Study of Lutetium-based scintillators for PET system design with 100-ps coincidence time resolution

Here, we evaluated fast Lu-based scintillation crystals for construction of a PET system with 100-ps coincidence time resolution (CTR). Four 3×3×10 mm
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LGSO crystals with decay times ranging from 33-38 ns, and 3×3×10 mm
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and 1.9×1.9×10 mm
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LSO crystals with decay times of 34-36 ns were tested. In order to achieve excellent CTR, we used a novel side-readout detector configuration where the long face of each crystal rod is coupled to multiple photo sensors. The light output, decay time, and energy performance were measured with a fast PMT. CTR was measured with crystals coupled side-on to SiPMs and waveforms were digitally sampled. In all of these studies we achieved ≤100 ps CTR.