Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model
Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model
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DOI：
10.1063/1.4950807
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发表时间：
2016-06-07
影响因子：
3.2
通讯作者：
Myers, G. M.
中科院分区：
文献类型：
--
作者：
Paziresh, M.;Kingston, A. M.;Myers, G. M.
双能计算机断层扫描以及 Alvarez 和 Macovski [Phys。医学。生物。 21, 733 (1976)] 透射强度 (AMTI) 模型在本研究中用于估计矿物学样品的密度 (rho) 和原子序数 (Z) 图。在这种方法中，衰减系数被表示为[Alvarez 和 Macovski, Phys.医学。生物。 21, 733 (1976)]以X射线与原子的两种最重要的相互作用的形式，即光电吸收（PE）和康普顿散射（CS）。这使得材料区分成为可能，因为 PE 和 CS 分别取决于材料的原子序数 (Z) 和密度 (rho) [Alvarez 和 Macovski, Phys.医学。生物。 21, 733 (1976)]。即使材料在单能谱上具有相似的衰减系数，双能成像也能够识别样本材料。我们使用完整的模型，而不是应用几种应用简化形式之一[Alvarez 和 Macovski，Phys。医学。生物。 21, 733 (1976); Siddiqui 等人，SPE 年度技术会议和展览（石油工程师学会，2004 年）； Derzhi，美国专利申请 13/ 527,660 (2012)； Heismann 等人，J. Appl。物理。 94、2073-2079（2003）； Park 和 Kim, J. 韩国物理学。苏克。 59、2709（2011）；阿布杜雷西提 (Abudurexiti) 等人，Radiol。物理。技术。 3、127-135（2010）；和 Kaewkhao 等人，J. Quant。光谱。辐射。转 109, 1260-1265 (2008)]。本文描述了使用 AMTI 模型对矿物样品的 rho 和 Z 图进行层析成像重建。完整的模型需要精确了解 X 射线能谱以及 PE 和 CS 常数以及原子序数和能量指数的校准，这些指数是根据模拟和校准测量的拟合估计的。本文使用的样本的估计 rho 和 Z 图像的平均相对误差分别为 2.62% 和 1.19%，最大相对误差分别为 2.64% 和 7.85%。此外，我们证明该方法在很大程度上解释了密度（rho）和原子序数（Z）重建中的束硬化效应。由 AIP 出版社出版。
Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (rho) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (rho) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U. S. patent application 13/ 527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073-2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127-135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260-1265 (2008)]. This paper describes the tomographic reconstruction of rho and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated rho and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (rho) and atomic number (Z) reconstructions to a significant extent. Published by AIP Publishing.