Should the brain imaging and dosimetry studies prove to be successful, we will continue with test/retest brain imaging studies. Test/retest studies with [18F]FMPEP-d2 will provide evidence of reproducibility and strengthen the assurance that this radioligand can be used to assess pathology. Previous investigations in developing a CB1 receptor PET tracer have demonstrated the need to test reproducibility (Terry, In Writing; Burns et al 2007).