基于三维医学影像的大鼠狭窄门静脉内的血液流动数值模拟

Numerical Simulation of Blood Flow in Stenosis Portal Vein in Rats Based on 3D Medical Images

摘要: 利用数值模拟研究大鼠具有病理特异性的处于中度狭窄内的门静脉内的血液流动，研究狭窄程度与左右分支流量比值以及流速分布的关系。从大鼠门静脉中度狭窄病理的3D-RA数据中重建57%、60.4%、61.39%、62.55%、64.13%五组不同狭窄程度的门静脉几何模型，血液流变学模型选择牛顿流体模型，利用商用CFD (Computational Fluid Dynamics)软件Ansys Fluent对该五组狭窄门静脉内的血液流动进行了数值模拟。结果表明血流动力学因素如流速、压力、壁面切应力、流动对壁面的冲击状况等因素与门静脉狭窄的发展密切相关，且门静脉狭窄程度的不同对门静脉左右分支过血流量以及左右肝叶的生长造成直接影响。最后基于数值模拟的结果，率定了大鼠门静脉狭窄程度与左右分支流量比值以及大鼠门静脉狭窄程度与PVVR比值的公式，可用于进一步研究门静脉狭窄程度与其流量比、PVVR比值之间的定量关系。

Abstract: Numerical simulations were used to study blood flow in the portal vein of rats with pathological specificity in moderate stenosis and to investigate the relationship between the degree of stenosis and the ratio of flow in the left and right branches and the distribution of flow velocity. The 3D-RA data of moderate stenosis in rat portal vein were reconstructed from the 3D-RA data of 57%, 60.4%, 61.39%, 62.55%, and 64.13% of different degrees of stenosis, and the blood rheological model was chosen as the pseudoplastic non-Newtonian fluid model. Commercial software Ansys Fluent is used to perform numerical simulations. The results showed that hemodynamic factors such as flow ve-locity, pressure, wall shear stress, and the impact of flow on the wall were closely related to the de-velopment of portal vein stenosis, and that the different degrees of portal vein stenosis had a direct effect on the overflow of the left and right branches of the portal vein as well as the growth of the left and right hepatic lobes. Finally, based on the results of numerical simulations, the equations for the ratio of the degree of portal vein stenosis to left and right branch flow in rats and the ratio of the degree of portal vein stenosis to PVVR in rats were determined, which can be used to further inves-tigate the quantitative relationship between the degree of portal vein stenosis and its flow ratio and PVVR ratio.