NCI protocol and pilot data: SWI scans indicate perivascular region of interest. Three ROIs (middle) are placed in the projection area, the association area and subcortical area. All 3 principle diffusivity components are then quantified for each ROI (top right). Perivascular diffusivity is then quantified (bottom right). Higher scores indicated impaired glymphatic clearance. CSF Flow quantification: MPRAGE (left) and CSF-PC visualising the direction of CSF flow in and around the brain. CD flow is then quantified with a further CSF-PC sequence.

Glymphatic system-CSF relationship with healthy ageing. Eight healthy controls (4 female) 21-59 years were scanned. Bivariate correlation analysis indicates that lower CD flow is associated with impaired glymphatic clearance (left) and glymphatic clearance declines with age (middle). However, CD CSF flow is not directly associated with age indicating that CD CSF flow is a larger mediator of glymphatic function than just age.