title: Limitations of small animal PET imaging with [18F]FDDNP and FDG for quantitative studies in a transgenic mouse model of Alzheimer's disease.
abstract: OBJECTIVE
  We evaluated the usefulness of small animal brain positron emission tomography (PET) imaging with the amyloid-beta (A beta) probe 2-(1-{6-[(2-[(18)F]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malonitrile ([(18)F]FDDNP) and with 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) for detection and quantification of pathological changes occurring in a transgenic mouse model of Alzheimer's disease (Tg2576 mice).
  
  
  METHODS
  [(18)F]FDDNP (n = 6) and FDG-PET scans (n = 3) were recorded in Tg2576 mice (age 13-15 months) and age-matched wild-type litter mates. Brain volumes of interest were defined by co-registration of PET images with a 3D MOBY digital mouse phantom. Regional [(18)F]FDDNP retention in mouse brain was quantified in terms of the relative distribution volume (DVR) using Logan's graphical analysis with cerebellum as a reference region.
  
  
  RESULTS
  Except for a lower maximum brain uptake of radioactivity in transgenic animals, the regional brain kinetics as well as DVR values of [(18)F]FDDNP appeared to be similar in both groups of animals. Also for FDG, regional radioactivity retention was almost identical in the brains of transgenic and control animals.
  
  
  CONCLUSIONS
  We could not detect regionally increased [(18)F]FDDNP binding and regionally decreased FDG binding in the brains of Tg2576 transgenic versus wild-type mice. However, small group differences in signal might have been masked by inter-animal variability. In addition, technical limitations of the applied method (partial volume effect, spatial resolution) for measurements in such small organs as mouse brain have to be taken into consideration.
authors.affiliation: Department of Radiopharmaceuticals & microPET Imaging, Austrian Research Centers GmbH-ARC, 2444, Seibersdorf, Austria. Claudia.Kuntner@arcs.ac.at
authors.forename: Claudia
authors.initials: C
authors.lastname: Kuntner
authors.forename: Adam L
authors.initials: AL
authors.lastname: Kesner
authors.forename: Martin
authors.initials: M
authors.lastname: Bauer
authors.forename: Robert
authors.initials: R
authors.lastname: Kremslehner
authors.forename: Thomas
authors.initials: T
authors.lastname: Wanek
authors.forename: Markus
authors.initials: M
authors.lastname: Mandler
authors.forename: Rudolf
authors.initials: R
authors.lastname: Karch
authors.forename: Johann
authors.initials: J
authors.lastname: Stanek
authors.forename: Tanja
authors.initials: T
authors.lastname: Wolf
authors.forename: Markus
authors.initials: M
authors.lastname: Müller
authors.forename: Oliver
authors.initials: O
authors.lastname: Langer
mesh_terms: D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D001923:Brain Chemistry; D004195:Disease Models, Animal; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D021621:Imaging, Three-Dimensional / Q000379:methods; D051379:Mice; D008822:Mice, Transgenic; D009570:Nitriles / Q000493:pharmacokinetics*; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D018709:Statistics, Nonparametric
chemical_list: C444520:2-(1-(6-((2-fluoroethyl)(methyl)amino)-2-naphthyl)ethylidene)malononitrile; D016229:Amyloid beta-Peptides; D009570:Nitriles; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18