The assessment of patient-specific abdominal aortic aneurysm (AAA) rupture risk using finite element (FE) modeling has been shown to be an improvement over current diameter-based prediction techniques (Fillinger, 2002, 2003). However, certain modeling assumptions are made which may have significant effects on the computed AAA wall stresses. For example, the FE meshes are based on composite computed tomography (CT) images obtained during multiple cardiac cycles. This results in meshes that are averaged representations of pressurized AAAs, yet are assumed to represent AAAs at the zero-stress state. Also, the proximal and distal ends of the AAA FE models are assumed to be fixed in place, which may be satisfactory boundary conditions, but have yet to be validated. Recent developments in dynamic magnetic resonance (dMR) imaging allow AAA cross-sectional images to be obtained at multiple locations and time points throughout a cardiac cycle. These images are used to determine the geometries and positions of AAAs at various times throughout the cardiac cycle.
Influence of the cardiac cycle on time–intensity curves using multislice dynamic magnetic resonance perfusion
