X-ray Phase-contrast Simulations of Fibrous Phantoms using GATE

The overall importance of x-ray phase-contrast imaging techniques has grown substantially due to their ability to generate contrast in a range of situations where traditional absorption imaging falls short. Monte Carlo simulations are a valuable tool for benchmarking and testing new acquisition and reconstruction techniques, as well as optimisation of the system and components design. GATE, an open source application layer on top of the Geant4 simulation software, is a versatile Monte Carlo tool for various types of medical imaging simulations. Currently, however, tools intended for phase-contrast imaging are not yet available within GATE. In this work, we introduce grating-based x-ray phase-contrast simulations in GATE, with specific focus on phantoms with fibrous microstructures. The simulations are based on a combination of Monte Carlo simulations in GATE for modelling the x-ray interactions in the sample, and subsequent numerical wave propagation in the interferometer, modelled in MATLAB. We show simulated computed tomography results for grating interferometry.