Contrast‐kinetics‐resolved whole‐heart coronary MRA using 3DPR

Slow contrast infusion was recently proposed for contrast‐enhanced whole‐heart coronary MR angiography. Current protocols use Cartesian k‐space sampling with empiric acquisition delays, potentially resulting in suboptimal coronary artery delineation and image artifacts if there is a timing error. This study aimed to investigate the feasibility of using time‐resolved three‐dimensional projection reconstruction for whole‐heart coronary MR angiography. With this method, data acquisition was started simultaneously with contrast injection. Sequential time frames were reconstructed by employing a sliding window scheme with temporal tornado filtering. Additionally, a self‐timing method was developed to monitor contrast enhancement during a scan and automatically determine the peak enhancement time around which optimal temporal frames were reconstructed. Our preliminary results on six healthy volunteers showed that by using time‐resolved three‐dimensional projection reconstruction, the contrast kinetics of the coronary artery system throughout a scan could be retrospectively resolved and assessed. In addition, the blood signal dynamics predicted using self‐timing was closely correlated to the true dynamics in time‐resolved reconstruction. This approach is useful for optimizing delineation of each coronary artery and minimizing image artifacts for contrast‐enhanced whole‐heart MRA. Magn Reson Med 63:970–978, 2010. © 2010 Wiley‐Liss, Inc.