Diffusion weighted imaging is largely used in medical imaging to diagnosis neuropathologies on patient. The signal of water diffusion along neurons is anisotropic. In the past 20 years, this signal is commonly estimated by a tensor and defined as Diffusion Tensor Imaging (DTI). The tensor groups the different cellular microstructures (neurons, myelin, astrocyte, microglia,...) in one compartiment. Recently, multi compartiments models have been proposed to take into account the different cellular microstructure and the heterogeneity. These models have been validated to the healthy subject. In this research, these multi compartiments models are assessed to characterize the Wallerian degeneration process in the spinal cord after the unilateral dorsal roots transection.