H. pylori infection plays a very important role in gastric carcinogenesis, progressing from chronic gastritis through atrophic gastritis, intestinal metaplasia, dysplasia and finally cancer. It is difficult to diagnose H. pylori related gastritis and gastric atrophy on the basis of endoscopic findings. Histology is currently considered to be the gold standard for detecting H. pylori infection. The reliability of detecting H. pylori infection histologically depends on the site, number, and size of gastric biopsy specimens. The blind biopsy sampling of normal appearing mucosa has the risk of missing pathology and sampling errors. Most studies conclude that as well as on expertise in staining and visualizing the bacteria. Considerable error also occurs in identifying gastric atrophy using blind biopsy sampling, and neither the original nor the revised version of the Sydney system reliably identifies more than half the cases in patients with confirmed gastric atrophy.

NBI is the most widely used system among several available image enhanced endoscopy systems. However, this technique has limitations such as dark imaging of distant lesions because of narrow-band illumination. Blue Laser Imaging (BLI) was developed to compensate for these inherent limitations of NBI. BLI uses narrow-band laser light combined with white light. This combination results in a bright image of the digestive mucosa, enabling the detailed visualization of both the microstructure and the microvasculature. However, BLI still is not able to obtain sufficient brightness for distant lesions. The newly developed Linked Color Imaging (LCI) system (FUJIFILM Co.) creates clear and bright endoscopic images by using short-wavelength narrow-band laser light combined with white laser light on the basis of BLI technology. This system can obtain bright endoscopic images even at a distant view because LCI has more intense white light than the short-wavelength narrow-band laser light. Short-wavelength narrow-band laser light enhances the vessels on the mucosal surface and the patterns of the mucosa, which means that BLI enables a clearer visualization of microvascular structures than does LCI. In contrast, LCI enhances differences in hue, in the red region of the spectrum, through digital processing. This makes red areas appear redder and white areas appear whiter. Thus, it is easier to recognize a slight difference in color of the mucosa. Therefore, LCI may facilitate the detection of H. pylori infection and gastric atrophy. Further studies are needed to confirm the utility of LCI.

Inclusion Criteria:

• Above 18 years old patients
• Who agree to participate in the study
• Patients with the indications for gastroduodenoscopy

Exclusion Criteria:

• Patients, who were receiving nonsteroidal anti-inflammatory drugs, pump inhibitors (PPI) or antibiotics in the last 3 weeks.
• Severe uncontrolled coagulopathy
• Prior history of gastric surgery.
• Pregnancy and lactation