Water diffusion is influenced by the changes in regional volume

Motivation: A direct examining the volume and diffusion indices of in vivo and ex vivo brains from the same individual is of great interest in linking clinical and histological studies. Goal(s): The goal of this study is to investigate the relationship between brain volume and diffusion indices in brain using in vivo and ex vivo brains from the same individual. Approach: Dwi indices and brain volumes of the whole brain, white matter, cerebral cortex, cerebellum, and 52 brain regions were compared in vivo and ex vivo from same individuals. Results: For each DWI index, AD was correlated with volume change in 40 cortical regions. Impact: This study successfully compared the same brain in vivo and ex vivo directly, and it sufficiently demonstrates the relationship between volume and diffusion indices. In particular, AD is most sensitive to regional volume changes.