title: Focal nodular hyperplasia: spoke-wheel arterial pattern and other signs on dynamic contrast-enhanced ultrasonography.
abstract: OBJECTIVE
  To evaluate the prevalence of spoke-wheel pattern and typical symptoms of focal nodular hyperplasia (FNH) by means of dynamic contrast-enhanced ultrasonography (CEUS) in relation to lesion size.
  
  
  METHODS
  Twenty-eight patients were included in the trial, in whom, based on the CEUS, we raised suspicion of hypervascularized liver lesion; there were 30 lesions altogether. The final diagnosis of FNH was verified by means of CT, MRI or lesion biopsy. Majority of patients (26) were females, compared to 2 male, with average age of 33.3 years. Average lesion size was 45.6 mm. Besides the ultrasound examination, we used also "blood pool" ultrasound contrast agent of second generation, sulphur hexafluoride (BR1); we evaluated enhancement of the lesion until the late stage-within 5 min from application.
  
  
  RESULTS
  In lesions larger than 3 cm (n=20), stellate vascular enhancement was found in 19 cases (95.0%) early in arterial phase. As for lesions smaller than 3 cm (n=10), spoke-wheel pattern was observed only in 3 cases (30%) and lesions smaller than 2 cm practically did not show this phenomenon at all (n=1; 17%). Generally, symptom of spoke-wheel pattern was observed in 22 cases, i.e. in 73.3%. In total, central scar was present in 63.3% (n=19) of cases. In lesions larger than 3 cm, it was present in 85.0% (n=17), in lesions smaller than 3 cm in 20% (n=2).
  
  
  CONCLUSIONS
  Contrast-enhanced ultrasonography can be the final diagnostic method for FNH larger than 3 cm which has typical spoke-wheel vessel structure on CEUS. If this phenomenon is not present and the central scar is not visible, specific diagnosis of FNH cannot be based solely on CEUS findings.
authors.affiliation: Department of Radiology, Charles University Hospital, Sokolská 581, CZ-500 05 Hradec Králové, Czech Republic. ungermann@post.cz
authors.forename: Leos
authors.initials: L
authors.lastname: Ungermann
authors.forename: Pavel
authors.initials: P
authors.lastname: Eliás
authors.forename: Jan
authors.initials: J
authors.lastname: Zizka
authors.forename: Pavel
authors.initials: P
authors.lastname: Ryska
authors.forename: Ludek
authors.initials: L
authors.lastname: Klzo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000000981:diagnostic imaging*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D013459:Sulfur Hexafluoride