Gadoxetic acid-enhanced MRI for hepatocellular carcinoma and hypointense nodule observed in the hepatobiliary phase

The aim of our study was to evaluate the diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance (MR) imaging both in the detection of hepatocellular carcinoma (HCC) and precancerous lesions and in the assessment of their evolution.A retrospective study was undertaken on 56 patients with chronic liver disease and suspected liver lesions. We evaluated the number, size and signal intensity of the nodules on dynamic and hepatobiliary MR images. Follow-up studies were carried out every 3 months. Statistical analysis was performed using the Fisher's exact test.A total of 120 nodules were identified in 41 patients. Of these, 92/120 nodules (76.6 \%; mean diameter 18.4 mm) showed the typical HCC vascular pattern: 90/92 nodules appeared hypointense and 2/92 were hyperintense on hepatobiliary phase images. An additional 28/120 hypointense, nonhypervascular nodules (23.3 \%; mean diameter 11 mm) were detected on hepatobiliary phase images, 15 of which showed hypointensity also on the equilibrium phase images. During the 3- to 12-month follow-up, 14/28 nodules (mean diameter 13.3 mm) developed the typical vascular pattern of HCC.Gadoxetic acid-enhanced MR imaging is useful for detecting HCC as well as hypovascular nodules with potential progression to HCC. Lesions measuring more than 10 mm in diameter are at higher risk of developing into HCC (p = 0.0128).