Value of gadoxetic acid-enhanced MRI and diffusion-weighted imaging in the differentiation of hypervascular hyperplastic nodule from small (<3 cm) hypervascular hepatocellular carcinoma in patients with alcoholic liver cirrhosis: A retrospective case-control study.

BACKGROUND: Hypervascular hyperplastic nodules (HHNs) occasionally develop in patients with alcoholic liver cirrhosis (ALC) and show arterial enhancement, thus mimicking hepatocellular carcinoma (HCC). Importantly, HHN as a benign lesion should be distinguished from HCC.

PURPOSE: To evaluate the value of gadoxetic acid-enhanced MRI (Gd-EOB-MRI) and diffusion-weighted imaging (DWI) in distinguishing HHN from small (<3 cm) hypervascular HCC (hHCC) in patients with ALC.

STUDY TYPE: Retrospective case-control study.

FIELD STRENGTH/SEQUENCE: 3.0T/in- and out-of-phase, T1 -weighted, T2 -weighted, diffusion-weighted, apparent diffusion coefficient, and dynamic gadoxetic acid-enhanced images.

POPULATION: Among 560 patients with ALC who underwent Gd-EOB-MRI and DWI, 12 patients with 28 HHNs and 22 patients with 29 hHCCs smaller than 3 cm were included.

ASSESSMENT: The following MRI features were evaluated by three independent radiologists: signal intensity (SI) on T1 -weighted, T2 -weighted, diffusion-weighted, and hepatobiliary phase (HBP) images; shape, homogeneity, and margin on HBP; diffusion restriction; intralesional fat; necrosis; hemorrhage; washout on portal venous phase (PVP) and/or transitional phase (TP); and capsular enhancement. Quantitative analysis was also conducted.

STATISTICAL TESTS: Univariate and multivariate analyses were performed to determine the significant MRI findings, and their diagnostic performance for the prediction of HHN was analyzed.

RESULTS: Lesion size of ≤16 mm (odds ratio [OR], 24.41; P = 0.007), low-to-iso SI on DWI (OR, 26.92; P = 0.007), and absence of washout on PVP and/or TP (OR, 31.84; P = 0.009) were significant independent factors for predicting HHN. When all three criteria were satisfied, the specificity was 100%. Compared with hHCCs, HHNs showed significantly smaller size (mean, 13.8 mm vs. 19.9 mm; P < 0.001) and higher mean SI value (994.0 vs. 669.5) and lesion-to-liver SI ratio (1.045 vs. 0.806) on HBP (P < 0.001, respectively).

DATA CONCLUSION: Gd-EOB-MRI and DWI may be helpful in differentiating HHN from small hHCC in patients with ALC.

LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019.