2. Biomedical Engineering Graduate Program, Faculty of Applied Science, University of British Columbia, Vancouver, BC, Canada.
3. Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
The correlation between plaque morphology as well as composition and plaque vulnerability has been the motivation for many recent studies. In a generic point of view, instability of atherosclerotic plaques is known to be the result of a thin fibrous cap and a large and highly compliant necrotic core area. There have been numerous two-dimensional (2D) and three-dimensional (3D) computational models mostly based on the finite element method (FEM) to assess the plaque vulnerability. It is well-known that 2D models are not reliable as they do not provide a consistent assessment on the vulnerability of plaques and are highly erroneous. 3D models offer a more effective evaluation but creating 3D models to be further assessed by computational means such as the finite element method is time-consuming. However, 2D models are easier to develop and are less time-consuming to assess. In this study, we propose a novel computational platform by which the plaque vulnerability is assessed using only 2D plaque models. We develop idealistic 2D models and their corresponding idealistic 3D models. The idealistic 3D models resemble the worst- and best-case scenarios for each 2D model. Using these 3D idealistic models, a standard error (SE) is estimated and then added to the peak stress values calculated earlier using 2D models. These SEs are also used to assess the probability of plaque stability. In this platform, the effect of viscoelasticity and anisotropy of the plaque composition is taken into consideration and the transmural pressure considered is similar to that of physiological conditions (dynamic pressure). The current study may suggest a more realistic insight to the prediction of atherosclerotic plaques rupture using 2D images.
Keywords: Finite element method, atherosclerotic plaque, large deformation theory, computational mechanics, numerical modeling