Spatial Resolution Of Positron Emission Tomography Research Articles

Twin BGO detectors for high resolution positron emission tomography

Twin BGO detectors and timing pulse shape discriminators for crystal identification have been developed for high spatial resolution positron emission tomography. Each detector consists of two BGO crystals and one single photomultiplier tube. The tube has a grid covering half the area of the photocathode window, and opposite to which stands one of the BGO crystals. The amplitude of the anode signals for the scintillation events in the grid side crystal is modulated by supplying negative pulses to the grid. Crystal identification is achieved by pulse shape discrimination for the detector signals. The design criteria of the electronic system and the performance are described. With suitable pulse shape discrimination, the erroneous positioning due to statistical noise is negligible and the coincidence time resolution for annihilation photon pairs is about 5.8 ns fwhm.