Whole-heart contrast-enhanced coronary magnetic resonance angiography using gradient echo interleaved EPI.

Whole-heart coronary MR angiography (MRA) is a promising method for detecting coronary artery disease. However, the imaging time is relatively long (on the order of 10-15 min). Such a long imaging time may result in patient discomfort and compromise the robustness of whole-heart coronary MRA due to increased respiratory and cardiac motion artifacts. The goal of this study was to optimize a gradient echo interleaved echo planar imaging (GRE-EPI) acquisition scheme for reducing the imaging time of contrast-enhanced whole-heart coronary MRA. Numerical simulations and phantom studies were used to optimize the GRE-EPI sequence parameters. Healthy volunteers were scanned with both the proposed GRE-EPI sequence and a 3D TrueFISP sequence for comparison purposes. Slow infusion (0.5 cc/sec) of Gd-DTPA was used to enhance the signal-to-noise ratio (SNR) of the GRE-EPI acquisition. Whole-heart images with the GRE-EPI technique were acquired with a true resolution of 1.0 x 1.1 x 2.0 mm(3) in an average scan time of 4.7 +/- 0.7 min with an average navigator efficiency of 44 +/- 6%. The GRE-EPI acquisition showed excellent delineation of all the major coronary arteries with scan time reduced by a factor of 2 compared with the TrueFISP acquisition.