Pixelated Scintillators for High Spatial Resolution and High Quantum Efficiency X-RayDetectors

用于高空间分辨率和高量子效率 X 射线探测器的像素化闪烁体

• 批准号: 9908617
• 负责人: Houxun Miao
• 金额: $ 22.48万
• 依托单位: GENERAL OPTICS, LLC
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-16 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9908617
• 关键词: Address; Area; Breast Microcalcification; Communities; Crystallization; Dental; Development; Diagnosis; Diagnostic radiologic examination; Digital Mammography; Dose; Engineering; Evaluation; Film; Frequencies; Goals; Government; Image; Light; Measures; Medical; Metals; Needles; Optics; Output; Performance; Persons; Phase; Photons; Process; Refractive Indices; Research; Resolution; Roentgen Rays; Scanning; Sedimentation process; Sensitivity and Specificity; Silicon; Small Business Innovation Research Grant; Structure; Surface; Testing; Thick; Thinness; Time; bioimaging; breast imaging; contrast imaging; design; detector; evaporation; experience; imaging system; improved; innovation; melting; microCT; performance tests; practical application; prototype; quantum; simulation

PROJECT SUMMARY/ABSTRACT The performance of many x-ray imaging systems is limited by the lack of x-ray detectors with simultaneous high quantum efficiency and high spatial resolution. As examples, digital mammography scanners typically have a resolution of ≥ 70 µm for high quantum efficiency, which is not sufficient to effectively detect small but critical microcalcifications. X-ray micro-CT scanners either use high quantum efficiency, low spatial resolution detectors together with high geometric magnification or use high spatial resolution, low quantum efficiency detectors with thin scintillators, which significantly limits the scan throughput. The low-resolution (typically ~ 100 µm) of commercial large area x-ray flat panel detectors made single-shot x-ray phase contrast imaging system not appropriate for most applications since the resolution is determined by the fringe period and has to be at least a few pixels. Research in pixelated scintillators during the last two decades have demonstrated pixel size determined spatial resolution. However, the light guiding (output) efficiency is very low (typically < 10%), which limits the practical application of such detectors in low dose medical x-ray diagnosis. The proposed research in this SBIR Phase I project will focus on developing high light guiding efficiency pixelated scintillators with specially designed and engineered sidewall surface reflectors of the pixels. The spatial resolution defined by the pixel size (down to 15 µm) and the light guiding efficiency comparable to commercial phosphor screens of the same thickness are to be demonstrated. General Optics proposes to bring such high efficiency pixelated scintillators to the market through Phase I research. The specific aims are: (1) develop processes to fabricate 30-µm and 15-µm pitch, up to 200 µm depth silicon pixel wells with ≈ 1 µm wall thickness, and engineer the sidewall surface for high reflectivity; (2) fill the wells with scintillator materials of CsI (Tl) and Gd2O2S:Tb; (3) Test the performance of the fabricated pixelated scintillators and compare them with commercial phosphor screens. Integration of the pixelated scintillators to large area CMOS cameras for fully integrated, large area x-ray detectors would be the next stage of this SBIR Phase I project.

项目总结/摘要 许多X射线成像系统的性能受到缺乏具有以下特征的X射线探测器的限制： 同时具有高量子效率和高空间分辨率。例如， 扫描仪通常具有≥ 70 µm的分辨率以获得高量子效率，这不足以 有效地检测小但关键的微钙化。X射线微型CT扫描仪要么使用高量子 低空间分辨率探测器与高几何放大率一起使用，或者使用高空间分辨率探测器。 分辨率低的量子效率探测器，带有薄的反射器，这大大限制了扫描 吞吐量商用大面积X射线平板探测器的低分辨率（通常约为100 µm） 使得单次激发X射线相衬成像系统不适合于大多数应用 分辨率由条纹周期确定，并且必须至少是几个像素。 在过去二十年中对像素化放大器的研究已经证明了像素大小确定 空间分辨率然而，光导（输出）效率非常低（通常< 10%），这限制了 这种探测器在低剂量医用X射线诊断中的实际应用。拟议的研究在 该SBIR第一阶段项目将集中于开发高导光效率的像素化照明器， 特别设计和工程化的像素侧壁表面反射器。空间分辨率定义 通过像素尺寸（低至15 µm）和与商业荧光粉相当的导光效率 将演示相同厚度的屏幕。 通用光学公司建议通过第一阶段将这种高效率的像素化光栅推向市场 research.具体目标是：（1）开发制造30-µm和15-µm间距，直至200 µm间距的工艺 深度硅像素威尔斯，壁厚为0.1 µm，并设计侧壁表面以获得高反射率; (2)用CsI（Tl）和Gd 2 O 2 S：Tb闪烁体材料填充威尔斯;（3）测试 制造的像素化荧光屏，并将它们与商业荧光屏进行比较。融合 像素化的放大器到大面积CMOS相机，用于完全集成的大面积X射线探测器， SBIR第一阶段项目的下一阶段。