Breath-hold MR angiography of human coronary arteries

This paper reports on an MR angiographic method for depicting coronary arteries. Challenges for coronary artery imaging include small vessel size and respiratory and cardiac motion. To overcome these problems, a fast gradient-echo sequence was designed that permits a cardiac-gated flow image to be obtained within a breath hold. Twenty healthy subjects were studied with a 1.5-T Siemens Magnetom whole-body imaging system and body coil. A two-dimensional, flow-compensated gradient-echo sequence, k-space segmentation, and radio-frequency prepulses were used with TE of 8 msec, field of view of 270 mm, 128 x 256 matrix, cardiac gating, 1 image per 12-16 second breath hold. An incremental flip angle series of 10 degrees, 22 degrees, 35 degrees, 50 degrees, 50 degrees, 50 degrees, 50 degrees, 50 degrees was used to maximize flow contrast. Portions of the proximal coronary arteries were seen in all subjects. The arteries could be tracked on sequential, overlapping, 4-mm-thick sections from the coronary ostia distally. No artifacts from respiration or pulsatile flow were apparent. The arteries also could be imaged obliquely to provide cross-sectional or longitudinal views