title: Differential diagnosis of colorectal polyps with narrow band imaging colonoscopy without magnification.
abstract: OBJECTIVE
  Narrow band imaging (NBI) endoscopy can be used for gross differentiation between the types of colonic polyps. This study was conducted as a retrospective study for estimation of the interobserver and intra-observer agreement of the pit pattern of the mucosal surface and the accuracy of histology prediction.
  
  
  METHODS
  A total of 159 patients underwent complete colonoscopy and 219 polyps examined by NBI endoscopy without magnification were assessed. Interobserver and intra-observer agreement were calculated by investigators in each group for determination of the surface pattern and prediction of histology based on the modified Kudo's classification using intraclass correlation coefficient.
  
  
  RESULTS
  Interobserver agreement for the surface pit pattern and prediction of polyp type was 0.84 and 0.73 in experienced endoscopists, and 0.86 and 0.62 in trainees, respectively. Intra-observer agreement for the surface pit patterns and prediction of polyp type was 0.81, 0.83, 0.85, 0.83, 0.56, 0.84, 0.51, 0.83, and 0.71; and 0.71, 0.70, 0.82, 0.54, 0.72, 0.37, 0.51, 0.34, and 0.30, respectively. The diagnostic accuracy for prediction of polyp type was 69.4% for experienced endoscopists and 72.9% for trainees.
  
  
  CONCLUSIONS
  NBI endoscopy without magnification showed fairly good inter and intra-observer agreement for the pit pattern of the mucosal surface and the accuracy of histology prediction; however, it had some limitation for differentiation of colon polyp histologic type. Training and experience with NBI is needed for improvement of accuracy.
authors.affiliation: Department of Internal Medicine, Kosin University College of Medicine, 262 Gamcheon-ro, Seo-gu, Busan 602-702, Korea.
authors.forename: Bong Jin
authors.initials: BJ
authors.lastname: Kim
authors.forename: Moo In
authors.initials: MI
authors.lastname: Park
authors.forename: Seun Ja
authors.initials: SJ
authors.lastname: Park
authors.forename: Won
authors.initials: W
authors.lastname: Moon
authors.forename: Eun Taek
authors.initials: ET
authors.lastname: Park
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: Chang Sup
authors.initials: CS
authors.lastname: Lim
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Yoo
authors.forename: Seong Joo
authors.initials: SJ
authors.lastname: Kang
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000175:diagnosis; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging; D012189:Retrospective Studies