Measuring 511 keV photon interaction locations in three dimensions using 3-D position sensitive scintillation detectors

We are studying a novel scintillation detector de sign for 511 keV photons whereby individual interaction locations are precisely determined in all three dimensions. In this paper, 511 keV photons enter the scintillation crystals from the top (´face-on´). A source could also be positioned so that annihilation radiation enters from the edge (´edge-on´). This multi-layer design enables direct measurement of each interaction of annihilation photons in all three dimensions. ´Depth of-Interaction´ is directly measured and does not need to be estimated as in many other designs, such as monolithic crystal designs or dual ended readout. In addition, a high light collection efficiency is obtained due to the large aspect ratio compared to more traditional designs where scintillation light is read out at the end of a long scintillation crystal element. Furthermore, the design enables dense crystal packing.