A comprehensive MRI-based computational model of blood flow in compliant aorta using radial basis function...

Area of Science:

• Biomedical Engineering
• Cardiovascular Imaging
• Computational Fluid Dynamics

Background:

• Thoracic aortic aneurysm (TAA) progression and rupture are poorly understood.
• Detailed study of aortic blood flow is crucial for TAA pathogenesis.
• Magnetic resonance imaging (MRI)-based computational fluid dynamics (CFD) can provide detailed aortic blood flow information.

Purpose of the Study:

• To develop and validate a novel computational approach for simulating aortic wall motion in TAA.
• To compare blood flow dynamics in static (rigid wall) versus dynamic (moving wall) simulations.
• To assess the utility of this approach for understanding TAA development.

Main Methods:

• Developed a radial basis function (RBF) interpolation method for dynamic aortic wall motion from 4D-flow MRI.
• Performed static and dynamic CFD simulations for healthy controls and a TAA patient.
• Utilized reconstructed 4D-flow MRI velocity profiles at the inlet with automatic registration.

Main Results:

• The RBF-based morphing approach accurately reproduced aortic geometries from 4D-flow MRI.
• Aortic wall movement was most pronounced in the ascending aorta, correlating with blood flow variations.
• Significant differences in wall shear stress and oscillatory shear index were observed between static and dynamic simulations.

Conclusions:

• The RBF-based morphing approach is accurate and efficient for capturing aortic kinematics in MRI-based CFD.
• This method is recommended for future TAA studies using broad population datasets.
• Improved understanding of TAA onset and growth can be achieved through this simulation technique.