title: Appearance of hepatocellular adenomas on gadoxetic acid-enhanced MRI.
abstract: OBJECTIVE
  The purpose of this study was to evaluate enhancement characteristics of hepatocellular adenomas (HCAs) using gadoxetic acid as a hepatocyte-specific MR contrast agent.
  
  
  METHODS
  Twenty-four patients with histopathologically proven HCAs were retrospectively identified. MRI consisted of T1- and T2-weighted (w) sequences with and without fat saturation (fs), multiphase dynamic T1-w images, and fs T1-w images during the hepatobiliary phase. Standard of reference was surgical resection (n = 19) or biopsy (n = 5). Images were analysed for morphology and contrast behaviour including signal intensity (SI) measurement on T1-w images normalised to the pre-contrast base line.
  
  
  RESULTS
  In total 34 HCAs were evaluated. All HCAs showed enhancement in the arterial phase; 38 % of HCAs showed reduced contrast enhancement ("wash-out") in the venous phase. All HCAs showed enhancement (SI increase, 56 ± 53 %; P <0.001) in the hepatobiliary phase, although liver uptake was stronger (96 ± 58 %). Thus, 31 of all HCAs (91 %) appeared hypointense to the surrounding liver in the hepatobiliary phase, while 3 out of 34 lesions were iso-/hyperintense.
  
  
  CONCLUSIONS
  Gadoxetic acid accumulates in HCAs in the hepatobiliary phase, although significantly less than in surrounding liver. Thus, HCA appears in the vast majority of cases as a hypointense lesion on hepatobiliary phase images.
  
  
  CONCLUSIONS
  • Magnetic resonance-specific contrast agents are now available for hepatic imaging. • Hepatocellular adenomas enhance with gadoxetic acid as in previous CT/MRI experience. • Enhancement during the hepatobiliary phase is less in HCAs than in liver. • Typical HCAs appear as hypointense lesions on T1-w hepatobiliary phase images. • True hyperintense HCA enhancement can occasionally occur during the hepatobiliary phase.
authors.affiliation: Klinik für Radiologie, Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.forename: Sheela
authors.initials: S
authors.lastname: Agarwal
authors.forename: Daniel
authors.initials: D
authors.lastname: Seehofer
authors.forename: Thomas
authors.initials: T
authors.lastname: Kröncke
authors.forename: Enrique Lopez
authors.initials: EL
authors.lastname: Hänninen
authors.forename: Incken-Birthe
authors.initials: IB
authors.lastname: Kramme
authors.forename: Peter
authors.initials: P
authors.lastname: Neuhaus
authors.forename: Sanjay
authors.initials: S
authors.lastname: Saini
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Christian
authors.initials: C
authors.lastname: Grieser
mesh_terms: D018248:Adenoma, Liver Cell / Q000175:diagnosis* / Q000473:pathology*; D000328:Adult; D000368:Aged; D001158:Arteries / Q000473:pathology; D001706:Biopsy / Q000379:methods; D003287:Contrast Media / Q000494:pharmacology*; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D019786:Gadolinium DTPA / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA