Guidelines for imaging focal lesions in liver cirrhosis.

Imaging cirrhotic patients for early detection of hepatocellular carcinoma remains a challenging issue despite many technological advances. In fact, nonmalignant hepatocellular lesions, such as regenerative or dysplastic nodules, may mimic a small tumor. Imaging protocols are aimed at showing the different vascular supply to the lesion. It is accepted that dynamic contrast-enhanced imaging techniques, including contrast ultrasound, multidetector computed tomography and magnetic resonance imaging, can establish the diagnosis of hepatocellular carcinoma in nodular lesions larger than 1 cm showing arterial hypervascularization with venous washout. Magnetic resonance imaging in combination with liver-specific contrast agents, including hepatocyte-targeted and reticuloendothelial system-targeted agents, may be useful to clarify questionable cases, due to its ability to show changes in hepatobiliary function or Kuppfer cell content associated with malignancy. However, even optimized imaging techniques remain relatively insensitive for the detection of tiny satellite nodules associated with the main tumor.