Enhanced Timing Performance of Dual-Ended PET Detectors for Brain Imaging Using Dual-Finishing Crystal Approach

Area of Science:

• Medical Physics
• Nuclear Instrumentation
• Radiological Imaging

Background:

• Positron Emission Tomography (PET) systems require high timing resolution for improved image quality.
• Optimizing detector performance, specifically time-of-flight (TOF) and depth-of-interaction (DOI) resolution, is critical for advanced PET applications like brain imaging.
• Current scintillation crystal finishing techniques present trade-offs between timing and other performance metrics.

Purpose of the Study:

• To introduce and evaluate a novel dual-finishing crystal method for enhancing the timing performance of dual-ended PET detectors.
• To investigate the impact of integrating polished and unpolished crystal surfaces on TOF and DOI resolutions.
• To assess the overall performance of dual-finishing detectors compared to conventional crystal finishing methods in PET.

Main Methods:

• Development of a dual-finishing scintillation crystal block by combining polished and unpolished surfaces.
• Construction of an 8x8 array of lutetium-based scintillator (LGSO) crystals with a 2 mm pitch.
• Comparative performance analysis of the dual-finishing detector against fully polished and fully unpolished crystal blocks, measuring timing, energy, and DOI resolutions.

Main Results:

• The dual-finishing method demonstrated a significant improvement in timing resolution, achieving 192.0 ± 12.8 picoseconds (ps).
• This represents a notable enhancement compared to fully polished (206.3 ± 9.4 ps) and unpolished (234.8 ± 17.9 ps) crystal blocks.
• Energy and DOI resolutions were maintained at good levels, indicating a balanced performance improvement.

Conclusions:

• The dual-finishing crystal technique is an effective strategy for enhancing timing resolution in PET detectors.
• This method offers a promising approach for developing next-generation PET systems with superior TOF capabilities, particularly for brain imaging.
• The improved timing resolution is vital for increasing sensitivity and spatial resolution in high-performance PET applications.