Reliability correction for functional connectivity: Theory and implementation.
Network properties can be estimated using functional connectivity MRI (fcMRI). However, regional variation of the fMRI signal causes systematic biases in network estimates including correlation attenuation in regions of low measurement reliability. Here we computed the spatial distribution of fcMRI reliability using longitudinal fcMRI datasets and demonstrated how pre-estimated reliability maps can correct for correlation attenuation. As a test case of reliability-based attenuation correction we estimated properties of the default network, where reliability was significantly lower than average in the medial temporal lobe and higher in the posterior medial cortex, heterogeneity that impacts estimation of the network. Accounting for this bias using attenuation correction revealed that the medial temporal lobe's contribution to the default network is typically underestimated. To render this approach useful to a greater number of datasets, we demonstrate that test-retest reliability maps derived from repeated runs within a single scanning session can be used as a surrogate for multi-session reliability mapping. Using data segments with different scan lengths between 1 and 30 min, we found that test-retest reliability of connectivity estimates increases with scan length while the spatial distribution of reliability is relatively stable even at short scan lengths. Finally, analyses of tertiary data revealed that reliability distribution is influenced by age, neuropsychiatric status and scanner type, suggesting that reliability correction may be especially important when studying between-group differences. Collectively, these results illustrate that reliability-based attenuation correction is an easily implemented strategy that mitigates certain features of fMRI signal nonuniformity.
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.|Department of Psychology and Center for Brain Science, Harvard University, Cambridge, Massachusetts.|Institute of Clinical Radiology, Ludwig Maximilians University Munich, Munich, Germany.
Sophia
S
Mueller
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.
Danhong
D
Wang
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.|Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.|Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Michael D
MD
Fox
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.|Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Ruiqi
R
Pan
Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Jie
J
Lu
Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Kuncheng
K
Li
Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Wei
W
Sun
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.|Department of Psychology and Center for Brain Science, Harvard University, Cambridge, Massachusetts.|Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts.
Randy L
RL
Buckner
Department of Radiology, Athinoula a. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.
Hesheng
H
Liu
D000328:Adult; D063132:Connectome / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
attenuation correction; default network; functional connectivity MRI; medial temporal lobe; reliability