title: A prospective comparative study of narrow-band imaging, chromoendoscopy, and conventional colonoscopy in the diagnosis of colorectal neoplasia.
abstract: BACKGROUND
  Discrimination between neoplastic and non-neoplastic lesions is crucial in colorectal cancer screening. Application of narrow-band imaging (NBI) in colonoscopy visualises mucosal vascular networks in neoplastic lesions and may improve diagnostic accuracy.
  
  
  OBJECTIVE
  To compare the diagnostic efficacy of NBI in differentiating neoplastic from non-neoplastic colorectal lesions with diagnostic efficacies of standard modalities, conventional colonoscopy, and chromoendoscopy.
  
  
  METHODS
  In this prospective study, 180 colorectal lesions from 133 patients were observed with conventional colonoscopy, and under low-magnification and high-magnification NBI and chromoendoscopy. Lesions were resected for histopathological analysis. Endoscopic images were stored electronically and randomly allocated to two readers for evaluation. Sensitivity, specificity and diagnostic accuracy of each endoscopic modality were assessed by reference to histopathology.
  
  
  RESULTS
  NBI and chromoendoscopy scored better under high magnification than under low magnification in comparison with conventional colonoscopy. The diagnostic accuracy of NBI with low or high magnification was significantly higher than that of conventional colonoscopy (low magnification: p = 0.0434 for reader 1 and p = 0.004 for reader 2; high magnification: p<0.001 for both readers) and was comparable to that of chromoendoscopy.
  
  
  CONCLUSIONS
  Both low-magnification and high-magnification NBI were capable of distinguishing neoplastic from non-neoplastic colorectal lesions; the diagnostic accuracy of NBI was better than that of conventional colonoscopy and equivalent to that of chromoendoscopy. The role of NBI in screening colonoscopy needs further evaluation.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Chiu
authors.forename: Chi-Yang
authors.initials: CY
authors.lastname: Chang
authors.forename: Chien-Chuan
authors.initials: CC
authors.lastname: Chen
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Lee
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
authors.forename: Jaw-Town
authors.initials: JT
authors.lastname: Lin
authors.forename: Chia-Tung
authors.initials: CT
authors.lastname: Shun
authors.forename: Hsiu-Po
authors.initials: HP
authors.lastname: Wang
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000175:diagnosis; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004396:Coloring Agents; D003937:Diagnosis, Differential; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007203:Indigo Carmine; D008297:Male; D008875:Middle Aged
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine