Depth Encoding PET Detector Using Two and Four Reflector Arrangements along Depth of Single Layer LYSO Array

In this paper, the depth encoding PET detector using different reflector arrangements along the depth of single layer LYSO crystal arrays with SiPM array single-ended readout was proposed. 2×2 LYSO arrays with crystal size of 3 mm×3 mm×20 mm using four and two reflector arrangements along the crystal depth were fabricated and measured. The experimental results show that all crystals can be clearly resolved from the measured flood histograms. For the detector with two reflector arrangements, the average probabilities to make correct assignment to each half and quarter of the crystals are 85.1% and 65.5%, respectively. For the detector with four reflector arrangements, the average probability to make correct assignment to each quarter of the crystals is 74.8%. The depth of interaction (DOI) resolution of the detector with four reflector arrangements is better than that of the detector with two reflector arrangements. The average energy resolutions of the two detectors are 18.0% and 12.2%. The depth encoding PET detector proposed in this paper achieves good DOI resolution with single-ended readout. The detector can be used to develop high performance dedicated brain, whole-body and total-body PET scanners in the future.