Incidence for progression of hypervascular HCC in hypovascular hepatic nodules showing hyperintensity on gadoxetic acid-enhanced hepatobiliary phase in patients with chronic liver diseases

The purpose of this study was to elucidate the incidence and risk factors for the progression of hyperintense nodules, observed in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI), to hypervascular hepatocellular carcinoma (HCC). Hypovascular nodules (n = 157) showing hyperintensity in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI were examined in 41 patients. All patients underwent computed tomography (CT) during hepatic arteriography and CT during arterial portography within one month of Gd-EOB-DTPA-enhanced MRI. The incidence of progression to hypervascular or classical HCC was calculated using the Kaplan-Meier method. Tumor size was determined by univariate and multivariate analysis to be an important risk factor of hypervascularization (p = 0.041, odds ratio 1.135). The cumulative incidences of hypervascularization in hypovascular nodules showing hyperintensity on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI were 2.4, 4.5, and 6.2 % at 12, 24, and 36 months, respectively. The incidence of hypervascularization was significantly increased in nodules > 10 mm in diameter (p = 0.00035). In patients with chronic liver disease, hypovascular nodules presenting as hyperintense in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI and > 10 mm in diameter have malignant potential for progression to hypervascular HCC and require careful management.