The noninvasive quantification of mitral regurgitation remains an impo
rtant clinical goal. Recently, the flow convergence method was develop
ed to estimate the regurgitant flow rate. This study used three-dimens
ional pulsatile computational simulations to evaluate the accuracy of
the flow convergence method in the presence of complicating factors su
ch as ventricular confinement, noncircular orifice shape, and the pres
ence of aortic outflow. Results showed that in the absence of aortic o
utflow and ventricular confinement, there was a plateau zone where the
calculated flow rate by the hemispheric formula approximated the true
flow rate, independent of the orifice shape. In the presence of aorti
c outflow and in chambers of physiologic dimensions, there was no long
er a clear zone where the hemispheric formula was valid. The hemi-elli
ptic modification of the flow convergence method worked in all cases,
independent of the degree of ventricular confinement or the presence o
f aortic outflow. Therefore, application of the hemi-elliptic formula
should be considered in future clinical studies.