A new approach to positron emission tomography

A recently developed detection principle for gamma rays offers the prospect of improving the performance of positron emission tomographic scanners. This detection principle is based on the use of BaF2 scintillator and photosensitive wire chambers. We present technical results obtained with a prototype detector. It is shown that the impact point of the gamma ray can be determined with a precision of a few mm and that the detection efficiency is 60% with a time resolution of 10 ns (FWHM). A scanner based on the new principle is described and its anticipated performance discussed.