Positron emission tomography (PET) is widely used in oncology. Fluorine-18-Fluorodeoxyglucose (18F-FDG) PET seems to be a powerful imaging method in diagnosis of breast cancer, gastric cancer, and colorectal cancer. However, our previous study has showed the limited diagnostic sensitivity of 18F-FDG PET in HCC lesions (54%), which makes 18F-FDG PET of no additional value to conventional imaging in the diagnosis of HCC. 11C-acetate PET has been used in the diagnosis of various malignant tumors. Compared with 18F-FDG PET, 11C-acetate PET has an increased sensitivity (63.6%) in diagnosis of well-differentiated HCC, which presents a high avidity for acetate rather than glucose. However, it still has a high rate of misdiagnoses, and has been insufficient to complement 18F-FDG PET for a better diagnosis.