Magnified endoscopy with texture and color enhanced imaging with indigo carmine for superficial nonampullary duodenal tumor: a pilot study

This pilot study aimed to investigate the utility of texture and color enhancement imaging (TXI) with magnified endoscopy (ME) for the preoperative diagnosis of superficial nonampullary duodenal epithelial tumors (SNADETs). We prospectively evaluated 12 SNADETs. The visibility for ME-TXI, ME with indigo carmine (ICME)—white-light imaging (WLI), ICME-TXI compared to ME-NBI (narrow-band imaging) was scored (+ 2 to − 2 ME-NBI was set as score 0) by 3 experts. Scores + 2 and + 1 were defined as improved visibility. The intra-observer and interobserver agreement for improved visibility of surface structure (SS) was evaluated. Sensitivity, specificity, and positive predictive value (PPV) for Vienna Classification (VCL) C4/5 associated with the preoperative diagnosis of ICME-TXI were analyzed. The SS visibility score of ICME-TXI was significantly higher than that of ME-NBI, ME-TXI, and ICME-WLI (P < 0.001 respectively). The kappa coefficients of reliability for intra-observer and interobserver agreement for the SS visibility improvement with ICME-TXI were 0.96, 1.00, 1.00 and 0.70, 0.96, 0.96 respectively. All endoscopists preferred ICME-TXI for visualizing SS mostly for all lesions. The sensitivity, specificity, and PPV (%) of ICME-TXI for VCL C4/5 were 80, 66.7, and 63.2, respectively. ICME-TXI facilitates the visibility of the SS of SNADETs and may contribute to their preoperative diagnosis.