Diffusion magnetic resonance imaging (DMRI) can give useful information on cellular structure and its structural changes. Salomé is used to reproduce some complicated shapes in d-dimensions (d=2,3) that are used to represent the natural structures of various biological tissue. The meshes representing these shapes are used as inputs to a finite element code that we built upon FENICS C++. Results were obtained for a model of globlastoma (cerebral tumor) as a Voronoi diagram which was used to observe the convergence of the apparent diffusion tensor in long-time limit to the effective diffusion tensor computed by homogenization theory.