Patient Specific Hemodynamics: Combined 4D Flow-Sensitive MRI and CFD

Both 4D flow-sensitive MRI and computational fluid dynamics (CFD) have successfully been applied to analyze complex 3D flow patterns in the cardiovascular system. However, both modalities suffer from limitations related to spatiotemporal resolution, measurement errors, and noise (MRI) or incomplete model assumptions and boundary conditions (CFD). The aim of this study was to directly compare the results of 4D flow-sensitive MRI and CFD in a simple model system in vitro and in complex models of the thoracic aorta in vivo. By comparing both modalities within a single framework, discrepancies were observed but the overall patterns were coherent. If adequate methods are used (e.g., patient-specific boundary conditions, fine boundary layer mesh), CFD can compute very accurate flow and vessel wall parameters, such as wall shear stress (WSS). The combination of 4D flow-sensitive MRI and CFD can be used to refine both methodologies, which may help to enhance the assessment and understanding of blood flow in vivo.