Three-Dimensional Coronary MR Angiography Performed with Subject-Specific Cardiac Acquisition Windows and Motion-Adapted Respiratory Gating

Abstract
OBJECTIVE. In coronary MR angiography, data are conventionally accepted in only short and fixed periods of the cardiac and respiratory cycles. We hypothesized that a more flexible and subject-specific approach to cardiac and respiratory gating may shorten scanning times while maintaining image quality.SUBJECTS AND METHODS. We implemented an acquisition technique that uses subject-specific acquisition windows in the cardiac cycle and a motion-adapted gating window for respiratory navigator gating. Cardiac acquisition windows and trigger delays were determined individually from a coronary motion scan. Motion-adapted gating used a 2-mm acceptance window for the central 35% of k-space and a 6-mm window for the outer 65% of k-space. In 10 subjects, three-dimensional coronary MR angiograms of the right and left coronary systems were acquired with this technique (the “adaptive technique”) as well as a conventional acquisition method, and the scanning times and image quality were compared. The adaptive technique ...