Motion correction for the quantification of mitral regurgitation using thecontrol volume method

Quantifying mitral regurgitation is difficult because of the complexity of the flow, geometry and motion of the mitral valve. In this paper a MRI comp atible phantom was built incorporating a left ventricle and mitral valve mo tion. Valve motion was obtained using a pneumatic piston. The mitral valve was made regurgitant and the regurgitant volume quantified using a modified control volume method. The modification to the method was the addition of mitral motion correction. This was attained by moving the control volume in unison with the mitral valve and by correcting for this motion in the inte gration of velocity. This correction was found to be simple, in that it rep resented the volume swept out by the moving control surface. The measured r egurgitant volume was compared to a second MR measurement using a single sl ice technique, made possible by the tubular construction of the phantom's l eft atrium. Regression analysis between these two methods produced a regres sion line of y = 0 + 1.02 x; R = 0.97; standard error of the estimate = 3.4 7 ml, Magn Reson Med 43:726-733, 2000. (C) 2000 Wiley-Liss, Inc.