The difference between thin-layer CT and enhanced CT in tumor screening mainly lies in the different thickness of scanning layer in the examination process. 1. Thin-layer CT: the thickness of thin layer, that is, bubble surface level, is not more than five millimeters, which can show the size, shape, inner structure and edge of tumor, and it is not easy to miss the tiny lesions with thick and thin scanning layer. 2. Enhanced CT: injecting contrast agent on the basis of plain CT, further diagnosis can be made by comparing the absorption of contrast agent by tumor and surrounding normal tissues. If you need to know the degree of tumor infiltration or distant metastasis, enhanced CT is needed, which can also help to judge the blood supply of suspected tumors and tumor tissues on blood vessels. Specific tests should be performed under the professional guidance of a physician.