High resolution 3D-RARE magnetic resonance imaging (MRI) was carried out in the brain of rats (n=114) of varying ages and cognitive performance. Volumetric comparison of total intracranial volume (TIV) and total ventricular system (TVS) was performed using an atlas based analysis. The TIV increases from young adult to middle age but plateaus through old age. Average body weight increases from young adult to middle age but decreases from middle age to old age. No significant difference was found in TVS volume between ages or cognitive ability.