Comparison of respiratory suppression methods and navigator locations for MR coronary angiography.

Abstract

Currently, breath-holding during MR coronary angiography is used to minimize respiratory motion. This technique requires patient cooperation and is associated with slice registration errors. The goal of this study was to evaluate alternative non-breath-hold techniques for MR coronary angiography during free breathing.Subjects underwent MR coronary angiography using an ECG-gated, fat-suppressed, segmented K-space, gradient-echo sequence. Images were obtained during free breathing using both real-time navigator gating and respiratory bellows gating. These were compared with images obtained during conventional breath-holding. The optimal navigator location (diaphragmatic or cardiac) was also studied. Image quality, registration error, and scan time were measured for all scans.Navigator gating for MR coronary angiography during free breathing resulted in image quality equivalent to that obtained during breath-holding and was superior to that obtained with respiratory bellows gating (p < .04). Also, navigator ...