Application of Linked Color Imaging（LCI） in Diagnosis of Early Gastric Cancer(EGC)

Inclusion Criteria: 1. High-risk group of gastric cancer: H. pylori infection; previously suffering from chronic atrophic gastritis, intestinal metaplasia, gastric ulcer, gastric polyps, residual stomach after surgery, hypertrophic gastritis, malignant anemia and other precancerous diseases of gastric cancer; 2. First degree relatives of patients with gastric cancer; 3. There are other high risk factors for gastric cancer (high salt, salted diet, smoking, heavy drinking, etc.). 4. Patients with early gastric cancer treated with endoscopic therapy (ESD, EMR). 5. The informed consent has been signed. Exclusion Criteria: 1. The TNM classification of cancer is consistent with those diagnosed by T2 above. 2. Patients with abnormal blood coagulation function or taking anticoagulants can not biopsy. 3. There were contraindications for gastroscopy. 4. A patient without self judgement; 5. Those who did not sign informed consent. 6. Previous gastroscopy has found suspicious lesions requiring careful examination.