Biomechanical Study Of Atheromatous Plaque Rupture

The rupture of atherosclerotic plaque is the major cause of stroke or heart attack. In this study, we discuss the mechanisms of plaque rupture based on idealized plaque models and patient-specific data by performing biomechanical analysis. A protocol of plaque vulnerability assessment is proposed based on medical imaging techniques and plaque stress analysis.We developed biomechanical models for atherosclerotic plaque with microstructural components. The mechanical stability of plaque is discussed by considering the physiological conditions such as boundary constraints from the myocardial tissue and lumen. The roles of inhomogeneous factors such as calcification and inflammation are discussed as well. To further include patient-specific variability and statistical characteristics, we constructed biomechanical models based on medical image processing. With the medical resonance imaging (MRI) data from 17 patients, we investigated the sensitivity of plaque stress on the contours of vascular walls and report their correlation. By combining the optical coherence tomography (OCT) and intravascular ultrasound (IVUS) techniques, we explored the biomechanical characteristics in 53 sets of plaque data from 30 patients, and report the statistical correlation between the microstructures of plaques and their stress. The results are discussed with the condition of thin cap fibroatheroma (TCFA).With our discussion on the idealized plaque models and patient-specific medical imaging data, we developed a set of quantitative, programmable tools for the analysis of plaque vulnerability, including image match and segmentation, structural modeling, stress calculation and statistical analysis. Considering the large volumes of medical imaging data available, the conclusions and tools reported in this work hold great promises in the clinical assessment and risk stratification of vulnerable plaques.