Simulation of X-ray Phase-contrast Computed Tomography of a Medical Phantom Comprising Particle and Wave Contributions

摘要

We present a simulation framework for X-ray phase-contrast computed tomography imaging (PCTI) inheriting the wave- as well as the particle-behavior of photons. The developed tool includes the modeling of a partially coherent X-ray source, the propagation of the X-ray photons through samples, and the interfering properties of photons. Hence, the simulation is capable of physically modeling a grating-based interferometric imaging system reported in e.g. Pfeiffer et al. The information gained comprises the three potentially measurable images, which are the absorption image, the phase image, and the darkfield image. Results on such a setup concerning spatial and temporal coherence will be shown. Samples consisting of elements and structures similar to biological tissue were implemented to demonstrate the applicability on medical imaging. For the purpose of CT-imaging a head-like phantom was simulated and the results show the advantage of PCTI for thick biological objects. The simulation was developed with a modular concept so that the influences of each imaging component can be considered seperately. Thus the grating based interferometry for X-ray phase-contrast imaging can be optimized towards dedicated medical applications using this simulation-tool.