LYSO

Cerium-doped lutetium-yttrium orthosilicate scintillator. Fast decay time (~40 ns) enables ToF PET.

Why it matters to buyers: LYSO vs BGO is the generational upgrade in PET crystals. Every ToF system uses LYSO or LSO.

Why it matters to engineers: LYSO is naturally mildly radioactive (Lu-176). Background is factored into calibration; idle-ring 'noise' is normal.