Development of a high resolution beta camera for a direct measurement of positron distribution on brain surface

We have developed and tested a high resolution beta camera far a direct measurement of positron distribution on brain surface of animals. The beta camera consists of a thin CaF/sub 2/(Eu) scintillator, a tapered fiber optics plate (taper fiber) and a position sensitive photomultiplier tube (PSPMT). The taper fiber is the key component of the camera. We have developed two types of beta cameras. One is 20 mm diameter field of view camera for imaging brain surface of cats. The other is 10 mm diameter camera for that of rats. Spatial resolutions of beta camera for cats and rats were 0.8 mm FWHM and 0.5 mm FWHM, respectively. We confirmed that developed beta cameras may overcome the limitation of the spatial resolution of the positron emission tomography (PET).