To explore the value and difference of narrow band imaging-magnifying endoscopy(NBI-ME)and endoscopic biopsy in the diagnosis of early gastric cancer and precancerous lesions.

Fifty patients with suspicious early gastric lesions or precancerous lesions as revealed by white light endoscopy(WLE)were enrolled in the study from March 2016 to June 2016 in Affiliated Hospital of Weifang Medical University.All lesions were observed through NBI-ME, and the types of crypt-opening were recorded to give a diagnosis.Biopsy specimens were then taken from suspicious lesions for pathological examination.All patients received endoscopic submucosal dissection(ESD)or surgical intervention.The types of crypt-opening were analyzed in combination with postoperative pathological diagnosis.The diagnosis of NBI-ME and endoscopic biopsy and postoperative pathological diagnosis were compared and analyzed.

There was significant difference in the type of crypt-opening and the postoperative pathological diagnosis(χ²=42.13, P<0.05). The sensitivity of NBI-ME for diagnosing low-grade intraepithelial neoplasia(LGIN)was significantly lower than that of endoscopic biopsy(P=0.02), but there was no statistical difference in diagnostic specificity and accuracy between the two modalities(P>0.05). The differences of sensitivity, specificity and accuracy between NBI-ME and endoscopic biopsy in the diagnosis of early gastric cancer were not statistically significant(P>0.05). The Kappa values of the consistency checks were 0.54(NBI-ME and postoperative pathological diagnosis)and 0.64(endoscopic biopsy and postoperative pathological diagnosis), with a statistically significant difference(P<0.05).

NBI-ME has a high clinical value in the diagnosis of early gastric cancer and precancerous lesions, but there are still differences compared with the results of pathological biopsy.NBI-ME can provide a great help to accurate endoscopic biopsy.