Intra-session test-retest reliability of functional connectivity in infants

Abstract

Resting functional MRI studies of the infant brain are increasingly becoming an important tool in developmental neuroscience. Whereas the test-retest reliability of functional connectivity (FC) measures derived from resting fMRI data have been characterized in the adult and child brain, similar assessments have not been conducted in infants. In this study, we examined the intra-session test-retest reliability of FC measures from 119 infant brain MRI scans from four neurodevelopmental studies. We investigated edge-level and subject-level reliability within one MRI session (between and within runs) measured by the Intraclass correlation coefficient (ICC). First, using an atlas-based approach, we examined whole-brain connectivity as well as connectivity within two common resting fMRI networks - the default mode network (DMN) and the sensorimotor network (SMN). Second, we examined the influence of run duration, study site, and scanning manufacturer (e.g., Philips and General Electric) on ICCs. Lastly, we tested spatial similarity using the Jaccard Index from networks derived from independent component analysis (ICA). Consistent with resting fMRI studies from adults, our findings indicated poor edge-level reliability (ICC = 0.14–0.18), but moderate-to-good subject-level intra-session reliability for whole-brain, DMN, and SMN connectivity (ICC = 0.40–0.78). We also found significant effects of run duration, site, and scanning manufacturer on reliability estimates. Some ICA-derived networks showed strong spatial reproducibility (e.g., DMN, SMN, and Visual Network), and were labelled based on their spatial similarity to analogous networks measured in adults. These networks were reproducibly found across different study sites. However, other ICA-networks (e.g. Executive Control Network) did not show strong spatial reproducibility, suggesting that the reliability and/or maturational course of functional connectivity may vary by network. In sum, our findings suggest that developmental scientists may be on safe ground examining the functional organization of some major neural networks (e.g. DMN and SMN), but judicious interpretation of functional connectivity is essential to its ongoing success.

Resting-state functional connectivity identifies individuals and predicts age in 8-to-26-month-olds

“…The test-retest reliability for single edges (i.e., individual connections), however, was low as shown by low average edge-level intra-class correlations (mean ICC = 0.20, SD = 0.13). This follows previous reports on low univariate reliability of single functional connections for infants ( Dufford et al, 2021 , Wang et al, 2021a ) and adults ( Noble et al, 2019 ).…”

“…To assess the stability and uniqueness of rsFC in our sample, we compared connectivity patterns calculated from two approximately 4-minute splits of fMRI data after rigorous motion exclusion and quality control. We found relatively stable FC multivariate patterns (split-half r = 0.5), which aligns with the medium intra-session reliability of rsFC in newborn infants reported by ( Wang et al, 2021a ). Single-edge ICC were low, however, which follows previous studies ( Noble et al, 2019 , Dufford et al, 2021 ).…”

“…But, the degree to which individuals’ unique functional connectome “fingerprints” ( Miranda-Dominguez et al, 2014 , Finn et al, 2015 ) are apparent in infancy is unclear. Although recent work has demonstrated medium to large intra-session reliability of resting-state functional connectivity in newborn infants ( Wang et al, 2021a ), other work suggests that functional connectome identifiability—a proxy for connectome reliability and uniqueness—is poor in infancy ( Dufford et al, 2021 )…”

The effect of general anesthesia on the test–retest reliability of resting-state fMRI metrics and optimization of scan length

“…Numerous studies have proven that scan length is one of the key parameters in the design of MRI scanning that plays an important role in generating robust and stable results, particularly in experiments where candidates are anesthetized or have difficulty staying during scanning. They have reported the appropriate scan duration to achieve a stable brain's functional connectivity in the wakeful state (Wang et al, 2011 , 2021 ; Birn et al, 2013 ; Liao et al, 2013 ; Mejia et al, 2018 ; Teeuw et al, 2021 ). For instance, Birn et al ( 2013 ) showed that the test–retest reliability of FC can be significantly improved by increasing the duration of scanning to 9–13 min or longer (Birn et al, 2013 ).…”

“…Thus, despite its potential, rs-fMRI suffers from significant variabilities involved in the BOLD signal that may cause difficulties in the replication of results across studies (Mason et al, 2007 ; Patriat et al, 2013 ). Several factors can contribute to the intra-subject variabilities and affect the reliability of estimated brain FC including head motion, physiological noise such as cardiac and respiratory effects, MRI acquisition parameters, and data analysis/standardization strategies (Birn, 2012 ; Guo et al, 2012 ; Zuo and Xing, 2014 ; Finn et al, 2017 ; Parkes et al, 2018 ; Wang et al, 2021 ).…”