The Xtal Cube PET Detector: 3D Scintillation Photon Detection by a 3D Crystal Array Using MPPCs

We have proposed a depth of interaction (DOI) PET detector named Xtal cube, in which a number of Multi-Pixel Photon Counters (MPPCs) are coupled on various positions of six surfaces of a segmented scintillation crystal block. There are no reflectors within the block, and the areas among MPPCs on the surface are covered with reflector. Each MPPC is thin and light solid-state photo-detector so that the crystal block can be closely placed on the PET detector ring. To study the characteristics of the Xtal cube, we constructed a crystal block consisting of six layers of a 6 x 6 segmented crystal array with Lu2xGd2(1-x)SiO5 (LGSO) crystals. Each crystal is 3.0 x 3.0 x 3.0 mm3. We examined crystal identification performance for different MPPC arrangements on the block surfaces, where we used 3-dimensional (3D) Anger-type position calculation. The preliminary experiments showed the possibility of a 3D detector having isotropic resolutions for PET.2009 IEEE Nuclear Science Symposium & Medical Imaging Conferenc