Performance characteristics of a positron emission mammographic (PEM) instr
ument were studied. This dedicated metabolic breast imaging system has spat
ial resolution of 2.8-mm full width at half maximum (FWHM), coincidence res
olving time of 12-nsec FWHM, and absolute efficiency of 3%. Hot spots with
diameter of 16 mm in a phantom with signal-to-background activity ratio of
6:1 were distinguishable with a scanning time of 5 minutes.