Gadolinium ethoxybenzyl diethylenetriamine pentaacetic Acid-enhanced magnetic resonance imaging findings of borderline lesions at high risk for progression to hypervascular classic hepatocellular carcinoma.

OBJECTIVES The objectives of the study were to assess the imaging features of hypovascular borderline lesions containing hypervascular foci on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and to evaluate the ability of Gd-EOB-DTPA-enhanced MRI to diagnose high-risk borderline lesions possibly consistent with early hepatocellular carcinoma (HCC). METHODS Institutional review board approval was obtained for this retrospective analysis of imaging findings, and informed consent was obtained from 217 consecutive patients undergoing Gd-EOB-DTPA-enhanced MRI and angiography-assisted computed tomography (CT) for examination of hepatocellular nodular lesions in cirrhotic livers. There were 73 nodules showing hypervascular foci in borderline lesions identified by angiography-assisted CT. Signal intensity patterns of the nodules were evaluated on hepatobiliary-phase Gd-EOB-DTPA-enhanced T1-weighted MRI obtained 20 minutes after intravenous injection of contrast media. RESULTS Among 73 high-risk borderline lesions, 59 were hypointense (81%), and 14 were isointense (19%), compared with background liver parenchyma. There were 27 untreated lesions followed by CT and/or MRI. Almost half of these nodules transformed into hypervascular HCC, regardless of signal intensities seen on hepatobiliary-phase Gd-EOB-DTPA-enhanced MRI. CONCLUSIONS Although many high-risk borderline HCC lesions are hypointense on hepatobiliary-phase Gd-EOB-DTPA-enhanced MRI, some high-risk borderline lesions are isointense and transform at the same rate into hypervascular HCC.