Non-invasive imaging of CSF-mediated brain clearance pathways via assessment of perivascular fluid movement with DTI MRI

The glymphatics system describes a CSF-mediated clearance pathway for the removal of potentially harmful molecules, such as amyloid beta, from the brain. As such, its components may represent new therapeutic targets to alleviate aberrant protein accumulation that defines the most prevalent neurodegenerative conditions. Currently, however, the absence of any non-invasive measurement technique prohibits detailed understanding of glymphatic function in the human brain and in turn, it's role in pathology. Here, we present the first non-invasive technique for the assessment of glymphatic inflow by using an ultra-long echo time, low b-value, multi-direction diffusion weighted MRI sequence to assess perivascular fluid movement (which represents a critical component of the glymphatic pathway) in the rat brain. This novel, quantitative and non-invasive approach may represent a valuable biomarker of CSF-mediated brain clearance, working towards the clinical need for reliable and early diagnost...

胶质淋巴系统（glymphatics system）是一种由脑脊液（Cerebrobrospinal Fluid, CSF）介导的清除通路，可将β淀粉样蛋白（amyloid beta）等潜在有害分子从大脑中清除。因此，该系统的组成成分可作为新型治疗靶点，用以缓解最常见神经退行性疾病所特有的异常蛋白质积累问题。然而当前，由于缺乏任何非侵入性测量技术，我们无法深入解析人类大脑中的胶质淋巴功能，进而难以明确其在病理过程中的作用。本研究首次提出了一种评估胶质淋巴流入的非侵入性技术：通过采用超长回波时间、低b值的多方向扩散加权磁共振成像（MRI）序列，检测大鼠大脑内的血管周液体流动——这正是胶质淋巴通路的关键组成部分。这种新颖、定量且非侵入性的方法或可成为脑脊液介导的大脑清除功能的极具价值的生物标志物，为满足临床对可靠、早期诊断的需求而推进相关研究。