eLife (Jul 2018)

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

  • Ian F Harrison,
  • Bernard Siow,
  • Aisha B Akilo,
  • Phoebe G Evans,
  • Ozama Ismail,
  • Yolanda Ohene,
  • Payam Nahavandi,
  • David L Thomas,
  • Mark F Lythgoe,
  • Jack A Wells

DOI
https://doi.org/10.7554/eLife.34028
Journal volume & issue
Vol. 7

Abstract

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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 diagnostic indicators of neurodegenerative conditions such as Alzheimer’s disease.

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