Effectiveness of color intensity analysis using updated autofluorescence imaging systems for serrated lesions

Abstract

Background and Aim We previously reported the effectiveness of color intensity analysis using autofluorescence imaging (AFI) for differentiating colorectal neoplastic lesions from non-neoplastic lesions. However, the ability of AFI systems for differentiating serrated lesions has not been evaluated. In the present study, we assessed the effectiveness of color intensity analysis using updated AFI systems for evaluating serrated lesions. Methods We retrospectively reviewed the data for 48 consecutive patients with 87 serrated lesions that were examined using updated AFI systems and resected at Jikei University Hospital. The mean green/red (G/R) ratio, which is obtained by dividing the mean green color intensities by the mean red color intensities, was calculated for each serrated lesion and compared between hyperplastic polyps, sessile serrated adenomas/polyps (SSA/P) with cytological dysplasia, and SSA/P without cytological dysplasia. We also assessed the area under the receiver operating characteristic curve (AUC) for determining SSA/P (both with and without cytological dysplasia) and SSA/P with cytological dysplasia. Results The AUC for determining SSA/P was 0.68; however, the AUC for determining SSA/P with cytological dysplasia was 0.97. With a cut-off for the G/R ratio of <0.93, the sensitivity, specificity, positive predictive value, and negative predictive value for SSA/P with cytological dysplasia were 95.5%, 91.0%, 77.8%, and 98.3%, respectively. Conclusion Color intensity analysis of serrated lesions using updated AFI systems could effectively distinguish SSA/P with cytological dysplasia from hyperplastic polyps and SSA/P without cytological dysplasia.