Volumetric/morphometric changes in brain structures are often investigated as markers for disease or drug-induced effects. Brain tissue has been shown to shrink during mild dehydration which is not typically controlled for in MRI studies thus potentially confounding the results. Quantitative T1 is expected to change in response to changes in water content of tissue. Here, we show for the first time, that T1 maps, generated as we suggest, can capture regional water shifts that result from changes in hydration status. These can be used to control for water shifts in volumetric/morphometric studies and may aid in the interpretation of results.