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在传统的CT系统中,系统的硬件成本和计算量都是非常巨大的．提出了一种利用偏移放置的面阵探测器的锥束CT系统,在这种系统中X射线束仅仅覆盖被扫描物体的一半体积,投影数据在探测器方向上是截断的,探测器尺寸和投影数据量都减少为传统CT系统的一半．在这种新型扫描方式下,现有的CT重建算法都不能处理．因此,提出了一种BPF形式的直接反投影重建方法．该方法不需要对投影数据重排,直接反投影滤波重建出最终的图像．因此,该算法在数学上更简洁,计算速度更快．最后,数值模拟实验和真实CT系统实验结果均验证了该系统和重建算法能够获得高质量的CT图像．
In the traditional CT system, the system’s hardware costs and computational costs are enormous. A cone-beam CT system using an offset-placed area array detector is proposed. In this system, the X-ray beam covers only half of the volume of the object being scanned. The projection data is truncated in the direction of the detector. The detector size And projection data are reduced to half of the traditional CT system. In this new scan mode, none of the existing CT reconstruction algorithms can handle it. Therefore, a direct backprojection method based on BPF is proposed. This method does not need to rearrange the projection data, and the back-projection filter reconstructs the final image. Therefore, the algorithm is mathematically simple and computationally faster. Finally, both the numerical simulation and the real CT system experimental results verify that the system and the reconstruction algorithm can obtain high quality CT images.