MR angiography and flow quantification of the internal mammary artery graft after minimally invasive direct coronary artery bypass.

Abstract

Six patients who had undergone minimally invasive direct coronary artery bypass surgery were examined to evaluate an MR imaging protocol that provided information about cardiac function, bypass graft patency, and flow characteristics with a single examination. Preliminary results suggest that our imaging protocol allows accurate follow-up of patients after minimally invasive direct coronary artery bypass surgery. Bypass graft patency was correctly determined in all patients. In four patients, anastomoses were visualized by MR angiography, and flow measurements revealed a volume range of 28-84 ml/min (native and grafted internal mammary arteries) and a trend for the flow values of bypass grafts to be lower than those of native vessels. Interobserver reproducibility was good (r = .99; slope, .98).