Hemodynamics in Patients with Aortic Coarctation: A Comparison of in vivo 4D-Flow MRI and FSI Simulation

Abstract

The analysis of quantitative hemodynamics provides information for the diagnosis and treatment planning in patients with aortic coarctation (CoA). Patient-specific computational fluid dynamics (CFD) simulations reveal detailed hemodynamic information, but their agreement with the clinical standard 4D-Flow magnetic resonance imaging (MRI) needs to be characterized. This work directly compares in vivo CFD fluid-structure interaction (FSI) simulations against 4D-Flow MRI in patients with CoA (N=5). 4D-Flow MRI-derived flow waveforms and cuff blood pressure measurements were used to tune the boundary conditions for the FSI simulations. Flow rates from 4D-Flow MRI and FSI were compared at cross-sections in the ascending aorta (AAo), CoA and descending aorta (DAo). Qualitative comparisons showed an overall agreement of flow patterns in the aorta between the two methods. The R2 values for the flow waveforms in the AAo, CoA, and DAo were 0.97, 0.84 and 0.81 respectively, representing a strong correlation between 4DFlow MRI measurements and FSI results. This work characterizes the use of patient-specific FSI simulations in quantifying and analyzing CoA hemodynamics to inform CoA treatment planning.