基于全局低分辨率CT扫描的合成层析成像技术
Global Low-Resolution CT Scan Regulated Tomo-synthesis
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摘要: 合成层析成像可由有限几个投影数据重建三维物体,与传统CT相比,该方法所需的射线剂量少得多。由于投影数据不完备,导致的重建图像伪影是合成层析成像的一个主要问题。本文提出一种对感兴趣区域进行合成层析成像方法,和其他方法相比可以得到更好的重建图像质量。该方法首先对目标进行低分辨率全局扫描,然后对感兴趣区域进行高分辨率局部扫描,最后,利用两次扫描的投影数据集合重建感兴趣区域的图像。数值仿真结果表明,用本方法重建感兴趣区域图像,要明显好于没有使用全局扫描信息的方法。Abstract: Tomosynthesis reconstructs a 3D object from a scan consisting of a limited number of projections. Hence, tomosynthesis requires much less radiation dosage as compared to computed tomography (CT). A major problem with tomosynthesis is image artifacts associated with incompleteness of data. In this paper, we propose a tomosynthesis approach to achieve higher image quality in a region of interest (ROI) than competing techniques. First, a low-resolution global CT scan is acquired. Then, a high-resolution local scan is performed with respect to the ROI. Finally, images of the ROI are reconstructed from these two datasets. Our numerical simulation results show that images of the ROI obtained by our approach are significantly better than the counterparts without using the global scan information.