title: Comparison of high-resolution magnification narrow-band imaging and white-light endoscopy in the prediction of histology in Barrett's oesophagus.
abstract: OBJECTIVE
  To evaluate whether there is any appreciable difference in imaging characteristics between high-resolution magnification white-light endoscopy (WLE-Z) and narrow-band imaging (NBI-Z) in Barrett's oesophagus (BE) and if this translates into superior prediction of histology.
  
  
  METHODS
  This was a prospective single-centre study involving 21 patients (75 areas, corresponding NBI-Z and WLE-Z images) with BE. Mucosal patterns (pit pattern and microvascular morphology) were evaluated for their image quality on a visual analogue scale (VAS) of 1-10 by five expert endoscopists. The endoscopists then predicted mucosal morphology based on four subtypes which can be visualized in BE. Type A: round pits, regular microvasculature; type B: villous/ridge pits, regular microvasculature; type C: absent pits, regular microvasculature; type D: distorted pits, irregular microvasculature. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were then compared with the final histopathological analysis and the interobserver variability calculated.
  
  
  RESULTS
  The overall pit and microvasculature quality was significantly higher for NBI-Z, pit: NBI-Z=6, WLE-Z=4.5, p < 0.001; microvasculature: NBI-Z=7.3, WLE-Z=4.9, p < 0.001. This translated into a superior prediction of histology (Sn: NBI-Z: 88.9, WLE-Z: 71.9, p < 0.001). For the prediction of dysplasia, NBI-Z was superior to WLE-Z (chi(2)=10.3, p < 0.05). The overall kappa agreement among the five endoscopists for NBI-Z and WLE-Z, respectively, was 0.59 and 0.31 (p < 0.001).
  
  
  CONCLUSIONS
  NBI-Z is superior to WLE-Z in the prediction of histology in BE, with good reproducibility. This novel imaging modality could be an important tool for surveillance of patients with BE.
authors.affiliation: Wolfson Digestive Diseases Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK. rajvinder.singh@health.sa.gov.au
authors.forename: Rajvinder
authors.initials: R
authors.lastname: Singh
authors.forename: Haris
authors.initials: H
authors.lastname: Karageorgiou
authors.forename: Victoria
authors.initials: V
authors.lastname: Owen
authors.forename: Klara
authors.initials: K
authors.lastname: Garsed
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Fortun
authors.forename: Edward
authors.initials: E
authors.lastname: Fogden
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Subramaniam
authors.forename: Anthony
authors.initials: A
authors.lastname: Shonde
authors.forename: Philip
authors.initials: P
authors.lastname: Kaye
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hawkey
authors.forename: Krish
authors.initials: K
authors.lastname: Ragunath
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000175:diagnosis / Q000473:pathology*; D004945:Esophagoscopy / Q000379:methods*; D004947:Esophagus / Q000098:blood supply / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted; D008027:Light; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity