title: Quantification of Gd-BOPTA uptake and biliary excretion from dynamic magnetic resonance imaging in rat livers: model validation with 153Gd-BOPTA.
abstract: OBJECTIVE
  We sought to develop and validate a pharmacokinetic model allowing description of the magnetic resonance (MR) signal intensity induced by the hepatobiliary contrast agent Gd-BOPTA and to quantify the overall Gd-BOPTA transport in rat liver.
  
  
  METHODS
  MR signal intensity was recorded during the perfusion of rat livers with Gd-DTPA, an extracellular contrast agent, and Gd-BOPTA, a hepatobiliary contrast agent. Similar experiments were conducted with Gd-labeled contrast agents for quantitative measurement in liver, bile and perfusate.
  
  
  RESULTS
  A complete 6-compartment, 8 parameter open model was first developed to describe the pharmacokinetics of the compound based on the radioactivity data analysis. Because perfusate and bile data were not available in MRI experiments, a reduced model (6-compartment, 5 parameters) was considered for the MRI data. The performance of the reduced model was tested using the radioactivity data. The reduced model successfully described the contrast agent amount in the liver and correctly predicted amounts in bile and perfusate.
  
  
  CONCLUSIONS
  Pharmacokinetic modeling of MR signal intensity induced by Gd-BOPTA permits quantification of Gd-BOPTA uptake and biliary excretion in rat livers.
authors.affiliation: Department of Radiology, Geneva University Hospitals, Geneva, Switzerland. corinne.planchamp@hcuge.ch
authors.forename: Corinne
authors.initials: C
authors.lastname: Planchamp
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Pastor
authors.forename: Luc
authors.initials: L
authors.lastname: Balant
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Becker
authors.forename: François
authors.initials: F
authors.lastname: Terrier
authors.forename: Marianne
authors.initials: M
authors.lastname: Gex-Fabry
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism*; D001692:Biological Transport; D003287:Contrast Media / Q000493:pharmacokinetics*; D005110:Extracellular Space / Q000378:metabolism; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008536:Meglumine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008954:Models, Biological; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine; D019786:Gadolinium DTPA