Deviation of geometric parameter from its design value of linear array detector computed tomography ( CT) would result in image quality degradation. A structural deviation calibration and parameters obtaining algorithm based on projections is developed to improve the accuracy. The algorithm uses a simple calibration phantom and serial projections to adjust the system structure and analytically estimate the geometric CT parameters. Calculations demonstrate that the algorithm is very accurate with the error less than 0.5%, and experiments show high quality images.%为了解决线阵探测器CT系统存在结构偏差、参数不准确偏离设计值,影响重建质量的难题,提出了一种基于简单模型和少量DR投影的线阵探测器CT系统调校和参数获取方法.该方法采用一个正交金属细丝模型,通过设计一系列的投影,依据投影图像对系统结构进行调整并进行简单计算,即可完成偏差校正及参数获取.计算和实验表明,通过该方法得到的系统参数误差小于5％,满足使用要求,重建图像质量很高.
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