The kidney can be selected for CT examination. CT plain scan can observe whether the kidney size, morphology, density and contour are abnormal, including the adrenal glands above the kidney, and generally cysts, calcifications and vascular smooth muscle lipomas can be diagnosed very clearly. In addition to plain scan, enhanced CT scan is also needed for early stage renal cancer. All renal malignant tumors have arterial phase enhancement. Therefore, the enhanced scan should scan the arterial phase, venous phase and equilibrium phase to differentiate the tumor from three different time phases.