Histology Validation of Generalized Diffusion Basis Spectrum Imaging in Postmortem Alzheimer Disease Brain

Motivation: Alzheimer disease pathology often begins in cortical gray matter, a non-invasive method for visualizing AD-related changes in gray matter is needed. Goal(s): Validate Generalized Diffusion Basis Spectrum Imaging (g-DBSI) as a tool for detecting microstructural components in both white and gray matter in postmortem AD brain tissues. Approach: We compared g-DBSI-derived maps with histology-based density maps using postmortem AD brain tissue samples to assess correlation and accuracy in capturing microstructural details. Results: Significant correlations were found between g-DBSI indices and histological density maps, supporting g-DBSI's effectiveness in representing cell nucleus and axon densities in gray matter and white matter in postmortem AD brain. Impact: g-DBSI could enable earlier, non-invasive monitoring of AD progression, offering a valuable tool for studying neuroinflammation and cellular changes directly in gray matter.