Cortical microstructure associations with amyloid PET in cognitively normal people

Compared to CTh, advanced dMRI measures showed more widespread associations with Aβ load. Greater hindered diffusion (i.e., higher APA, FA) associations with greater Aβ burden may reflect cellular hypertrophy or inflammatory microglia infiltration increasing the number of diffusion barriers in early stages, irrespective of tau status. In contrast, lower neurite dispersion (ODI) could be driven by neurite loss and neurodegeneration; these effects were greater in tau+ participants. dMRI measures may offer insight into early pathological disease processes.