Implementation Of A Double-Grating Interferometer For Phase-Contrast Computed Tomography In A Conventional System Nanotorn (R) M

Visualizing the internal architecture of large soft tissue specimens within the laboratory environment in a label-free manner is challenging, as the conventional absorption contrast tomography yields a poor contrast. In this communication, we present the integration of an X-ray double-grating interferometer (XDGI) into an advanced, commercially available micro computed tomography system nanotom (R) tn with a transmission X-ray source and a micrometer-sized focal spot. The performance of the interferometer is demonstrated by comparing the registered three-dimensional images of a human knee joint sample in phase- and conventional absorption-contrast modes. XDGI provides enough contrast (1.094 +/- 0.152) to identify the cartilage layer, which is not recognized in the conventional mode (0.287 +/- 0.003). Consequently, the two modes are complementary, as the present XDGI set-up only reaches a spatial resolution of (73 +/- 6)mu m, whereas the true micrometer resolution in the absorption-contrast mode has been proven. By providing complimentary information, XDGI is especially a supportive quantitative method for imaging soft tissues and visualizing weak X-ray absorbing species in the direct neighborhood of stronger absorbing components at the microscopic level. (C) 2018 Author(s).