Development of a prototype Compton camera consisting of high-resolution scintillator detectors

Area of Science:

• Nuclear instrumentation
• Gamma-ray imaging technology
• Medical physics and detector development

Background:

• Compton cameras are crucial for gamma-ray imaging applications.
• High-resolution detectors are needed for improved imaging performance.
• Advanced image reconstruction algorithms can enhance image quality.

Purpose of the Study:

• To develop and characterize a prototype Compton camera with high-resolution scintillator detectors.
• To evaluate the performance of simple back-projection and MLEM reconstruction algorithms.
• To assess the spatial and energy resolution of the developed Compton camera.

Main Methods:

• Utilized a Compton camera prototype with gadolinium aluminum gallium garnet (GAGG) and lutetium yttrium orthosilicate (LYSO) crystal arrays.
• Employed energy calibration using known gamma-ray sources.
• Implemented and compared simple back-projection and maximum-likelihood expectation maximization (MLEM) image reconstruction methods.

Main Results:

• The scatterer detector (GAGG) achieved an energy resolution of 10.4% at 511 keV.
• The absorber detector (LYSO) provided an interaction depth resolution of ~2 mm and energy resolution of 19.4% at 511 keV.
• MLEM reconstruction achieved a spatial resolution of ~1 mm, significantly improving image contrast and reducing artifacts compared to back-projection.

Conclusions:

• The prototype Compton camera demonstrates promising performance for gamma-ray imaging.
• MLEM iterative reconstruction significantly enhances image quality over simple back-projection.
• The developed system shows potential for various applications requiring high-resolution gamma-ray imaging.