Assessment of hemodynamic parameters distribution in normal carotid artery by using computational fluid dynamics based on CE-MRA data

This study was to analyze the in vivo distribution of wall shear stress (WSS), velocity and in-plane pressure difference in normal carotid artery by using computational fluid dynamics (CFD) based on contrast-enhanced MRA (CE-MRA) data and to determine whether there were differences in these hemodynamic parameters between atherosclerosis-free and atherosclerosis-prone areas. CE-MRA was performed on 16 normal carotid arteries to obtain carotid three-dimensional surface data. CFD analysis was then performed to estimate those parameters in atherosclerosis-free (distal common carotid artery and distal internal carotid artery) and atherosclerosis-prone (carotid bifurcation) areas. One-way analysis of variance (ANOVA) was conducted to analyze differences among these three areas. CFD analysis revealed that WSS and velocity were significantly lower in carotid bifurcation compared to distal common carotid artery (CCA) (P =0.011, P <0.001, respectively) and distal internal carotid artery (ICA) (P <0.001, P <0.001, respectively). While in-plane pressure difference was significantly higher in carotid bifurcation compared to distal CCA (P <0.001) and distal ICA (P =0.005). Hemodynamic environment in carotid bifurcation of normal carotid artery which assessed by using CFD analysis appeared to be with lower WSS and lower velocity, while with higher in-plane pressure difference. These characterizations might facilitate the initiation of atherosclerosis.