Advanced Remanufacturing and Technology Centre, Intelligent Product Verification Group, Singapore.
Singapore Institute of Manufacturing Technology, Precision Measurements Group, Singapore.
J Xray Sci Technol. 2020;28(2):219-230. doi: 10.3233/XST-190595.
X-ray sources with acceleration voltages of 450 kV typically have large focal spot sizes that lead to low spatial resolution computed tomography (CT) data. In this work a method to improve the spatial resolution of 450 kV CT is developed. The proposed method relies on using vertical subpixel detector shifting and deconvolution to generate a projection-set that has double the number of pixels in the direction parallel to the axis of rotation. The results show that the proposed method is able to increase the 10% modulation transfer function of the considered system from 3 lp/mm to 4 lp/mm. In addition, a scan of a metal additively manufactured component with periodic features of approximately 200 μm is used to demonstrate the method; small features that were not fully resolved in a conventional scan become resolvable when the proposed method is used.
X 射线源的加速电压为 450kV 时，通常具有较大的焦点尺寸，导致空间分辨率较低的计算机断层扫描（CT）数据。在这项工作中，开发了一种提高 450kV CT 空间分辨率的方法。该方法依赖于使用垂直亚像素探测器移动和反卷积来生成一个投影集，该投影集在与旋转轴平行的方向上的像素数量是原来的两倍。结果表明，所提出的方法能够将所考虑系统的 10%调制传递函数从 3lp/mm 提高到 4lp/mm。此外，还使用具有约 200μm 周期性特征的金属增材制造组件的扫描来演示该方法；当使用所提出的方法时，在常规扫描中未完全分辨的小特征变得可分辨。
