Velocity Measurement at Carotid Siphon: Quantitative Comparison of Phase Contrast MRI and Computational Fluid Dynamics

Phase contrast magnetic resonance imaging (PC MRI) and the computational fluid dynamics (CFD) are two of the most important technologies in the investigation on the velocity field in blood vessels in vivo. In order to quantitatively compare the differences between the two methods, the blood flow velocity measurements based on PC MRI and patient-specific CFD were conducted at internal carotid artery from 9 healthy volunteers. The 3D velocity field calculated from PC MRI data were compared with CFD simulation in 5 planes covering the carotid siphon. Then the resistance index (RI), and errors in the magnitude and direction of velocity were calculated between the two methods. The results showed that the flow patterns of PC MRI and CFD were similar, and the velocity distribution and RI was in good agreement. But there were significant differences in the velocity magnitude near the posterior knee and vessel wall, while the directional error was larger at the center of the artery. These comparison between PC MRI and CFD may guide the development of CFD technology and improve its accuracy.