The function of water molecule exchange on the plasma membrane by aquaporins was evaluated using HEK293T cultured cells. Time-dependent diffusion magnetic resonance imaging (MRI), in which diffusion time (DT) was varied in 14 steps from 13 to 784 ms, was used to observe differences in water molecules and the permeability of the cell membrane with and without aquaporin inhibition. The diffusion coefficient increased with increasing DT in normal cells, but not in aquaporin 4-inhibited cells. These results suggest that time-dependent diffusion MRI may capture the function of water molecule exchange at the plasma membrane.