Utilizing Diffusion Models to Evaluate Brain Glymphatic Function Through Perivascular Space Enlargement Analysis

Motivation: This study uses a non-invasive diffusion model to evaluate the mechanism of glymphatic dysfunction linked to PVS enlargement. Goal(s): First, investigate the relationship between glymphatic function, enlarged PVS volume fraction, and age; second, evaluate glymphatic function's mediation and moderation in age-related changes of PVS volume. Approach: T1w images map PVS areas, divided into white matter (WM) and subcortical regions, to analyze fluid signal fraction (from high b-value DWI) and pseudo-diffusion axial diffusivity (from low b-value DWI) within the PVS. Results: Age-related changes in PVS and glymphatic function were observed only in the WM area, where fluid amount acts as moderator Impact: These findings enhance our understanding of the brain's glymphatic system and guide future research into its mechanisms, emphasizing the importance of considering regional differences in glymphatic function's role in PVS changes.