An ultrasonic diagnostic imaging system is described which quantifies regurgitant flow through a mitral valve. A flow quantification processor (34) in the ultrasound system produces a mathematical model of a flow velocity field proximal to a regurgitant orifice. The velocity field model produces values of velocity vectors directed toward the regurgitant orifice. These modeled values are modified for the effects of ultrasound physics and ultrasound system operation to produce expected velocity values. The expected velocity values are compared with actual Doppler velocities measured by the ultrasound system, and the differences accumulated to a mean square error which is used to adjust parameters of the model such as the orifice location and flow velocities. When this iterative processing converges with a desired comparison, parameters derived from the finally adjusted model are used to calculate the true orifice location, flow rate, and volume flow.
