X-ray phase and dark-field computed tomography without optical elements

X-ray diffusive dark -field imaging, which allows spatially unresolved microstructure to be mapped across a sample, is an increasingly popular tool in an array of settings. Here, we present a new algorithm for phase and dark -field computed tomography based on the x-ray Fokker -Planck equation. Needing only a coherent x-ray source, sample, and detector, our propagation -based algorithm can map the sample density and dark-field/diffusion properties of the sample in 3D. Importantly, incorporating dark -field information in the density reconstruction process enables a higher spatial resolution reconstruction than possible with previous propagationbased approaches. Two sample exposures at each projection angle are sufficient for the successful reconstruction of both the sample density and dark -field Fokker -Planck diffusion coefficients. We anticipate that the proposed algorithm may be of benefit in biomedical imaging and industrial settings. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement