Split-Bregman Algorithm with Attenuation Correction for L-Shell Polychromatic X-ray Fluorescence Computed Tomography
Split-Bregman Algorithm with Attenuation Correction for L-Shell Polychromatic X-ray Fluorescence Computed Tomography
复制标题
L 壳多色 X 射线荧光计算机断层扫描的具有衰减校正的 Split-Bregman 算法
DOI：
10.1166/jmihi.2020.2971
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发表时间：
2020-03-01
影响因子：
--
通讯作者：
Ding，Ning
中科院分区：
文献类型：
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作者：
Liu，Long;Ma，Bo;Ding，Ning
基于多色X射线的L壳层X射线荧光计算机断层扫描是一种很有前途的早期癌症诊断成像技术。但是，自吸收的存在和扫描时间长限制了其在临床上的应用。在这项工作中，重建方法的基础上分裂Bregman
提出了一种利用稀疏视图投影数据的算法。此外，该算法还考虑了衰减效应。在衰减校正中，考虑了包括X射线能量和铂浓度的因素。然后计算加权因子
在基于Split-Bregman重建方法的像素贡献函数中加入衰减校正过程中的最后，用一个直径为8 mm的圆柱体模，通过Monte Carlo模拟验证了该方法的可行性。体模
包含四个插入物，所有插入物的直径均为1.5 mm，并且分别填充有0.10%、0.20%、0.40%和0.80%的铂溶液。实验结果表明，与传统的图像处理方法相比，该方法在信噪比和最低检测灵敏度方面都有较大的提高。
传统的MLEM用45个投影重建的图像的对比度噪声比已经优于用60个投影重建的图像。当在我们的方法中使用60个投影并与MLEM中的60个投影进行比较时，
填充0.10%铂溶液的插入物的比率从6.49增加到36.90，表明其高效率和稳健性。
L-shell X-ray fluorescence computed tomography based on polychromatic X-rays is a promising imaging technique for early cancer diagnosis. However, the presence of self-absorption and the long scanning time limit its usage in clinic. In this work, a reconstruction method based on split-Bregman
algorithm which used sparseview projection data was proposed. Furthermore, the attenuation effect was also considered in the algorithm. In the attenuation correction, factors including the X-ray energy and the platinum concentration were taken into account. Then weighted factors calculated
in the procedure of attenuation correction were added into the contribution function of pixels in the split-Bregman based reconstruction method. In the end, the feasibility of this method was tested using a cylindrical phantom with 8 mm in diameter by the Monte Carlo simulation. The phantom
contained four inserts, all of which were 1.5 millimeter in diameter and filled with 0.10%, 0.20%, 0.40% and 0.80% platinum solutions, respectively. The results show that both the contrast-to-noise ratios and lowest detectable sensitivities are improved for the proposed method, comparing to
the conventional MLEM. The contrast-to-noise ratios of images reconstructed by our method with 45 projections are already better than that reconstructed by MLEM with 60 projections. When using 60 projections in our method and comparing to 60 projections in the MLEM with correction, the contrast-to-noise
ratio of the insert filled with 0.10% platinum solutions increased from 6.49 to 36.90, indicating its high efficiency and robustness.