Assessing the Functional Severity of Carotid Artery Stenosis Using an Image-Based Hemodynamic Modeling Method

Area of Science:

• Cardiovascular research
• Medical imaging
• Computational fluid dynamics

Background:

• Distal-to-proximal pressure ratio (dpPR) is superior to diameter stenosis rate (DSR) for assessing carotid artery stenosis (CAS) functional severity.
• dpPR cannot be directly measured from vascular imaging, unlike DSR.

Purpose of the Study:

• Develop a hemodynamic modeling method to predict dpPR using clinically available medical images.
• Enable non-invasive assessment of CAS functional severity.

Main Methods:

• Employed a multiscale modeling approach integrating 3D CAS hemodynamic models with systemic hemodynamics.
• Incorporated patient-specific geometry from computed tomography angiography (CTA) images.
• Validated the 3D model with in vitro experiments and the multiscale model with invasive pressure wire measurements.

Main Results:

• Model-predicted dpPR showed strong agreement with invasive measurements (mean relative error -0.8%, SD 2.5%).
• dpPR moderately correlated with DSR (r=-0.55, p=0.003).
• Circle of Willis (CoW) anatomy significantly influences the dpPR-DSR relationship.

Conclusions:

• Multiscale modeling based on CTA images offers a practical method for assessing CAS hemodynamic impact.
• CoW anatomy is critical for understanding the relationship between dpPR and DSR in CAS.
• Systemic cerebral hemodynamics are important for evaluating CAS functional severity.