An intracerebral beta microprobe for studying radiotracer kinetics in freely moving animals

A scintillation microprobe has been developed to directly measure the positron decay activity from radiotracers in live animals. The probe consists of a small LSO crystal coupled to an optical fiber which is read out with a photomultiplier tube operated in a single photon counting mode. Positron conversions in the crystal are detected with high efficiency due to the excellent stopping power and high light output of LSO, and allows for the direct determination of the positron emitter concentration in a localized region of tissue. The probe can be used in the study of chemical kinetics and the development of new radiotracers in awake and freely moving animals.