Example systems and methods concern systems and methods for modeling conduction in a volume. In one embodiment, diffusion eigenvalues of a plurality of diffusion tensors are received. The diffusion tensors are associated with an anatomical structure having heterogeneous and anisotropic tissues. In one embodiment, the diffusion eigenvalues of the diffusion tensors are calculated from imaging data. Then one or more conductance ratios of a conductivity tensor are set based, at least in part, on one or more diffusion ratios of a corresponding diffusion tensor. The conductance eigenvalues of a conductivity tensor can then be calculated based, at least in part, on the one or more conductance ratios of the conductivity tensor. A volume-conductor model of the anatomical structure is generated based, at least in part, on the plurality of calculated conductivity tensors.
