title: Nondiffuse fatty change of the liver: discerning pseudotumor on MR images enhanced with ferumoxides-initial observations.
abstract: OBJECTIVE
  To clarify the findings of nondiffuse fatty change of the liver on ferumoxides-enhanced magnetic resonance (MR) images.
  
  
  METHODS
  Of 202 patients who underwent ferumoxides-enhanced MR imaging, eight who had nondiffuse fatty change of the liver at computed tomography (CT) were examined as study subjects. MR imaging findings before and 1 hour after ferumoxides administration were compared with CT findings.
  
  
  RESULTS
  Focal fatty areas of the liver showing low attenuation on CT images were depicted as areas of relatively high intensity on the ferumoxides-enhanced T1-weighted images in all patients. On enhanced T2-weighted images, focal fatty change showed relatively high intensity in three and isointensity in one of the four patients. Focal spared areas appearing as areas of relatively high attenuation on CT images were depicted as areas of relatively low intensity on the ferumoxides-enhanced T1- and T2-weighted images in all patients.
  
  
  CONCLUSIONS
  Although prior reports of hepatic MR imaging with ferumoxides indicated that there is accumulation of ferumoxides within focal fatty areas that are no longer seen after the administration of contrast medium, this study revealed that focal fatty change and focal spared areas of fatty liver may be pseudotumors because of the relatively high intensity of fatty areas of the liver. Radiologists can distinguish these conditions from hepatic tumors by using the opposed-phase gradient-echo sequence or the fat-saturation technique.
authors.affiliation: Departments of Radiology and Oncoradiology, Nara Medical University, 840 Shijo-cho, Kashihara-shi, Nara 634-8522, Japan. hirohashi@my.email.ne.jp
authors.forename: S
authors.initials: S
authors.lastname: Hirohashi
authors.forename: K
authors.initials: K
authors.lastname: Ueda
authors.forename: H
authors.initials: H
authors.lastname: Uchida
authors.forename: W
authors.initials: W
authors.lastname: Ono
authors.forename: J
authors.initials: J
authors.lastname: Takahama
authors.forename: M
authors.initials: M
authors.lastname: Takewa
authors.forename: S
authors.initials: S
authors.lastname: Kitano
authors.forename: H
authors.initials: H
authors.lastname: Ohishi
mesh_terms: D000368:Aged; D003287:Contrast Media; D003911:Dextrans; D005234:Fatty Liver / Q000175:diagnosis*; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide