Enhanced Wide-Field Gamma Camera System with Hybrid Coded Aperture and Pinhole Collimation

Gamma cameras are vital for detecting and localizing radioactive sources. Coded aperture imaging is widely used in such systems, but traditional coded mask detectors have limited fields of view (FOV, 20°–60°), requiring repeated angular adjustments that increase acquisition time and reduce efficiency. Expanding FOV with multiple detectors is possible but adds cost and bulk. To address these limitations, this paper presents a novel large-FOV gamma imaging system that integrates coded aperture and pinhole collimators. The coded aperture module achieves a maximum FOV of 46.2°, while the integrated pinhole component extends the total FOV to 104°. System performance was evaluated through Monte Carlo simulations using the GATE platform and further validated experimentally. Results confirm effective imaging of low-, medium-, and high-energy radioactive sources, with angular resolutions of 2°, 4°, and 5° in the coded aperture, hybrid, and pinhole dominant regions, respectively. The proposed system combines portability, extended FOV, high spatial resolution, and energy adaptability, making it a promising tool for efficient and reliable radiation-source detection and localization in nuclear security and related applications.