title: Behavior of hepatocellular adenoma on real-time low-mechanical index contrast-enhanced ultrasonography with a second-generation contrast agent.
abstract: OBJECTIVE
  The purpose of this study was to describe the behavior of histologically proven hepatocellular adenoma (HCA) on low-mechanical index (MI) contrast-enhanced ultrasonography (CEUS).
  
  
  METHODS
  A review of the databases from 4 academic hospitals revealed 18 patients (15 female and 3 male; mean age, 40 years; range, 25-71 years) with 25 histologically proven HCA lesions who were studied with CEUS at a low MI (0.04-0.1).
  
  
  RESULTS
  Twenty-four of 25 lesions (96%; 95% confidence interval [CI], 80.5%-99.3%) showed high-intensity enhancement, scored as 3 on a scale of 0 to 3, whereas only 1 lesion (4%; 95% CI, 0.7%-19.5%) was scored as 2. The time of peak enhancement ranged between 10 and 19 seconds (average, 13 seconds). All but 1 of the 25 lesions (96%; 95% CI, 80.5%-99.3%) showed early homogeneous and centripetal enhancement during the hepatic arterial phase. No portal venous phase enhancement was observed in any lesion because all showed rapid wash-out (100%; 95% CI, 86.7%-100%). Twenty lesions (80%; 95% CI, 60.9%-91.1%) were found to be isoechoic to slightly hypoechoic during the portal phase, and 19 (76%; 95% CI, 56.6%-88.5%) were isoechoic to mildly hypoechoic, whereas 7 (24%; 95% CI, 11.5%-43.4%) were hypoechoic during the late phase.
  
  
  CONCLUSIONS
  Contrast-enhanced ultrasonography is an effective technique for identifying the microvascular and macrovascular characteristics of HCA. Typically, HCA shows early (10-19 seconds) and centripetal enhancement during the arterial phase and isoechogenicity or mild hypoechogenicity during the portal phase, remaining slightly hypoechoic or isoechoic during the late phase in most cases.
authors.affiliation: Department of Radiology, University of Rome La Sapienza, Rome, Italy. paolo.ricci@uniroma1.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Ricci
authors.forename: Vito
authors.initials: V
authors.lastname: Cantisani
authors.forename: Mirko
authors.initials: M
authors.lastname: D'Onofrio
authors.forename: Dushyant
authors.initials: D
authors.lastname: Sahani
authors.forename: Elisa
authors.initials: E
authors.lastname: Pagliara
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Calliada
authors.forename: Erturk
authors.initials: E
authors.lastname: Mehmet
authors.forename: Kalva
authors.initials: K
authors.lastname: Sanjeva
authors.forename: Nicola
authors.initials: N
authors.lastname: Faccioli
authors.forename: Roberto
authors.initials: R
authors.lastname: Pozzi-Mucelli
authors.forename: Ugo
authors.initials: U
authors.lastname: D'Ambrosio
authors.forename: Roberto
authors.initials: R
authors.lastname: Passariello
mesh_terms: D018248:Adenoma, Liver Cell / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D003199:Computer Systems; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride