Paper Info
Title
The Whole-Brain "Global" Signal from Resting State fMRI as a Potential Biomarker of Quantitative State Changes in Glucose Metabolism.
Abstract
The evolution of functional magnetic resonance imaging to resting state (R-fMRI) allows measurement of changes in brain networks attributed to state changes, such as in neuropsychiatric diseases versus healthy controls. Since these networks are observed by comparing normalized R-fMRI signals, it is difficult to determine the metabolic basis of such group differences. To investigate the metabolic basis of R-fMRI network differences within a normal range, eyes open versus eyes closed in healthy human subjects was used. R-fMRI was recorded simultaneously with fluoro-deoxyglucose positron emission tomography (FDG-PET). Higher baseline FDG was observed in the eyes open state. Variance-based metrics calculated from R-fMRI did not match the baseline shift in FDG. Functional connectivity density (FCD)-based metrics showed a shift similar to the baseline shift of FDG, however, this was lost if R-fMRI "nuisance signals" were regressed before FCD calculation. Average correlation with the mean R-fMRI signal across the whole brain, generally regarded as a "nuisance signal," also showed a shift similar to the baseline of FDG. Thus, despite lacking a baseline itself, changes in whole-brain correlation may reflect changes in baseline brain metabolism. Conversely, variance-based metrics may remain similar between states due to inherent region-to-region differences overwhelming the differences between normal physiological states. As most previous studies have excluded the spatial means of R-fMRI metrics from their analysis, this work presents the first evidence of a potential R-fMRI biomarker for baseline shifts in quantifiable metabolism between brain states.
Year
DOI
Venue
2016
10.1089/brain.2015.0394
BRAIN CONNECTIVITY
Keywords
Field
DocType
baseline state,default mode,energy metabolism,functional connectivity,neuronal activity,resting state
Energy metabolism,Neuroscience,Resting state fMRI,Biomarker (medicine),Positron emission tomography,Medicine,Carbohydrate metabolism,Pathology,Default mode network,Functional magnetic resonance imaging,Internal medicine,Cardiology,Correlation
Journal
Volume
Issue
ISSN
6
6
2158-0014
Citations 
PageRank 
References 
0
0.34
0
Authors
6
Name
Order
Citations
PageRank
Garth John Thompson11558.55
Valentin Riedl2133.39
Timo Grimmer371.81
Alexander Drzezga4375.91
Peter Herman592.94
Fahmeed Hyder6429.53