Quantitative investigation of phase retrieval from X-ray phase-contrast tomographic images

X-ray phase-contrast tomographic microimaging is a powerful tool to reveal the internal structure of opaque soft-matter objects that are not easily seen in standard absorption contrast. In such low Z materials, the phase shift of X-rays transmitted can be important as compared to the absorption. An easy experimental set up that exploits refractive contrast fori-nation can deliver images that are providing detailed structural information. Applications are abundant in fields including polymer science and engineering, biology, biomedical engineering, life sciences, zoology, water treatment and filtration, membrane science, and micro/nanomanufacturing. However, available software for absorptive contrast tomography cannot be simply used for structure retrieval as the contrast fori-ning effect is different. In response, CSIRO has developed a reconstruction code for phase-contrast imaging. Here, we present a quantitative comparison of a micro phantom manufactured at SSLS with the object reconstructed by the code using X-ray images taken at SSLS. The phantom is a 500 gm thick 800 mu m diameter cylindrical disk of SU-8 resist having various eccentric cylindrical bores with diameters ranging from 350 gm to 40 mu m. Comparison of these parameters that are well known from design and post-manufacturing measurements with reconstructed ones gives encouraging results.