Contrast-enhanced breath-hold MR angiography for evaluating patency of coronary artery bypass grafts

OBJECTIVE. The purpose of this study was to evaluate the ability of contrast-enhanced breath-hold MR angiography to reveal patency of coronary artery bypass grafts (CABGs). SUBJECTS AND METHODS. We evaluated 45 grafts (29 saphenous vein bypass grafts, 12 left internal mammary artery grafts, and four right internal mammary artery grafts) for occlusion or patency. Fifteen patients who had undergone CABG surgery underwent three-dimensional breath-hold ECG-triggered contrast-enhanced MR angiography at 1.5-T and conventional coronary angiography imaging within 24 hr of each other. MR angiograms were evaluated independently by two radiologists. Agreement between MR angiography and coronary angiography (the reference standard) was measured using Cohen's kappa statistic. RESULTS. One saphenous vein bypass graft was revealed as occluded by coronary angiography but was shown as patent by MR angiography and was excluded from statistical analysis. MR angiography was in agreement with coronary angiography in 42 of 44 grafts (kappa = .90; p < .001: sensitivity, 93%; specificity, 97%). CONCLUSION. Contrast-enhanced breath-hold MR angiography is a promising, rapid, and useful diagnostic technique for detecting graft patency in patients who have undergone CABG surgery.