Evaluation of the effectiveness of color intensity analysis using a second-generation autofluorescence imaging system for diminutive colorectal polyp differentiation.

Background and Aim: We previously reported the effectiveness of color tone intensity analysis using autofluorescence imaging (AFI) for distinguishing between colorectal neoplastic and non-neoplastic lesions. Moreover, a second-generation AFI system has become commercially available in Japan. In the present study, we assessed the effectiveness of color tone intensity analysis using a second-generation AFI system for evaluating diminutive colorectal lesions.
Methods: We retrospectively reviewed the cases of 35 consecutive patients with 101 diminutive colorectal lesions that were examined using a second-generation AFI system and resected at the Jikei University Hospital. We estimated the mean green-to-red (G/R) ratio - obtained by dividing the green color tone intensity by the red color tone intensity - of the lesions and compared the values of the neoplastic and non-neoplastic lesions. We also assessed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AFI system for neoplastic lesion identification.
Results: The mean G/R ratios of the non-neoplastic and neoplastic lesions were 1.06 and 0.87, respectively; the mean G/R ratio significantly differed between the neoplastic and non-neoplastic lesions. Using the second-generation AFI system, neoplastic lesions were identified with a sensitivity, specificity, PPV, and NPV of 94.2%, 91.8%, 92.5%, and 93.8%, respectively.
Conclusion: Color intensity analysis of diminutive colorectal polyps using the second generation AFI system could effectively distinguish between neoplastic and non-neoplastic lesions.
(© 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.)