ANATOMICALLY CONSTRAINED ELECTRICAL-IMPEDANCE TOMOGRAPHY FOR 3-DIMENSIONAL ANISOTROPIC BODIES

As shown previously for two-dimensional geometrics, anisotropy effects should not be ignored in electrical impedance tomography (EIT) and st ructural information is important for the reconstruction of anisotropi c conductivities, Here, we will describe the static reconstruction of an anisotropic conductivity distribution for the more realistic three- dimensional (3-D) case, Boundaries between different conductivity regi ons are anatomically constrained using magnetic resonance imaging (MRI ) data, The values of the conductivities are then determined using gra dient-type algorithms in a nonlinear-indirect approach, At each iterat ion, the forward problem is solved by the finite element method, The a pproach is used to reconstruct the 3-D conductivity profile of a canin e torso. Both computational performance and simulated reconstruction r esults are presented together with a detailed study on the sensitivity of the prediction error with respect to different parameters, In part icular, the use of an intracavity catheter to better extract interior conductivities is demonstrated.