Morphologies and waveforms of mitral and tricuspid regurgitation visualized with 4D flow MRI. Multiple morphologies of mitral regurgitation were identified, characterized as (a) large-orifice eccentric, (b) complex, broad-based, (c) narrow-orifice eccentric regurgitation with a long segment of proximal turbulent signal loss. In addition, high-velocity, wide-orifice tricuspid regurgitation is also shown (d). Flow curves on the bottom highlight the duration and temporal relationship of mitral regurgitation relative to the aortic and pulmonary outflow.