Is there an indication for computed tomography and magnetic resonance imaging in the evaluation of coronary artery bypass grafts?

This meta-analysis evaluates the diagnostic accuracy of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for bypass graft occlusion and stenosis detection compared with coronary angiography in post-coronary artery bypass graft patients. The indication for noninvasive imaging in post-coronary artery bypass graft patients with these techniques is discussed. Overall, MRI had significantly lower sensitivity (81%) and specificity (91%) for occlusion detection than MDCT (96% and 98%, respectively). Only 2 studies assessed the accuracy of stenosis detection with MRI. Stenosis detection with MDCT had a pooled sensitivity of 89% and specificity of 97%. Multidetector computed tomography is therefore superior to MRI for the noninvasive detection of coronary bypass graft occlusion and stenosis. For stenosis detection, the accuracy of MDCT is, however, not sufficient to warrant a wide clinical use. The remaining indication for MRI-guided bypass graft assessment is in combination with myocardial evaluation such as magnetic resonance perfusion, wall motion, and stress test as a "one-stop-shop" procedure.