Contrast-enhanced magnetic resonance imaging of 102 nodules in cirrhosis: correlation with histological findings on explanted livers

Abstract

To analyze Gd-EOB-DTPA-enhanced magnetic resonance (MR) findings of nodules (low-grade dysplastic nodules-LGDNs; high-grade dysplastic nodules-HGDN, and hepatocellular carcinoma-HCC), histologically identified on cirrhotic, explanted livers. IRB approval was obtained for this study. Thirty-four patients underwent Gd-EOB-DTPA-enhanced MR examinations (1.5T system), that included 20-min delayed hepatobiliary (HB) phase imaging, before undergoing orthotopic liver transplantation (OLT; mean time MR-OLT: 2.7 months). A total of 102 hepatic nodules were identified and analyzed at histopathological examination, and classified as LGDN, HGDN, and HCC. Two radiologists by consensus performed a quantitative (enhancement ratios, ERs) and a qualitative analyses of signal intensities of identified nodules on vascular dynamic phases (30-35 s after injection-arterial phase; 180-190 s after injection late phase) and on HB phases. Correlation between nodules MR patterns and histological classification was analyzed by means of dedicated statistical software. No differences were appreciable among ERs of HGDN and HCCs on HB phase (P > 0.001). Lesions' enhancement on vascular dynamic and on HB phases significantly correlated to histological classification of nodules (P < 0.0001). Nodular hyperintensity on arterial phase and hypointensity on late phase were highly predictive for HCC (PPV 100%), with a moderate sensitivity (72.5%). Nodular hypointensity on HB phase was detected on 39/40 HCCs (sensitivity 97.5%) and in 21/30 HGDNs, whereas no LGDN showed it. Hyperenhancement on arterial phase and hypointensity on late phase are the most specific clues for the diagnosis of HCC. Hypointensity on HB phase shows a PPV of 100% in suggesting nodular premalignancy/malignancy, independently from nodular dynamic vascular enhancement.