Timing, Energy, and Spatial Characterization of Highly Sampled Monolithic PET Detectors with Different Thicknesses

Area of Science:

• Medical Imaging
• Nuclear Physics
• Detector Technology

Background:

• The Hybrid dedicated TOF-PET (HyPET) project aims to improve prostate imaging.
• It utilizes a hybrid detector design with pixelated front and monolithic back layers.

Purpose of the Study:

• To experimentally evaluate four different thicknesses (5, 7.5, 10, 15 mm) of LYSO monolithic blocks for the rear detector layer.
• To characterize their performance in terms of energy, time, and spatial resolution.

Main Methods:

• Four detector configurations with varying LYSO monolithic block thicknesses were tested.
• Characterization involved scanning with a fan beam and using a Neural Network for spatial resolution estimation.

Main Results:

• Energy resolution remained consistent at ~17% across all configurations.
• Spatial resolution (FWHM) improved with decreasing thickness, achieving 1.02 ± 0.10 mm for 5 mm blocks.
• Time resolution also improved with thinner blocks, reaching 275 ± 26 ps for 5 mm blocks.

Conclusions:

• The 5 mm thick LYSO monolithic blocks offer superior spatial and time resolution for the rear detector layer in TOF-PET systems.
• This finding supports the optimization of detector design for enhanced prostate imaging in the HyPET project.