A pulsatile 3D flow relevant to thoracic hemodynamics: CFD - 4D MRI comparison

Application Area 7: Biomedical Flows

Application Challenge AC7-04

Abstract

3D time-resolved phase-contrast magnetic resonance imaging (3D cine PC-MRI, also known as 4D Flow MRI) is a clinical method of growing interest, which allows a non-invasive and non-ionizing access to blood velocity fields. The knowledge of hemodynamics that it brings could help clinicians in the detection and follow-up of numerous cardiovascular diseases. However, 4D Flow MRI presents some limitations, such as poor spatio-temporal resolution, imaging artefacts or machine-specific variability. From another perspective, CFD simulations can also provide 3D velocity fields, while avoiding some of the experimental constraints due to the MRI acquisition process.

The objective of the current application challenge is to compare CFD and 4D Flow MRI in a well-controlled environment. For this, an experimental set-up containing a non-deformable phantom has been developed. This phantom has been geometrically designed to contain some of the typical topology found in the cardiovascular system, and thus the associated flow patterns of interest. The in vitro 4D Flow measurements have been recorded under a pulsatile flow rate. The flow in the corresponding numerical phantom has been simulated by means of an in-house LES solver. Finally, some post-processing steps needed for a comparison of the two methods will be presented.

The methods described in the present Application Challenge are mainly based on T. Puiseux's PhD work [1], which has been reported in Puiseux et al. (2019) [2] and serves as the basis for ongoing research on \textit{in silico} MRI (Puiseux et al. 2021 [3]).