A Patient-Specific Three-Dimensional Hemodynamic Model of the Circle of Willis
Hamed Rezaie1, Ali Ashrafizadeh2, Afsaneh Mojra2
1Department of Mechanical Engineering, K. N. Toosi University of Technology, 15 Pardis St., Tehran, 1999143344, Iran. h.rezaie@mail.kntu.ac.ir.
Insights
This study numerically models blood flow in the Circle of Willis (CoW) to identify disease-prone areas. The computational model accurately captures hemodynamic characteristics for predicting patient-specific risks.
Area of Science:
- Biomedical Engineering
- Computational Fluid Dynamics
- Cerebrovascular Research
Background:
- The Circle of Willis (CoW) is a critical cerebral arterial network.
- Understanding blood flow hemodynamics in the CoW is vital for predicting neurological diseases.
- Previous studies have attempted hemodynamic analysis with varying degrees of complexity.
Purpose of the Study:
- To develop and validate a patient-specific computational model of the Circle of Willis (CoW).
- To predict regions within the CoW that are susceptible to disease development.
- To analyze hemodynamic parameters like blood pressure, velocity, and wall shear stress.
Main Methods:
- A realistic 3D model of a patient-specific CoW was constructed using medical imaging and CAD software.
- Arterial walls were modeled as elastic conduits using the Mooney-Rivlin hyperelastic model.
- Blood flow was simulated as a non-Newtonian fluid (Carreau model) using the finite element method (ADINA software).
- An experimental pulsatile velocity profile was applied at the CoW entrance.
Main Results:
- The computational model successfully simulated hemodynamic characteristics of the CoW.
- Calculations included blood pressure, velocity, and arterial wall shear stress distribution.
- Comparison with published data for a simplified model showed good agreement.
- The model demonstrated the potential to identify hemodynamically vulnerable regions.
Conclusions:
- The developed patient-specific computational model is effective for analyzing CoW hemodynamics.
- This approach can accurately predict disease-prone locations within the Circle of Willis.
- The findings support the use of computational modeling for personalized cerebrovascular risk assessment.
Abstract:
Circle of Willis (CoW) is one of the most important cerebral arteries in the human body and various attempts have been made to study the hemodynamic of blood flow in this vital part of the brain. In the present study, blood flow in a patient specific CoW is numerically modeled to predict disease-prone regions of the CoW. Medical images and computer aided design software are used to construct a realistic three-dimensional model of the CoW for this particular case. The arteries are considered as elastic conduits and the interactions between arterial walls and the blood flow are taken into account. Mooney-Rivlin hyperelastic model is used to describe the behavior of arterial walls and blood is considered as a non-Newtonian fluid obeying the Carreau model. An available experimental-based pulsatile velocity profile is used at the entrance of the CoW. The finite element-based commercial software, ADINA, is used to solve the governing equations. Blood pressure and velocity and arterial wall shear stress are calculated in different regions of the CoW. A simplified form of the model is also compared with the available published data. Results affirmed that the proposed computational model has the potential to capture the hemodynamic characteristics of the CoW. The computational results can be used to determine disease-prone locations for a given CoW.
