Indrajit I K, Souza J D, Bedi V S, Pant R
Classified Specialist, INHS ASVINI, Colaba, Mumbai.
Senior Advisor(Radiodiagnosis and Imaging), INHS ASVINI, Colaba, Mumbai.
Med J Armed Forces India. 2005 Oct;61(4):360-3. doi: 10.1016/S0377-1237(05)80068-1. Epub 2011 Jul 21.
3D Computed Tomographic Angiography (CTA) is a noninvasive volumetric imaging technique increasingly used for evaluation of vascular system. The introduction of Multidetector CT (MDCT) has increased scanning speed, allowing shorter acquisition time, greater volume coverage and decreased contrast requirement while diminishing respiratory motion artifacts. Thin-slice collimation protocols are routinely used which generate isotropic 3D voxels that improve image quality. The ideal CTA study requires scanning at peak vascular enhancement for optimal opacification of arteries with separation of arteries and veins. MDCT has enabled complete lower extremity inflow and runoff studies with a single injection, as well as thin-section CTA covering the entirety of the Carotid arteries and Circle of Willis. Sixteen row MDCT has increased scanning speed further facilitating the development of novel applications such as coronary CTA. CTA when perfomed with MDCT offers a "one scan - many views" option useful in imaging vascular diseases. CTA has important advantages over conventional angiography, such as reduced risk, diminished time and better patient acceptance. With MDCT, 3D CTA is crossing vessel tortuosity and evaluation of vessel fragility.
三维计算机断层血管造影（CTA）是一种无创容积成像技术，越来越多地用于评估血管系统。多排螺旋CT（MDCT）的引入提高了扫描速度，缩短了采集时间，扩大了容积覆盖范围，减少了对比剂用量，同时减少了呼吸运动伪影。常规使用薄层准直方案，可生成各向同性的三维体素，提高图像质量。理想的CTA检查需要在血管强化峰值时进行扫描，以使动脉最佳显影并区分动脉和静脉。MDCT能够通过一次注射完成完整的下肢血流灌注和流出道检查，以及覆盖整个颈动脉和 Willis 环的薄层CTA检查。16排MDCT进一步提高了扫描速度，进一步推动了冠状动脉CTA等新应用的发展。与MDCT一起进行的CTA提供了“一次扫描——多种视角”的选择，对血管疾病成像很有用。CTA相对于传统血管造影具有重要优势，如风险降低、时间缩短和患者接受度更高。借助MDCT，三维CTA正在突破血管迂曲并评估血管脆性。
