Harding G, Kosanetzky J, Neitzel U
Med Phys. 1987 Jul-Aug;14(4):515-25. doi: 10.1118/1.596063.
Coherent scattering of x-ray photons leads to the phenomenon of x-ray diffraction, which is widely used for determining atomic structure in materials science. A technique [x-ray diffraction computed tomography (CT)] is described, analogous to conventional CT, in which the x-ray diffraction properties of a stack of two-dimensional object sections may be imaged. The technique has been investigated using a first generation (single pencil beam) CT scanner to measure small angle coherent scatter, in addition to the customary transmitted radiation. Diffraction data from a standard CT performance phantom obtained with this new technique and with an x-ray diffractometer are compared. The agreement is satisfactory bearing in mind the poor momentum resolution of our apparatus. The dose and sensitivity of x-ray diffraction CT are compared with those of conventional transmission CT. Diffraction patterns of some biological tissues and plastics presented in a companion paper indicate the potential of x-ray diffraction CT for tissue discrimination and material characterization. Finally, possibilities for refinement of the technique by improving the momentum resolution are discussed.
X射线光子的相干散射导致了X射线衍射现象，该现象在材料科学中广泛用于确定原子结构。本文描述了一种类似于传统计算机断层扫描（CT）的技术——X射线衍射计算机断层扫描（CT），其中可以对二维物体截面堆栈的X射线衍射特性进行成像。除了常规的透射辐射外，还使用第一代（单束铅笔束）CT扫描仪研究了该技术，以测量小角度相干散射。将用这种新技术和X射线衍射仪从标准CT性能模型获得的衍射数据进行了比较。考虑到我们仪器的动量分辨率较差，二者的一致性令人满意。将X射线衍射CT的剂量和灵敏度与传统透射CT的剂量和灵敏度进行了比较。在一篇配套论文中给出的一些生物组织和塑料的衍射图样表明了X射线衍射CT在组织鉴别和材料表征方面的潜力。最后，讨论了通过提高动量分辨率来改进该技术的可能性。
