Abstract
Objective—To assess kinetic 2-([18F]fluoro)-2-deoxy-d-glucose (18FDG) uptake in the brain of anesthetized healthy adult dogs by use of positron emission tomography (PET) and to determine whether 18FDG uptake differs among anatomic regions of the brain.
Animals—5 healthy Beagles.
Procedures—Each isoflurane-anesthetized dog was administered 18FDG IV (dose range, 3.0 to 5.2 mCi), and PET data were acquired for 2 hours. A CT scan (without contrast agent administration) was performed to allow more precise neuroanatomic localization. Defined regions of interest within the brain were drawn on reconstructed image data. Standard uptake values (SUVs) for 18FDG were calculated to generate time-activity curves and determine time to peak uptake.
Results—Time-activity curve analysis identified 4 regional uptake patterns: olfactory, gray matter, white matter, and other (brainstem, cerebellum, and occipital and frontal regions). The highest maximum SUVs were identified in the olfactory bulbs and cerebral gray matter, and the lowest maximum SUV was identified in cerebral white matter. Mean time to peak uptake ranged from 37.8 minutes in white matter to 82.7 minutes in the olfactory bulbs.
Conclusions and Clinical Relevance—Kinetic analysis of 18FDG uptake revealed differences in uptake values among anatomic areas of the brain in dogs. These data provide a baseline for further investigation of 18FDG uptake in dogs with immune-mediated inflammatory brain disease and suggest that 18FDG-PET scanning has potential use for antemortem diagnosis without histologic analysis and for monitoring response to treatment. In clinical cases, a 1-hour period of PET scanning should provide sufficient pertinent data.
