Development of the HiLight™ scintillator for computed tomography medical imaging
Development of the HiLight™ scintillator for computed tomography medical imaging
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DOI：
10.1016/s0168-9002(03)01022-2
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发表时间：
2003-06-01
影响因子：
1.4
通讯作者：
Lynch, MJ
中科院分区：
文献类型：
--
作者：
Duclos, SJ;Greskovich, CD;Lynch, MJ
计算机断层扫描（CT）医学扫描仪的图像质量对余辉、辐射损伤和X射线探测器中使用的散射器的光学不均匀性极其敏感。这对设计具有最佳性能的闪烁体材料提出了坚韧的挑战。讨论将集中在第一个商业化的透明陶瓷闪烁体，（Y，Gd）（2）O-3：Eu基HiLight（TM）闪烁体在GE医疗系统的CT产品中使用的开发和性能。陶瓷闪烁体平台的灵活性使其能够满足CT成像不断变化的需求，自1988年以来，它已成功纳入全球8000多个CT系统。陶瓷工艺使得以ppm水平均匀共掺杂成为可能，以控制导致余辉的电子缺陷，将其降低到低于CT图像中可检测性的水平。在受控的氧气气氛中对材料进行退火，再加上氧气沿着陶瓷中的晶界快速扩散，可将辐射损伤降低到可忽略的值。这些材料的瞬时热释光将作为电子陷阱能级的诊断进行讨论，电子陷阱能级是余辉和辐射损伤的原因。最后，随着现代CT系统扫描速度要求的提高，Eu激活剂和其他稀土离子之间的能量转移可用于加速闪烁体的辐射衰变，确保材料在未来CT系统中的持续生存能力。(C)2003 Elsevier Science B. V.保留所有权利。
The image quality of computed tomography (CT) medical scanners is extremely sensitive to afterglow, radiation damage and optical non-uniformities of scintillators used in X-ray detectors. This represents a tough challenge in the design of scintillator materials with optimum properties. Discussion will center on the development and properties of the first commercialized transparent ceramic scintillator, the (Y,Gd)(2)O-3:Eu-based HiLight(TM) scintillator used in GE Medical System's CT products. The flexibility of the ceramic scintillator platform has enabled it to be engineered to satisfy the changing needs of CT imaging, which is demonstrated by its successful incorporation into over 8000 CT systems worldwide since 1988. The ceramic process makes possible uniform co-doping at ppm levels to control electronic defects responsible for afterglow, reducing it to levels below detectibility in CT images. Annealing of the material in controlled oxygen atmospheres, combined with rapid oxygen diffusion along grain boundaries in the ceramic, reduces radiation damage to negligible values. Transient thermoluminescence of these materials will be discussed as a diagnostic of electronic trap levels,responsible for both afterglow and radiation damage. Finally, with the increased scan speed requirements of modern CT systems, energy transfer between the Eu activator and other rare-earth ions can be used to speed the radiative decay of the scintillator, ensuring the material's continued viability in future CT systems. (C) 2003 Elsevier Science B.V. All rights reserved.