Computational modelling of pixelated CdZnTe detectors for x- and γ- ray imaging applications
Computational modelling of pixelated CdZnTe detectors for x- and γ- ray imaging applications
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用于 X 射线和 γ 射线成像应用的像素化 CdZnTe 探测器的计算建模
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
D. Darambara
中科院分区：
文献类型：
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作者：
M. Myronakis;M. Zvelebil;D. Darambara
碲锌镉（CdZnTe）探测器目前用于采用γ射线光子的医学成像系统中。随着新的成像技术，如光子计数和能量加权X射线成像越来越受到研究兴趣，CdZnTe被认为是一个新的光在计算机断层扫描，断层合成和其他X射线成像应用的潜在用途。然而，由于相对昂贵，CdZnTe可以通过先进的计算建模来帮助探测器和成像系统优化。在这项工作中，像素化CdZnTe探测器的计算建模使用一个集成的框架，结合有限元和蒙特卡罗数值方法，以获得现实的探测器models.Various探测器的厚度和像素尺寸的设计和它们的性能进行了研究，在电荷感应效率，探测效率和能量分辨率。检测效率和能量分辨率进行评估的单能光子束的能量范围内使用的医疗X射线成像应用，如乳房X射线摄影术和计算机断层扫描。展示了该框架的一些功能。小于100μm的小像素尺寸易于产生电荷传输效应，例如扩散，特别是在较大厚度（> 0.5 mm）中，并且在像素化几何形状中的使用可能有限。随着厚度和像素尺寸的减小，检测效率受到荧光和光子逃逸的影响。能量分辨率受射束几何形状的影响，并且根据射束宽度的不同，可以在103%到11%之间变化。该框架提供了一个通用平台和一个强大的工具，可用于设计和优化由任何半导体材料制成的半导体探测器，成像系统和信号校正技术。
Cadmium Zinc Telluride (CdZnTe) detectors are currently used in medical imaging systems employing γ-ray photons. As new imaging techniques such as photon-counting and energy-weighted x-ray imaging are gaining research interest, CdZnTe is seen under a new light for potential use in computed tomography, tomosynthesis and other x-ray imaging applications. However, being relatively expensive, CdZnTe could be favoured by advanced computational modelling to assist in detector and imaging system optimisation. In this work, pixelated CdZnTe detectors are computationally modelled using an integrated framework that combines the Finite Element and Monte Carlo numerical methods to obtain realistic detector models.Various detector thickness and pixel sizes are designed and their performance is investigated in terms of charge induction efficiency, detection efficiency and energy resolution. Detection efficiency and energy resolution are assessed for monoenegergetic photon beams within the energy range used in medical x-ray imaging applications such as mammography and computed tomography. Some of the capabilities of the framework are demonstrated. Small pixel sizes, below 100μm are prone to charge transport effects such as diffusion, especially in larger thickness ( > 0.5 mm) and may have limited use in pixelated geometries. Detection efficiency is affected by fluorescence and photon escape as thickness and pixel size decrease. Energy resolution is affected by beam geometry and can vary from ∼ 3% to 11% depending on the beam width. The framework provides a generic platform and a powerful tool that can be used in the design and optimisation of semiconductor detectors made from any semiconductor material, imaging systems and signal correction techniques.
DOI：
10.1148/radiology.197.1.300
发表时间：
2019-09
期刊：
Advances in Clinical Radiology
影响因子：
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作者：
Andrew D. A. Maidment
通讯作者：
Andrew D. A. Maidment