Image quality dependence on thickness of sliced rat kidney taken by a simplest DEI construction

The excised rat kidney slices were investigated using a simplified diffraction-enhanced imaging (DEI) configuration with only two crystals: the first one working as monochromator and the second one working as analyzer in the Bragg geometry that was developed at Beijing Synchrotron Radiation Facility (BSRF). Many fine anatomic structures of the sliced rat kidneys with thickness of 2 mm and 120 μm can be distinguished clearly in the DEI images that were obtained at the shoulder of a rocking curve. The authors would like to emphasize that the thick and thin slices DEI provides very different images; in the thick sample only the structure with the big density gradient or that near the surface where X-ray comes out can be distinguished, while in the thin ones some fine structures, which can not be distinguished at the thick sample under the same condition, can be seen very clearly. The reason related with the counteraction of δ(x,y,z) gradient in the integral process along the X-ray path inside the thick sample is discussed.