Frija G, Schouman-Claeys E, Lacombe P, Bismuth V, Ollivier J P
Service de Radiologie, Hôpital Raymond Poincaré, Garches, France.
J Comput Assist Tomogr. 1989 Mar-Apr;13(2):226-32. doi: 10.1097/00004728-198903000-00007.
This is a prospective study comparing selective angiography and magnetic resonance (MR) imaging in the evaluation of the patency of coronary artery bypass grafts (CABGs). Twenty-eight patients with 52 grafts were studied (10 internal mammary artery grafts, 19 saphenous vein grafts including 2 sequential grafts, and 15 right coronary artery saphenous vein grafts). The mean interval between MR imaging and the surgical procedure was 13.2 months. Results obtained with angiography were as follows: 39 patent grafts; 4 patent but stenotic (greater than 50%); 9 occluded CABGs. Magnetic resonance imaging was performed with axial imaging, spin echo images, and electrocardiographic gating. Grafts that were normal on angiographic examination appeared without a signal on both the first and the second echoes in 38 of 39 cases. Grafts that were patent but presented significant stenosis as evidenced by angiography presented the same appearance. In one case, there was an aspect corresponding to a decreased blood flow (presence of a signal on the first echo that became stronger on the second echo). The CABG occlusion was determined in seven of nine cases. Occluded grafts twice presented a signal variation corresponding to an old thrombus formation. In two cases, only the origin of the graft was visible without any visualization of its distal portion. In three other cases, neither the proximal nor the distal portions of the graft were identified. Among six CABGs that could not be identified, three were patent. This study demonstrated that MR imaging makes it possible to correctly identify patent CABGs, but this modality has significant limitations because patent but stenotic CABGs may present in the same way as patent CABGs without stenosis. On the other hand, the correct identification of occluded grafts may be accurately performed using MR imaging.
这是一项前瞻性研究，比较选择性血管造影和磁共振（MR）成像在评估冠状动脉旁路移植术（CABG）血管通畅性方面的作用。对28例患者的52条移植血管进行了研究（10条乳内动脉移植血管、19条大隐静脉移植血管，包括2条序贯移植血管，以及15条右冠状动脉大隐静脉移植血管）。MR成像与手术之间的平均间隔时间为13.2个月。血管造影的结果如下：39条移植血管通畅；4条通畅但狭窄（大于50%）；9条CABG闭塞。采用轴位成像、自旋回波图像和心电图门控进行磁共振成像。血管造影检查正常的移植血管在39例中的38例中，在第一和第二回波上均无信号显示。血管造影显示通畅但存在明显狭窄的移植血管表现相同。在1例中，有一个对应血流减少的表现（第一回波上有信号，在第二回波上变强）。9例中有7例确定了CABG闭塞。闭塞的移植血管两次出现对应陈旧血栓形成的信号变化。在2例中，仅可见移植血管的起始部，其远端部分未见显示。在另外3例中，移植血管的近端和远端部分均未识别出。在6条无法识别的CABG中，3条是通畅的。这项研究表明，MR成像能够正确识别通畅的CABG，但这种方法有显著局限性，因为通畅但狭窄的CABG可能与无狭窄的通畅CABG表现相同。另一方面，使用MR成像可以准确地正确识别闭塞的移植血管。
