Fig. 3
4D flow CMR-based characterization of flow dynamics in a 30-year-old woman with unicuspid aortic valve before and after aortic valve repair. a Velocity-coded 4D flow CMR reveals an accelerated and highly eccentric asymmetric flow jet (indicated by yellow and red streamlines) and a pronounced helical (arrows) and vortical flow pattern (arrowhead) in the ascending aorta before surgery. The flow jet impacts and travels along the right-anterior aortic wall. b Extracted analysis plane (solid line) at the aortic valve level shows regurgitation of insufficient bicuspid valve (20%) (c) Extracted analysis plane (dashed line) at the level of the mid-ascending aorta shows the marked eccentric flow pattern (relative flow displacement: 0.37), resulting in increased global WSS (0.9 N/m2). d After surgery, velocity-coded 4D flow CMR shows reduced helical and vortical flow with a more cohesive central flow pattern more parallel to the vessel wall of the ascending aorta. e Extracted analysis plane at the aortic valve level shows decreased regurgitation (5.8%) after surgery (f) Extracted analysis plane at the level of the mid-ascending aorta demonstrates a more centralized flow (relative flow displacement: 0.24), resulting in decreased global WSS (0.37 N/m2) after aortic valve repair