title: i-Scan high-definition white light endoscopy and colorectal polyps: prediction of histology, interobserver and intraobserver agreement.
abstract: OBJECTIVE
  Aim of the study was the evaluation of high-definition white light (HDWL) i-Scan endoscopy for diagnostic prediction of histology, inter- and intraobserver agreement for colorectal polyps.
  
  
  METHODS
  In this prospective single-center cohort study, a skilled endoscopist, with HDWL i-Scan, predicted on real-time the histology of 150 polyps from 78 patients undergoing colonoscopy. Subsequently, four endoscopists, not involved in the collection of cases, predicted the polyps' histology (neoplastic vs nonneoplastic) and repeated the assessment after 6 months.
  
  
  RESULTS
  Real-time assessment of the lesions predicted a correct histology in 138/150 cases with a sensitivity, specificity, and accuracy of 95, 82, and 92 %, respectively. Sensitivity, specificity, and accuracy of post-acquisition evaluation were 87.7, 61.7, and 82.2 %, respectively. The κ values of inter- and intraobserver agreement of prediction of histology were 0.462 (0.373-0.537) and 0.657 (0.523-0.917). Among the subset of polyps (n = 82) with good/excellent quality image, sensitivity and accuracy of HDWL i-Scan improved (97 %, p = 0.003 and 94 %, p = 0.002, respectively) as well as κ value of interobserver agreement (0.699).
  
  
  CONCLUSIONS
  HDWL i-Scan technology helps for characterization of polyps of the colon with good accuracy even if it cannot replace, at the moment, the histopathological examination. Reproducibility among operators is supported by a moderate substantial interobserver and intraobserver agreement.
authors.affiliation: Digestive Endoscopy Unit, New Civil Hospital S. Agostino Estense of Modena, Modena, Italy. flaviapigo@virgilio.it
authors.forename: Flavia
authors.initials: F
authors.lastname: Pigò
authors.forename: Helga
authors.initials: H
authors.lastname: Bertani
authors.forename: Mauro
authors.initials: M
authors.lastname: Manno
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Mirante
authors.forename: Angelo
authors.initials: A
authors.lastname: Caruso
authors.forename: Carmelo
authors.initials: C
authors.lastname: Barbera
authors.forename: Raffaele
authors.initials: R
authors.lastname: Manta
authors.forename: Gabrio
authors.initials: G
authors.lastname: Bassotti
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Olivetti
authors.forename: Rita Luisa
authors.initials: RL
authors.lastname: Conigliaro
mesh_terms: D003111:Colonic Polyps / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008027:Light; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity