MR imaging flow velocity mapping of aortic regurgitation

MR imaging affords excellent display of aortic disease, but clinical usefulness has been limited by inability to quantify aortic regurgitation. Previous studies have shown that the distal extent of aortic diastolic flow reversal is proportional to the severity of aortic regurgitation. The authors describe a phase reconstruction technique which shows the direction of diastolic blood flow throughout the aorta. Long-axis spin-echo and gradient-echo sequences through the center of the aortic lumen were performed at multiple points in the cardiac cycle. Phase-sensitive reconstruction was then done. Reversal of diastolic flow direction in the distal thoracic aorta correlated with severe aortic regurgitation on aortography. Absence of flow reversal correlated with absent or mild aortic regurgitation on aortography