OBJECTIVE: The expanding applications of Compton cameras in biomedical imaging demand precise simulation and reconstruction methods that incorporate realistic physics to optimize performance. To address this need, this study develops an integrated computational framework that combines a Geant4-based Monte Carlo simulation with a dedicated image reconstruction algorithm. APPROACH: Compared with previous approaches, this framework accurately models inter-pixel energy deposition crosstalk and depth of interaction in Monte Carlo simulation, while also accounting for multiple Compton scattering. In addition, it incorporates accurate models into the system matrix calculation within the list-mode maximum-likelihood expectation-maximization image reconstruction algorithm, including the Compton scattering cross section, the spatial resolution of both the scatterer and absorber detectors, and Doppler broadening effects. MAIN RESULTS: The framework was validated through simulations of a proposed medical Compton camera design employing a silicon scatterer and a cadmium zinc telluride absorber. Compared with conventional simplified models, the proposed accurate system matrix model yields a marked improvement in reconstruction quality across diverse source geometries, including ideal point, planar, and line sources, as well as hot sources with a uniform background. SIGNIFICANCE: This work establishes a high-fidelity framework that enables both physically realistic simulation and quantitatively accurate image reconstruction for Compton cameras. By rigorously validating the model's advantage across multiple source types, it provides an essential tool for advancing the design, optimization, and practical application of Compton imaging systems in biomedical imaging.
Zhijun Chi (Fri,) studied this question.