Test-retest reproducibility of structural and proxy estimates of brain connectivity at rest
Year: 2025
Type: article
Abstract: While structural connectivity (SC) reflects actual neural connections, proxy estimates of brain connectivity such as functional connectivity (FC) from functional MRI, intersubject covariance of regional gray matter volume (GMV cov ) from structural MRI, and intersubject covariance of regional 18F-fluorodeoxyglucose uptake (FDG cov ) from PET are derived from statistical dependencies between regional measurements. Understanding reproducibility of these estimates is crucial for capturing physiological and pathological changes in brain connectivity. Here, we compared test-retest reproducibility of group-level SC, FC, GMV cov , and FDG cov in the same 55 healthy subjects at rest using a simultaneous PET/MRI acquisition protocol. Sparsity-based thresholding resulted in coefficients of variation of 2.7%, 3.1%, 3.6%, and 5.1% for SC, FDG cov , GMV cov , and FC, respectively. Strength-based thresholding resulted in relative proportion of repeatedly (test-retest) present connections (PRPC) of 77%, 56%, and 54% for GMV cov , FDG cov , and FC, respectively. Absolute PRPC were 2.50%, 0.64%, and 0.25% for FDG cov , FC, and GMV cov , respectively. Overall, stronger connections exhibited higher reproducibility, arguing in favour of thresholding as a necessary analytical step. SC was most reproducible. Among the proxy estimates, the highest absolute PRPC was found for FDG cov . FDG cov enables to study brain connectivity in a reproducible manner over the largest part of the brain.
Source: NeuroImage
Institutions: TUM Klinikum, Technical University of Munich, University of Liège
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,540
Funder: Deutsche Forschungsgemeinschaft
Awards: G1977758936, G2617013783
OpenAlex ID: W4415541785