Patients with H. pylori gastritis, gastric atrophy, intestinal metaplasia most commonly have no visible lesions on white-light endoscopy, although endoscopic findings may include antral nodularity, absent rugae, prominent gastric vessels white mucosal deposits. However, the sensitivity and specificity of these gross findings for underlying histological findings is poor. Therefore a number of image-enhancement techniques including chromoendoscopy using mucosal dyes or endoscopy-based virtual chromo-endoscopy (e.g., narrow band imaging) have been proposed. Narrow band imaging is the most widely investigated.