Multi-Animal Simultaneous PET/MR Imaging

Common applications for preclinical PET include tracer development and use of specialized animal strains (knock-out mice or disease models) to investigate novel drugs or address biological questions that are not easily studied in humans. Frequently, developmental tracers are initially evaluated in small test batches before scaling up production. Production of multiple small batch tracers often using iterative chemistries in developmental phases can be costly. When using short halflife isotopes (e.g. 11C half-life = 20-minutes) a single batch of tracer may only be enough for a single scan before tracer activity decays. Even when using the most commonly synthesized 11C radioisotopes, radiochemistry and cyclotron costs present a cost burden. Studies of disease progression and evaluation of therapeutic interventions often employ longitudinal designs with control groups and 6-12 animals per cohort. Where kinetic details are desired, scan times required may reach 60 minutes or longer, so it not feasible to perform multiple scans using one synthesis of radiotracer. Typically, the total dose available is not a limiting factor in small-animal studies, and a single synthesis of radiotracer provides enough dose for many animals. For these reasons, researchers in preclinical PET frequently attempt to maximize efficiency by performing multi-animal PET scans. Multi-Animal Simultaneous PET/MR Imaging Iris Y Zhou1, Christian T Farrar1, Joseph Mandeville1, Michael S. Placzek1, Nicholas J Rotile1, Cesar Molinos Solsona2, Todd Sasser2, Shadi A Esfahani1, Michael Heidenreich2 and Peter Caravan1