Gadoxetic acid-enhanced MRI findings of early hepatocellular carcinoma as defined by new histologic criteria.

PURPOSE

To describe the imaging features of early hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced MRI (Gd-EOB-MRI) in comparison with multidetector computed tomography (MDCT) examinations.

MATERIALS AND METHODS

We analyzed imaging findings of 19 pathologically proven early HCC lesions in 15 patients who underwent both MDCT and Gd-EOB-MRI at 3.0 Tesla (T) units before surgery. MRI included in-phase and out-of-phase T1-weighted dual-echo gradient-recalled-echo sequences, dynamic T1-weighted images before and after bolus injection of gadoxetic acid disodium, fat-saturated T2-weighted fast spin-echo sequences, and T1-weighted hepatobiliary phase images 20 min after contrast injection. Two radiologists retrospectively evaluated the signal intensities and enhancement features on MRI and MDCT.

RESULTS

None of the lesions displayed arterial enhancement and washout on MDCT. On Gd-EOB-MRI, six (32%) lesions showed T2-hyperintensity, five (26%) lesions showed signal drop on opposed-phase. Three lesions (16%) showed arterial enhancement and washout. Twelve (63%), 13 (68%), and 15 (79%) lesions were hypointense on hepatic venous, equilibrium, and hepatobiliary phase, respectively.

CONCLUSION

Most early HCCs did not show arterial enhancement and washout pattern on both MDCT and Gd-EOB-MRI. Gd-EOB-MRI may provide several ancillary findings for diagnosis of early HCC such as decreased hepatobiliary uptake, T2 hyperintensity and signal drop in opposed phase.