Impact of Partial Echo on 4D Flow MRI: The Insight From Synthetic MRI.

The aim of this study is to investigate the impact of the partial echo on 4D flow MRI sequences thanks to in silico coupled MRI-CFD (computational fluid dynamics) simulations. Two sequences are studied: one with a full echo (FE) and another using partial echo (PE) with an echo symmetry fraction of 0.75. MRI-CFD simulations are conducted on an in silico pulsatile flow phantom for a sinusoidal inflow and a physiological inflow typical of the ascending aorta. For both inflow signals, PE-based simulations exhibited better compliance with their matching CFD simulations compared to the FE ones. The reduction of flow misregistration artifacts achieved through the use of PE appears to be more beneficial than the drawback of incomplete k-space filling. The MRI-CFD framework presented in this study appears as a useful tool to investigate the design of MRI sequences and to stratify its different sources of errors.