Flow pattern analysis in a highly stenotic patient-specific carotid bifurcation model using a turbulence model

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Carotid artery stenosis significantly increases stroke risk.
• Understanding blood flow dynamics is crucial for assessing plaque vulnerability.
• Current models may not fully capture complex flow patterns in severe stenosis.

Purpose of the Study:

• To investigate blood flow patterns in carotid bifurcation with severe stenosis.
• To evaluate wall shear stress (WSS) and pressure drop using a novel transitional flow model.
• To correlate hemodynamic variables with plaque vulnerability in patient-specific models.

Main Methods:

• Combined in vivo magnetic resonance imaging (MRI) for patient-specific geometry and boundary conditions.
• Employed a newly developed two-equation transitional model for computational fluid dynamics (CFD) simulation.
• Analyzed flow velocity, wall shear stress (WSS), and oscillatory shear index (OSI).

Main Results:

• Predicted peak time-averaged WSS of approximately 73 Pa at the stenosis throat.
• Identified high WSS regions at the stenosis throat.
• Observed high OSI values (up to 0.50) associated with helical flow patterns post-stenosis.

Conclusions:

• A transitional turbulent flow model shows potential for analyzing hemodynamics in severe carotid stenosis.
• Patient-specific MRI data combined with CFD can reveal critical flow phenomena.
• Findings provide a basis for investigating links between hemodynamics and plaque vulnerability for risk assessment.