Edge enhanced X-ray phase tomography

Sample parameters that are involved in the projection data of Computed Tomography reconstruction have to fulfill the rotational invariance, i.e., the contribution to the projection data of a single sample point has to be invariant respect to the illumination direction. In the reconstruction procedure of the Diffraction Enhanced Peak Imaging (DEPI) technique, while the Inverse Radon Transform is fulfilled, the rotation invariance is no longer satisfied because of the contribution induced by refraction at the edge of the sample. However, DEPI experimental results address the question how the edge contrast is generated. In this contribution, theoretical simulations of DEPI have been performed to investigate the edge contrast due to the refraction process and to test the rotation invariance condition of the DEPI-CT reconstruction algorithm