Parenchymal CSF Fraction and DTI‐ALPS in Brain Aging

The perivascular space (PVS) functions as part of a brain clearance system that drains interstitial fluid and solutes including Aβ and tau from brain parenchyma and is associated with the development of AD. Recent developed imaging tools of cerebral parenchymal CSF fraction (CSFF)1 and diffusion tensor imaging along perivascular spaces index (DTI‐ALPS)2 provide an insight of the perivascular CSF flow and early PVS pathology in the cerebral cortex. We applied CSFF and DTI‐ALPS in an elderly cognitive normal cohort to investigate its value in brain aging.