Agent Based with Finite Element Method for Plaque Progression in the Carotid Artery.

Atherosclerosis is condition characterized by arterial lumen stenosis through the formation of a plaque (atheroma). Plaques can be comprised of foam cells, fatty substances, lipids, cholesterol, cellular waste products, elastin, collagen, fibrin, calcium and many other constituents. A new computational model for plaque progression in the carotid artery using coupled Agent Based Method (ABM) and Finite Element Method (FEM) was developed. The ABM was coupled with an initial Wall Shear Stress (WSS) profile, which triggers a pathologic vascular remodeling by perturbing the baseline cellular activity and favoring lipid infiltration and accumulation within the arterial wall. The ABM model takes shear stress and LDL initial distribution from the lumen and starts iterative calculation inside the wall for lipid infiltration and accumulation using a random number generator for each time step. After ABM iterations, both wall lipid distribution and wall geometry are changed. Fluid-structure solver is running and lumen domain is calculated again. First results show good agreement between proposed method and clinical measurements in the follow up 3D Ultrasound image reconstruction. The integrated model ABM and FEM can help to predict the evolution of atherosclerotic plaque which is very significant for appropriate diagnostics and vascular treatment planning.