Simulation of Single Grid-based Phase-contrast Digital Tomosynthesis (PC-DTS)

Digital tomosynthesis (DTS) is a geometric tomography technique by a limited-angle scan which has been popularly used in both medical and industrial X-ray imaging applications. However, conventional DTS remains limited by low contrast especially in imaging samples of low atomic number Z such as breast and cartilage tissues. In this work, we applied the recently proposed phase-contrast imaging (PCI) technique, the so-called single grid-based PCI, to DTS in attempt to overcome this limitation. PCI has superior soft-tissue imaging capability while DTS has improved image contrast. Combining the two techniques can therefore considerably improve the X-ray imaging performance. We developed a useful simulation platform for single grid-based phase-contrast DTS reconstruction and performed a systematic simulation using a three-dimensional (3D) numerical breast phantom. In the simulation, an X-ray grid having a lead strip density of 200 lines/inch was used and the DTS scan comprised 41 projections within an angle range of θ = ±40° at an X-ray energy of 25 keV. We successfully reconstructed DTS images of much improved contrast, compared to conventional DTS images, which demonstrates the viability of the proposed approach.