title: Comparative study of conventional colonoscopy, chromoendoscopy, and narrow-band imaging systems in differential diagnosis of neoplastic and nonneoplastic colonic polyps.
abstract: OBJECTIVE
  To identify the feasibility of the narrow-band imaging (NBI) method compared with that of conventional colonoscopy and chromoendoscopy for distinguishing neoplastic and nonneoplastic colonic polyps.
  
  
  METHODS
  This study enrolled consecutive patients who underwent colonoscopy using a conventional colonoscope between January and February 2006 at Chang-Gung Memorial Hospital, Linkou Medical Center, Taiwan. These 78 patients had 110 colorectal polyps. During the procedure, conventional colonoscopy first detected lesions, and then the NBI system was used to examine the capillary networks. Thereafter indigo carmine (0.2%) was sprayed directly on the mucosa surface prior to evaluating the crypts using a conventional colonoscope. The pit patterns were characterized using the classification system proposed by Kudo. Finally, a polypectomy or biopsy was performed for histological diagnosis.
  
  
  RESULTS
  Of the 110 colorectal polyps, 65 were adenomas, 40 were hyperplastic polyps, and five were adenocarcinomas. The NBI system and pit patterns for all lesions were analyzed. For differential diagnosis of neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic) polyps, the sensitivity of the conventional colonoscope for detecting neoplastic polyps was 82.9%, specificity was 80.0% and diagnostic accuracy was 81.8%, significantly lower than those achieved with the NBI system (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%) and chromoendoscopy (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%). Therefore, no significant difference existed between the NBI system and chromoendoscopy during differential diagnosis of neoplastic and nonneoplastic polyps.
  
  
  CONCLUSIONS
  The NBI system identified morphological details that correlate well with polyp histology by chromoendoscopy.
authors.affiliation: Department of Gastroenterology and Hepatology, Lin-Kou Medical Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Ming-Yao
authors.initials: MY
authors.lastname: Su
authors.forename: Chen-Ming
authors.initials: CM
authors.lastname: Hsu
authors.forename: Yu-Pin
authors.initials: YP
authors.lastname: Ho
authors.forename: Pang-Chi
authors.initials: PC
authors.lastname: Chen
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Lin
authors.forename: Cheng-Tang
authors.initials: CT
authors.lastname: Chiu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D004396:Coloring Agents; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007203:Indigo Carmine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
chemical_list: D004396:Coloring Agents; D007203:Indigo Carmine