With the development of imaging and the increase of health awareness of the public, routine medical checkups have been gradually popularized and the chance of small intrahepatic occupancies being detected has increased significantly. First of all this is a good trend, malignant tumors such as liver cancer can only be effectively treated for long-term survival if they are detected early. If symptoms such as abdominal pain are already present, the prognosis is relatively poor. The so-called intrahepatic occupancy is the growth of abnormal masses in the liver that are not found in normal liver, which can be large or small. Large ones can be benign, such as hemangioma, liver cyst, etc., while small ones can be malignant, such as hepatocellular liver cancer, cholangiocellular liver cancer, or metastatic liver cancer. Then what are the criteria for determining intrahepatic occupancy? First of all, hepatocellular hepatocellular carcinoma, which accounts for about 90% or more of liver malignant tumors, can be confirmed either clearly by puncture pathological examination (gold standard) or by clinical diagnosis derived from medical history and imaging examination. Pathologic diagnosis is universal in the diagnosis of malignancy, but has the disadvantage of being invasive and relatively little punctured tissue, making it easy to miss the diagnosis. Imaging examination judgment has important clinical significance in the diagnosis of hepatocellular liver cancer. Different hepatocellular carcinoma organizations at home and abroad have established different diagnostic criteria. However, for the general public, they only need to know the following aspects: 1. whether there is a background of liver disease such as hepatitis B and C; 2. whether there is enhancement in the arterial phase of the lesion by CT and MRI enhancement, and whether there is reduction in the signal of the lesion in the portal phase (you can read the report card, which is usually stated), and the enhancement must be done, otherwise it has no diagnostic effect; 3. check AFP, CEA, CA199 and other tumor markers. PET-CT is not a necessary test for hepatocellular carcinoma imaging diagnosis. Except for hepatocellular liver cancer, pathological examination is necessary for the diagnosis of other malignant tumors in the liver to confirm the diagnosis and give further treatment according to the type of pathology.