Design optimization using GATE Monte Carlo simulations for a sub-0.5 mm resolution PET scanner with 3-layer DOI...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biophysics

Background:

• Spatial resolution is critical for identifying small brain structures in rodent positron emission tomography (PET) imaging.
• Previous PET scanner development achieved submillimeter resolution but exceeded 0.5 mm due to crystal pitch and layer design.
• Optimizing depth-of-interaction (DOI) detectors is key for enhancing PET scanner performance.

Purpose of the Study:

• To design and optimize a sub-0.5 mm resolution PET scanner using 3-layer DOI detectors.
• To evaluate different crystal layer designs for improved spatial resolution in rodent brain PET imaging.
• To leverage GATE Monte Carlo simulations for PET scanner design optimization.

Main Methods:

• Utilized GATE Monte Carlo simulations to optimize three 3-layer LYSO crystal array designs (A: 4+4+7 mm, B: 3+4+4 mm, C: 3+3+5 mm) with a 0.8 mm crystal pitch.
• Evaluated spatial resolution and imaging performance using point source and resolution phantoms with analytical and iterative algorithms.
• The proposed PET scanner features 2 rings with 16 DOI detectors each, providing 23.4 mm axial coverage.

Main Results:

• Design C demonstrated the most uniform spatial resolution up to a 15 mm radial offset.
• The 0.45 mm diameter rod structures were clearly resolved with design C when using an iterative algorithm.
• GATE simulation results showed good agreement with experimental data for radial resolution.

Conclusions:

• Optimized crystal layer design using GATE simulations significantly improved PET scanner resolution for mouse brain imaging.
• Achieved sub-0.5 mm spatial resolution, a critical advancement for detailed rodent brain PET studies.
• The optimized design enables clearer visualization of fine neuroanatomical details in rodent models.