Coronary MR angiography.

The principles underlying coronary MR angiographic pulse sequences are reviewed, including basic coronary anatomy, motion, and flow physiology. Coronary MR angiographic techniques can be subdivided into breath-hold (single or repeated) and nonbreath-hold techniques. The recent introduction of navigator pulses for real-time respiratory gating or triggering allows nonbreath-hold or repeated breath-hold 3-D coronary MR angiography, and will allow a more widespread use of this technique.