Systematic changes to the apparent diffusion tensor of in vivo rat brain measured with an oscillating-gradient spin-echo sequence

► Clear frequency-dependent changes were measured over the range 33.3-133.3 Hz. ► All selected regions showed clear increases in mean diffusivity. ► Fractional anisotropy may either increase or decrease depending on tissue type. ► Orientation of principal eigenvector is independent of frequency for all ROIs. ► Frequency range covers effective diffusion-times from 7.5 ms down to 1.875 ms.