Possibilities and prospects of noninvasive bypass diagnosis. Comparison of different nuclear magnetic resonance tomography methods with conventional coronary angiography

OBJECTIVE: The aim of the study was to evaluate the patency of coronary artery bypass grafts (CABGs) with different MR imaging techniques. PATIENTS: 25 patients with 63 bypass grafts and a total of 78 distal anastomoses were studied at a 1.5-Tesla scanner. A 2-D T2-weighted breath-hold turbo spin echo sequence (Haste), a 3-D breath-hold contrast-enhanced MR angiography sequence (Fisp-3-D), and 3-D angiography sequence in navigator techniques were used. RESULTS: With the Haste and Fisp-3-D sequences, 44 of the 47 patent and 14 of the 16 occluded grafts were recognized, the sensitivity and specificity were 94% and 88%, respectively. With the Haste sequence, 80% (43/54) of the distal anastomoses were seen in good image quality, and with the Fish-3-D sequence 70% (38/54). The navigator sequence showed less sensitivity and specificity (74% and 63%, respectively). CONCLUSION: The patency of CABGs can be evaluated noninvasively with the Haste and the Fisp-3-D angiography sequences. Better results can be expected with the development of a blood-pool contrast medium and an improvement of the spatial resolution.