Perivascular space fluid contributes to diffusion tensor imaging changes in white matter

Farshid Sepehrband, Ryan P. Cabeen, Jeiran Choupan, Giuseppe Barisano, Meng Law, Arthur W. Toga, for the Alzheimer’s Disease Neuroimaging Initiative

Research output: Contribution to journalArticleResearchpeer-review

51 Citations (Scopus)


Diffusion tensor imaging (DTI) has been extensively used to map changes in brain tissue related to neurological disorders. Among the most widespread DTI findings are increased mean diffusivity and decreased fractional anisotropy of white matter tissue in neurodegenerative diseases. Here we utilize multi-shell diffusion imaging to separate diffusion signal of the brain parenchyma from non-parenchymal fluid within the white matter. We show that unincorporated anisotropic water in perivascular space (PVS) significantly, and systematically, biases DTI measures, casting new light on the biological validity of many previously reported findings. Despite the challenge this poses for interpreting these past findings, our results suggest that multi-shell diffusion MRI provides a new opportunity for incorporating the PVS contribution, ultimately strengthening the clinical and scientific value of diffusion MRI.

Original languageEnglish
Pages (from-to)243-254
Number of pages12
Publication statusPublished - 15 Aug 2019
Externally publishedYes


  • Bias
  • Diffusion tensor imaging
  • Perivascular space

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