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Computing and visualising intra-voxel orientation-specific relaxation–diffusion features in the human brain

de Almeida Martins, João P. LU ; Tax, Chantal M.W. ; Reymbaut, Alexis LU ; Szczepankiewicz, Filip LU orcid ; Chamberland, Maxime ; Jones, Derek K. and Topgaard, Daniel LU (2021) In Human Brain Mapping 42(2). p.310-328
Abstract

Diffusion MRI techniques are used widely to study the characteristics of the human brain connectome in vivo. However, to resolve and characterise white matter (WM) fibres in heterogeneous MRI voxels remains a challenging problem typically approached with signal models that rely on prior information and constraints. We have recently introduced a 5D relaxation–diffusion correlation framework wherein multidimensional diffusion encoding strategies are used to acquire data at multiple echo-times to increase the amount of information encoded into the signal and ease the constraints needed for signal inversion. Nonparametric Monte Carlo inversion of the resulting datasets yields 5D relaxation–diffusion distributions where contributions from... (More)

Diffusion MRI techniques are used widely to study the characteristics of the human brain connectome in vivo. However, to resolve and characterise white matter (WM) fibres in heterogeneous MRI voxels remains a challenging problem typically approached with signal models that rely on prior information and constraints. We have recently introduced a 5D relaxation–diffusion correlation framework wherein multidimensional diffusion encoding strategies are used to acquire data at multiple echo-times to increase the amount of information encoded into the signal and ease the constraints needed for signal inversion. Nonparametric Monte Carlo inversion of the resulting datasets yields 5D relaxation–diffusion distributions where contributions from different sub-voxel tissue environments are separated with minimal assumptions on their microscopic properties. Here, we build on the 5D correlation approach to derive fibre-specific metrics that can be mapped throughout the imaged brain volume. Distribution components ascribed to fibrous tissues are resolved, and subsequently mapped to a dense mesh of overlapping orientation bins to define a smooth orientation distribution function (ODF). Moreover, relaxation and diffusion measures are correlated to each independent ODF coordinate, thereby allowing the estimation of orientation-specific relaxation rates and diffusivities. The proposed method is tested on a healthy volunteer, where the estimated ODFs were observed to capture major WM tracts, resolve fibre crossings, and, more importantly, inform on the relaxation and diffusion features along with distinct fibre bundles. If combined with fibre-tracking algorithms, the methodology presented in this work has potential for increasing the depth of characterisation of microstructural properties along individual WM pathways.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
diffusion MRI, fibre ODF, fibre-specific metrics, partial volume effects, tensor-valued diffusion encoding, white matter
in
Human Brain Mapping
volume
42
issue
2
pages
310 - 328
publisher
Wiley-Blackwell
external identifiers
  • pmid:33022844
  • scopus:85092074536
ISSN
1065-9471
DOI
10.1002/hbm.25224
language
English
LU publication?
yes
id
5d46e0e9-88dc-425e-bfd2-d7809ef0653e
date added to LUP
2020-11-03 12:23:42
date last changed
2024-04-17 17:38:11
@article{5d46e0e9-88dc-425e-bfd2-d7809ef0653e,
  abstract     = {{<p>Diffusion MRI techniques are used widely to study the characteristics of the human brain connectome in vivo. However, to resolve and characterise white matter (WM) fibres in heterogeneous MRI voxels remains a challenging problem typically approached with signal models that rely on prior information and constraints. We have recently introduced a 5D relaxation–diffusion correlation framework wherein multidimensional diffusion encoding strategies are used to acquire data at multiple echo-times to increase the amount of information encoded into the signal and ease the constraints needed for signal inversion. Nonparametric Monte Carlo inversion of the resulting datasets yields 5D relaxation–diffusion distributions where contributions from different sub-voxel tissue environments are separated with minimal assumptions on their microscopic properties. Here, we build on the 5D correlation approach to derive fibre-specific metrics that can be mapped throughout the imaged brain volume. Distribution components ascribed to fibrous tissues are resolved, and subsequently mapped to a dense mesh of overlapping orientation bins to define a smooth orientation distribution function (ODF). Moreover, relaxation and diffusion measures are correlated to each independent ODF coordinate, thereby allowing the estimation of orientation-specific relaxation rates and diffusivities. The proposed method is tested on a healthy volunteer, where the estimated ODFs were observed to capture major WM tracts, resolve fibre crossings, and, more importantly, inform on the relaxation and diffusion features along with distinct fibre bundles. If combined with fibre-tracking algorithms, the methodology presented in this work has potential for increasing the depth of characterisation of microstructural properties along individual WM pathways.</p>}},
  author       = {{de Almeida Martins, João P. and Tax, Chantal M.W. and Reymbaut, Alexis and Szczepankiewicz, Filip and Chamberland, Maxime and Jones, Derek K. and Topgaard, Daniel}},
  issn         = {{1065-9471}},
  keywords     = {{diffusion MRI; fibre ODF; fibre-specific metrics; partial volume effects; tensor-valued diffusion encoding; white matter}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{310--328}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Human Brain Mapping}},
  title        = {{Computing and visualising intra-voxel orientation-specific relaxation–diffusion features in the human brain}},
  url          = {{http://dx.doi.org/10.1002/hbm.25224}},
  doi          = {{10.1002/hbm.25224}},
  volume       = {{42}},
  year         = {{2021}},
}