Compton PET: a layered structure PET detector with high performance.

Area of Science:

• Medical Imaging
• Detector Physics

Background:

• High-resolution PET detector design faces a trade-off between spatial resolution and efficiency.
• Traditional designs can suffer from light trapping due to total internal reflection, limiting performance.

Discussion:

• A new layered detector module with optically separated crystal slabs and four-sided silicon photomultiplier (SiPM) readout was developed.
• This geometry enhances light collection efficiency by minimizing total internal reflection.
• Individual digitization of SiPM signals using a 64-channel TOFPET-2 module enables precise event measurement.

Key Insights:

• Achieved a FWHM energy resolution of 10.3% and timing resolution of 348 ps.
• Demonstrated a FWHM spatial resolution of 1.1 ± 0.1 mm using a trained neural network for position decoding.
• The layered design allows for increased detection efficiency by adding depth without sacrificing resolution.

Outlook:

• Future systems can improve sensitivity by adding more layers, as each layer's measurements are independent.
• The detector design facilitates partial recovery of position information for Compton scatter events.
• This advancement offers a promising path for next-generation PET scanners with improved performance and sensitivity.