Blood flow analysis in the circle of Willis using computed tomography scan images and fluid-structure interactions method

Study of blood flow in cerebral arteries is of great importance in recognition of initiation and critical conditions of arterial diseases in the brain. So, in this investigation with the novel assumption of arteroal wall deformability, blood flow and arterial wall shear stress in the circle of Willis were analyzed. CT angiography images were used to design the geometry and available model for solving blood flow. Finite elements method was utilized to solve the problem. With the study of the wall of the arteries, the behavior of the hyperelastic was assumed. Therefore, the solution of the flow is studied by the method of fluid-structure interaction. The boundary conditions of the fluid (blood), including multi-branching as well as autoregulation, were investigated at the inlet and outlet of the arteries. The maximum shear stress on the wall was equal to 3.9 Pascal. In addition, blood pressure in the upper arteries in circle of Willis was significantly reduced as compared to the blood pressure at the outlet of the heart. Analysis of shear stress contour in diastol showed that the maximum shear stress occurs in PCA, while it is minumum in initial parts of PCA. Approach of this study to use radiological images of specific humans can be helpful in diagnosis of initiation and development of arterial diseases. Moreover, in acute situations of these diseases, through anticipating of dangers such as tearing of the vessels due to variations of wall shear stress, such a performed simulation may aid physicians for probable treatments.