Phase contrast in laboratory-based X-ray CT

When scanning weakly attenuating samples using an X-ray tube with a very small focal spot size, the acquired projections not only contain absorption contrast, but also phase contrast due to refraction of the X-rays. Although the resulting edge enhancement can be beneficial in radiography, the tomographic reconstruction of such mixed projections using a conventional algorithm yields cross-sections that are severely distorted by so-called phase contrast artefacts.