Coronary artery bypass grafting (CABG) is effective and successful in treating diffuse coronary artery disease. However, recurrences of the symptoms after CABG are documented in 4% to 8% of the patients within 1 year. These symptoms are most often due to graft occlusions. Arterial grafts have comparatively good patency rates, but among venous grafts 7% are occluded within 1 week, 15% to 20% are occluded within 1 year, and almost half are occluded within 10 years.Evaluation of graft patency is crucial in symptomatic patients after CABG. Coronary angiography, the gold standard in evaluating graft patency after CABG, is a stressful and invasive procedure. Since the 1980s, several other diagnostic methods (most of them noninvasive) have been used to evaluate graft patency. However, none of these tests has been widely accepted as accurate in this application. As a consequence of certain characteristics of venous and arterial conduits, multislice computed tomography (MSCT) can evaluate them more effectively than it can evaluate native coronary arteries. Although MSCT assessment of vessels can be hindered by calcification or metallic clips, arterial and venous conduits are typically free of calcification; clips remain a problem. In the present study, we evaluated the diagnostic accuracy of MSCT in assessing coronary artery bypass grafts.