Performance characterization of a new high resolution PET scintillation detector

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Detector Physics

Background:

• Current Positron Emission Tomography (PET) systems face limitations in spatial resolution and sensitivity.
• Advancements in detector technology are crucial for improving diagnostic accuracy in PET imaging.
• Optimizing scintillator crystal design and photodetector coupling is key to enhancing PET performance.

Purpose of the Study:

• To present the performance of a new high-resolution PET detector concept utilizing edge-on incident annihilation radiation.
• To evaluate the spatial, energy, and timing resolution of the novel detector module.
• To compare experimental results with theoretical predictions for the coincidence point spread function (PSF).

Main Methods:

• Developed a PET detector module with dual 8x8 LYSO scintillator arrays (0.91x0.91x1 mm crystals).
• Coupled scintillator arrays to position-sensitive avalanche photodiodes (PSAPDs) for precise interaction localization.
• Measured energy resolution, coincident time resolution, and coincidence point spread function (PSF) using a 500 μm spherical source.

Main Results:

• Achieved an average energy resolution of 14.6 ± 1.7% FWHM for 511 keV photons.
• Determined an average coincident time resolution of 2.98 ± 0.13 ns FWHM.
• Measured an average coincidence PSF FWHM of 0.837 ± 0.049 mm, showing good uniformity and agreement with theoretical calculations.

Conclusions:

• The new PET detector concept demonstrates promising submillimeter spatial resolution and excellent timing characteristics.
• The edge-on detection approach enables simultaneous recording of all three spatial coordinates.
• Further optimization is needed to mitigate performance degradation caused by Compton interactions.