Modeling and Realistic Simulation of the Carotid Artery Birfurcation Using 3-D Image Segmentation Implemented in a Commercial Software Package for Hemodynamic Simulation (cvSim™)

Abstract

Stroke is the third leading cause of death and a major cause of disability in the United States. Extracranial carotid artery disease is a major risk factor for stroke. Local hemodynamic forces are important in the development and progression of atherogenesis with areas of low and oscillatory wall shear stress (WSS) such as those occurring in the carotid bifurcation being more prone to atheroma development. Despite the importance of WSS in atherosclerosis, there is currently no practical means of measuring this variable clinically. Computational fluid dynamics (CFD) simulations of patient-specific models built from imaging data may provide a clinically relevant solution [1]. For CFD results to be clinically applicable, they need to replicate hemodynamic and imaging measurements to provide physiologic WSS values and the simulation and quantification process must be conducted in a time-frame consistent with the short duration needed for plaque and intima-media thickness assessment. LaDisa, Migrino and colleagues recently reported on a rapid and practical means of generating WSS maps associated with carotid atherosclerosis using patient-specific CFD models derived from 2D and Doppler ultrasound for flow information and MRI for 3D structure before and after 6 months of statin treatment [2]. Although these results were achieved after 17±8 hours/patient instead of days or weeks for prior models, model construction, quantification of results and simulation time were the most time consuming portions of the simulation process with CFD model construction being the most user-intensive portion of the process.