We have suggested the combination use of Amplitude Difference Index Ring Filter (ADR) and Positive Convergence Index Ring Filter (PCR), for the first step processing of extraction of the pulmonary nodules. Applying those two filters whose behavior is different is effective for extracting nodules. In this study, we applied those two filters and the classification method for reduction of false positive based on the local average similarities of k-Nearest-Neighbor patterns in individual categories to LIDC. The result showed that those 3D methods are effective for extraction of the nodule in thin slice chest CT, the same as in thick one.