Room: AAPM ePoster Library
The purpose of this work is to extend a previously developed Monte Carlo (MC) algorithm for grating interferometry (GI) systems and to show its capability to simulate GI setups using incoherent sources.
X-ray GI offers absorption, differential phase, and dark-field contrast, which makes it a promising candidate for clinical applications, e.g. grating interferometry breast CT (GI-BCT) or laboratory X-ray GI setups for pathology. Simulations for the estimation of patient and design relevant quantities are of great value in the design process of clinical GI devices. However, due to the occurrence of interference and scattering effects there is currently no simulation framework that can simulate clinical setups in acceptable simulation times.
A previously in-house developed MC extension library for EGSnrc that adds rules for photon transport based on quantum mechanics is further extended for the simulation of incoherent sources in GI. As a feasibility study and for validation different experimental setups, including a laboratory X-ray GI setup for pathology are simulated. The measured visibility was compared with the corresponding MC simulation results on a field of view of 5 cm, which is an order of magnitude larger than what has been done with current state of the art full MC simulation frameworks.
The results suggest that the extended MC algorithm can successfully simulate the impact of the source and phase gratings on the incoherent x-ray beam. The visibility of the interference fringes is similar to experimental results. Simulation were parallelized on 50 nodes with a simulation time of about 22 hours per node.
The extended GI MC algorithm is capable to simulate interference patterns occurring in GI setups using incoherent sources on cm-sized field of view, while reducing simulation times significantly.