Sakellaris T, Spyrou G, Tzanakos G, Panayiotakis G
Department of Medical Physics, School of Medicine, University of Patras, 265 00 Patras, Greece.
Phys Med Biol. 2005 Aug 21;50(16):3717-38. doi: 10.1088/0031-9155/50/16/005. Epub 2005 Jul 28.
Selenium is among the materials under investigation that may form effective detectors and provide a major contribution to digital mammography. Till the final image formation, there is an intervention of the x-ray photons transformation to primary electrons and their subsequent ionizing drift towards the electrodes that collect them. The characteristics of the generated primary electrons inside a-Se material such as their angular, spatial and energy distribution affect the characteristics of the final image. A Monte Carlo based model has been developed that simulates the x-ray irradiation of an a-Se detector plate, including primary photon interactions (photoelectric absorption, coherent and incoherent scattering), as well as secondary ones, such as fluorescence (Kalpha, Kbeta) and emission of Auger electrons. The angular, spatial and energy distributions for the generated primary electrons inside a-Se have been produced for various mammographic x-ray spectra and their usefulness in designing and optimizing a detector made of a-Se for digital mammography is discussed.
硒是正在研究的可能形成有效探测器并对数字乳腺摄影做出重大贡献的材料之一。在最终图像形成之前，会有一个X射线光子转化为初级电子以及随后它们向收集电极进行电离漂移的过程。非晶硒（a-Se）材料内部产生的初级电子的特性，如它们的角度、空间和能量分布，会影响最终图像的特性。已经开发了一个基于蒙特卡洛的模型，该模型模拟了非晶硒探测器板的X射线照射，包括初级光子相互作用（光电吸收、相干和非相干散射）以及次级相互作用，如荧光（Kα、Kβ）和俄歇电子发射。针对各种乳腺摄影X射线光谱，生成了非晶硒内部产生的初级电子的角度、空间和能量分布，并讨论了它们在设计和优化用于数字乳腺摄影的非晶硒探测器方面的实用性。
