ABSTRACT
Hepatocellular carcinoma (HCC) is the sixth most frequent cancer in the world and the third most common cause of cancer-related mortality (1). HCC mostly develops in patients with chronic liver disease caused by viral hepatitis or alcohol abuse. More than 80% of all HCC tumors worldwide occur when the underlying chronic liver disease has reached the stage of cirrhosis (2). Carcinogenesis in liver cirrhosis is a complex multistep process characterized by the development of nonmalignant hepatocellular lesions that eventually progress into frank HCC (3). Imaging patients with cirrhosis for early detection of HCC, therefore, is a challenging issue. It is accepted that dynamic contrast-enhanced imaging techniques [including contrast ultrasound (US), multidetector computed tomography (CT), and magnetic resonance imaging (MRI)] can establish the diagnosis of HCC in nodular lesions larger than 1 cm demonstrating arterial hypervascularization with venous washout. Two different approaches can be currently used to detect and characterize nodular lesions in cirrhosis: (i) the vascular approach, which is aimed at showing the different vascular supply of HCC and nonmalignant hepatocellular lesions by using dynamic imaging techniques (including contrast-enhanced US, multidetector computed tomography (CT), and magnetic resonance imaging (MRI) (3), and (ii) the cellular approach, which relies on the ability of MRI in combination with liver-specific contrast agents (including hepatocyte-targeted agents and reticuloendothelial system-targeted agents) to show the changes in hepatobiliary function or Kupffer cell content as associated with malignancy (4).
