title: The diagnostic utility of narrow band imaging magnifying endoscopy in clinical practice in a population with intermediate gastric cancer risk.
abstract: OBJECTIVE
  Narrow band imaging (NBI) and NBI-magnifying endoscopy (ME) have been reported to facilitate the diagnosis of intestinal metaplasia (IM) and early gastric cancer (EGC) in high-risk populations. This study aimed at comparing the detection rate of focal gastric lesions by NBI against white light endoscopy (WLE), and examined the utility of NBI-ME in differentiating gastric mucosal pathology in a population with intermediate gastric cancer risk.
  
  
  METHODS
  Chinese patients aged 35-70 years undergoing diagnostic gastroscopy (GIF FQ260Z) by six experienced endoscopists were enrolled prospectively. The sequence of endoscopic evaluation was WLE followed by NBI. Focal lesions were re-examined by NBI-ME. The incremental diagnostic yield of NBI over WLE and ability of NBI-ME to differentiate gastric mucosal pathology were analyzed.
  
  
  RESULTS
  Over a 30-month period, 458 patients (mean age: 52 years; men: 53.7%; Helicobacter pylori positive: 20.1%) were recruited. WLE detected a focal gastric lesion in 43.7% (200/458). WLE made a definitive diagnosis in 148 out of 200 patients (147 benign lesions and one gastric cancer), whereas NBI-ME correctly clarified the nature of the remaining 52 lesions (benign: 51; EGC: one). NBI detected an additional 69 out of 458 lesions (type 0_IIa: 91.3%; type 0_IIb: 8.7%) missed by WLE; the diagnoses based on NBI-ME were IM (67/69), EGC (1/69), and benign lesion (1/69). Interobserver agreement study revealed a κ statistic of 0.71.
  
  
  CONCLUSIONS
  NBI detected IM missed by WLE. NBI-ME was useful in differentiating the pathology of focal gastric mucosal lesions.
authors.affiliation: Department of Gastroenterology, Changi General Hospital, Singapore, Singapore. tiing_leong_ang@cgh.com.sg
authors.forename: Tiing Leong
authors.initials: TL
authors.lastname: Ang
authors.forename: Kwong Ming
authors.initials: KM
authors.lastname: Fock
authors.forename: Eng Kiong
authors.initials: EK
authors.lastname: Teo
authors.forename: Jessica
authors.initials: J
authors.lastname: Tan
authors.forename: Choo Hean
authors.initials: CH
authors.lastname: Poh
authors.forename: Jeannie
authors.initials: J
authors.lastname: Ong
authors.forename: Daphne
authors.initials: D
authors.lastname: Ang
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005773:Gastroscopy / Q000379:methods*; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008679:Metaplasia / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology; D008875:Middle Aged; D015588:Observer Variation; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D011446:Prospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology