Tissue-equivalent materials for construction of tomographic dosimetry phantoms in pediatric radiology
Tissue-equivalent materials for construction of tomographic dosimetry phantoms in pediatric radiology
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DOI：
10.1118/1.1592641
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发表时间：
2003-08-01
期刊：
影响因子：
3.8
通讯作者：
Bolch, WE
中科院分区：
文献类型：
--
作者：
Jones, AK;Hintenlang, DE;Bolch, WE
组织等效材料有多种用途，包括诊断和治疗物理中的常规质量保证和质量控制。它们经常用于研究，以测量给接受各种治疗程序的患者的剂量。然而，在诊断放射学中遇到的低光子能量的研究中，很少有组织等效材料被开发出来。在本文中，我们提出了一系列组织等效（TE）材料，旨在以诊断光子能量放射学模拟人体组织。这些组织等效材料包括STES- nb（新生儿软组织替代品）、bes - nb（新生儿骨组织替代品）、LTES（新生儿以及儿童/成人肺组织替代品）、STES（儿童/成人软组织替代品）和BTES（儿童/成人骨组织替代品）。在所有情况下，目标参考元素组成都取自ORNL程式化计算模型系列中指定的元素组成。对于每种材料，质量密度、质量衰减系数（10- 150kev）和质量能量吸收系数（10- 150kev）的参考值在材料选择和制造约束允许的范围内尽可能紧密匹配。在10-150 keV的诊断能量范围内，新生TE材料的mu/rho和mu(en)/rho值与其ORNL参考值的最大偏差分别为0 -3%和+2% -3%。对于儿童/成人TE材料，mu/rho和mu(en)/rho的最大偏差分别为+1.5% -3%和+3% -3%。使用新生儿CR x线片典型的66 kVp光谱对窄束几何形状下的x射线通量衰减进行简单计算表明，本文提出的组织等效材料对新生儿参考软组织、骨骼和肺组织的吸收剂量估计，STES-NB的深度吸收剂量分别在3.6%、3.2%和1.2%之间。(C) 2003年美国医学物理学家协会。
Tissue equivalent materials have a variety of uses, including routine quality assurance and quality control in both diagnostic and therapeutic physics. They are frequently used in a research capacity to measure doses delivered to patients undergoing various therapeutic procedures. However, very few tissue equivalent materials have been developed for research use at the low photon energies encountered in diagnostic radiology. In this paper, we present a series of tissue-equivalent (TE) materials designed to radiographically mimic human tissue at diagnostic photon energies. These tissue equivalent materials include STES-NB (newborn soft tissue substitute), BTES-NB (newborn bone tissue substitute), LTES (newborn as, well as a child/adult lung tissue substitute), STES (child/adult soft tissue substitute), and BTES (child/adult bone tissue substitute). In all cases, targeted reference elemental compositions are taken from those specified in the ORNL stylized computational model series. For each material, reference values of mass density, mass attenuation coefficients (10-150 keV), and mass energy-absorption coefficients (10-150 keV) were matched as closely as permitted by material selection and manufacturing constraints. Values of mu/rho and mu(en)/rho for the newborn TE materials are noted to have maximum deviations from their ORNL reference values of from 0 to -3% and from +2% to -3%, respectively, over the diagnostic energy range 10-150 keV For the child/adult TE materials, these same maximal deviations of mu/rho and mu(en)/rho are from +1.5% to -3% and from +3% to -3%, respectively. Simple calculations of x-ray fluence attenuation under narrow-beam geometry using a 66 kVp spectrum typical of newborn CR radiographs indicate that the tissue-equivalent materials presented here yield estimates of absorbed dose at depth to within 3.6% for STES-NB, 3.2% for BTES-NB, and 1.2% for LTES of the doses assigned to reference newborn soft, bone, and lung tissue, respectively. (C) 2003 American Association of Physicists in Medicine.