Positron ring system using anger-type detectors

The PENN-PET scanner has been studied to characterize its performance and evaluate its capabilities. This design offers high spatial resolution in all three dimensions, high sampling density along all three axes without scanner motion, a large axial aceptance angle, good energy resolution, and good timing resolution. This results in three-dimensional imaging capability with high sensitivity and low scatter and random backgrounds. The spatial resoltuion is 5.5 mm (FWHM) in all directions near the center. The true sensitivity, for a brain-sized object, is a maximum of 85 kCPS/μCi/ml and the scatter fraction is a minimum of 10%, both depending on the lower level energy threshold. The scanner can handle up to 5 mCi in the field-of-view, at which point the randoms equals the true coincidences and the detectors reach their countrate limit. We have so far acquired F-FDG brain studies and cardiac studies, which show the applicability of our scanner for both brain and whole-body imaging. With the results to date we feel that this design results in a simple yet high performance scanner which is applicable to many types of static and dynamic clinical studies. We continue to pursue areas that will lead to improvements in performance. In addition, the PENN-PET scanner gives us the opportunity to study volume imaging in ways that are not possible with other existing PET scanners