title: Role of contrast-enhanced sonography in differentiation of subtypes of hepatocellular adenoma: correlation with MRI findings.
abstract: OBJECTIVE
  Hepatocellular adenomas (HCAs) are divided into three subtypes according to genotype and phenotype. The two main subgroups are hepatocyte nuclear factor 1α (HNF1α)-inactivated HCA and inflammatory HCA. Specific imaging features of these subgroups of adenoma have been delineated with MRI. The aim of this study was to document the contrast-enhanced sonographic (CEUS) features specific for adenoma subtypes and to correlate them with MRI findings.
  
  
  METHODS
  We retrospectively analyzed data on 38 patients with HCA confirmed at pathologic examination in all cases. All cases were classified with MRI.
  
  
  RESULTS
  HNF1α-inactivated HCA (n = 16) was found to have a homogeneous hyperechoic aspect at baseline gray-scale sonography, isovascularity or moderate hypervascularity with mixed filling in the arterial phase, and isoechogenicity in the portal and late portal venous phases. Homogeneous hyperechogenicity during B-mode sonography was the most specific pattern (sensitivity, 88%; specificity, 91%) and correlated with diffuse fat repartition observed on MR images obtained with chemical-shift sequences. In inflammatory HCA (n = 17) the association of arterial hypervascularity with centripetal filling, linear vascularities, peripheral rim of sustained enhancement, and central washout in the late venous phase was specific (sensitivity, 64%; specificity, 100%). Discrepancy between delayed washout during CEUS and sustained enhancement during MRI could be related to differences between gadolinium and microbubbles in diffusing in the interstitial spaces. In the five other HCA cases (four unclassified, one β-catenin activated) CEUS showed characteristics of benign hepatocellular tumors with no specific features.
  
  
  CONCLUSIONS
  HNF1α-inactivated HCA and inflammatory HCA had characteristic CEUS patterns. Delayed washout, an unusual finding in benign hepatic lesions, is of particular interest and was a characteristic of inflammatory HCA subtype.
authors: Department of Radiology, Hôpital Saint-André, 1 Rue Jean Burguet, Bordeaux, 33076, France. herve.laumonier@gmail.com
authors: Hervé
authors: H
authors: Laumonier
authors: Hélène
authors: H
authors: Cailliez
authors: Charles
authors: C
authors: Balabaud
authors: Laurent
authors: L
authors: Possenti
authors: Jessica
authors: J
authors: Zucman-Rossi
authors: Paulette
authors: P
authors: Bioulac-Sage
authors: Hervé
authors: H
authors: Trillaud
mesh_terms: D018248:Adenoma, Liver Cell / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D010641:Phenotype; D010743:Phospholipids; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography; D051176:beta Catenin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D051538:Hepatocyte Nuclear Factor 1-alpha; D009942:Organometallic Compounds; D010743:Phospholipids; D051176:beta Catenin; C420843:contrast agent BR1; D008536:Meglumine; C072417:gadoterate meglumine; D013459:Sulfur Hexafluoride