Fig. 9.

Multi-step changes of drainage vessels and peritumoral enhancement during hepatocarcinogenesis. In DNs or early HCCs, the main drainage route from the tumor is intranodular or perinodular hepatic vein. However, because hepatic veins disappear from the tumor during very early stage of hepatocarcinogenesis, drainage vessels change to hepatic sinusoids. In moderately differentiated HCC with pseudocapsule formation, the communication between tumor sinusoids and the surrounding hepatic sinusoids are also blocked, and then, the portal venules in the pseudocapsule finally become the main drainage vessel from the tumor. In accordance with the changes of the drainage vessels, thin to thick corona enhancement appears surrounding the tumor.