基于等值线拟合的X射线双能CT快速投影分解算法

针对双能计算机断层成像（DECT）图像重建算法中的非线性投影分解问题，提出一种基于等值线拟合的快速投影分解算法。建立高、低能投影线性近似的等值线拟合模型；基于泰勒级数展开，采用粗粒度正向计算、细粒度反向求解方法，获得高精度的解析解，生成等值线方程；将高、低能投影非线性联合求解问题转化为求解高、低能等值线的交点问题，从而实现双能投影的快速分解。实验结果表明，该方法避免了非线性迭代求解和投影查表匹配，在减小投影分解噪声波动的同时，显著提高了投影分解速度，与投影匹配方法相比分解速度提高约两个数量级。

Abstract

Aiming at the nonlinear projection decomposition problem in the image reconstruction by dual-energy computed tomography (DECT), a fast projection decomposition algorithm based on isotransmission line fitting is proposed. A linearly approximated isotransmission line fitting model is established for high and low energy projections. Based on the Taylor series expansion, the coarse-grain forward calculation and fine-grain reverse calculation are used to get the analytical solution with high accuracy, and the isotransmission line equations are generated. The nonlinear solution problem is transformed into the problem to solve intersections of high and low energy projection isotransmission lines, and thus the fast decomposition of dual energy projections is realized. The experimental results show that the proposed method avoids the nonlinear iteration and the projection matching, reduces noise fluctuation in projection decomposition, and improves the projection decomposition rate significantly. Compared to the projection matching method, the proposed method improves the decomposition rate by about two orders of magnitude.

参考文献

[1] Johnson T R. Dual-energy CT: General principles[J]. American Journal of Roentgenology, 2012, 199(5): S3-S8.

[2] 赵云松, 张慧滔, 赵星, 等. 双能谱CT的迭代重建模型及重建方法[J]. 电子学报, 2014, 42(4): 666-671.

Zhao Yunsong, Zhang Huitao, Zhao Xing, et al. Iterative reconstruction model and reconstruction method for dual energy computed tomography[J]. Acta Electronica Sinica, 2014, 42(4): 666-671.

[3] 李保磊, 张耀军. 基于投影匹配的X射线双能计算机层析成像投影分解算法[J]. 光学学报, 2011, 31(3): 0311002.

Li Baolei, Zhang Yaojun. Projection decomposition algorithm of X-ray dual-energy computed tomography based on projection matching[J]. Acta Optica Sinica, 2011, 31(3): 0311002.

[4] Fessler J A, Elbakri I A, Sukovic P, et al. Maximum-likelihood dual-energy tomographic image reconstruction[C]. SPIE, 2002, 4684: 38-49.

[5] Sukovic P, Clinthorne N H. Penalized weighted least-squares image reconstruction for dual energy X-ray transmission tomography[J]. IEEE Transactions on Medical Imaging, 2000, 19(11): 1075-1081.

[6] Dong X, Niu T Y, Zhu L. Combined iterative reconstruction and image-domain decomposition for dual energy CT using total-variation regularization[J]. Medical Physics, 2014, 41(5): 051909.

[7] Niu T Y, Dong X, Petrongolo M, et al. Iterative image-domain decomposition for dual-energy CT[J]. Medical Physics, 2014, 41(4): 041901.

[8] Alvarez R E, Macovski A. Energy selective reconstruction in X-ray computed tomography[J]. Physics in Medicine and Biology, 1976, 21(5): 733-744.

[9] Kalender W A, Perman W H, Vetter J R, et al. Evaluation of a prototype dual-energy computed tomographic apparatus. I. Phantom studies[J]. Medical Physics, 1986, 13(3): 334-339.

[10] Ying Z, Naidu R, Crawford C R. Dual energy computed tomography for explosive detection[J]. Journal of X-Ray Science and Technology, 2006, 14(4): 235-256.

[11] Tang Z W, Hu G S. Dual energy CT imaging in cone-beam micro-CT for improved attenuation coefficient measurement[J]. Tsinghua Science and Technology, 2011, 16(4): 352-357.

[12] Liu Y Y, Cheng J P, Zhang L, et al. A low-cost dual energy CT system with sparse data[J]. Tsinghua Science and Technology, 2014, 19(2): 184-194.

[13] Sidky E Y, Yu L F, Pan X C, et al. A robust method of X-ray source spectrum estimation from transmission measurements: Demonstrated on computer simulated, scatter-free transmission data[J]. Journal of Applied Physics, 2005, 97: 124701.

[14] 张慧滔, 张朋. 基于计算层析成像扫描数据的X射线能谱估计方法[J]. 光学学报, 2013, 33(11): 1134001.

Zhang Huitao, Zhang Peng. X-ray spectrum estimation method from scanning data of computed tomography phantoms[J]. Acta Optica Sinica, 2013, 33(11): 1134001.

李磊, 王林元, 蔡爱龙, 韩玉, 闫镔, 包尚联. 基于等值线拟合的X射线双能CT快速投影分解算法[J]. 光学学报, 2016, 36(8): 0834001. Li Lei, Wang Linyuan, Cai Ailong, Han Yu, Yan Bin, Bao Shanglian. Projection Decomposition Algorithm for X-Ray Dual-Energy Computed Tomography Based on Isotransmission Line Fitting[J]. Acta Optica Sinica, 2016, 36(8): 0834001.

基于等值线拟合的X射线双能CT快速投影分解算法

关于本站 Cookie 的使用提示

全站搜索

基于等值线拟合的X射线双能CT快速投影分解算法

相关论文

相关资讯

关于本站 Cookie 的使用提示

全站搜索