van Stevendaal U, Schlomka J P, Harding A, Grass M
Philips Research Laboratories, Sector Technical Systems, Röntgenstrasse 24-26, D-22335 Hamburg, Germany.
Med Phys. 2003 Sep;30(9):2465-74. doi: 10.1118/1.1598731.
Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter form factor of the investigated object. Reconstruction from coherently scattered x-rays is commonly done using algebraic reconstruction techniques (ART). In this paper, we propose an alternative approach based on filtered back-projection. For the first time, a three-dimensional (3D) filtered back-projection technique using curved 3D back-projection lines is applied to two-dimensional coherent scatter projection data. The proposed algorithm is tested with simulated projection data as well as with projection data acquired with a demonstrator setup similar to a multi-line CT scanner geometry. While yielding comparable image quality as ART reconstruction, the modified 3D filtered back-projection algorithm is about two orders of magnitude faster. In contrast to iterative reconstruction schemes, it has the advantage that subfield-of-view reconstruction becomes feasible. This allows a selective reconstruction of the coherent-scatter form factor for a region of interest. The proposed modified 3D filtered back-projection algorithm is a powerful reconstruction technique to be implemented in a CSCT scanning system. This method gives coherent scatter CT the potential of becoming a competitive modality for medical imaging or nondestructive testing.
相干散射计算机断层扫描（CSCT）是一种重建式X射线成像技术，可生成被研究对象的空间分辨相干散射形状因子。从相干散射X射线进行重建通常使用代数重建技术（ART）。在本文中，我们提出了一种基于滤波反投影的替代方法。首次将使用弯曲三维反投影线的三维（3D）滤波反投影技术应用于二维相干散射投影数据。所提出的算法用模拟投影数据以及用类似于多线CT扫描仪几何结构的演示装置采集的投影数据进行了测试。虽然产生的图像质量与ART重建相当，但改进的3D滤波反投影算法快约两个数量级。与迭代重建方案相比，它具有子视野重建变得可行的优点。这允许对感兴趣区域的相干散射形状因子进行选择性重建。所提出的改进3D滤波反投影算法是一种可在CSCT扫描系统中实现的强大重建技术。该方法使相干散射CT有潜力成为医学成像或无损检测的一种有竞争力的模态。
