Abstract：
Objective.Accurate simulation of human tissues is imperative for advancements in diagnostic imaging, particularly in the fields of dosimetry and image quality evaluation. Developing Tissue Equivalent Materials (TEMs) with radiological characteristics akin to those of human tissues is essential for ensuring the reliability and relevance of imaging studies. This study presents the development of a mathematical model and a new toolkit (TEMPy) for obtaining the best composition of materials that mimic the radiological characteristics of human tissues. The model and the toolkit are described, along with an example showcasing its application to obtain desired TEMs.Approach.The methodology consisted of fitting volume fractions of the components of TEM in order to determine its linear attenuation coefficient as close as possible to the linear attenuation coefficient of the reference material. The fitting procedure adopted a modified Least Square Method including a weight function. This function reflects the contribution of the x-ray spectra in the suitable energy range of interest. TEMPy can also be used to estimate the effective atomic number and electron density of the resulting TEM.Main results.TEMPy was used to obtain the chemical composition of materials equivalent to water and soft tissue, in the energy range used in x-ray imaging (10 -150 keV) and for breast tissue using the energy range (5-40 keV). The maximum relative difference between the linear attenuation coefficients of the developed and reference materials was ±5% in the considered energy ranges.Significance.TEMPy facilitates the formulation of TEMs with radiological properties closely mimicking those of real tissues, aiding in the preparation of physical anthropomorphic or geometric phantoms for various applications. The toolkit is freely available to interested readers.
摘要：
目的：准确模拟人体组织对于诊断成像的进步至关重要，特别是在剂量学和图像质量评估领域。开发具有类似于人体组织的放射学特性的组织等效材料（TEM）对于确保成像研究的可靠性和相关性至关重要。这项研究提出了数学模型和新工具包（TEMPy）的开发，以获得模仿人体组织放射学特征的最佳材料成分。描述了模型和工具包，方法：该方法包括拟合TEM成分的体积分数，以确定其线性衰减系数尽可能接近参考材料的线性衰减系数。拟合过程采用了包含权函数的改进的最小二乘法。该函数反映了X射线光谱在感兴趣的合适能量范围内的贡献。TEMPy也可用于估计所得TEM的有效原子序数和电子密度。＆＃xD;主要结果：使用TEMPy获得了相当于水和软组织的材料的化学成分，在X射线成像中使用的能量范围（10-150keV）和乳腺组织使用的能量范围（5-40keV）。在所考虑的能量范围内，开发材料和参考材料的线性衰减系数之间的最大相对差异为±5％。＆＃xD;意义：TEMPy有助于组织等效材料的配方，其放射学特性与真实组织的放射学特性非常相似，帮助准备各种应用的物理拟人化或几何体模。该工具包免费提供给感兴趣的读者。
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