Towards a rapid extraction of three-dimensional Lagrangian coherent structures from in vivo 4D-MRI

Interventricular fluid dynamics are complex and three-dimensional. Moreover, under pathological conditions, such as aortic regurgitation, the complexity of the ventricular flow requires fast and efficient three-dimensional analysis tools. Therefore, this study aims to extend the application of Lagrangian descriptors to identify three-dimensional coherent structures in cardiovascular flows. Using in vivo 4D-MRI velocity fields, ventricular coherent structures in the presence of aortic regurgitation are compared to structures in healthy patients. The results show that the method based on Lagrangian descriptors can rapidly extract flow coherent structures when compared to other approaches. Moreover, the identified structures in the presence of aortic regurgitation reveal the breakup of the optimized left ventricular filling structures.