Abstract #0759

Evaluation of fMRI Signal Versus Receptor Occupancy Using Simultaneous PET/fMRI

Christin Y. Sander¹,², Jacob M. Hooker¹, Bruce R. Rosen¹,³, Joseph B. Mandeville¹

¹A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States; ²Electrical Engineering, Massachusetts General Hospital, Cambridge, MA, United States; ³Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States

In this study, we applied simultaneous PET/fMRI for the first time to directly relate fMRI signal to receptor occupancies in vivo. Using varying doses of a dopamine D2 antagonist in non-human primates, we showed that function (as measured by fMRI) is linearly related to occupancy (derived from PET), that dynamic time courses are matched between fMRI and PET and that we can obtain a measure of basal dopamine levels with the combined PET/fMRI measurement.