High-performance dual-ended SiPM readout for TOF-PET with BGO and LYSO:Ce

Area of Science:

• Nuclear Instruments and Methods
• Medical Physics
• Instrumentation

Background:

• Timing performance is critical for time-of-flight positron emission tomography (PET).
• Light transport in crystals limits timing resolution, especially for high aspect-ratio crystals with single-ended readout.
• Degraded time information from optical photons traveling away from the photodetector and increased optical path length variance affect Cherenkov photons.

Purpose of the Study:

• To investigate the timing properties of LYSO:Ce and BGO crystals using a dual-ended SiPM readout configuration.
• To mitigate timing limitations caused by light transport in PET detectors.
• To explore the potential of dual-ended readout for combining ultra-fast timing with high gamma-ray detection efficiency.

Main Methods:

• Studied timing properties of cerium-doped lutetium-yttrium-oxyorthosilicate (LYSO:Ce) and bismuth germanate (BGO) crystals.
• Employed a symmetric dual-ended SiPM readout configuration.
• Utilized time-based depth-of-interaction correction and adaptive timestamp weighting to optimize timing.

Main Results:

• Achieved a coincidence time resolution (CTR) of 234 ± 4 ps FWHM for BGO crystals.
• Measured a CTR of 98 ± 2 ps for LYSO:Ce crystals, aligning with theoretical predictions.
• Demonstrated significant timing improvements for both Cherenkov photons in BGO and scintillation in LYSO:Ce.

Conclusions:

• Dual-ended SiPM readout substantially enhances timing performance in PET imaging.
• This technique offers a pathway to improved diagnostic accuracy by optimizing gamma-ray detection.
• The study validates the benefits of dual-ended readout for advanced PET detector designs.