MR Imaging of Hypervascular Lesions in the Cirrhotic Liver: A Diagnostic Dilemma

Abstract

Cirrhosis is characterized by a spectrum of hepatocellular nodules that mark the progression from regenerative nodules to low- and high-grade dysplastic nodules, followed by small and large hepatocellular carcinomas (HCCs). Characterization of small nodules on the basis of imaging and histopathologic findings is complicated by an overlap in findings associated with each type of nodule, a reflection of their multistep transitions. Vascularity patterns change gradually as the nodules evolve, with an increasing shift from predominantly venous to predominantly arterial perfusion. Regenerative and low-grade dysplastic nodules demonstrate predominantly portal perfusion and contrast enhancement similar to that of surrounding parenchyma. Differentiation of high-grade dysplastic nodules and well-differentiated HCCs on the basis of dynamic imaging and histologic findings is challenging, with a high rate of false-negative results. Some small nodules that lack hypervascularity may be early HCCs. Progressed small and large HCCs usually present no diagnostic difficulty because of their characteristic findings. Although characterization of hypervascular lesions in the cirrhotic liver is difficult, it is a key step in disease management and is the radiologist's responsibility.

Intrahepatic cholangiocarcinomas mimicking other lesions

“…This hypervascular pattern may be confused with the hypervascular pattern of HCC which is the more common malignancy seen in cirrhotic livers, leading to an erroneous diagnosis of HCC. In addition, vascular shunts are relatively common in cirrhotic livers, causing perfusional pseudolesions, and may lead to an erroneous diagnosis of a benign lesion [16].…”

Utility of diffusion-weighted magnetic resonance imaging in diagnosing hepatocellular carcinoma in cirrhotic liver

“…Regardless of its DCE-MRI findings; if a cirrhotic nodule invaded the portal venous and/or hepatic venous channels, it was diagnosed as HCC 5,10,11 ( Figure 1). A cirrhotic nodule was accepted as DN if it was iso-or hyperintense on T1-weighted images, iso-or hypointense on T2-weighted images, iso-or hypointense in the arterial phase, and isointense relative to the adjacent liver parenchyma [1][2][3][4][5]9 . Also, previous DCE-MRI of the patients with DN were evaluated and if the lesions were stable at two years' follow-up, then they were accepted as DN 12 .…”

“…Nodules in cirrhosis can present as regenerative, siderotic or dysplastic nodules, and lead to hepatocellular carcinoma (HCC) 1 . Early detection and differentiation of HCC are important for appropriate and curative treatment methods 2,3 .…”

Hepatocellular carcinoma: Advances in diagnostic imaging

“…While the imaging modalities have greatly evolved and the detection rate of liver nodules has increased in the past decade, characterization of atypical hyperplastic/ dysplastic nodules with small HCCs are still challenging (38). The following features are characteristic for HCC, the combination of these features could yield a definite diagnosis in most cases.…”