From structure to function: leveraging embedded multimodal imaging to explore brain connectivity

smoia
@SteMoia
s.moia.research@gmail.com

Maastricht, 31.10.2024

Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands;    physiopy (https://github.com/physiopy)

Stefano Moia, 2024

From structure to function: leveraging embedded multimodal imaging to explore brain connectivity

Maastricht, 31.10.2024

Blood Oxygen Level Dependent (BOLD) signal

Image courtesy of Dimo Ivanov

BOLD signal: "Functional Networks"

Biswal et al., 1995 (Magn. Reson. Med.)

r(X, Y) = \frac{\text{cov}(X, Y)}{\sigma_X \sigma_Y}

Pearson correlation:

Whole brain functional connectivity

Huang et al., 2018 (Proc. IEEE)

From timeseries to graphs

x1

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x8

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t
y
t=1
x1=y1

From timeseries to graphs

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t
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t=2
x2=y1

From timeseries to graphs

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t
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t=3
x3=y1

From timeseries to graphs

x1

x2

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x1

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x3

x8

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x1

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From timeseries to graphs

x1

x2

x3

x8

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x1

x2

x3

x8

...

x1

x2

x3

...

x8

t=1
x1=y1

From timeseries to graphs

x1

x2

x3

x8

...

x1

x2

x3

x8

...

x1

x2

x3

...

x8

t=2
x2=y1=x1_{t1}

From timeseries to graphs

x1

x2

x3

x8

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x1

x2

x3

x8

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x1

x2

x3

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x8

t=3
x3=y1=x2_{t2}
x_{k_{t}}=\sum x_{j_{t-1}}

Graph Signal Processing

Ortega 2022 (Introduction to Graph signal Processing)

Preti et al. (2019) Nat. Commun.;  Huang et al. (2018) Proc. IEEE

Graph Signal Processing: Filtering

Decomposition
to access
"graph" spectral domain

NiGSP is an open development (python) toolbox to apply
Graph Signal Processing on neuroimaging data

It offers a set of function for filter creations, filtering, visualisation,
and metrics computations

Applying Graph Signal Processing: NiGSP

Moia et al. (2023) Zenodo

Preti et al. (2019) Nat. Commun.; Griffa et al. (2022) Neuroimage;  Forrer et al. (2024) Biol. Psychiatry

pip install nigsp[all]

nigsp -f timeseries.nii.gz -s sc_mtx.tsv -a atlas.nii.gz --informed-surrogates -n 1000

Moia et al. (2023) Zenodo; based on Preti, Van De Ville (2019) Nat. Commun. and Griffa et al. (2022) Neuroimage

Applying Graph Signal Processing: NiGSP

Sneak peak

BOLD

Neuronal
fluctuations

Physiological
fluctuations

Disentangling fluctuations with GSP

Thanks to...

That's all folks!

smoia
@SteMoia
s.moia.research@gmail.com

...you for the (sustained) attention!

...the MR-methods group @UM

Part of this research is supported by the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101109770

Stefano Moia, 2024

Find the presentation at:

slides.com/ephraim24/mbic-multimodal-connectivity/scroll

...the MIP:Lab @ EPFL

Any question [/opinions/objections/...]?