Computer-Based Platform for Phase Contrast Tomosynthesis: Targeting an Application for Breast Imaging

This paper presents a computer-based system dedicated to x-ray phase contrast (PhC) imaging research. It consists of two main modules: (a) a module for generation of x-ray PhC images from computational phantoms and (b) a module for image reconstruction. The module for generation of x-ray images consists of submodules dedicated to modelling of computational phantoms, modelling the image acquisition geometry and formation of x-ray images. The module for image reconstruction is a software tool, based on an in-house built reconstruction techniques class library, which is a dedicated object-oriented library for x-ray based applications. The computer-based system is tested for its feasibility to generate correctly PhC projection images and to reconstruct from them, considering a breast tomosynthesis setup. Two computational phantoms were designed for the simulations: a 4 cm thick polymethyl methacrylate phantom with air channels and a 2 cm thick rectangular polystyrene flask filled with epoxy resin mixture. Images in a tomosynthesis mode were generated and tomograms were calculated by using the reconstruction module. Simulations were validated with the help of experimental study conducted at beamline ID17, ESRF. Results show good visual agreement between simulated and experimentally obtained images. The platform, after its complete evaluation, may be useful in studying new x-ray imaging techniques based on phase contrast. Applications are foreseen also in education and training.