Voxel-Wise Brain Graphs From Diffusion MRI : Intrinsic Eigenspace Dimensionality and Application to Functional MRI
Behjat, Hamid ; Tarun, Anjali ; Abramian, David ; Larsson, Martin LU
and Ville, Dimitri Van De
(2023)
In IEEE Open Journal of Engineering in Medicine and Biology
p.1-12
- Abstract
<italic>Goal:</italic> Structural brain graphs are conventionally limited to defining nodes as gray matter regions from an atlas, with edges reflecting the density of axonal projections between pairs of nodes. Here we explicitly model the entire set of voxels within a brain mask as nodes of high-resolution, subject-specific graphs. <italic>Methods:</italic> We define the strength of local voxel-to-voxel connections using diffusion tensors and orientation distribution functions derived from diffusion MRI data. We study the graphs' Laplacian spectral properties on data from the Human Connectome Project. We then assess the extent of inter-subject variability of the Laplacian eigenmodes via a procrustes... (More)
<italic>Goal:</italic> Structural brain graphs are conventionally limited to defining nodes as gray matter regions from an atlas, with edges reflecting the density of axonal projections between pairs of nodes. Here we explicitly model the entire set of voxels within a brain mask as nodes of high-resolution, subject-specific graphs. <italic>Methods:</italic> We define the strength of local voxel-to-voxel connections using diffusion tensors and orientation distribution functions derived from diffusion MRI data. We study the graphs' Laplacian spectral properties on data from the Human Connectome Project. We then assess the extent of inter-subject variability of the Laplacian eigenmodes via a procrustes validation scheme. Finally, we demonstrate the extent to which functional MRI data are shaped by the underlying anatomical structure via graph signal processing. <italic>Results:</italic> The graph Laplacian eigenmodes manifest highly resolved spatial profiles, reflecting distributed patterns that correspond to major white matter pathways. We show that the intrinsic dimensionality of the eigenspace of such high-resolution graphs is only a mere fraction of the graph dimensions. By projecting task and resting-state data on low-frequency graph Laplacian eigenmodes, we show that brain activity can be well approximated by a small subset of low-frequency components. <italic>Conclusions:</italic> The proposed graphs open new avenues in studying the brain, be it, by exploring their organisational properties via graph or spectral graph theory, or by treating them as the scaffold on which brain function is observed at the individual level.
(Less)
- author
- Behjat, Hamid
; Tarun, Anjali
; Abramian, David
; Larsson, Martin
LU
and Ville, Dimitri Van De
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- Brain, Brain graph, diffusion MRI, Diffusion tensor imaging, Eigenvalues and eigenfunctions, Functional magnetic resonance imaging, functional MRI, graph signal processing, Laplace equations, spectral graph theory, Task analysis, Tensors
- in
- IEEE Open Journal of Engineering in Medicine and Biology
- pages
- 12 pages
- publisher
- IEEE - Institute of Electrical and Electronics Engineers Inc.
- external identifiers
-
- scopus:85153797247
- ISSN
- 2644-1276
- DOI
- 10.1109/OJEMB.2023.3267726
- language
- English
- LU publication?
- yes
- id
- 45f0998c-3d27-4229-97ab-76167edaa8f3
- date added to LUP
- 2023-07-14 12:28:21
- date last changed
- 2023-08-23 14:27:07
@article{45f0998c-3d27-4229-97ab-76167edaa8f3,
abstract = {{<p><italic>Goal:</italic> Structural brain graphs are conventionally limited to defining nodes as gray matter regions from an atlas, with edges reflecting the density of axonal projections between pairs of nodes. Here we explicitly model the entire set of voxels within a brain mask as nodes of high-resolution, subject-specific graphs. <italic>Methods:</italic> We define the strength of local voxel-to-voxel connections using diffusion tensors and orientation distribution functions derived from diffusion MRI data. We study the graphs&#x0027; Laplacian spectral properties on data from the Human Connectome Project. We then assess the extent of inter-subject variability of the Laplacian eigenmodes via a procrustes validation scheme. Finally, we demonstrate the extent to which functional MRI data are shaped by the underlying anatomical structure via graph signal processing. <italic>Results:</italic> The graph Laplacian eigenmodes manifest highly resolved spatial profiles, reflecting distributed patterns that correspond to major white matter pathways. We show that the intrinsic dimensionality of the eigenspace of such high-resolution graphs is only a mere fraction of the graph dimensions. By projecting task and resting-state data on low-frequency graph Laplacian eigenmodes, we show that brain activity can be well approximated by a small subset of low-frequency components. <italic>Conclusions:</italic> The proposed graphs open new avenues in studying the brain, be it, by exploring their organisational properties via graph or spectral graph theory, or by treating them as the scaffold on which brain function is observed at the individual level.</p>}},
author = {{Behjat, Hamid and Tarun, Anjali and Abramian, David and Larsson, Martin and Ville, Dimitri Van De}},
issn = {{2644-1276}},
keywords = {{Brain; Brain graph; diffusion MRI; Diffusion tensor imaging; Eigenvalues and eigenfunctions; Functional magnetic resonance imaging; functional MRI; graph signal processing; Laplace equations; spectral graph theory; Task analysis; Tensors}},
language = {{eng}},
pages = {{1--12}},
publisher = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
series = {{IEEE Open Journal of Engineering in Medicine and Biology}},
title = {{Voxel-Wise Brain Graphs From Diffusion MRI : Intrinsic Eigenspace Dimensionality and Application to Functional MRI}},
url = {{http://dx.doi.org/10.1109/OJEMB.2023.3267726}},
doi = {{10.1109/OJEMB.2023.3267726}},
year = {{2023}},
}