Assessment of plaque stability by means of high-resolution MRI and finite element analyses of local stresses and strains

To date no adequate diagnostic strategy exists for the assessment of plaque stability. Current approaches focus on identification of high-risk morphological features in cross-sectional images, such as thin caps and large lipid pools. Plaque stability, however, is a 3D mechanical problem, whose solution requires information on both the geometry and the mechanical properties of the involved tissue components. This preliminary in vitro study is aimed to create multicomponent morphological and material models of human diseased arteries from cadavers. Morphological models are based on highly resolved MR images. Material models are fitted to mechanical testing data of single tissue components. Subsequent finite element analysis allows computation of local stresses and strains, whereas consideration of fracture properties provides a basis for the plaque stability assessment. Results demonstrate the complex mechanical behavior of diseased arteries, suggesting that reliable plaque stability assessment requires a combination of appropriate MR protocols, segmentation algorithms and mechanical analysis.