A time-of-flight multi-probe system for positron imaging

A time-of-flight (TOF) multi-probe system has been developed to measure the distribution of positron-emitting tracers in the body. Time-of-flight information in this system is used as the primary position information in the direction between the detector probes. The system uses two banks of eight detector probes, each of which is composed of a truncated pyramid BaF/sub 2/ crystal and a 26 mm diameter photomultiplier tube (Hamamatsu R5320). The average coincidence time resolution for possible 64 coincidence pairs is 180 ps FWHM, which corresponds to 2.7 cm in space. The system performance such as count rate and imaging capabilities were evaluated using phantoms. The results show that a low-cost positron imaging system can be constructed using the TOF detector probes.