Gastric cancer is the third most common cause of cancer-related death worldwide (1). Upper endoscopy is necessary to detect neoplastic macroscopic features at an early stage, but subtle abnormalities in the gastric mucosa are often missed or misdiagnosed (1). Helicobacter pylori (Hp) is involved in the pathogenesis of gastric diseases, such as, peptic ulcers, gastric lymphoma, and gastric cancer. Therefore, the necessity to recognize malignant gastric lesions at an early stage is imperative.

Previous I-SCAN™ technology uses white light as illumination light and digital post-processing of the reflection afterwards creates images yielding the virtual chromoendoscopic image. Emission of white light alone causes a potential limitation for the current I-SCAN™ technology to obtain high-quality images of microvascular patterns on the mucosal surface compared to narrow band imaging (NBI) with optical magnification.

Pentax Medical (HOYA, Tokyo, Japan) developed the Optical Enhancement™ (OE) System, which combines bandwidth-limited light with an endoscopy video system. The OE System combines digital signal processing with optical filters that limit the spectral characteristics of the illuminating light, connecting the peaks of the hemoglobin absorption spectrum (415 nm, 540 nm, and 570 nm) to create a continuous wavelength spectrum. This system has two modes that use different filters to optimize the visualization of specific features. Mode 1 is designed to improve visualization of microvessels with enough light. Mode 2 is designed to improve contrast of white-light observation by bringing the color tone of the overall image closer to that of natural color (white color tone) with more light than Mode 1 filter.

In addition, high definition optical magnification endoscopes have been developed and can combine high-definition imaging with optical magnification to produce detailed images with magnification of up to 136×. This imaging technique facilitates the evaluation of the superficial vascular aspects of the mucosa, enabling the identification of early signs of inflammation or lesions not previously seen with conventional endoscopy.

Inclusion Criteria:

• above 18 years of age
• agreed to participate in the study
• patients with dyspepsia in accordance with Rome criteria

Exclusion Criteria:

• those taking NSAIDS, PPIs or antibiotics three weeks prior invitation
• severe uncontrolled coagulopathy
• prior history of gastric surgery
• those pregnant or nursing females

A sample size was estimated with a 95% confidence interval and a 10% margin of error, based on the results of C. Robles et al. All consecutive participants will have dyspepsia according to the Rome IV criteria, and needs to be ≥18 years old. Participants need to have an epigastric pain syndrome (defined as localized pain or burning pain in the upper abdomen at least once a week, which was intermittent, nongeneralized, not relieved by defecation, and did not meet the criteria for pathology of the gallbladder or sphincter of Oddi); and/or a postprandial distress syndrome (defined as the presence of a nagging feeling of postprandial fullness after normal-volume meals, and/or early satiety that prevented the completion of a regular meal several times a week). The criteria need to be present within the 3 months prior to enrolment, and to have started ≥6 months prior to diagnosis of dyspepsia.