Digital x-ray imaged based on Hgl2 polycrystalline films

本提案的目标是开发一种新的探测器技术，用于基于碘化汞多晶薄膜耦合到大面积平板非晶硅（a-Si：H）薄膜晶体管（TFT）寻址读出阵列的数字X射线成像。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十倍，从而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，这在许多医学诊断程序中具有至关重要的意义，例如乳房X线摄影。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，我们开发了多晶碘化汞薄膜在其厚度，多晶晶粒的尺寸，层的均匀性和良好的电性能方面的高度控制的生长技术。在第二阶段的工作中，我们将完成碘化汞薄膜的开发，并使用最初的小型商用平板a-Si：H读出器（约2“x2”）构建X射线成像探测器。然后，我们将扩大薄膜生长设备，并构建大面积（约14”x 17”）的X射线成像探测器。薄膜生长过程将被优化以降低生产成本。这种新的X射线成像仪将在空间分辨率、增益、线性度、噪声、均匀性和探测量子效率方面与当前的商业探测器进行表征和比较。成像能力将在我们的实验室和加州大学洛杉矶分校医学院进行测试，使用狭缝和幻影。拟议的商业应用：人们对数字射线照相检测器在医疗诊断应用、材料无损评估、生物和其他材料样品的X射线衍射以及天文观测中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600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 HgI2 polycrystalline films coupled to large area flat 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-fold 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 image, 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 developed techniques for highly controlled growth of polycrystalline HgI2 films in terms of their thickness, sizes of the polycrystalline grains, uniformity of layers and good electrical properties. In the Phase II effort we will finalize the HgI2 film development and construct x-ray imaging detectors using initially small commercial flat panel a-Si:H readouts (approximately 2"x2"). Then we will scale up the film growth equipment and construct large area (approximately 14" x 17") x-ray imaging detector. The film growth process will be optimized for low production cost. This new x- ray imager will be characterized and compared with current commercial detectors in terms of spatial resolution, gain, linearity, noise, uniformity, and detective quantum efficiency. The imaging capabilities will be tested in our laboratory and at UCLA School of Medicine with the use of slits and phantoms. PROPOSED COMMERCIAL APPLICATIONS: There is a strong interest in application of digital radiographic detectors for medical diagnostic applications, nondestructive 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 600 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.