Aortic three-dimensional (3D) blood flow was evaluated by 4D flow MRI in 14 healthy volunteers with normal trileaflet valves and 14 patients with unicuspid (n = 3), bicuspid (n = 9, 3 "true" bicuspid, 3 right-left (RL), 3 right-noncoronary (RN) leaflet fusion, and quadricuspid aortic valves (n = 2). 
4D flow MRI
From unicuspid to quadricuspid: influence of aortic valve morphology on aortic three-dimensional hemodynamics.PURPOSE
 To assess the impact of aortic valve morphology on aortic hemodynamics between normal tricuspid and congenitally anomalous aortic valves ranging from unicuspid to quadricuspid morphology.


 Aortic three-dimensional (3D) blood flow was evaluated by 4D flow MRI in 14 healthy volunteers with normal trileaflet valves and 14 patients with unicuspid (n = 3), bicuspid (n = 9, 3 "true" bicuspid, 3 right-left (RL), 3 right-noncoronary (RN) leaflet fusion, and quadricuspid aortic valves (n = 2).  Data analysis included the co-registered visualization of aortic valve morphology with systolic 3D blood flow.  The influence of valve morphology on aortic hemodynamics was quantified by valve flow angle.


 All RL-bicuspid aortic valve (BAV) were associated with flow jets directed toward the right anterior aortic wall while RN-fusion and unicuspid valves resulted in flow jet patterns toward the right-posterior or posterior wall.  Flow angles were clearly influenced by valve morphology (47° ± 10, 28° ± 2, 29° ± 18, 18° ± 12, 15° ± 2 for unicuspid, true BAV, RN-BAV, RL-BAV, quadricuspid valves) and increased compared with controls (7.2° ± 1.1, P = 0.001).


 CONCLUSION
 Altered 3D aortic hemodynamics are impacted by the morphology of congenitally malformed aortic valves.
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