Washout Appearance in Gd-EOB-DTPA-Enhanced MR Imaging: A Differentiating Feature Between Hepatocellular Carcinoma With Paradoxical Uptake on the Hepatobiliary Phase and Focal Nodular Hyperplasia-Like Nodules

Abstract

Purpose To identify the most reliable imaging features for differentiating hepatocellular carcinoma with paradoxical uptake on the hepatobiliary phase (HCCpara) from focal nodular hyperplasia (FNH)-like nodules using Gd-EOB-DTPA-enhanced MRI. Materials and Methods This was a retrospective study. Twenty patients with HCCpara and 21 patients with FNH-like nodules were included. The following MRI features were evaluated using 3.0 Tesla unit by two radiologists: signal intensity (SI) on T1-, T2-, and diffusion-weighted imaging (DWI), arterial enhancement pattern, washout appearance on the portal venous phase (PVP) and/or transitional phase (TP), uptake pattern on the hepatobiliary phase (HBP), T2 scar, EOB scar, and chemical shift on in- and out-of-phase images. Multivariate logistic regression analysis was performed to assess MRI features for prediction of HCCpara. Results Compared with FNH-like nodules, HCCpara had significantly more frequent heterogeneous T1 SI (P < 0.0001), T2 hyperintensity (P=0.032), heterogeneous arterial enhancement (P<0.0001), washout appearance on the PVP and/or TP (P < 0.0001), heterogeneous uptake on the HBP (P < 0.0001), absence of EOB scar (P < 0.0001), and hyperintensity on DWI (P = 0.004). Multivariate logistic regression analysis revealed washout appearance as the only independent imaging feature associated with HCCpara (odds ratio, 7.019; P=0.042). Washout appearance also showed the best diagnostic performance with a sensitivity of 90% and a specificity of 100%. Conclusion Washout appearance on the PVP and/or TP is the most reliable imaging feature for differentiating HCCpara from FNH-like nodules.