Correlation between narrow band imaging and nonneoplastic gastric pathology: a pilot feasibility trial

Background: A novel narrow band imaging (NBI) system is able to visualize the mucosal and vascular network in the GI tract. Objective: The aim of the current study was to test the feasibility of NBI to predict gastric histologic diagnosis. Design: A pilot feasibility study. Setting: Veterans Affairs Medical Center. Patients: Forty-seven patients undergoing upper endoscopy for various indications were prospectively enrolled. Methods: The gastric body and antrum were systematically examined by NBI before targeted biopsies. Images were graded according to the mucosal (ridge/villous and circular) and vascular patterns and correlated with histologic findings in a blinded manner. Main Outcome Measurements: Final histologic diagnosis based on updated Sydney classification system. Results: Overall, 25 patients (53.1%) had a normal biopsy specimen, 13 (27.6%) had non-Helicobacter pylori gastritis, 4 (8.5%) had H pylori gastritis, and 5 (10.6%) had intestinal metaplasia. The sensitivity, specificity, and positive predictive value of a regular mucosal and vascular pattern for the diagnosis of normal mucosa/mild gastritis were 89%, 78%, and 94%, respectively The sensitivity and specificity of an irregular pattern with decreased density of vessels for the diagnosis of H pylori were 75% and 88%, and that of the ridge/villous pattern for the diagnosis of intestinal metaplasia were 80% and 100%, respectively. Limitation: The small number of patients with H pylori and intestinal metaplasia was the main limitation. Conclusions: This is the first U.S. study of NBI for gastric lesions. NBI may help predict in vivo histologic diagnosis of gastric pathologic conditions with a good degree of accuracy. Future larger studies are needed.