title: Simplified quantification of small animal [18F]FDG PET studies using a standard arterial input function.
abstract: OBJECTIVE
  Arterial input function (AIF) measurement for quantification of small animal PET studies is technically challenging and limited by the small blood volume of small laboratory animals. The present study investigated the use of a standard arterial input function (SAIF) to simplify the experimental procedure.
  
  
  METHODS
  Twelve [(18)F]fluorodeoxyglucose ([(18)F]FDG) PET studies accompanied by serial arterial blood sampling were acquired in seven male Sprague-Dawley rats under isoflurane anaesthesia without (every rat) and with additional (five rats) vibrissae stimulation. A leave-one-out procedure was employed to validate the use of a SAIF with individual scaling by one (1S) or two (2S) arterial blood samples.
  
  
  RESULTS
  Automatic slow bolus infusion of [(18)F]FDG resulted in highly similar AIF in all rats. The average differences of the area under the curve of the measured AIF and the individually scaled SAIF were 0.11+/-4.26% and 0.04+/-2.61% for the 1S (6-min sample) and the 2S (4-min/43-min samples) approach, respectively. The average differences between the cerebral metabolic rates of glucose (CMR(glc)) calculated using the measured AIF and the scaled SAIF were 1.31+/-5.45% and 1.30+/-3.84% for the 1S and the 2S approach, respectively.
  
  
  CONCLUSIONS
  The use of a SAIF scaled by one or (preferably) two arterial blood samples can serve as a valid substitute for individual AIF measurements to quantify [(18)F]FDG PET studies in rats. The SAIF approach minimises the loss of blood and should be ideally suited for longitudinal quantitative small animal [(18)F]FDG PET studies.
authors.affiliation: Department of Neurology, University Hospital Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany. pmeyer@ukaachen.de
authors.forename: Philipp T
authors.initials: PT
authors.lastname: Meyer
authors.forename: Valentina
authors.initials: V
authors.lastname: Circiumaru
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Cardi
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Thomas
authors.forename: Harshali
authors.initials: H
authors.lastname: Bal
authors.forename: Paul D
authors.initials: PD
authors.lastname: Acton
mesh_terms: D000465:Algorithms; D000818:Animals; D001158:Arteries / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003198:Computer Simulation; D019788:Fluorodeoxyglucose F18 / Q000097:blood* / Q000493:pharmacokinetics; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008955:Models, Cardiovascular; D049268:Positron-Emission Tomography / Q000379:methods* / Q000662:veterinary*; D011865:Radioisotope Dilution Technique; D019275:Radiopharmaceuticals / Q000097:blood / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18