Quantification of in-plane motion of the coronary arteries during the cardiac cycle: Implications for acquisition window duration for MR flow quantification

Motion of the coronary arteries during the heart cycle can result in image blurring and inaccurate now quantification by MR. This condition applies pa rticularly for longer acquisition windows that are typical of breath-hold c oronary now measurements. To determine the sensitivity of the technique to in-plane motion of different coronary arteries, the temporal variation in c oronary position was measured in a plane perpendicular to the proximal port ion of the vessel. The results indicated the presence of substantial displa cement of the coronary arteries within the cardiac cycle, with a magnitude of motion approximately twice as large for the right as for the left corona ry arteries. An estimation of the resulting vessel blurring was calculated, showing that the duration of the acquisition window for high spatial resol ution coronary now acquisitions should be less than 25 to 120 msec, dependi ng on the specific coronary artery studied. In addition. these data specify optimal acquisition window placement for high resolution coronary angiogra phy.