title: Focal nodular hyperplasia of the liver: diffusion-weighted magnetic resonance imaging characteristics using high b values.
abstract: OBJECTIVE
  To qualitatively and quantitatively assess the presentation of hepatic focal nodular hyperplasia (FNH) at diffusion-weighted magnetic resonance imaging (DWMRI) using multiple high b values.
  
  
  METHODS
  Twenty-five patients with 27 FNHs had liver DWMRI at 1.5 T using free-breathing acquisition and 3 b values (0, 600, 1000 s/mm). Focal nodular hyperplasias were evaluated qualitatively using visual analysis of diffusion-weighted magnetic resonance (DWMR) images and quantitatively using conventional apparent diffusion coefficient (ADC) and normalized ADC measurements.
  
  
  RESULTS
  All FNHs (100%) were visible on b0 DWMR images; 26 of the 27 FNHs (96%), on b600 DWMR images; and 21 of the 27 FNHs (78%), on b1000 DWMR images. A total of 18 of the 27 FNHs (67%) exhibited a hyperintense central scar on the b0 DWMR images that remained visible on the b600 and b1000 DWMR images in 6 of the 27 FNHs (22%). Conventional ADC value of FNHs (1.318 × 10 mm/±0.208) was significantly lower than that of adjacent hepatic parenchyma (1.414 × 10 mm/s ± 1.95) (P = 0.0003), although a substantial overlap was found. The use of normalized ADC using the liver as reference organ resulted in a more restricted distribution of ADC values (variation coefficient, 5.3%).
  
  
  CONCLUSIONS
  Focal nodular hyperplasias show a wide range of morphological features at DWMRI using high b values. Further studies are needed to fully investigate as to what extent normalized ADC may result in better lesion characterization.
authors.affiliation: From the *Department of Abdominal Imaging, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris; †Université Paris-Diderot, Sorbonne Paris Cité; ‡UMR INSERM 965-Paris 7 "Angiogenèse et recherche translationnelle"; §Department of Radiology, Hôpital Robert Debré, Reims Cedex; and ∥Department of Pathology, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Dohan
authors.forename: Philippe
authors.initials: P
authors.lastname: Soyer
authors.forename: Youcef
authors.initials: Y
authors.lastname: Guerrache
authors.forename: Christine
authors.initials: C
authors.lastname: Hoeffel
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Gavini
authors.forename: Rachid
authors.initials: R
authors.lastname: Kaci
authors.forename: Mourad
authors.initials: M
authors.lastname: Boudiaf
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed; D018608:Ultrasonography, Doppler
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine