Aortic and mitral regurgitation: Quantification using moving slice velocity mapping

Comprehensive assessment of the severity of valvular insufficiency includes quantification of regurgitant volumes. Previous methods lack reliable slic e positioning with respect to the valve and are prone to velocity offsets d ue to through-plane motion of the valvular plane of the heart. Recently, th e moving slice velocity mapping technique was proposed. In this study, the technique was applied for quantification of mitral and aortic regurgitation . Time-efficient navigator-based respiratory artifact sup pression was achi eved by implementing a prospective k-space reordering scheme in conjunction with slice position correction. Twelve patients with aortic insufficiency and three patients with mitral Insufficiency were studied. Aortic regurgita nt volumes were calculated from diastolic velocities mapped with a moving s lice 5 mm distal to the aortic valve annulus. Mitral regurgitant flow was i ndirectly assessed by measuring mitral. inflow at the level of the mitral a nnulus and net aortic outflow. Regurgitant fractions, derived from velocity data corrected for through-plane motion, were compared to data without cor rection for through-plane motion. In patients with mild and moderate aortic regurgitation, regurgitant fractions differed by 60% and 15%, on average, when comparing corrected and uncorrected data, respectively. Differences in severe aortic regurgitation were less (7%). Due to the large orifice area of the mitral valve, differences were still substantial in moderate-to-seve re mitral regurgitation (19%). The moving slice velocity mapping technique was successfully applied in patients with aortic and mitral regurgitation. The importance of correction for valvular through-plane motion is demonstra ted. (C) 2001 Wiley-Liss, Inc.