Interlaced phase stepping in phase-contrast x-ray tomography

We report on an interlaced acquisition scheme in grating-based x-ray phase-contrast tomography in which different viewing angles are used to retrieve a single differential phase projection. This interlaced acquisition scheme is particularly beneficial for region-of-interest tomography since it substantially reduces the artifacts caused by the external region and can eliminate the need for stop-and-go motion of the tomography rotation axis. In this letter, the higher accuracy of the region-of-interest phase reconstructions obtained with the interlaced approach is demonstrated by numerical simulation and experimental results.