Source Department of Gastroenterology and Hepatology Vienna General Hospital and Medical University, Vienna, Austria - markus.peck@meduniwien.ac.at.

Hepatocellular carcinoma (HCC) is a common cancer worldwide. Effective treatment to allow long-term survival requires early diagnosis, which can only be achieved by regular surveillance by ultrasound. As soon as a suspicious lesion is detected, more sophisticated imaging has to be employed in order to definitely establish the diagnosis of HCC. Imaging should be done by either contrast-enhanced multidetector computed tomography (MDCT) or by dynamic contrast-enhanced magnetic resonance imaging (dynamic MRI). Most tumors, especially the ones larger than 2 cm in diameter, can be diagnosed non-invasively by a typical pattern of early arterial enhancement on contrast-enhanced imaging and venous or delayed-phase wash-out. In some instances, in particular in tumors between 10 and 20 mm, a definitive diagnosis cannot be reached by non-invasive imaging and biopsy has to be used for histologic diagnosis. While it might become possible in the future to develop serologic surveillance tests for early diagnosis of HCC, currently regular ultrasound at 6 to 12 months interval is the method of choice for this purpose.