title: Histopathologically confirmed focal nodular hyperplasia of the liver: gadoxetic acid-enhanced MRI characteristics.
abstract: OBJECTIVE
  The purpose of this study was to evaluate enhancement characteristics of histopathologically confirmed focal nodular hyperplasia (FNHs) with gadoxetic acid-enhanced MRI.
  
  
  METHODS
  Twenty-seven patients with all histopathologically proven FNHs 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=24) or biopsy (n=3). Images were analyzed for morphology and contrast behavior including signal intensity (SI) measurement on T1-w images normalized to the pre-contrast base line.
  
  
  RESULTS
  In total 36 FNHs were evaluated. All FNHs showed enhancement in the arterial phase, significant reduction contrast enhancement ("wash-out") in the late dynamic phases was not present. In the hepatobiliary phase, all FNHs (100%) showed enhancement (overall SI increase, 118% (±91%), P<0.001) with at least partial hyperintensity to the liver. Upon visual comparison, 3 of 36 FNHs appeared with heterogeneous/partial enhancement (8%) and 7 (19%) showed rim-accentuated enhancement.
  
  
  CONCLUSIONS
  The typical enhancement pattern of FNH with gadoxetic acid consists of arterial hyperperfusion, no wash-out during the venous phase, and at least partial hyperintensity compared to the liver in the hepatobiliary phase. Partial hypointensity or rim-accentuated enhancement rarely occurs.
authors.affiliation: Klinik für Radiologie, Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Berlin, Germany. christian.grieser@charite.de
authors.forename: Christian
authors.initials: C
authors.lastname: Grieser
authors.forename: Ingo G
authors.initials: IG
authors.lastname: Steffen
authors.forename: Daniel
authors.initials: D
authors.lastname: Seehofer
authors.forename: Incken-Birthe
authors.initials: IB
authors.lastname: Kramme
authors.forename: Robert
authors.initials: R
authors.lastname: Uktolseya
authors.forename: Christian
authors.initials: C
authors.lastname: Scheurig-Muenkler
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Timm
authors.initials: T
authors.lastname: Denecke
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000473:pathology*; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA