Diagnostic accuracy of narrow-band imaging for the differentiation of neoplastic from non-neoplastic colorectal polyps: a meta-analysis

Aim Narrow-band imaging (NBI) is a novel imaging technology that makes the superficial vasculature of gastrointestinal mucosa visible. However, the real accuracy for the differentiation of neoplastic from nonneoplastic polyps by NBI for the colorectum is still unknown. Method A meta-analysis was carried out of studies which assessed the precision of NBI in the diagnosis of colorectal neoplastic polyps. Searches included PubMed and Embase and two reviewers independently assessed their quality with a modified version of the QUADAS and STARD tools. The study pooled estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC). Results There were 11 relevant original papers which fulfilled the inclusion criteria. The pooled sensitivity and specificity were 0.92 (95% CI 0.90-0.93) and 0.83 (95% CI 0.81-0.86) respectively. The AUC for NBI was 0.95 [SE 0.01; DOR 53.72 (95% CI 35.66-80.92)]. The sensitivity and specificity were 0.92 (95% CI 0.90-0.94) and 0.81 (95% CI 0.78-0.84) with magnification, and 0.91 (95% CI 0.88-0.93) and 0.86 (95% CI 0.82-0.89) without magnification. For the mucosal pattern sensitivity and specificity were 0.90 (95% CI 0.85-0.940) and 0.88 (95% CI 0.82-0.93), and for vascular pattern intensity they were 0.92 (95% CI 0.90-0.94) and 0.88 (95% CI 0.83-0.91). Conclusion Narrow-band imaging, with or without magnification, has a high diagnostic precision for colorectal neoplastic polyps using either vascular pattern intensity or mucosal pattern assessment as the measure.