Noninvasive evaluation of coronary bypass grafts by magnetic resonance imaging. Comparison of the Haste and Fisp-3-D sequences with the conventional coronary angiography

The aim of the study was to evaluate the patency of coronary artery bypass grafts (CABG) with the 2D and 3D magnetic resonance (MR) imaging techniques . 29 patients with 74 bypass grafts and a total of 91 distal anastomoses we re studied on a 1.5 Tesla scanner using a phased array body coil. A 2D T-2 weighted breath-hold turbo spin echo sequence (Haste) and a 3D breath hold contrast enhanced MR angiography sequence (Fisp-3-D) were performed. With t he Haste and Fisp-3-D sequences 55 of the 58 patent and 15 of the 16 occlud ed grafts were recognized; the sensitivity and specifity were 95 % and 94 % , respectively. With the Haste sequence 74 % (47/63) and with the Fisp-3-D sequence 64 % (40/63) of the distal anastomoses were seen in good image qua lity. Only 3 of 8 significant grafts stenoses were detected. The patency of CABGs can be evaluated non-invasively with the Haste and the Fisp-3-D angiography sequences. Better results can be expected with the de velopment of a blood-pool contrast medium and the combination of MR flow me asurements with imaging techniques.