Hemodynamic in Aortic Coarctation Using MRI-Based Inflow Condition

Image-based CFD can support diagnosis, treatment decision and planning. The ability of CFD to calculate pressure drop across the aortic coarctation is the focus of the 2013 STACOM Challenge. The focus of our study was inflow conditions. We compared a MRI-based inlet velocity profile with a swirl and an often used plug velocity profile without swirl. The unsteady flow simulations were performed using the solver FLUENT with consideration of the challenge specifications. For outflows, the constant outflow ratios of the supra-aortic vessels were set. The consideration of a secondary flow swirl at the inlet of the ascending aorta significantly affect reduce the calculated pressure drop across the aortic coarctation and hence the treatment decision. Furthermore, using MRI-measured flow rates at the ascending and the descending aorta without a proof of data consistency could result in an overestimated pressure drop due to overestimated flow into the supra-aortic vessels.