title: Test-retest reliability of pain-related brain activity in healthy controls undergoing experimental thermal pain.
abstract: Although functional magnetic resonance imaging (fMRI) has been proposed as a method to elucidate pain-related biomarkers, little information exists related to psychometric properties of fMRI findings. This knowledge is essential for potential translation of this technology to clinical settings. The purpose of this study was to assess the test-retest reliability of pain-related brain activity and how it compares to the reliability of self-report. Twenty-two healthy controls (mean age = 22.6 years, standard deviation = 2.9) underwent 3 runs of an fMRI paradigm that used thermal stimuli to elicit experimental pain. Functional MRI summary statistics related to brain activity during thermal stimulation periods were extracted from bilateral anterior cingulate cortices and anterior insula. Intraclass correlations (ICCs) were conducted on these summary statistics and generally showed "good" test-retest reliability in all regions of interest (ICC range = .32-.88; mean = .71); however, these results did not surpass ICC values from pain ratings, which fell within the "excellent" range (ICC range = .93-.96; mean = .94). Findings suggest that fMRI is a valuable tool for measuring pain mechanisms but did not show an adequate level of test-retest reliability for fMRI to potentially act as a surrogate for individuals' self-report of pain.
  
  
  CONCLUSIONS
  This study is one of the first reports to demonstrate the test-retest reliability of fMRI findings related to pain processing and provides a comparison to the reliability of subjective reports of pain. This information is essential for determining whether fMRI technology should be potentially translated for clinical use.
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida.
authors.forename: Janelle E
authors.initials: JE
authors.lastname: Letzen
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida.
authors.forename: Landrew S
authors.initials: LS
authors.lastname: Sevel
authors.affiliation: Department of Rehabilitation Sciences, University of Florida, Gainesville, Florida.
authors.forename: Charles W
authors.initials: CW
authors.lastname: Gay
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: O'Shea
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida.
authors.forename: Jason G
authors.initials: JG
authors.lastname: Craggs
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Florida, Gainesville, Florida.
authors.forename: Donald D
authors.initials: DD
authors.lastname: Price
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida. Electronic address: merobin@ufl.edu.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Robinson
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006358:Hot Temperature; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D011594:Psychometrics; D015203:Reproducibility of Results; D057566:Self Report; D055815:Young Adult
keywords: Functional magnetic resonance imaging; anterior cingulate cortex; insula; test-retest reliability