Narrow-band imaging for optical diagnosis of duodenal villous atrophy in patients with suspected coeliac disease: A systematic review and meta-analysis

Background: Narrow-band imaging (NBI) is a readily accessible imaging technique that enhances mucosal visualisation, allowing for a more accurate assessment of duodenal villi. However, its role in the diagnosis of coeliac disease (CD) in clinical practice remains limited. Methods: We systematically searched several databases in June 2023 for studies evaluating the diagnostic accuracy of NBI for detecting duodenal villous atrophy (VA) in patients with suspected CD. We calculated the summary sensitivity, specificity, and likelihood ratios using a bivariate random-effects model. The study followed PRISMA guidelines and was registered at PROSPERO (CRD42023428266). Results: A total of 6 studies with 540 participants were included in the meta-analysis. The summary sensitivity of NBI to detect VA was 93% (95% CI, 81% - 98%), and the summary specificity was 95% (95% CI, 92% - 98%). The area under the summary receiver operating characteristic curve was 0.98 (95% CI, 96 - 99). The positive and negative predictive values of NBI were 94% (95% CI, 92% - 97%) and 92% (95% CI, 90% – 94%), respectively. Conclusion: NBI is an accurate non-invasive tool for identifying and excluding duodenal VA in patients with suspected CD. Further studies using a validated classification are needed to determine the optimal role of NBI in the diagnostic algorithm for CD.