Coronary flow reserve: noninvasive measurement in humans with breath-hold velocity-encoded cine MR imaging.

Abstract

To measure coronary vasodilator reserve with breath-hold velocity-encoded cine magnetic resonance (MR) imaging. Eight healthy adult volunteers underwent 1.5-T MR imaging. Velocity-encoded cine images were acquired at seven to 13 temporal phases in 25 seconds, with k-space segmentation and view-sharing reconstruction (+/- 1 m/sec velocity-encoding value) (repetition time msec/echo time msec = 16/9). Flow velocity in the left anterior descending (LAD) artery was measured twice before and twice after administration of dipyridamole (0.56 mg per kilogram of body weight). Peak diastolic coronary flow velocity in the LAD artery was 14.8 cm/sec +/- 1.9 (mean +/- standard deviation) in the baseline state. It increased significantly (P< .01) to 46.3 cm/sec +/- 10.2 after dipyridamole administration, with an average coronary reserve of 3.14 +/- 0.59. Interstudy and interobserver reproducibilities for measurement of peak diastolic velocity were, respectively, 9.5% +/- 1.6 and 7.0% +/- .2.5 in the baseline state and 6.8% +/- 2.2 and 3.4% +/- 1.5 after dipyridamole administration. Breath-hold velocity-encoded cine MR imaging provided reproducible assessment of coronary flow reserve in humans.