Hepatocellular Carcinoma in the Cirrhotic Liver: Evaluation Using Computed Tomography and Magnetic Resonance Imaging

Hepatocellular carcinoma is the fifth most common tumor in patients worldwide and the third most common cause of cancer-related death, after lung and stomach cancer. Cirrhosis of the liver is the strongest predisposing factor for hepatocellular carcinoma, with approximately 80% of cases of hepatocellular car-cinoma developing in a cirrhotic liver. The annual incidence of hepatocellular carcinoma is 2.0% to 6.6% in patients with cirrhosis compared with 0.4% in patients without cirrhosis. The 5-year survival rates of patients undergoing curative therapies for hepato cellular carcinoma, including liver transplant, hepatic resection, and percutaneous ablative techniques, range between 40% and 75%. Orthotropic liver transplant offers the prima facie cure for both hepatocellular carcinoma and liver cirrhosis. In hepatocellular carcinoma confined to the liver without macrovascular invasion, patients with a single tumor <= 5 cm or up to 3 tumors <= 3 cm each had a 5-year survival rate of 75% and a disease-free survival rate of 83%. In the adult population, liver transplant for hepatocellular carcinoma yields good results for patients whose tumor masses do not exceed the Milan criteria. The diagnosis of hepatocellular carcinoma using imaging tests has had a substantial impact on transplant decisions. Radiologists should be aware of this responsibility and exercise the utmost scrutiny before making a diagnosis of hepatocellular carcinoma. Erroneous diagnosis of hepatocellular carcinoma based on imaging tests could deny deserving patients the opportunity of a life-saving liver transplant and result in unnecessary liver transplants for others. Contrast-enhanced magnetic resonance imaging and helical computed tomography are the best imaging techniques currently available for the noninvasive diagnosis of hepatocellular carci noma. With techno-logical advances in hardware and software, diffusion-weighted imaging can be readily applied to the liver with resulting improved image quality.