Narrow band imaging versus white light gastroscopy in detecting potentially premalignant gastric lesions: a randomized prospective crossover study.
Narrow band imaging (NBI) detects mucosal surface details (pit pattern) as well as the microvasculature pattern of mucosa. In premalignant conditions the pattern and regularity of pits and microvasculature are altered. We aimed to assess whether NBI is superior to conventional white light gastroscopy (WLG) in detecting potentially premalignant gastric lesions. We conducted a randomized prospective crossover study from January 2009 to July 2009. Patients above 45 years of age with dyspepsia in absence of alarm symptoms underwent gastric mucosal examination using WLG and NBI in the same session by different endoscopists who were blinded to each other's endoscopy findings. Biopsy was taken if required at the end of the second gastroscopy after a third observer reviewed reports of both scopists. The yield of gastric potentially premalignant lesions (atrophic gastritis, intestinal metaplasia, dysplasia, adenomatous polyp) was compared for both procedures. Two hundred [mean age 52.3 (6.4) years, males-66 %] patients participated in the study. Thirty-two patients were diagnosed to have potentially premalignant lesions using both modalities. No patient had early gastric cancer. WLG detected lesions in 17 patients (atrophic gastritis in 12, atrophic gastritis with intestinal metaplasia in 5) and NBI in 31 patients (atrophic gastritis in 22, atrophic gastritis with intestinal metaplasia in 9). The sensitivity of lesion detection by NBI was significantly higher than WLG (p = 0.001). NBI was superior to WLG for detection of atrophic gastritis and intestinal metaplasia.