title: 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.
authors.affiliation: Department of Psychology, University of Maryland, Baltimore County, MD, USA ; Department of Anatomy and Neurobiology, School of Medicine, University of Maryland, Baltimore, MD, USA ; Department of Pain and Neural Sciences, School of Dentistry, and UM Center to Advance Chronic Pain Research, University of Maryland, Baltimore Country, MD, USA.
authors.forename: Raimi L
authors.initials: RL
authors.lastname: Quiton
authors.affiliation: Department of Pain and Neural Sciences, School of Dentistry, and UM Center to Advance Chronic Pain Research, University of Maryland, Baltimore Country, MD, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Keaser
authors.affiliation: Department of Diagnostic Radiology & Nuclear Medicine & Magnetic Resonance Research Center, School of Medicine, University of Maryland, Baltimore Country, MD, USA.
authors.forename: Jiachen
authors.initials: J
authors.lastname: Zhuo
authors.affiliation: Department of Diagnostic Radiology & Nuclear Medicine & Magnetic Resonance Research Center, School of Medicine, University of Maryland, Baltimore Country, MD, USA.
authors.forename: Rao P
authors.initials: RP
authors.lastname: Gullapalli
authors.affiliation: Department of Pain and Neural Sciences, School of Dentistry, and UM Center to Advance Chronic Pain Research, University of Maryland, Baltimore Country, MD, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Greenspan
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Anterior insula; Cingulate cortex; Intraclass correlation coefficient; Reliability coefficient; Repeatability; Reproducibility