title: A dual tracer PET-MRI protocol for the quantitative measure of regional brain energy substrates uptake in the rat.
abstract: We present a method for comparing the uptake of the brain's two key energy substrates: glucose and ketones (acetoacetate [AcAc] in this case) in the rat. The developed method is a small-animal positron emission tomography (PET) protocol, in which (11)C-AcAc and (18)F-fluorodeoxyglucose ((18)F-FDG) are injected sequentially in each animal. This dual tracer PET acquisition is possible because of the short half-life of (11)C (20.4 min). The rats also undergo a magnetic resonance imaging (MRI) acquisition seven days before the PET protocol. Prior to image analysis, PET and MRI images are coregistered to allow the measurement of regional cerebral uptake (cortex, hippocampus, striatum, and cerebellum). A quantitative measure of (11)C-AcAc and (18)F-FDG brain uptake (cerebral metabolic rate; μmol/100 g/min) is determined by kinetic modeling using the image-derived input function (IDIF) method. Our new dual tracer PET protocol is robust and flexible; the two tracers used can be replaced by different radiotracers to evaluate other processes in the brain. Moreover, our protocol is applicable to the study of brain fuel supply in multiple conditions such as normal aging and neurodegenerative pathologies such as Alzheimer's and Parkinson's diseases.
authors.affiliation: Research Center on Aging and Department of Physiology and Biophysics, Université de Sherbrooke.
authors.forename: Maggie
authors.initials: M
authors.lastname: Roy
authors.forename: Scott
authors.initials: S
authors.lastname: Nugent
authors.forename: Sébastien
authors.initials: S
authors.lastname: Tremblay
authors.forename: Maxime
authors.initials: M
authors.lastname: Descoteaux
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beaudoin
authors.forename: Luc
authors.initials: L
authors.lastname: Tremblay
authors.forename: Roger
authors.initials: R
authors.lastname: Lecomte
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Cunnane
mesh_terms: D000090:Acetoacetates / Q000493:pharmacokinetics; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002250:Carbon Radioisotopes; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats
chemical_list: D000090:Acetoacetates; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C016635:acetoacetic acid