Time-Dependent Wall Shear Stress Measurement in Middle Cerebral Artery (MCA) using Bi-Exponential Curve Fitting of Phase Contrast MR Angiography

Namkug Kim¹, SeonKyu Lee²

Vascular wall shear stress (WSS) is believed to play a critical role in the processes of atherosclerosis. WSS could be used to assess vascular disease initiation and proliferation processes. In this study, we sought to develop a method suitable for time-dependent measurements of WSS in the M1 segment of the MCA with robust lumen segmentation and PVE suppression. To suppress partial volume effects (PVE), bi-exponential curve fitting with wall boundary outliers was performed on velocity profiles. The measured range of WSS is about 4.41~ 6.402 Pa. In addition, the lumen cross-sectional area of MCA and WSS were evaluated at all-time points of the cardiac cycle and their temporal changes including luminal diameter, luminal area change, color-coded WSS on MRI were measured.