DIGITAL X-RAY IMAGERS BASED ON HGI2 POLYCRYSTALLINE FILM

该提案的目标是开发一种新的用于数字X射线成像的检测器技术，该技术基于Hgl 2多晶膜耦合到大面积平板非晶硅（a-Si：H）薄膜晶体管（TFT）寻址的读出阵列。与利用耦合到a-Si：H读出阵列的磷光体的检测器相比，这种新型成像检测器在优化时将提供对X射线的灵敏度的数量级改进和上级空间分辨率。探测器灵敏度的提高将使患者的辐射剂量减少10倍，以获得同等质量的图像。空间分辨率的提高将直接影响图像的质量1，这在许多医学诊断程序（如乳房X线摄影）中具有至关重要的意义。此外，数字功能将允许方便的无胶片图像采集、检索和存储。数字图像处理、计算机辅助诊断和提供真实的时间图像的能力在许多医学诊断中具有明显的优势。在本提案的第一阶段，我们将开发高度控制多晶Hgl 2薄膜生长的技术，包括其厚度、多晶增益的尺寸、层的均匀性和良好的电性能。薄膜沉积最初将使用1”至2”正方形的样品进行。样品的厚度将从100 - 500微米增长。开发的生长方法将很容易扩展到更大的区域。该工艺将被优化以降低生产成本。在第二阶段，我们将完成Hgl 2薄膜的开发，并使用商业平板a-Si：H读出器构建大面积（约10”x10”）X射线成像探测器。然后，将在我们的实验室和UCLA医学院使用狭缝和幻影对这种新的X射线成像器的灵敏度、空间分辨率和成像能力进行表征。拟定商业应用：人们对数字射线照相检测器在医疗诊断应用、材料的非破坏性评估、生物和其他材料样品的X射线衍射以及天文观测方面的应用有着浓厚的兴趣。保守估计，仅在医疗领域，每年每1000人就有800多张X光图像。拟议的探测器将是非常有吸引力的，这个巨大的商业细分市场，由于数量级的性能改进，他们将提供。

The goal of this proposal is to develop a new detector technology for digital x-ray imaging based on Hgl2 polycrystalline films coupled to large area fiat panel amorphous silicon (a-Si:H) thin-film transistor (TFT)addressed readout arrays. This novel Imaging detector when optimized will provide order of magnitude improvements in sensitivity to x-rays and superior spatial resolution compared to detectors utilizing scintillating phosphors coupled to a-Si:H readout arrays. The increased sensitivity of the detector will allow for a ten-old reduction in radiation dose to a patient for an equivalent quality image. The enhancement of the spatial resolution will have a direct impact on the quality of the image1 which has paramount importance in many medical diagnostic procedures such as mammography. In addition, digital capabilities will allow for convenient film-less image acquisition, retrieval, and storage. Digital image processing, computer-assisted diagnosis, and the ability to provide real time images have distinct advantages in many medical diagnostics. During Phase I of this proposal we will develop techniques for highly controlled growth of polycrystalline Hgl2 films In terms of their thickness, sizes of the polycrystalline gains, uniformity of layers and good electrical properties. The film depositions will initially be done with samples ranging from 1" to 2" square. The thickness of the samples will be grown from 1OO-5O0 microm. The developed growth methods will be easily scalable to much larger areas. The process will be optimized for low production cost. In Phase II we will finalize the Hgl2 film development and construct large area (about 10" x10") x-ray imaging detector using a commercial fiat panel a-Si:H readout This new x-ray imager will then be characterized for sensitivity, spatial resolution and imaging capabilities in our laboratory and at UCLA School of Medicine with the use of slits and phantoms. PROPOSED COMMERCIAL APPLICATION: There is a strong interest in application of digital radiographic detectors for medical diagnostic applications, non-destructive evaluation of materials, x-ray diffraction of biological and other material samples, and astronomical observations. Conservative estimates are that in the medical area alone there are over 800 x-ray images produced per 1000 population per year. The proposed detectors will be highly attractive to this enormous commercial market segment due to the order of magnitude performance improvements that they will offer.