Su1409 A Novel Classification System (N.A.C.) for the Characterisation Colonic Polyps Using FICE Without Optical Magnification: A New Classification System (N.A.C.)

Abstract

month after, all images were reevaluated by the assessors. Kappa ( ) statistics were used to calculate interand intraobserver agreement. Result: Images of 40 lesions in the 37 patients were included in the test set and were evaluated by 4 assessors. The mean value for the interobserver agreement for vascular pattern was 0.76 (95% CI, 0.60-0.92) and for the surface pattern was 0.61 (95% CI, 0.360.86). The value for the interobserver agreement of vascular pattern was significantly higher than surface pattern (P 0.04). The mean value for intraobserver agreement for vascular pattern was 0.87 (95%CI, 0.75-1.00) and for surface pattern was 0.79 (95%CI 0.60-0.98). There was no significant difference. The sensitivity, the specificity and the overall accuracy of diagnosis of invasive cancer based on magnifying NBI, were 78.7% (95%CI, 66.3-88.1%), 100% (95%CI, 96.3-100%) and 91.8%(95%CI, 86.5-95.6%), respectively. Conclusion: The interobserver agreement of vascular pattern was more reliable than that of surface pattern, and magnifying NBI was useful to distinguish invasive cancer from adenoma. More studies should be necessary for evaluation of usefulness and reliability of surface pattern analysis by magnifying NBI.