3181d7e898.
Multidetector row computed tomography (MDCT) has been used for cardiothoracic imaging since the advent of 4-slice computed tomography (CT) in 1999. Available since 2004, 64-slice CT systems are currently considered a prerequisite for successfully integrating cardiothoracic CT into routine clinical algorithms. Developments are ongoing that aim to solve the remaining challenges of cardiothoracic CT. In this review article, we focus on 3 aspects that have significantly influenced the design of newer CT scanners. (1) A faster scan speed enables coverage of the cardiothoracic anatomy in shorter scan times, which is beneficial for patients with limited ability to cooperate and opens new clinical possibilities. A coveted goal for cardiac CT is a "snapshot image" of the entire heart in 1 cardiac cycle, which can be obtained by using MDCT systems with area detectors or dual-source CT systems with electrocardiogram (ECG)-triggered high-pitch spiral. (2) Techniques to reduce the radiation dose to the patient, such as ECG-controlled dose modulation, ECG-triggered sequential CT, low kV scanning, and iterative reconstruction, have gained considerable attention as a consequence of the ongoing discussion of radiation exposure by CT. (3) New developments aim to establish a role for CT in the functional imaging of the lung and of the heart beyond the mere visualization of anatomy. Evaluation of the first-pass enhancement of the myocardium, with single-energy or with dual-energy data acquisition, and cardiac perfusion examinations may have the potential to enhance the application spectrum of cardiac CT by providing the means to determine the hemodynamic relevance of coronary artery stenosis.
多层螺旋 CT（MDCT）自 1999 年 4 层 CT 问世以来，一直用于心胸成像。自 2004 年以来，64 层 CT 系统目前被认为是成功将心胸 CT 整合到常规临床算法中的先决条件。目前正在开发旨在解决心胸 CT 剩余挑战的技术。在这篇综述文章中，我们重点介绍了 3 个方面，这些方面对新型 CT 扫描仪的设计产生了重大影响。（1）更快的扫描速度可在更短的扫描时间内覆盖心胸解剖结构，这对合作能力有限的患者有益，并开辟了新的临床可能性。心脏 CT 的一个理想目标是在 1 个心动周期内获得整个心脏的“快照图像”，这可以通过使用具有面积探测器的 MDCT 系统或具有心电图（ECG）触发的高速螺旋的双源 CT 系统来实现。（2）作为 CT 辐射暴露持续讨论的结果，降低患者辐射剂量的技术，如 ECG 控制剂量调制、ECG 触发的连续 CT、低千伏扫描和迭代重建，已引起广泛关注。（3）新的发展旨在为 CT 在肺和心脏的功能成像中的作用建立一个基础，超越仅仅观察解剖结构。评估心肌的初次通过增强，使用单能或双能数据采集，以及心脏灌注检查，可能通过提供确定冠状动脉狭窄的血流动力学相关性的手段，增强心脏 CT 的应用范围。
