MCGPU: GPU-accelerated Monte Carlo X-ray Imaging Simulator

MCGPU [1,2] is an open-source x-ray imaging simulation software to generate virtual x-ray projections of computational anatomical models described by voxels. The simulator can replicate radiographic or computed tomography devices, and it is particularly fitted to replicate mammography systems, as demonstrated in its use in a large virtual imaging trial project [7]. Other variants of the software intended to simulate other imaging modalities such as Positron Emission Tomography (PET) [3] have also been developed. The physics-based Monte Carlo algorithm implemented in MCGPU is based on the general-purpose algorithm and atomic interactions models from PENELOPE. A key innovation of MCGPU is the use of Graphics Processing Units (GPU) to maximize the simulation speed, which enabled the simulation of tomographic modalities with hundreds of views, and the simulation of thousands of patient images in virtual trials [7]. The foundation of the implemented Monte Carlo algorithm is the random sampling of billions of independent x-ray tracks from a computational x-ray source model, their transport through the patient anatomy represented by voxels (including modeling of absorption and scattering events), and their detection in a computational model of an x-ray detector. The latest version of the MCGPU source code, input files for example simulations, and compilation instructions are available at the GitHub repository