title: Diagnostic accuracy of narrow band imaging for predicting colon polyp histology can be affected by polyp characteristics.
abstract: OBJECTIVE
  Narrow band imaging (NBI) is an optical endoscopic technique for predicting polyp histology during colonoscopy. However, it has not been elucidated the impact of polyp characteristics on the diagnostic capabilities of NBI. We aimed to evaluate which polyp characteristics can influence the diagnostic accuracy of NBI for discriminating neoplastic from non-neoplastic colorectal polyps.
  
  
  METHODS
  A total of 232 colorectal polyps from 134 patients undergoing screening or surveillance colonoscopy were retrospectively analyzed. White light imaging (WLI) and NBI images of polyps were assessed by two experienced endoscopists and two trainees and then compared with histopathology.
  
  
  RESULTS
  When classified according to polyp morphology, NBI as well as WLI had a significantly lower sensitivity and diagnostic accuracy for non-polypoid lesions than for polypoid lesions in both experienced and trainee groups. In contrast, the specificity of NBI and WLI for non-polypoid lesions was higher than that for polpyoid lesions. As for polyp size, the diagnostic accuracy of NBI for polyps ≤5mm was significantly lower than for polyps of 6 to 9mm or ≤10mm in the experienced group.
  
  
  CONCLUSIONS
  NBI had a significantly lower diagnostic accuracy for predicting polyp histology in non-polypoid or diminutive colorectal lesions.
authors.forename: Sangheun
authors.initials: S
authors.lastname: Lee
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Moon
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Cho
authors.forename: Hee Man
authors.initials: HM
authors.lastname: Kim
authors.forename: Ki Joon
authors.initials: KJ
authors.lastname: Han
authors.forename: Hyeon Geun
authors.initials: HG
authors.lastname: Cho
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Ha Eun
authors.initials: HE
authors.lastname: Oh
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Song
authors.forename: Sang Yeop
authors.initials: SY
authors.lastname: Yi
authors.forename: Nak-Hoon
authors.initials: NH
authors.lastname: Son
mesh_terms: D000328:Adult; D000368:Aged; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging / Q000379:methods*; D012189:Retrospective Studies