A layered single-side readout depth of interaction time-of-flight-PET detector

Area of Science:

• Medical Imaging Physics
• Detector Technology
• Positron Emission Tomography (PET)

Background:

• Current PET detectors face trade-offs between depth of interaction (DOI) capability, timing resolution, and readout complexity.
• Existing DOI detectors often compromise timing performance, while high-timing detectors lack DOI information.
• Single-side readout is desirable for simplifying detector design and potentially improving performance.

Purpose of the Study:

• To evaluate a novel scintillator-based PET detector concept combining staggered layers for DOI and one-to-one readout for timing.
• To assess the impact of crystal polishing and readout schemes on detector performance through light transport simulations.
• To determine the feasibility of achieving both DOI capability and superior timing resolution in a single PET detector design.

Main Methods:

• Light transport simulations were performed on a 4-layer staggered scintillator array design.
• Two readout schemes were investigated: one-to-one coupling and conventional light sharing.
• The effect of polished versus unpolished crystal pixels on performance metrics was analyzed.

Main Results:

• Unpolished crystal pixels demonstrated superior performance across all metrics compared to polished pixels.
• One-to-one readout of the first layer enabled accurate DOI extraction using a simple signal threshold.
• The proposed layered detector achieved timing resolutions of 91-164 ps per layer, outperforming a conventional non-DOI detector (148 ps).

Conclusions:

• The proposed detector design effectively combines DOI determination with excellent timing resolution.
• Unpolished crystals and one-to-one readout of the first layer are key to achieving optimal performance.
• This concept presents a promising advancement for developing next-generation DOI-Time-of-Flight PET detectors.