The property of signal-to-noise and its variation over spatial frequency in differential phase contrast CT

The differential phase contrast CT implemented with x-ray Talbot interferometry is a new CT imaging technology with the potential of significantly improving contrast sensitivity of the conventional attenuation-based x-ray CT. The research and development along this scientific/technological path have seen increasing activities recently. Via theoretical derivation, system modeling, analysis and computer simulation, we have investigated the differential phase contrast CT´s properties in signal, noise and signal-to-noise transfer. In this paper, we investigate the differential phase contrast CT´s signal-to-noise transfer property as a function of spatial frequency that is dependent on dimension of the detector cell used for data acquisition and size of the lesion to be detected. The preliminary data show that, owing to the substantial difference in their noise power spectrum NPS(k), the differential phase contrast CT outperforms the conventional CT in the signal-to-noise at scenarios wherein small lesions are to be detected using a detector with fine cells. The data presented in this paper may provide an insightful understanding of differential phase contrast CT´s imaging capability and the guidelines on its performance optimization for extensive preclinical and eventually clinical applications.