The imaging features of early stage hepatocellular carcinoma have many atypical features, especially in the context of cirrhosis, and can be easily confused with a variety of focal lesions. 1.Ultrasound and ultrasonography (CEUS): Ultrasonography is currently used as a regular screening tool for screening, especially for high-risk groups with a history of hepatitis B. However, in practice, it is easily affected by the size of the lesion, sensitivity of the machine and the level of the operator, etc. CEUS is based on general ultrasonography with intravenous injection of ultrasound contrast, which can observe the blood perfusion and distribution of microvascular network in organs and tumors. The successful use of ultrasound contrast agent in abdominal tumors, especially in occupying liver lesions, is a major technical breakthrough in the field of ultrasound medicine in recent years. The sensitivity and specificity of CEUS in a group of patients with tumor diameter less than 2 cm were 94.7% and 81.8%, respectively, and in a group of patients with tumor diameter greater than 2 cm, the diagnostic rate was 100%, indicating that CEUS can significantly improve the diagnosis of early stage hepatocellular carcinoma. The sensitivity and accuracy of CEUS in the diagnosis of early-stage liver cancer were significantly improved. 2.Computed tomography (CT) scan: CT is the main means to diagnose liver cancer in clinical practice, and CT scan and enhanced scan are easier to diagnose typical liver cancer, and CT three-dimensional reconstruction can show the relationship between liver tumor and intrahepatic vessels and surrounding tissues. CT examination has important differential diagnostic significance in distinguishing early hepatocellular carcinoma from other small hepatic occupancies (such as hepatic hemangioma, hepatic small metastases and cirrhotic nodules). In a study of 43 cases of early liver cancer, Zhao et al. found that the sensitivity of multistage dynamic CT for early liver cancer was 97.5%-97.6%, and the sensitivity for microscopic liver cancer (≤1 cm in diameter) was 90.0%-95.0%. In addition, CT perfusion imaging (CTP) technique has good reference value for early diagnosis of liver cancer. Multi-phase dynamic enhancement of the liver and CTP combined scan play an increasing role in the diagnosis of liver cancer, and have a greater reference value for the early diagnosis of liver cancer. MRI: MRI is one of the important examination methods for liver tumor, with the advantages of multi-sequence imaging and three-dimensional imaging, and is an important imaging tool for early detection and differential diagnosis of liver cancer, which can detect liver cancer of about 1.0 cm in diameter and is significant for early diagnosis. The use of contrast agents can further improve the contrast of MRI images, among which liver-specific MRI contrast agents have been a hot topic of research in recent years. At present, MRI contrast multiphase dynamic enhancement examination has become a more routine examination method for occupying liver lesions, and plays an important role in the detection and characterization of lesions. DSA is an accurate and effective method for early diagnosis of hepatocellular carcinoma, but it is more accurate and sensitive than CT scan, ultrasound and nuclear scan. DSA is an accurate and effective method for early diagnosis of hepatocellular carcinoma compared with CT scan, ultrasound, and nuclear scan. DSA is an invasive procedure, so it is seldom used alone to diagnose early hepatocellular carcinoma. DSA is an invasive procedure, so it is rarely used alone to diagnose early-stage liver cancer, but is mainly used as an adjunct to hepatic artery chemoembolization for liver cancer.