3D Tensor Reconstruction in X-Ray Dark-Field Tomography

X-ray dark-field imaging is a novel technique which provides complementary information on structural variation and density fluctuation. It allows to obtain object structures at micrometer scale and also contains information on the orientation of these structures. Since it can be acquired by a conventional X-ray imaging system, dark-field imaging has great potential for medical diagnosis. However, fully recovering 3D orientations in dark-field reconstruction still remains unexplored. In this paper, we propose an improved reconstruction method based on the zero-constrained dark-field reconstruction by Bayer et al. and a simplified principle axes transformation. A well-defined phantom containing representative 3D orientations is reconstructed in our experiment. On average, the structure orientations in the reconstructed volume differ from the ground truth by 9%. Within the boundaries of an object, the error drops to 6%. Application of this method in real diagnosis data can be expected in future.