Positron Emission Tomography (PET) is a nuclear imaging modality that makes use of a range of positron-emitting tracers to provide images that reflect different parameters relevant to tumor biology. Tumor cells generally differ from normal cells in many respects, including rates of glucose utilization, proliferation and protein synthesis. PET tracers such as glucose and thymidine analogs, and amino acids, generally show high uptake in tumor cells. Indeed, whole-body PET imaging with 18Ffluorodeoxyglucose (FDG) is now a well established diagnostic procedure that is used for staging and assisting in management choices of patients with many different types of cancers. Recent developments in PET technology are leading towards more specialized PET systems, particularly for breast imaging and applications in breast cancer. The motivation is to obtain better performance at a lower cost than with conventional whole-body PET scanners. It is clear that PET technology is playing a prominent and an increasingly visible role in modem cancer research and clinical diagnosis. However, there is urgent need for improvement in PET instrumentation in order to exploit the full potential of this powerful imaging modality. The goal of the proposed effort is to investigate crystals of a new promising scintillator for PET imaging.