title: Interobserver agreement for the detection of Barrett's esophagus with optical frequency domain imaging.
abstract: BACKGROUND
  Optical frequency domain imaging (OFDI) is a second-generation form of optical coherence tomography (OCT) providing comprehensive cross-sectional views of the distal esophagus at a resolution of ~7 μm.
  
  
  OBJECTIVE
  Using validated OCT criteria for squamous mucosa, gastric cardia mucosa, and Barrett's esophagus (BE), the objective of this study was to determine the inter- and intra-observer agreements by a large number of OFDI readers for differentiating these tissues.
  
  
  METHODS
  OFDI images were obtained from nine subjects undergoing screening and surveillance for BE. Sixty-four OFDI image regions of interest were randomly selected for review. A training set of 19 images was compiled distinguishing squamous mucosa from gastric cardia and BE using previously validated OCT criteria. The ten readers then interpreted images in a test set of 45 different images of squamous mucosa (n = 15), gastric cardia (n = 15), or BE (n = 15). Interobserver agreement differentiating the three tissue types and BE versus non-BE mucosa was determined using multi-rater Fleiss's κ value. The images were later randomized again and four readers repeated the test 3 weeks later to assess intraobserver reliability.
  
  
  RESULTS
  All ten readers showed excellent agreement for the differentiation of BE versus non-BE mucosa (κ = 0.811 p < 0.0001) and for differentiating BE versus gastric cardia versus squamous mucosa (κ = 0.866, p < 0.0001). For the four readers who repeated the test, the median intraobserver agreement (BE vs. non-BE) was high (κ = 0.975, IQR: 0.94, 1.0).
  
  
  CONCLUSIONS
  Trained readers have a high interobserver agreement for differentiating BE, squamous, and gastric cardia mucosa using OFDI.
authors.affiliation: Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, 40 Blossom Street, Boston, MA 02114, USA. jsauk@partners.org
authors.forename: Jenny
authors.initials: J
authors.lastname: Sauk
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Coron
authors.forename: Lauren
authors.initials: L
authors.lastname: Kava
authors.forename: Melissa
authors.initials: M
authors.lastname: Suter
authors.forename: Michalina
authors.initials: M
authors.lastname: Gora
authors.forename: Kevin
authors.initials: K
authors.lastname: Gallagher
authors.forename: Mireille
authors.initials: M
authors.lastname: Rosenberg
authors.forename: Ashwin
authors.initials: A
authors.lastname: Ananthakrishnan
authors.forename: Norman
authors.initials: N
authors.lastname: Nishioka
authors.forename: Gregory
authors.initials: G
authors.lastname: Lauwers
authors.forename: Kevin
authors.initials: K
authors.lastname: Woods
authors.forename: William
authors.initials: W
authors.lastname: Brugge
authors.forename: David
authors.initials: D
authors.lastname: Forcione
authors.forename: Brett E
authors.initials: BE
authors.lastname: Bouma
authors.forename: Guillermo
authors.initials: G
authors.lastname: Tearney
mesh_terms: D000368:Aged; D001471:Barrett Esophagus / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D061848:Optical Imaging / Q000379:methods*