title: Distinguishing hepatic metastasis from hemangioma using gadoxetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To retrospectively determine the findings of gadoxetic acid-enhanced magnetic resonance imaging (MRI) to distinguish hemangioma and metastasis of the liver.
  
  
  METHODS
  The University's ethics committee approved this retrospective study. We assessed 45 patients without chronic liver disease who underwent gadoxetic acid-enhanced MRI. Diagnosis of 58 metastases and 47 hemangiomas was confirmed using histopathology or multimodality evaluation. Two radiologists independently assessed the following MRI findings of metastasis and hemangioma: their appearance on T2-weighted images (T2WI) and dynamic contrast enhancement patterns after gadoxetic acid administration. The metastasis and hemangioma findings were compared using Fisher exact test. The lesion-to-liver signal intensity ratio on hepatocyte phase was compared using the Mann-Whitney U test. Multivariate analysis was performed to identify independent imaging findings distinguishing the 2 diseases. Receiver operating characteristic analysis was used to estimate the diagnostic ability of gadoxetic acid-enhanced MRI to distinguish metastasis from hemangioma.
  
  
  RESULTS
  The lesion-to-liver signal intensity ratio was comparable in both diseases. Peripheral-dot enhancement, ring-like, geographic, and moderate late-phase enhancement, rapid contrast filling, and bright signal on T2WI could differentiate between the 2 diseases. In multivariate analysis, bright signal on T2WI (94%-98% in hemangioma and 13%-25% in metastasis) and ring-like enhancement (4% in hemangioma and 58%-60% in metastasis) were the independent findings suggesting hemangioma and metastasis, respectively. The areas under the receiver operating characteristic curves to distinguish metastasis from hemangioma were 0.95 and 0.98 for Reader 1 and 2, respectively.
  
  
  CONCLUSIONS
  Reliable findings to distinguish hepatic metastasis from hemangioma on gadoxetic acid-enhanced MRI were ring-like enhancement on arterial-phase images and bright signal on T2WI.
authors.affiliation: Department of Radiology, University of Yamanashi, Chuo, Japan.
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Kojiro
authors.initials: K
authors.lastname: Onohara
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sou
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Sano
authors.forename: Ali
authors.initials: A
authors.lastname: Muhi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006391:Hemangioma / Q000175:diagnosis*; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA