MRI指数协会Glymphatic系统淀粉样蛋白沉积和认知在轻度认知障碍和阿尔茨海默病

Basic Concepts of the Proposed MRI Measures for Indirect Noninvasive Evaluation of Glymphatic System Compartments in Healthy and Pathologic States (A) Based on the glymphatic hypothesis, subarachnoid CSF normally enters the brain's interstitial space from the periarterial space [as indexed by the PVSVF (i)] through the AQP4 channel expressed in the astrocyte end-feet and then mixes with the ISF and waste solutes in the brain. The resulting CSF/ISF exchange [as indexed by the FW-WM (ii)] and waste products, such as Aβ, are then drained out of the brain by the perivenous efflux pathway [as indexed by the ALPS index (iii)]. (B) In a pathologic state, such as in Alzheimer disease, glymphatic dysfunction due to brain waste (i.e., Aβ) accumulation might cause enlargement of the PVS, increased brain extracellular FW, and decreased perivenous efflux, as reflected by the higher PVSVF (iii), higher FW-WM (ii), and lower ALPS index (iii), respectively.