LYSO
Cerium-doped lutetium-yttrium orthosilicate scintillator (Lu_(2-x)Y_xSiO_5:Ce). Fast decay time (~40 ns) and high light yield make it the modern standard PET crystal — enabling Time-of-Flight PET. LSO (lutetium oxyorthosilicate, no yttrium) is the close-cousin scintillator used by Siemens; the two have similar physics and are often referenced interchangeably in the trade.
Why it matters to buyers: LYSO / LSO vs BGO is the generational upgrade in PET crystals. Every ToF system uses LYSO or LSO. PMT-era LYSO platforms (Discovery 690, Biograph mCT) and SiPM-era platforms (Discovery MI, Biograph Vision, Vereos) all use the same scintillator family with different readout electronics.
Why it matters to engineers: LYSO is naturally mildly radioactive because of Lu-176 (2.6% natural abundance, half-life ~3.8×10¹⁰ years). Background is factored into calibration; idle-ring "noise" is normal. Decommissioning has to handle Lu-176 per local radioactive-material regulations; some manufacturers offer take-back programs. See PET / CT decommissioning.
Related
- BGO (predecessor scintillator)
- SiPM (current readout)
- Time-of-Flight
- TrueV
- PET / CT
- PET / MR
- Discovery 690 LYSO crystal
- Siemens LSO PET detector
- First Digital PET (2016)
- PET / CT Decommissioning