The application of endoscopic narrow-band imaging in the diagnosis of Barrett’s esophagus (BE) is a pathological phenomenon in which the squamous epithelium of the lower esophagus is replaced by a single layer of columnar epithelium with or without intestinalization, which is a precancerous lesion of esophageal adenocarcinoma. Narrow-band imaging (NBI) is an emerging endoscopic imaging technique in recent years, which is mainly used to observe the morphology of microscopic glandular ducts and microvessels on the mucosal surface of the GI tract, so as to detect some lesions that are difficult to be detected under normal endoscopy, to guide targeted biopsy more accurately, and to improve the diagnosis rate of GI lesions. In this study, we retrospectively analyzed the data of 30 patients with BE diagnosed by endoscopy and pathology in our hospital, and compared the clarity of Barrett’s esophageal lesions under conventional white light palpation and NBl mode, with the aim of exploring the value of NBI in the diagnosis of BE patients. 1. data and methods 1.1 Clinical data Thirty cases with Barrett’s esophagus diagnosed by gastroscopy and confirmed by pathology in our hospital during the period from 02 2015 to 07 2015. There were 18 male cases and 12 female cases; age 32-75 years, mean age 50.8±11.2 years. 1.2 Methods Apparatus: Olympus-290 system electronic gastroscope was used for operation. Endoscopic procedure: endoscopy was performed under oral local anesthetic or intravenous general anesthesia, and all cases were operated by a senior endoscopist, who first observed the esophagus, stomach, and duodenum with a general endoscope throughout, recorded the results, and saved the images. After completion, the endoscope was placed at the lower end of the esophagus to observe the esophageal mucosa, and after finding the suspicious lesion, attention was paid to the morphology of the lesion, the boundary and the color difference between the lesion and the surrounding area (Figure 1), and the lesion outline was also evaluated for calculated endoscopic clarity. After the above examination was completed, biopsy tissue was taken under the target at the lesion using biopsy forceps and sent for pathological examination, and the biopsy tissue sections were all stained with HE (hematoxylin eosin) for observation to obtain clear pathological results. 1.3 Diagnostic criteria for Barrett’s esophagus According to the consensus opinion on the diagnosis and treatment of BE formulated in Chongqing in 2005, the orolateral end of the gastric mucosal folds was considered as the gastroesophageal junction, and the diagnosis of BE could be confirmed if there was obvious upward displacement of the dentate line or orange-red gastric mucosa at the lower end of the esophagus, and columnar epithelial hyperplasia was confirmed by biopsy at the corresponding site. 1.4 Endoscopic clarity evaluation The operating physician and another endoscopist The endoscopic images were evaluated jointly by the operating physician and another endoscopist for clarity, and the evaluation method was as follows: unclear: 1 point; blurred: 2 points; clear: 3 points; very clear: 4 points. 1.5 Statistical methods SPSS 19.0 statistical software was used to analyze the data by rank sum test, and P≤0.05 indicated that there was a statistical difference. 2. Results A comparison of the clarity of the images of 30 lesions found by both modes of NBI and conventional white light endoscopy showed that there was a significant difference in the display of the contours of Barrett’s esophagus lesions between the two modes, and the NBI mode was significantly better than conventional white light endoscopy, as shown in Table 1. Table 1 Comparison of image clarity between NBI and conventional white light endoscopy in 30 cases (cases) Lesion contour image clarity score total p-value 1 score 2 score 3 score 4 score NBI006241140.00 Conventional white light 21015379 3. Discussion Barrett’s esophagus is one of the high-risk factors for esophageal adenocarcinoma, and its risk of developing esophageal adenocarcinoma is 30-50 times higher than that of the general population. Numerous studies have found that carcinoma of the gastric cardia and adenocarcinoma of the lower esophagus are closely related to Barrett’s esophagus. Pathological study found that the carcinogenesis process of BE is special intestinal epithelial metaplasia ( SIM) SIM → low degree of heterogeneous hyperplasia → high degree of heterogeneous hyperplasia → carcinoma in situ → invasive adenocarcinoma, and its annual occurrence of esophageal adenocarcinoma is about 0.5%:0.07% compared with normal people. Therefore, early diagnosis and treatment and close monitoring of the early lesions of BE are the keys to interrupt the evolution of cancer. In the past, four-quadrant biopsy was used as the gold standard to diagnose the presence of precancerous lesions in BE under conventional endoscopy, i.e., biopsies were taken at 1-50px intervals in four quadrants. Since precancerous lesions in BE cannot be detected by the naked eye under ordinary endoscopy, the four-quadrant method has disadvantages such as blindness of the sampling site and bleeding from previous biopsies that affect the visual field. In recent years, the widespread use of staining endoscopy (mainly iodine staining) has significantly improved the detection rate of early esophageal cancer and precancerous lesions. Compound iodine solution staining is a simple and inexpensive method, but may lead to iodine allergy, pharyngitis, pneumonia, and discomfort such as nausea and pain, etc. KONDO et al. demonstrated that sodium thiosulfate significantly reduced retrosternal discomfort. Because of these reasons, and the significant increase in examination time with esophageal chemical staining endoscopy has limited its use. The NBI technique involves rotating the endoscopic red, green, and blue (red/green/blue,RGB) filter and narrowing the light at three different wavelengths of red, green, and blue using a filter, leaving only a narrow band of light at 415, 540, and 600 nm, which focuses the light mainly on the surface of the mucosa and reduces light scattering, resulting in a clearer image. Since the wavelength absorbed by hemoglobin is around 415 nm, blue light can be well absorbed by hemoglobin, which can display the microscopic glandular duct morphology and microvascular morphology on the surface of the GI mucosa more clearly. The NBI mode was used to observe the mucosa of BE, and the clarity of the images was compared with that of ordinary endoscopy, and targeted pathological biopsies were performed under the guidance of the NBI mode. The results showed that the NBI mode could clearly observe the size and contour range of the BE mucosa compared with the conventional white light mode. The accuracy of NBI-guided targeted biopsy of BE mucosa SIM was 93%, and the sensitivity and specificity were 89% and 95%, respectively, in the study by Zizheng Go et al. In addition, compared with endoscopic staining, NBI is easy and time-saving to perform, and it can be quickly switched between normal and NBI modes with the push of a button. Qi Yanrong et al. selected 176 patients with endoscopic diagnosis of BE and observed them in conventional white light palpation, NBl mode and 1.2% iodine solution staining mode, and biopsied all suspicious lesions. The sensitivity and negative predictive value of both NBI and compound iodine solution were 100%, and the specificity of both was 89.8 and 91.7%, respectively, which were better than the results of conventional white light endoscopy, indicating that BE combined with early esophageal adenocarcinoma has high sensitivity and high negative predictive value, and its results are comparable to those obtained by staining with compound iodine solution. In conclusion, NBI can achieve “electronic staining” of lesions without dyes, which can significantly improve the clarity of lesion contours in Barrett’s esophagus and guide targeted biopsies, and is of great value in the diagnosis of Barrett’s esophagus.