CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, 32816, USA.
Department of Mathematics, University of Central Florida, Orlando, 32816, USA.
Sci Rep. 2018 Jan 11;8(1):522. doi: 10.1038/s41598-017-19089-w.
X-ray diffraction tomography (XDT) records the spatially-resolved X-ray diffraction profile of an extended object. Compared to conventional transmission-based tomography, XDT displays high intrinsic contrast among materials of similar electron density and improves the accuracy in material identification thanks to the molecular structural information carried by diffracted photons. However, due to the weak diffraction signal, a tomographic scan covering the entire object typically requires a synchrotron facility to make the acquisition time more manageable. Imaging applications in medical and industrial settings usually do not require the examination of the entire object. Therefore, a diffraction tomography modality covering only the region of interest (ROI) and subsequent image reconstruction techniques with truncated projections are highly desirable. Here we propose a table-top diffraction tomography system that can resolve the spatially-variant diffraction form factor from internal regions within extended samples. We demonstrate that the interior reconstruction maintains the material contrast while reducing the imaging time by 6 folds. The presented method could accelerate the acquisition of XDT and be applied in portable imaging applications with a reduced radiation dose.
X 射线衍射层析成像（XDT）记录了扩展物体的空间分辨 X 射线衍射轮廓。与传统的基于透射的层析成像相比，XDT 在具有相似电子密度的材料之间显示出高固有对比度，并通过携带衍射光子的分子结构信息提高了材料识别的准确性。然而，由于衍射信号较弱，要使整个物体的层析扫描更具可操作性，通常需要同步加速器设施。医学和工业应用中的成像应用通常不需要检查整个物体。因此，非常需要一种仅覆盖感兴趣区域（ROI）的衍射层析成像方式，以及具有截断投影的后续图像重建技术。在这里，我们提出了一种桌面衍射层析成像系统，它可以解析扩展样品内部的空间变化衍射形式因子。我们证明，内部重建在保持材料对比度的同时，将成像时间缩短了 6 倍。所提出的方法可以加速 XDT 的采集，并应用于具有降低辐射剂量的便携式成像应用。
