A large area, silicon photomultiplier-based PET detector module.

Area of Science:

• Medical Imaging
• Particle Detectors
• Nuclear Instrumentation

Background:

• Silicon photomultipliers (SiPMs) enable compact, efficient, and magnetic field-hardened positron emission tomography (PET) scanners.
• Developing large field-of-view PET scanners requires effective methods for utilizing SiPM arrays.

Purpose of the Study:

• To explore techniques for combining two SiPM arrays into a building block for a small animal PET scanner.
• To assess the performance of a novel SiPM-based detector module for PET applications.

Main Methods:

• Constructed a module with a 26 × 58 array of LYSO elements coupled to two SensL SiPM arrays.
• Utilized new multiplexing electronics and a light guide to spread scintillation light for event position calculation.
• Implemented a cooling jacket to control the temperature of the detector module and electronics.

Main Results:

• Successfully identified all detector elements, including those at the seam between SiPM arrays.
• Cooling from 28 °C to 16 °C increased peak-to-valley contrast ratio by ~45%.
• Energy resolution for 511 keV photons improved from 18.8% to 17.8% with cooling; coincidence timing resolution was ~2100 ps.

Conclusions:

• The developed SiPM module is suitable for constructing small animal PET scanners.
• Cooling enhances SiPM performance, improving contrast and energy resolution.
• The module will be integrated into a PET scanner for use with a 3T MRI scanner.