About 20% of liver cancer patients have normal alpha fetoprotein. 80% of liver cancer patients have significantly elevated alpha fetoprotein and greater than 200ng/ml or 400ng/ml, but there are a few patients with normal alpha fetoprotein in about 20% of patients. At this time, if ultrasound, CT or MRI reveals an occupying lesion in the liver, the imaging is in line with the imaging characteristics of fast in and fast out, i.e. rapid enhancement in the arterial phase and disappearance of rapid enhancement in the portal phase, which is in line with the typical imaging characteristics of hepatocellular carcinoma. In a few patients, if there is no obvious fast-in-fast-out imaging features and there is an occupying lesion in the liver, pathological puncture biopsy is needed to clarify.