Intersession reliability of fMRI activation for heat pain and motor tasks

Abstract

As the practice of conducting longitudinal fMRI studies to assess mechanisms of pain-reducing interventions becomes more common, there is a great need to assess the test–retest reliability of the pain-related BOLD fMRI signal across repeated sessions. This study quantitatively evaluated the reliability of heat pain-related BOLD fMRI brain responses in healthy volunteers across 3 sessions conducted on separate days using two measures: (1) intraclass correlation coefficients (ICC) calculated based on signal amplitude and (2) spatial overlap. The ICC analysis of pain-related BOLD fMRI responses showed fair-to-moderate intersession reliability in brain areas regarded as part of the cortical pain network. Areas with the highest intersession reliability based on the ICC analysis included the anterior midcingulate cortex, anterior insula, and second somatosensory cortex. Areas with the lowest intersession reliability based on the ICC analysis also showed low spatial reliability; these regions included pregenual anterior cingulate cortex, primary somatosensory cortex, and posterior insula. Thus, this study found regional differences in pain-related BOLD fMRI response reliability, which may provide useful information to guide longitudinal pain studies. A simple motor task (finger-thumb opposition) was performed by the same subjects in the same sessions as the painful heat stimuli were delivered. Intersession reliability of fMRI activation in cortical motor areas was comparable to previously published findings for both spatial overlap and ICC measures, providing support for the validity of the analytical approach used to assess intersession reliability of pain-related fMRI activation. A secondary finding of this study is that the use of standard ICC alone as a measure of reliability may not be sufficient, as the underlying variance structure of an fMRI dataset can result in inappropriately high ICC values; a method to eliminate these false positive results was used in this study and is recommended for future studies of test–retest reliability.

The pulvinar nucleus and antidepressant treatment: dynamic modeling of antidepressant response and remission with ultra-high field functional MRI

“…Test-retest reliability remains an issue for potential clinical application of fMRI. Several studies with only fair to moderate ICC values in pain paradigms were reported [53], while others find slightly better values [54]. Yet, spatial activation patterns [55] and noise [56] appear to be stable over measuring time-points.…”

Test-retest reliability of pain-related functional brain connectivity compared with pain self-report

“…These studies have used intraclass correlations (ICCs), which is a measure of TRR. Quiton et al [26] measured intersession reliability of signal amplitude representinghealthy individuals’ brain activity during a thermal pain task. Across several days, ICCs ranged from 0.31–0.78 for task-related signal amplitude in “cortical pain network” regions.…”

Between- and within-site variability of fMRI localizations

“…Our within-site ICCs values for the motor task indicate a high performance stability of the local clinical fMRI teams. The values are in the upper range of those reported in the literature [Aron et al, 2006;Kong et al, 2007;Quiton et al, 2014]. Withinsite ICCs for a somatosensory task have not previously been reported.…”