A Bayesian framework for modelling the regional variation of white matter microstructure

We present a Bayesian framework for the group-wise comparison of the regional variation of tissue parameters estimated from diffusion-weighted MRI (DW-MRI) over an anatomical region of interest (ROI). The regional variation model (RVM) fits a geometric model of parameter variation directly to the DW-MRI signals which captures the spatial changes in a natural way as well as reducing the effects of noise. We use the technique to localise tissue changes due to healthy aging in the mid-sagittal CC and detect increases in diffusivity in the genu and splenium of the older group.