Objective To study the diagnostic value of i-Scan in Colorectal neoplasm.Methods 180 Colorectal polypus were discovered by high definition colonoscopy.The pit pattern(PP)was observed by i-Scan to predict pathological patterns and to compare the results of pathological check-up and chromoendoscopy.Results As to the i-Scan of high definition colonoscopy,the diagnostic accuracy rate was 86.2%,the sensitivity was 78.9%,the specificity was 87.4%,the positive predictive value was 89.8%,and the negative predictive...