title: The effect of isoflurane on18F-FDG uptake in the rat brain: a fully conscious dynamic PET study using motion compensation.
abstract: BACKGROUND
  In preclinical positron emission tomography (PET) studies an anaesthetic is used to ensure that the animal does not move during the scan. However, anaesthesia may have confounding effects on the drug or tracer kinetics under study, and the nature of these effects is usually not known.
  
  
  METHODS
  We have implemented a protocol for tracking the rigid motion of the head of a fully conscious rat during a PET scan and performing a motion compensated list-mode reconstruction of the data. Using this technique we have conducted eight rat studies to investigate the effect of isoflurane on the uptake of18F-FDG in the brain, by comparing conscious and unconscious scans.
  
  
  RESULTS
  Our results indicate that isoflurane significantly decreases the whole brain uptake, as well as decreasing the relative regional FDG uptake in the cortex, diencephalon, and inferior colliculi, while increasing it in the vestibular nuclei. No statistically significant changes in FDG uptake were observed in the cerebellum and striata.
  
  
  CONCLUSIONS
  The applied event-based motion compensation technique allowed for the investigation of the effect of isoflurane on FDG uptake in the rat brain using fully awake and unrestrained rats, scanned dynamically from the moment of injection. A significant effect of the anaesthesia was observed in various regions of the brain.
authors.affiliation: Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium. matthew.bickell@gmail.com.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Spangler-Bickell
authors.affiliation: Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: de Laat
authors.affiliation: Brain & Mind Centre and the Faculty of Health Sciences, University of Sydney, Sydney, Australia.|Department of Nuclear Medicine, Westmead Hospital, Sydney, Australia.
authors.forename: Roger
authors.initials: R
authors.lastname: Fulton
authors.affiliation: Department of Radiopharmacy, KU Leuven, Leuven, Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Bormans
authors.affiliation: Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Nuyts
keywords: Anaesthesia; FDG; Motion compensation; PET; Preclinical