Transabdominal Ultrasound with Echoenhancement by Contrast Media in the Diagnosis of Hepatocellular Carcinoma

According to the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD), ultrasound (US) is the recommended tool for surveillance of patients at risk of developing hepatocellular carcinoma (HCC). Larger HCCs can be diagnosed with a high accuracy by conventional US. However, the differentiation of smaller malignant lesions in cirrhotic livers can be improved by contrast-enhanced ultrasound (CEUS). Second-generation contrast agents consisting of microbubbles enable us to visualize specific tumor vascularization patterns. With CEUS, it is not only possible to detect and characterize HCC nodules, but to control the effects of ablation techniques of HCC as well, evaluating the former lesion with respect to complete necrosis or residual viable tumor. Limitations of CEUS are its inability to characterize lesions distant to the applicator. Moreover, so far the use of contrast agents in US did not result in increased sensitivity in the detection of small HCCs (<1 cm). Thus, there is currently no indication to use contrast agents to increase the detection rate of HCC in patients undergoing US surveillance.