PT  - JOURNAL ARTICLE
AU  - Farshid Sepehrband
AU  - Ryan P Cabeen
AU  - Jeiran Choupan
AU  - Giuseppe Barisano
AU  - Meng Law
AU  - Arthur W Toga
AU  - the Alzheimer’s Disease Neuroimaging Initiative
TI  - Perivascular space fluid contributes to diffusion tensor imaging changes in white matter
AID  - 10.1101/395012
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 395012
4099  - http://biorxiv.org/content/early/2019/01/11/395012.short
4100  - http://biorxiv.org/content/early/2019/01/11/395012.full
AB  - 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 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.HighlightsPerivascular space (PVS) fluid significantly contributes to diffusion tensor imaging metricsIncreased PVS fluid results in increased mean diffusivity and decreased fractional anisotropyPVS contribution to diffusion signal is overlooked and demands further investigation