Numerical simulation of flow behavior in basilar bifurcation computed tomography angiography

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Computational Fluid Dynamics

Background:

• Cerebral aneurysms pose a significant risk of rupture.
• Accurate modeling of blood flow dynamics is crucial for understanding aneurysm progression and rupture risk.
• Previous models often simplified the dynamic nature of aneurysm walls.

Purpose of the Study:

• To develop and validate a realistic moving boundary deformation model for cerebral aneurysms using 4D-CTA data.
• To investigate the impact of aneurysm wall motion on key hemodynamic factors.
• To compare hemodynamic parameters under moving versus rigid boundary conditions.

Main Methods:

• Construction of a high-temporal-resolution moving boundary deformation model from 4D-CTA.
• Numerical simulations of blood flow within basilar artery aneurysms.
• Evaluation of four hemodynamic factors: wall shear stress (WSS), wall shear stress divergence (WSSD), oscillatory shear index (OSI), and residual residence time (RRT).

Main Results:

• The moving boundary model accurately captured aneurysm wall dynamics.
• Significant differences in spatial-averaged WSS and maximum WSSD were observed between moving and rigid boundary conditions, particularly during peak systole.
• Substantial variations in OSI and RRT were also found, highlighting the importance of wall motion.

Conclusions:

• Aneurysm wall motion significantly influences hemodynamic factors.
• The developed 4D-CTA based moving boundary model provides a more realistic representation of blood flow dynamics.
• These findings have implications for improved aneurysm assessment and treatment planning.