Both diffusion weighted MRI and Sodium MRI are imaging techniques sensitive to tissue microstructure. The two methods provide complementary information and use tissue models to interpret observed signals to obtain tissue-specific parameters. We investigated the relationship between several tissue-parameters of the two models in the white matter and in the Corpus Callosum. Our results suggests that, the measured cell volume fraction of sodium agrees with diffusion basis spectrum images features. This opens to the possibility of using sodium MRI to investigate pathological tissues and recover complementary information to those we can retrieve with diffusion MRI.