From medical images to anatomically accurate finite element grids

The successful application of computational modelling of blood flow for the planning of surgical and interventional procedures to treat cardiovascular diseases strongly depends on the rapid construction of anatomical models. The large individual variability of the human vasculature and the strong de pendence of blood flow characteristics on the vessel geometry require model ling on a patient-specific basis. Various image processing and geometrical modelling techniques are integrated for the rapid construction of geometric al surface models of arteries starting from medical images. These discretel y defined surfaces are then used to generate anatomically accurate finite e lement grids for hemodynamic simulations. The proposed methodology operates directly in 3D and consists of three stages. In the first stage, the image s are filtered to reduce noise and segmented using a region-growing algorit hm in order to obtain a properly defined boundary of the arterial lumen wal ls. In the second stage, a surface triangulation representing the vessel wa lls is generated using a direct tessellation of the boundary voxels. This s urface is then smoothed and the quality of the resulting triangulation is i mproved. Finally, in the third stage, the triangulation is subdivided into so-called discrete surface patches for surface gridding, the desired elemen t size distribution is defined and the finite element grid generated. Copyr ight (C) 2001 John Wiley & Sons, Ltd.