The compensation for asynchronous cardiac quiescence in coronary wall MR imaging

The aim of the present study was to assess the incremental benefit of compensating asynchronous cardiac quiescence in coronary wall MR imaging. With the approval of IRB, black-blood coronary wall MR imaging was performed on 30 older subjects (90 coronary wall segments). For round 1 coronary wall MR imaging, acquisition windows were traditionally set within rest period _4-chamber. Totally 51 of 90 images were ranked as "good" images and resulted in an interpretability rate of 57%. Then, an additional cine-MR was centered at coronary segments to obtain rest period _{cross-sectional}. The rest period_overlap (the intersection between rest period_4-chamber and rest period _{cross-sectional}) was measured for each coronary segment. The "good" images had a longer rest period_overlap and higher acquisition coincidence rate (the percentage of acquisition window covered by the rest period_overlap) than "poor" images. Coronary wall rescans (round 2) were completed at 39 coronary segments that were judged as having "poor" images in round 1 scans. The acquisition window was set within the rest period_overlap. For the round 2 images, 17 of 39 (44%) coronary segments were ranked as "good" images. The overall interpretability rate (68 of 90, 76%) was significantly higher than that of the round 1 images alone. Our data demonstrated that asynchronous cardiac quiescence adversely affects the performance of coronary wall MR imaging. Individualizing acquisition windows based on multi-plane cine-MR helps to compensate for this motion discrepancy and to improve image quality.