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

Abstract

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.