Gamma-ray imaging is a research area focused on detecting and imaging gamma rays, which are highly energetic forms of electromagnetic radiation. These gamma rays are typically emitted from sources such as nuclear reactions, radioactive decay, and astrophysical phenomena. Gamma-ray imaging techniques use specialized detectors and imaging algorithms to locate and visualize the distribution of gamma-ray sources in various applications, including homeland security, medical imaging, environmental monitoring, and astrophysics. The goal of gamma-ray imaging is to provide high-resolution, sensitive, and quantitative images of gamma-ray sources for scientific research and practical applications.