Large-Area SiPM Pixels (LASiPs): A cost-effective solution towards compact large SPECT cameras

Area of Science:

• Medical Imaging Physics
• Detector Technology
• Nuclear Medicine

Background:

• Current Single Photon Emission Computed Tomography (SPECT) scanners utilize bulky and heavy photomultiplier tubes (PMTs).
• Replacing PMTs with silicon photomultipliers (SiPMs) could reduce SPECT camera size, weight, and cost.
• The limited sensitive area of individual SiPMs presents a major challenge for full-body SPECT applications.

Purpose of the Study:

• To introduce Large-Area SiPM Pixels (LASiPs) as a solution to the limited sensitive area of SiPMs for SPECT.
• To develop and test a LASiP prototype and a proof-of-concept micro-camera for SPECT imaging.
• To validate system performance and simulation models for future large-scale SPECT camera implementation.

Main Methods:

• Developed a LASiP prototype with a sensitive area 8 times larger than standard 6x6 mm² SiPMs.
• Constructed a micro-camera using a NaI(Tl) crystal coupled with 4 LASiPs.
• Evaluated imaging performance using a 99mTc capillary, measuring spatial and energy resolution, and validated with Geant4 simulations.

Main Results:

• Achieved an intrinsic spatial resolution of approximately 2 mm.
• Obtained an energy resolution of approximately 11.6% at 140 keV.
• Validated experimental measurements with Geant4 simulations for system modeling.

Conclusions:

• LASiPs offer a viable solution to enhance SiPM-based SPECT detector technology.
• The developed micro-camera demonstrates promising imaging capabilities for SPECT applications.
• Simulation models can guide the optimization and implementation of LASiPs in future large-scale SPECT cameras.