title: Arterial input function sampling without surgery in rats for positron emission tomography molecular imaging.
abstract: OBJECTIVE
  The purpose of this study was to develop a minimally invasive procedure to derive an arterial input function (AIF) in rats through tail artery blood sampling for pharmacokinetic modeling in preclinical PET molecular imaging studies. The procedure involved a microvolumetric blood counter (μBC) and a correction to compensate for delay and dispersion of the automatic blood sampling.
  
  
  METHODS
  AIFs were simultaneously obtained from femoral and tail arteries in rats, manually and using a μBC, after (18)F-FDG injection (n=6) in order to compare the shape of the AIFs and the kinetic analysis results at equilibrium and after implementation of a dispersion correction method. These AIFs were used to estimate the myocardial metabolic rate of glucose (MMRG). AIFs were also obtained from a single withdrawal site by three methods to confirm accurate MMRG values: manual tail artery (n=5), μBC tail artery (n=5), and μBC femoral artery (n=3).
  
  
  RESULTS
  Simultaneous withdrawal at equilibrium results in similar AIF shapes and influx rate constants (Ki) from Patlak analysis (P>0.05). Manually withdrawn and dispersion-corrected μBC AIFs in the simultaneous experiment did not reveal statistically different shapes and constants (K(1), K(i)) from a three-compartment kinetic analysis, regardless of the withdrawal methods or sites (P>0.05). Kinetic analysis of the three single-site blood sampling methods yielded similar MMRG (one-way ANOVA; Patlak, P=0.52; three-compartment, P=0.10).
  
  
  CONCLUSIONS
  Both minimally invasive manual withdrawal and dispersion-corrected μBC-based blood sampling in the tail artery are reliable methods for deriving AIFs for pharmacokinetic follow-up studies in the same animal.
authors.affiliation: Department of Nuclear Medicine and Radiobiology, Sherbrooke Molecular Imaging Center, Étienne-Le Bel Clinical Research Center of CHUS, Université de Sherbrooke, Québec, Canada.
authors.forename: Etienne
authors.initials: E
authors.lastname: Croteau
authors.forename: Eric
authors.initials: E
authors.lastname: Poulin
authors.forename: Sébastien
authors.initials: S
authors.lastname: Tremblay
authors.forename: Véronique
authors.initials: V
authors.lastname: Dumulon-Perreault
authors.forename: Otman
authors.initials: O
authors.lastname: Sarrhini
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
authors.forename: Roger
authors.initials: R
authors.lastname: Lecomte
mesh_terms: D000818:Animals; D001158:Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D057054:Molecular Imaging; D009206:Myocardium / Q000378:metabolism; D049268:Positron-Emission Tomography; D051381:Rats
chemical_list: D019788:Fluorodeoxyglucose F18; D005947:Glucose