Image Reconstruction Analysis for Positron Emission Tomography With Heterostructured Scintillators

Area of Science:

• Medical Physics
• Detector Technology
• Materials Science

Background:

• Next-generation radiation detectors require improved performance.
• Structure engineering offers a novel approach to detector design.
• Time-of-flight positron emission tomography (TOF-PET) demands precise timing measurements.

Purpose of the Study:

• To investigate the performance of heterostructured scintillators for TOF-PET.
• To evaluate the impact of layered BGO and plastic scintillators on detector timing resolution and sensitivity.
• To develop simulation and reconstruction methods for complex detector designs.

Main Methods:

• Monte Carlo simulations were used to model a TOF-PET geometry with heterostructured scintillators.
• Detector time resolution was calculated based on deposited and shared energy in BGO and plastic layers.
• Events were categorized by coincidence time resolution (CTR) for reconstruction using Gaussian TOF kernels.
• Performance was assessed using a NEMA IQ phantom.

Main Results:

• Heterostructured scintillators improved CTR to 204 ± 49 ps (100-μm plastic) and 220 ± 41 ps (50-μm plastic), compared to 276 ps for bulk BGO.
• Sensitivity decreased with thinner plastic layers (32% for 100-μm, 52% for 50-μm).
• Heterostructures demonstrated better contrast recovery in early reconstruction iterations, while BGO achieved a superior contrast-to-noise ratio later.

Conclusions:

• Heterostructured scintillators offer a promising avenue for enhancing TOF-PET timing resolution.
• The trade-off between sensitivity and timing resolution needs careful consideration in detector design.
• The developed simulation and reconstruction techniques provide valuable tools for evaluating novel detector architectures.