title: Contrast-enhanced ultrasound of focal nodular hyperplasia: a matter of size.
abstract: OBJECTIVE
  To assess the contrast-enhanced ultrasound (CEUS) frequencies of centrifugal enhancement, spoke-wheel sign and central scar in focal nodular hyperplasia (FNH) as a function of lesion size.
  
  
  METHODS
  Ninety-four FNHs were retrospectively reviewed to assess their largest diameter and enhancement pattern, including centrifugal enhancement from one central artery, spoke-wheel sign, diffuse or centripetal enhancement, central scar and late-phase washout.
  
  
  RESULTS
  Mean FNH-lesion size was 3.7 ± 2.1 cm. Only 43.6 % of FNHs had centrifugal enhancement, with a spoke-wheel pattern (23.4 %) or without (20.2 %), while 56.4 % showed diffuse or centripetal enhancement. Centrifugal enhancement was observed in 73.9 % of FNHs ≤3.1 cm and 14.6 % of FNHs >3.1 cm (P < 10(-4)). Size and frequency of centrifugal enhancement were negatively correlated (r = -0.57, P < 10(-4)). The spoke-wheel pattern was also seen more frequently in smaller (37 %) than in larger FNHs (10.4 %) (P < 10(-3)). Late-phase washout was described in 5.3 % of FNHs and was not size-dependent. Lesions with a central scar were larger than those without, respectively, 5.7 ± 1.7 and 3.6 ± 2.0 cm (P = 0.012).
  
  
  CONCLUSIONS
  Typical centrifugal enhancement yielding a confident FNH diagnosis is seen significantly more frequently when the lesion is ≤3.1 cm.
  
  
  CONCLUSIONS
  • CEUS yields confident diagnoses of FNHs ≤3.1 cm • The larger the FNH, the lower the diagnostic sensitivity of CEUS • Final diagnosis of FNHs >3.1 cm should be obtained with MRI not CEUS.
authors: Radiology Department, Hôpital Beaujon APHP, 92118, Clichy, Cedex, France.
authors: Caroline
authors: C
authors: Bertin
authors: Sophie
authors: S
authors: Egels
authors: Mathilde
authors: M
authors: Wagner
authors: Isabelle
authors: I
authors: Huynh-Charlier
authors: Valérie
authors: V
authors: Vilgrain
authors: Olivier
authors: O
authors: Lucidarme
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013459:Sulfur Hexafluoride; D018608:Ultrasonography, Doppler / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride