Monolithic scintillator PET detectors with intrinsic depth-of-interaction correction

Area of Science:

• Medical Imaging
• Nuclear Instrumentation

Background:

• Positron Emission Tomography (PET) relies on accurate detection of annihilation photons.
• Depth-of-Interaction (DOI) measurement is crucial for improving PET spatial resolution.
• Previous monolithic detectors offered intrinsic DOI correction.

Purpose of the Study:

• To characterize next-generation monolithic PET detectors with double-sided readout (DSR).
• To evaluate the performance of rectangular and trapezoidal LYSO:Ce crystals with DSR.
• To assess the impact of DOI correction on spatial resolution at various incidence angles.

Main Methods:

• Developed PET detectors using monolithic LYSO:Ce scintillation crystals.
• Employed Hamamatsu S8550SPL avalanche photodiode (APD) arrays for front and back readout (DSR).
• Characterized detector performance including spatial resolution, energy resolution, and timing resolution.

Main Results:

• Achieved a spatial resolution of approximately 1.05 mm FWHM at the detector center for rectangular crystals.
• Demonstrated stable spatial resolution up to 30 degrees incidence angle due to accurate DOI correction.
• Measured energy resolution of approximately 11% FWHM and coincidence timing resolution of 2.8 ns FWHM.
• Trapezoidal crystals showed comparable performance to rectangular ones while enhancing system sensitivity.

Conclusions:

• The developed DSR monolithic PET detectors offer excellent spatial, energy, and timing resolutions.
• Accurate intrinsic DOI correction is key to maintaining high spatial resolution across wide angles.
• These detectors are poised to significantly enhance the performance of future PET systems.