Risk of hypervascularization in small hypovascular hepatic nodules showing hypointense in the hepatobiliary phase of gadoxetic acid-enhanced MRI in patients with chronic liver disease.

PURPOSE

The purpose of this study was to elucidate the incidence and risk factors for the progression of hypointense nodules observed in the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) of hypervascular hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Hypovascular nodules (112) showing hypointensity in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI were examined in 54 patients. All patients underwent computed tomography during hepatic arteriography and computed tomography during arterial portography (CTAP) within a month after Gd-EOB-DTPA-enhanced MRI. According to the tumor size, 112 nodules were divided into two groups: those >10 mm in diameter (group A, n = 39) and those ≤10 mm in diameter (group B, n = 73). The incidence of progression to hypervascular HCC was calculated using the Kaplan-Meier method.

RESULTS

The incidence of hypervascularization was significantly higher in group A nodules than in group B nodules (p < 0.0001). Tumor size (p < 0.0001) and hypoattenuation in CTAP (p = 0.0004) showed significant correlation with hypervascularization.

CONCLUSION

Hypointense nodules observed in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI with diameters of >10 mm had a high probability of hypervascularization.