Associations between Extracellular Diffusivity Along Perivascular Space (eALPS) and Structural Abnormalities in Brain

Non-invasive measure of glymphatic function or flow in vivo has gained a great attention from neuroscience research community. Diffusion tensor imaging (DTI) can provide a mean that measures the diffusivity along perivascular space (ALPS). However, conventional DTI captures diffusion indices from both tissue and free water compartments due to partial volume effects, which may raise a concern about validity of DTI-ALPS index for glymphatic function. In this work, we present a novel method that can extract extracellular diffusivity (i.e., eALPS) using free water eliminated DTI and investigate the relationship between eALPS and structural abnormalities in brain.