Fraunhofer Development Center for X-ray Technology (Fraunhofer EZRT), Fürth 90762, Germany.
Med Phys. 2013 Aug;40(8):081922. doi: 10.1118/1.4813896.
In this paper, the authors propose a new method for computed tomography (CT) data acquisition, which requires almost no rotational movement of the system or the object, respectively.
The new method is taking advantage of the fact that variations of magnification, e.g., by change of distance between x-ray focal spot and detector, will provide both different beam angles and ray paths with respect to the object. In other words, the rotational movement is substituted by one or more linear movements of the x-ray source toward the object under inspection. The authors present a theoretical evaluation of this new translational acquisition scheme.
The mathematical implementation of image reconstruction are discussed and results from simulations with varying measurement parameters are shown. The image quality is evaluated by quantitative numbers.
Translational x-ray CT generally allows for reconstructing images with adequate quality. However, the image quality suffers from the lack of data compared to conventional 180° acquisition methods and, due to the irregular sampling of Radon space, spatial resolution as well as artifacts depend on the position within the image.
本文提出了一种新的计算机断层扫描（CT）数据采集方法，该方法分别要求系统和物体几乎不进行旋转运动。
新方法利用了放大率的变化，例如通过改变 X 射线焦点和探测器之间的距离，将提供相对于物体的不同光束角度和射线路径。换句话说，旋转运动被 X 射线源相对于待检查物体的一个或多个线性运动所取代。作者对这种新的平移采集方案进行了理论评估。
讨论了图像重建的数学实现，并展示了具有不同测量参数的模拟结果。通过定量数字评估图像质量。
与传统的 180°采集方法相比，平移 X 射线 CT 通常可以重建出具有足够质量的图像。然而，由于数据缺乏，与传统的 180°采集方法相比，图像质量较差，并且由于拉德空间的不规则采样，空间分辨率以及伪影取决于图像内的位置。
