title: Multiarterial phase dynamic MRI of small early enhancing hepatic lesions in cirrhosis or chronic hepatitis: differentiating between hypervascular hepatocellular carcinomas and pseudolesions.
abstract: OBJECTIVE
  The purpose of this study was to assess the value of multiarterial phase contrast-enhanced dynamic MRI of the whole liver obtained during a single breath-hold for small early enhancing hepatic lesions in patients with cirrhosis or chronic hepatitis, emphasizing the distinction between hypervascular hepatocellular carcinomas and pseudolesions.
  
  
  METHODS
  The study population included 40 patients with cirrhosis or chronic hepatitis who had small early enhancing hepatic lesions (a total of 70 lesions: 40 hepatocellular carcinomas, 30 pseudolesions). All patients underwent multiarterial phase contrast-enhanced dynamic MRI (six phases) of the whole liver during a single breath-hold.
  
  
  RESULTS
  Twenty-one (53%) of 40 hypervascular hepatocellular carcinomas showed rapid central washout after early enhancement of the lesion as well as peritumoral coronal enhancement, but these findings were not observed in any hypervascular pseudolesions (p < 0.001). In 19 hepatocellular carcinomas without rapid central washout, early enhancement of the lesion appeared at the second, third, or fourth phase (mean, 2.5 phases). In eight of these 19 hepatocellular carcinomas, lesion enhancement disappeared by the sixth phase. Conversely, in 30 hypervascular pseudolesions, early enhancement of the lesion appeared at the second, third, fourth, or fifth phase (mean, 3.0 phases). In 28 of these 30 pseudolesions, lesion enhancement continued until the sixth phase.
  
  
  CONCLUSIONS
  Rapid central washout after the early enhancement of the lesion and coronal enhancement surrounding the lesion are highly specific and diagnostic findings of small hypervascular hepatocellular carcinomas if present at multiarterial phase contrast-enhanced dynamic MRI. Hypervascular pseudolesions tend to show prolonged enhancement during the arterial phase compared with hypervascular hepatocellular carcinomas.
authors.affiliation: Department of Radiology, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Ayame
authors.initials: A
authors.lastname: Shimizu
authors.forename: Shinji
authors.initials: S
authors.lastname: Koike
authors.forename: Katsumi
authors.initials: K
authors.lastname: Sasaki
authors.forename: Naofumi
authors.initials: N
authors.lastname: Matsunaga
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hibino
authors.forename: Masanao
authors.initials: M
authors.lastname: Yuhara
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006521:Hepatitis, Chronic / Q000175:diagnosis*; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged