Stevens G M, Saunders R, Pelc N J
Department of Radiology and Department of Applied Physics, Stanford University, California 94305, USA.
Med Phys. 2001 Jul;28(7):1472-81. doi: 10.1118/1.1382609.
A test-bed system has been developed for imaging phantoms with tomosynthesis and volumetric computed tomography. This system incorporates an amorphous silicon flat panel detector on a movable gantry and a computer-controlled rotational positioning stage. In this paper, an analysis of the sensitivity of reconstructed images to geometrical misalignment is presented. Application of this method to circular digital tomosynthesis is examined, with spatial resolution in the focal plane as the criterion for evaluating the effect of misalignment. A software-based method is presented for correcting data for imperfect system alignment prior to image reconstruction. Experimental results yield reconstructed images with spatial resolution approaching the theoretical limit based on detector pixel size and accounting for data interpolation.
已开发出一种试验台系统，用于通过断层合成和容积计算机断层扫描对体模进行成像。该系统在可移动机架上集成了非晶硅平板探测器和计算机控制的旋转定位台。本文对重建图像对几何失准的敏感性进行了分析。研究了该方法在圆形数字断层合成中的应用，以焦平面上的空间分辨率作为评估失准影响的标准。提出了一种基于软件的方法，用于在图像重建之前对不完美的系统对准数据进行校正。实验结果得到的重建图像的空间分辨率接近基于探测器像素大小并考虑数据插值的理论极限。
