An improved multicrystal 2-D BGO detector for PET

The authors evaluate and compare two 2-D array detectors for PET (positron emission tomography). Both consist of an 8*8 array of small BGO crystals coupled to a 2*2 array of photomultiplier tubes. The depth of the crystals is 3 cm in one detector and 2 cm in the other. The 2-cm detector is obviously superior in terms of material costs, but it is also superior in energy resolution per crystal, and in its ability to identify clearly the crystal containing the primary interaction. The authors present a flexible and robust algorithm for crystal identification in such array detectors. The prospect of obtaining still better spatial resolution from such block detectors, with increased numbers of crystals, is discussed.<>