AIM:To evaluate the efficacy of computer-assisted color analysis of colorectal lesions using a novel auto-fluorescence imaging(AFI)system to distinguish neoplastic lesions from non-neoplastic lesions and to predict the depth of invasion.METHODS:From January 2013 to April 2013,consecutive patients with known polyps greater than 5 mm in size who were scheduled to undergo endoscopic treatment at The Jikei University Hospital were prospectively recruited for this study.All lesions were evaluated using a novel AFI system,and color-tone sampling was performed in a region of interest determined from narrow band imaging or from chromoendoscopy findings without magnification.The green/red(G/R)ratio for each lesion on the AFI images was calculated automatically using a computer-assisted color analysis system that permits real-time color analysis during endoscopic procedures.RESULTS:A total of 88 patients with 163 lesions were enrolled in this study.There were significant differences in the G/R ratios of hyperplastic polyps(non-neoplastic lesions),adenoma/intramucosal cancer/submucosal(SM)superficial cancer,and SM deep cancer(P<0.0001).The mean±SD G/R ratios were 0.984±0.118in hyperplastic polyps and 0.827±0.081 in neoplastic lesions.The G/R ratios of hyperplastic polyps were significantly higher than those of neoplastic lesions(P<0.001).When a G/R ratio cut-off value of>0.89 was applied to determine non-neoplastic lesions,the sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy were 83.9%,82.6%,53.1%,95.6%and 82.8%,respectively.For neoplastic lesions,the mean G/R ratio was 0.834±0.080 in adenoma/intramucosal cancer/SM superficial cancer and 0.746±0.045 in SM deep cancer.The G/R ratio of adenoma/intramucosal cancer/SM superficial cancer was significantly higher than that of SM deep cancer(P<0.01).When a G/R ratio cut-off value of<0.77 was applied to distinguish SM deep cancers,the sensitivity,specificity,PPV,NPV,and accuracy were80.0%,84.4%,29.6%,98.1%and 84.1%,respectively.CONCLUSION:The novel AFI system with color analysis was effective in distinguishing non-neoplastic lesions from neoplastic lesions and might allow determination of the depth of invasion. AIM: To evaluate the efficacy of computer-assisted color analysis of colorectal lesions using a novel auto-fluorescence imaging (AFI) system to distinguish neoplastic lesions from non-neoplastic lesions and to predict the depth of invasion. METHODS: From January 2013 to April 2013, consecutive patients with known polyps greater than 5 mm in size who were scheduled to undergo endogenous treatment at The Jikei University Hospital were prospectively recruited for this study. All lesions were evaluated using a novel AFI system, and color-tone sampling was performed in a region of interest determined from narrow band imaging or from chromoendoscopy findings without magnification. green / red (G / R) ratio for each lesion on the AFI images was calculated automatically using a computer-assisted color analysis system that permits real-time color analysis during endoscopic procedures. RESULTS: A total of 88 patients with 163 lesions were enrolled in this study. Here are significant differences in the G / R r atios of hyperplastic polyps (non-neoplastic lesions), adenoma / intramucosal cancer / submucosal (SM) superficial cancer, and SM deep cancer (P <0.0001) .The mean ± SD G / R ratios were 0.984 ± 0.118 in hyperplastic polyps and 0.827 ± 0.081 in neoplastic lesions.The G / R ratios of hyperplastic polyps were significantly higher than those of neoplastic lesions (P <0.001) .When a G / R ratio cut-off value of> 0.89 was applied to determine non-neoplastic lesions, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 83.9%, 82.6%, 53.1%, 95.6% and 82.8%, respectively. For neoplastic lesions, the mean G / R ratio was 0.834 ± 0.080 in adenoma / intramucosal cancer / SM superficial cancer and 0.746 ± 0.045 in SM deep cancer. The G / R ratio of adenoma / intramucosal cancer / SM superficial cancer was significantly higher than that of SM deep cancer (P <0.01). When a G / R ratio cut-off value of <0.77 was applied to distinguish SM deep cancers, the sensitivity, specificity, PPV, NPV, and accuracy w ere80.0%, 84.4%, 29.6%, 98.1% and 84.1%, respectively.CONCLUSION: The novel AFI system with color analysis was effective in distinguishing non-neoplastic lesions from neoplastic lesions and might allow determination of the depth of invasion.