Fast high lutetium content scintillators as candidates for APD-based phoswich detectors with depth-of-interaction (DOI)

The recent introduction of several new fast, high light yield versions of generic cerium-doped lutetium silicates (LSO, LGSO, LYSO...) has widened the list of potential candidates for phoswich detectors dedicated to medical imaging applications. Furthermore, digital signal processing methods based on adaptive filter theory now provide powerful approaches for crystal identification, even with scintillators having small decay time differences (¿¿). The LabPET¿ digital signal processing technology was used to investigate the crystal identification performance of phoswich scintillator pairs with decay times in the range of 32 to 77 ns. The scintillator initial photon emission rate 70 was found to directly impact the identification error rate, particularly for fast phoswich crystal pairs with small A¿. Overall, error rates of less than 10% were measured for phoswich pairs with ¿¿ > 5 ns and less than 1 % for ¿¿ > 20 ns, which is fully adequate for typical PET imaging applications.