Optimized light sharing for high-resolution TOF PET detector based on digital silicon photomultipliers

Area of Science:

• Medical Imaging
• Nuclear Physics
• Detector Technology

Background:

• Current whole-body PET scanners use 4 mm pixel size scintillator arrays.
• Smaller pixel sizes (e.g., 2 mm) can enhance image spatial resolution.
• Digital Photon Counters (DPCs) are emerging photosensors for PET applications.

Purpose of the Study:

• Evaluate the performance of Philips Digital Photon Counting (PDPC) DPC for high-resolution TOF PET scanners.
• Compare two detector configurations using DPCs for PET imaging.
• Assess the suitability of DPCs for next-generation PET systems.

Main Methods:

• Two detector configurations were tested with DPC arrays and LYSO crystals.
• Configuration 1: DPC coupled to LYSO block via a 1 mm light guide.
• Configuration 2: DPC directly coupled to a LYSO matrix with a dedicated reflector arrangement.

Main Results:

• Configuration 1 achieved 14.5% average energy resolution and 376 ps timing resolution.
• Configuration 2 achieved 11% average energy resolution and 295 ps timing resolution.
• The direct coupling with reflector arrangement yielded superior performance.

Conclusions:

• DPCs are suitable photosensors for high-resolution TOF PET detectors.
• The reflector arrangement enhances PET detector performance.
• Matrix size optimization addresses count loss issues from dark counts.