Movie 1:
Flow quantification from 4D flow MRI in a 59-year-old man with severe MR and multiple regurgitation jets by observer 1. Mitral valve (MV) forward flow is quantified using valve tracking. MV regurgitant flow is quantified using flow tracking. A) 4D flow MRI streamlines of forward and backward MV flow, with 2-chamber cine bSSFP background image for anatomic reference. B) Color-coded projection of 4D flow MRI through-plane velocities onto the valve tracking plane (during forward flow) and flow tracking plane (during regurgitation), which was used to contour the flow region of interest for every timestep. During MV regurgitation, aorta outflow is also visible in the velocity projection. C) 4D flow MRI streamlines of forward and backward MV and AV flow, with 3-chamber cine bSSFP background image for anatomic reference. MV regurgitation jet shears along the septal side of the left atrial wall, close to the aortic root. AV regurgitation was also quantified using flow tracking.