Diffusion tensor image analysis along the perivascular space inversely correlates with age in healthy subjects

Abstract

AbstractBackgroundThe glymphatic system is a brain waste fluid clearance system. Glymphatic dysfunction of glymphatic system has been seen in normal aging in many neurological diseases. Diffusion tensor image analysis along the perivascular space (DTI‐ALPS) is a novel MRI method to assess the glymphatic function. In this study, we aim to evaluate the changes in glymphatic system by aging with DTI‐ALPS method.MethodWe investigated DTI‐ALPS indices of 49 healthy subjects underwent MRI scans. Anatomical T1w MPRAGE and multi‐shell diffusion‐weighted MRI were acquired on a 3T Siemens Prisma scanner. Diffusion MRI (dMRI) images were corrected for distortions induced by susceptibility and eddy current. To evaluate the glymphatic system activity, an index called ALPS index was calculated. Linear regression analysis was used to evaluate the correlation of age and ALPS.ResultResults showed that DTI‐ALPS index inversely correlates with age: R = ‐0.42, p<0.05, meaning glymphatic system activity inversely correlates with aging in healthy subjects.ConclusionUnderstanding the factors affecting glymphatic function might help better understanding the underlying mechanism of neurological diseases and healthy aging.