Patients frequently suffer from cognitive impairments following brain radiotherapy. Ionizing radiations are known to induce various brain alterations and impair neurogenesis. Following whole cerebral irradiation (3X5 Gy), we found significant changes in non-Gaussian water diffusion parameters (ADC0 and kurtosis) and related S-index, a new diffusion biomarker sensitive to changes in tissue microstructure, in the subventricular zone, a site of adult neurogenesis and in the olfactory bulbs. MRS exhibited a longitudinal decrease in taurine specifically in the olfactory bulbs. These results suggest that diffusion MRI and MRS could be used to monitor changes induced by radiation injury.