近年来,脑血管疾病的发病率持续上升,大脑因为其特殊的颅内构造以及对温度的高度敏感性而备受关注。与人体其他器官相比,目前微血管脑网络的定量数据仍较匮乏。Willis环作为大脑核心血管结构,现有的研究未能全面分析Willis环闭合回路几何结构中的流动与传热行为,其精确建模对于深入理解脑血管系统的结构和功能、探究相关脑部疾病机理具有重要意义。本文基于人体大脑电子计算机断层扫描（CT）图像进行三维建模以模拟Willis环内血液流动,并进行血流动力学分析。研究结果表明,Willis环的非对称环形结构与非对称非环形结构和对称环形结构相比,拥有最大的Nu¯，分别提高了5.9%和8.4%,且在边界条件发生变化时Willis环的非对称环形结构的∆Nu¯变化量最小,使得Willis环在具有较强稳定性的同时,拥有更强的换热能力。Willis环的血流数值模拟可为发病机理及临床诊断提供一定参考。
In recent years, the incidence of cerebrovascular diseases continues to rise, and the brain has attracted much attention due to its special intracranial structure and high sensitivity to temperature. Compared with other organs, the quantitative data of human microvascular brain network is still scarce. The Willis circle is the core vascular structure of the brain. The existing research has not comprehensively analyzed the flow and heat transfer behavior in the geometric structure of the Willis circle closed loop. Its accurate modeling is of great significance for understanding the structure and function of the cerebrovascular system and exploring the related brain disease mechanism. In this paper, three-dimensional modeling based on computed tomography (CT) images of the human brain is used to simulate the blood flow in the Willis ring and perform hemodynamic analysis. The results show that the asymmetric ring structure of the Willis ring has the largest increase of 5.9% and 8.4%, respectively, compared with the asymmetric non-ring structure and the symmetric ring structure. When the boundary conditions change, the asymmetric ring structure of the Willis ring has the smallest amount of change, which makes the Willis ring have stronger stability and stronger heat transfer capacity. The numerical simulation of blood flow in the circle of Willis can provide reference for pathogenesis and clinical diagnosis.
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