title: Is narrow band imaging superior to high-definition white light endoscopy in the assessment of diminutive colorectal polyps?
abstract: OBJECTIVE
  Diminutive polyps measuring ≤ 5 mm in size constitute 80% of polyps in the colon. We prospectively assessed the performance of high-definition white light endoscopy (hWLE) and narrow band imaging (NBI) in differentiating diminutive colorectal polyps.
  
  
  METHODS
  In this prospective, multicenter study, videos of 50 diminutive polyps (31 hyperplastic, 19 adenomatous) in hWLE followed by NBI (total 100 videos) were initially obtained and placed in random order into five separate folders (each folder 20 videos). Eight endoscopists were then invited to predict the histology (each endoscopist 100 videos, 800 video assessments in all). Polyps were classified into types 1-3 (hyperplastic) and type 4 (adenoma). Feedback on individual performance was given after each folder (20 videos) was assessed.
  
  
  RESULTS
  The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in differentiating hyperplastic from adenomatous polyps by hWLE (400 videos) and NBI (400 videos) were 67.8%, 90.7%, 81.7%, 82.1%, and 82.0%; and 82.2%, 81.5%, 73.1%, 88.2%, and 81.8%, respectively. In the pretest and post-test analysis, the accuracy with NBI improved markedly from 68.8% to 91.3% (P = 0.001) compared with hWLE, 76.3-78.8% (P = 0.850). Overall, the interobserver agreement was 0.46 for hWLE (moderate) and 0.64 for NBI (good).
  
  
  CONCLUSIONS
  NBI was as accurate as hWLE in differentiating diminutive colorectal polyps. Once a learning curve was reached, NBI achieved significantly higher accuracies with good interobserver agreement. Using a simplified classification, a didactic learning session and feedback on performance, diminutive colorectal polyps could be predicted with high accuracies with NBI.
authors.affiliation: Gastroenterology Unit, Division of Medicine, Lyell McEwin Hospital, University of Adelaide, Adelaide, South Australia. rajvindersingh2003@yahoo.com
authors.forename: Rajvinder
authors.initials: R
authors.lastname: Singh
authors.forename: Yasser Maqbool
authors.initials: YM
authors.lastname: Bhat
authors.forename: Prem Harichander
authors.initials: PH
authors.lastname: Thurairajah
authors.forename: Mohit Pramod
authors.initials: MP
authors.lastname: Shetti
authors.forename: Mahesh
authors.initials: M
authors.lastname: Jayanna
authors.forename: Garry
authors.initials: G
authors.lastname: Nind
authors.forename: William
authors.initials: W
authors.lastname: Tam
authors.forename: Russell
authors.initials: R
authors.lastname: Walmsey
authors.forename: Micheal
authors.initials: M
authors.lastname: Bourke
authors.forename: Alan
authors.initials: A
authors.lastname: Moss
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.forename: Peter
authors.initials: P
authors.lastname: Bampton
authors.forename: Ian
authors.initials: I
authors.lastname: Roberts-Thomson
authors.forename: Mark
authors.initials: M
authors.lastname: Schoeman
authors.forename: Graeme
authors.initials: G
authors.lastname: Tucker
mesh_terms: D018256:Adenomatous Polyps / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003111:Colonic Polyps / Q000175:diagnosis; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis; D007417:Intestinal Polyps / Q000175:diagnosis*; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging; D015588:Observer Variation; D012007:Rectum / Q000473:pathology*; D012680:Sensitivity and Specificity; D014741:Video Recording