title: From the RSNA refresher courses: screening the cirrhotic liver for hepatocellular carcinoma with CT and MR imaging: opportunities and pitfalls.
abstract: The inherent distortion of the appearance of liver parenchyma by the underlying pathologic changes of cirrhosis can obscure and simulate malignancy at imaging. That hepatocellular carcinoma is the most common abdominal malignancy worldwide and occurs most often in patients with chronic liver disease and cirrhosis compounds this problem. Magnetic resonance (MR) imaging and, to a lesser extent, computed tomography (CT) can depict the underlying nodular and fibrotic changes in patients with cirrhosis, particularly when siderotic nodular regeneration is present. Application of state-of-the-art helical CT and MR imaging techniques has improved the ability to detect hepatocellular carcinoma in this population, but, even with these advances, fewer than 50% of small tumors are detected with either of these techniques in a screening population. Dynamic hepatic arterial-phase contrast material-enhanced imaging is essential with both CT and MR imaging to achieve even these levels of success. Benign lesions that simulate tumor tissue are encountered in many patients with cirrhosis and include focal fibrosis, infarcted regenerative nodules, arteriovenous shunts, hemangiomas, pseudoaneurysms, and focal transient hepatic enhancement. An awareness of the imaging characteristics of these lesions can help one avoid a mistaken diagnosis of hepatocellular carcinoma in many cases.
authors.affiliation: Department of Radiology, University of Pittsburgh School of Medicine, 200 Lothrop St, Pittsburgh, PA 15213, USA. baronrl@msx.upmc.edu
authors.forename: R L
authors.initials: RL
authors.lastname: Baron
authors.forename: M S
authors.initials: MS
authors.lastname: Peterson
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003287:Contrast Media; D003937:Diagnosis, Differential; D006801:Humans; D008103:Liver Cirrhosis / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media