Perivascular and parenchymal fluid characteristics are related to age and cognitive performance across the lifespan

Abstract

Perivascular spaces (PVS) play a critical role in fluid transfer and waste clearance in the brain, but few studies have explored how alterations to perivascular fluid flow may impact brain maturation and behavior. This study aims to characterize age-related alterations to perivascular and parenchymal fluid flow characteristics across the lifespan in typically developing children (8-21 years) and aging adults (35-90 years) and assess their contribution to cognition. In this study, we employ multi-compartment diffusion models, neurite orientation dispersion and density imaging (NODDI) and tissue tensor imaging (TTI), to quantify free water diffusion characteristics within automatically defined perivascular spaces using enhanced PVS contrasts, the surrounding parenchyma, and at variable distances from the PVS. Our findings show free water diffusion characteristics within the PVS and surrounding parenchyma are associated with age and cognitive scores.