S1320 Accuracy of Linked Color Imaging (LCI) in Prediction of Active Helicobacter pylori Infection—A Prospective Study

Introduction: Prevalence of Helicobacter pylori infection worldwide varies from 50 to 80%. Test and treat strategy for H. pylori have been recommended for all patients with symptoms. Linked color imaging (LCI) is a novel Image enhanced endoscopy (IEE) technology which has been utilized for this purpose. In this study we tested the accuracy of LCI in our center in predicting H. pylori infection. Methods: Study Design: Prospective observational cohort study. Inclusion Criteria: Patients more than 18 years old undergoing esophagogastroduodenoscopy for dyspeptic symptoms in whom H.pylori infection was suspected. Study protocol: Pilot study was conducted among experts with images of 50 patients in white light imaging endoscopy (WLI) and LCI. The ability to detect H. pylori positivity on LCI improved when shades of crimson namely cerise and deep blush were included. Results: Study involved 181 patients (69% males) aged 45.7 years (16-84). Epigastric burning was the most common symptom followed by abdominal pain. Histopathological examination (HPE) was positive for H. pylori gastritis in 114(63%) patients. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of WLI for diagnosing H. pylori infection are 70.27%, 47.34%, 64.03%, 54.17%, 60.4% respectively, and that of LCI are 83.22%, 71.24%, 82.89% 71.64%, 78.73% respectively (LCI better than WLI. (P < 0.001)). Experts performed better than non-experts. Experts and non-experts performed better with LCI than WLI (P < 0.001). For WLI images, moderate agreement was noted amongst the experts and moderate to fair between the experts and the non-experts and amongst the non-experts. Interobserver agreement was better with LCI. There was at least moderate agreement between all the observers. All 3 shades of crimson had specificity of more than 84% for diagnosing H. pylori infection but the sensitivity of individual colors is poor. LCI has a good performance in all the diagnostic metrics when data of all 3 shades of crimson were combined. Conclusion: LCI can be used to predict the diagnosis of H. pylori gastritis with an accuracy of 79%. When the color palette of crimson is extended to include cerise and deep blush shades performance of LCI increases compared to crimson alone.