Statistical iterative reconstruction for spectral phase contrast CT

Recently, we have investigated a new algorithm for combining grating-based differential phase contrast radiography and spectral radiography. The algorithm extracts two basis material images and a dark-field image by simultaneously using the spectral and the phase contrast information. Numerical simulations have shown that the combination of these two imaging methods benefits from the strengths of the individual methods while the weaknesses are mitigated. Quantitatively accurate basis material images are obtained and the additional phase shift information leads to highly reduced basis material image noise levels compared to conventional spectral material decomposition. In this work, we extend our approach to spectral phase contrast CT by developing a one-step statistical iterative reconstruction algorithm. In numerical simulations, we demonstrate the potential for further dose reductions as well as the possibility of eliminating the time-consuming phase stepping procedure which is incompatible with a continuously rotating gantry.