title: Interobserver agreement among endoscopists on evaluation of polypoid colorectal lesions visualized with the Pentax i-Scan technique.
abstract: OBJECTIVE
  Advances in colonoscopy, such as the Pentax i-Scan electronic technique, have the potential to improve the early detection of colorectal cancer. The aim of this multicentre study was to assess the interobserver agreement in the visualization of the surface and margins of colorectal polyps and in distinguishing neoplastic from non-neoplastic polyps.
  
  
  METHODS
  Eight expert endoscopists examined 400 mixed previously recorded images of polyps taken with different Pentax i-Scan settings in order to give an evaluation of the surface of the polyp and regular colonic mucosa, the pit-pattern and the nature of the lesion.
  
  
  RESULTS
  A total of 400 mixed images of polyps with a diameter >5mm and <10mm were stored for analysis. Overall, there was a Kf agreement of 0.370 (p<0.001) and 0.306 (p<0.001) regarding pit-pattern and margins, respectively. The Kf agreement for the difference between neoplastic and non-neoplastic lesions was of 0.446 (p<0.001).
  
  
  CONCLUSIONS
  We observed good interobserver agreement in the evaluation of neoplastic and non-neoplastic lesions and poor agreement in the evaluation of pit-pattern and margins. Adequate training is required in order to interpret images acquired with the i-Scan technique.
authors.affiliation: Gastrointestinal Endoscopy, San Paolo University Hospital, Milan, Italy. enzo.masci@ao-sanpaolo.it
authors.forename: Enzo
authors.initials: E
authors.lastname: Masci
authors.forename: Benedetto
authors.initials: B
authors.lastname: Mangiavillano
authors.forename: Cristiano
authors.initials: C
authors.lastname: Crosta
authors.forename: Giancarla
authors.initials: G
authors.lastname: Fiori
authors.forename: Cristina
authors.initials: C
authors.lastname: Trovato
authors.forename: Paolo
authors.initials: P
authors.lastname: Viaggi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zambelli
authors.forename: Federico
authors.initials: F
authors.lastname: Buffoli
authors.forename: Teresa
authors.initials: T
authors.lastname: Staiano
authors.forename: Guido
authors.initials: G
authors.lastname: Manfredi
authors.forename: Francesco
authors.initials: F
authors.lastname: Manguso
authors.forename: Monica
authors.initials: M
authors.lastname: Arena
authors.forename: Tara
authors.initials: T
authors.lastname: Santoro
authors.forename: Edi
authors.initials: E
authors.lastname: Viale
authors.forename: Pier Alberto
authors.initials: PA
authors.lastname: Testoni
mesh_terms: D000368:Aged; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation