Doriot P A, Chappuis F, Rutishauser W
Centre de Cardiologie, Hôpital Cantonal Universitaire, Genève, Suisse.
Ann Cardiol Angeiol (Paris). 1988 Dec;37(10):575-8.
In cardiology, digital subtraction angiography after intravenous injection of contrast medium allows only the visualization of relative large structures as the ventricles and the great vessels. Subselective intra-arterial injections are attractive, but do not provide an appreciable reduction of the injected amount of contrast medium. A reduction is possible with selective injections, but good subtraction is only possible for non-moving arteries or for arteries with truly periodic movement (ECG gated subtraction). With the improvement of spatial and temporal resolution, digital angiography (without image subtraction) could replace conventional angiography, provided that the main problem of prohibitive costs associated to the stockage of image sequences with high spatial (1024 x 1024) and temporal (25 images/s) resolution is solved. At the present, however, the cinefilm 35 mm is still unbeaten in density of information, handling and costs. In interventional cardiology, the visualization of small coronary branches and of fine, fast moving guide-wires is improved by the digitalization of the images at the source, pulsed fluoroscopy, progressive scanning of the TV camera with temporary stockage of image sequences and the selective reinforcement of the image contrast in real time. Digital angiography is also more attractive than the cinefilm in view of a better exploitation of the information contained in angiographic sequences by sophisticated, computer assisted methods. For instance, parametric imaging for analysis of the contraction and relaxation of the left ventricle, or for the visualization of the progression of contrast medium to investigate the coronary circulation, condensing in one single image the information looked for, are fields where digital angiography has given new impulses to cardiologic research.
在心脏病学中，静脉注射造影剂后的数字减影血管造影仅能显示相对较大的结构，如心室和大血管。选择性动脉内注射很有吸引力，但并不能显著减少造影剂的注射量。选择性注射有可能减少造影剂用量，但只有在动脉不移动或具有真正周期性运动（心电图门控减影）时才能实现良好的减影效果。随着空间和时间分辨率的提高，数字血管造影（无图像减影）有望取代传统血管造影，前提是要解决与存储高空间分辨率（1024×1024）和时间分辨率（每秒25帧图像）的图像序列相关的高昂成本这一主要问题。然而目前，35毫米电影胶片在信息密度、操作便利性和成本方面仍具有优势。在介入心脏病学中，通过对源图像进行数字化、脉冲荧光透视、电视摄像机的逐行扫描并临时存储图像序列以及实时选择性增强图像对比度，可以更好地显示小的冠状动脉分支和精细、快速移动的导丝。考虑到通过复杂的计算机辅助方法能更好地利用血管造影序列中包含的信息，数字血管造影也比电影胶片更具吸引力。例如，用于分析左心室收缩和舒张的参数成像，或用于观察造影剂推进以研究冠状动脉循环，将所需信息浓缩在一张图像中的这些领域，数字血管造影为心脏病学研究带来了新的动力。
