An improved multicrystal 2-D BGO detector for PET

The authors evaluate and compare two 2-D array detectors for positron emission tomography (PET). Both consisted of an 8×8 array of small BGO crystals coupled to a 2×2 array of photomultiplier tubes. The depth of the crystals was 3 cm in one detector and 2 cm in the other. The 2-cm detector is superior in terms of material costs, in energy resolution per crystal, and in its ability to clearly identify the crystal containing the primary interaction. A flexible and robust algorithm is presented 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