title: Dose-dependency and rate of decay of efficacy of Resovist on MR images in a rat cirrhotic liver model.
abstract: OBJECTIVE
  To investigate the dose-dependency and half-life of decay of the signal reduction by super-paramagnetic iron oxides on three different spin-echo images in a rat model of cirrhosis.
  
  
  METHODS
  For normal and cirrhotic liver, signal intensities were measured 15 minutes after injection of Resovist (range, 1-40 mumol Fe/kg) on three different spin-echo images. Subsequently, recovery of signal intensity was monitored up to 2 weeks after injection.
  
  
  RESULTS
  The dose-dependency of efficacy was somewhat less at all doses and imaging parameters in cirrhotic liver. However, the submaximal effect was obtained at a dose of 20 mumol Fe/kg, the same as in normal liver. The rate of decay of the efficacy in cirrhotic liver was similar to or faster than that in normal liver.
  
  
  CONCLUSIONS
  The dose-dependency and rate of decay of efficacy of Resovist in cirrhosis were similar to those in normal liver, although the efficacy was less in cirrhotic liver and both the dose-dependency and rate of decay of efficacy were dependent on imaging parameters.
authors.affiliation: Basic Research Institute, Nihon Schering K.K., Osaka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Tsuji
authors.forename: S
authors.initials: S
authors.lastname: Ihara
authors.forename: M
authors.initials: M
authors.lastname: Brautigam
authors.forename: T
authors.initials: T
authors.lastname: Miyazawa
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003911:Dextrans; D004305:Dose-Response Relationship, Drug; D052203:Ferrosoferric Oxide; D006207:Half-Life; D007501:Iron / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D010087:Oxides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019047:Phantoms, Imaging; D051381:Rats; D017208:Rats, Wistar; D013853:Thioacetamide / Q000633:toxicity
chemical_list: D002273:Carcinogens; D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D013853:Thioacetamide; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide