Quantitative Methods for Comparisons between Velocity Encoded MR-Measurements and Finite Element Modeling in Phantom Models

摘要

Wall Shear Stress is a key factor in the development of atherosclerosis. To assess the WSS in-vivo, velocity encoded MRI is combined with geometry measurements by 3D MR-Angiography (MRA) and with blood flow calculations using the Finite Element Method (FEM). The 3D geometry extracted from the MRA data was converted to a mesh suitable for FEM calculations. Aiming at in-vivo studies the goal of this study was to quantify the differences between FEM calculations and MRI measurements. Two phantoms, a curved tube and a carotid bifurcation model were used. The geometry and the time-dependent flow-rate (measured by MRI) formed input for the FEM calculations. For good data quality, 2D velocity profiles were analyzed further by the Kolmogorov-Smirnov method. For the curved tube calculations and measurements matched well (prob_(KS) approximately above 0.20). The carotid needs further investigation in segmentation and simulation to obtain similar results. It can be concluded that the error-analysis performs reliably.