Flat-panel x-ray imaging detector with avalanche gain

描述（由申请人提供）：本提案的目的是开发一种具有可编程增益的实用平板X射线成像探测器，以满足高级X射线成像应用中对宽动态范围平板探测器日益增长的需求。该探测器采用三个主要部件：结构化碘化铯（CsI）闪烁体，用于将X射线转换为光子;雪崩非晶硒（a-Se）光电导体，HARP（高增益雪崩浪涌非晶光电导体），将光学图像转换为电荷并提供可编程增益;以及大面积有源矩阵（AM）薄膜晶体管（TFT）阵列，以实时电子地读出图像。该探测器被命名为SHARP-AMFPI（闪烁体-HARP有源矩阵平板成像仪）。它能够以X射线成像预期的最低剂量（0.1 <R）产生X射线量子噪声限制图像，实际上每个像素只有一个X射线光子。对于高剂量应用（例如，射线照相术），HARP的增益将降低，以确保宽动态范围，而不会出现探测器饱和。在我们以前的工作中，我们已经建立了SHARP-AMFPI使用模型和小规模成像原型的所有组件的理论和实验可行性。本论文的目标是研制一种实用的大面积SHARP-AMFPI探测器，该探测器具有分布电阻界面层（RIL），以实现稳定可靠的雪崩增益。我们的目标将通过以下三个具体目标来实现：（1）开发大面积RIL技术，以实现SHARP-AMFPI中稳定的雪崩增益;（2）优化RIL特性，以允许HARP与TFT阵列集成，并实现所需的表面拓扑结构和成像性能;（3）证明实用的大面积SHARP-AMFPI的上级成像性能和可靠性。一旦实现这些目标，将产生一个新的AMFPI，准备用于临床翻译，并允许在多模态临床应用中的X射线成像的应用取得重大进展。 公共卫生相关性：在拟议的工作中，我们将开发用于低剂量成像的下一代X射线平板探测器。它将荧光透视中的X射线检测效率提高5倍，同时通过可编程增益保持双模式荧光透视/X射线摄影操作的能力。

DESCRIPTION (provided by applicant): The objective of this proposal is to develop a practical flat-panel x-ray imaging detector with programmable gain in order to address the increasing demand for wide dynamic range flat panel detectors in advanced x-ray imaging applications. The proposed detector employs three major components: a structured cesium iodide (CsI) scintillator to convert x-rays to optical photons; an avalanche amorphous selenium (a-Se) photoconductor, HARP (High-gain Avalanche Rushing amorphous Photoconductor), to convert the optical image to charge and provide a programmable gain; and a large area active matrix (AM) thin film transistor (TFT) array to read out the image electronically in real-time. The proposed detector has been named SHARP-AMFPI (Scintillator-HARP Active Matrix Flat-Panel Imager). It is capable of producing x-ray quantum noise limited images at the lowest dose expected for x-ray imaging (0.1 <R), which virtually has only one x-ray photon per pixel. For high dose applications (e.g. radiography) the gain of HARP will be decreased to ensure wide dynamic range without detector saturation. In our previous work we have established the theoretical and experimental feasibility of all components of SHARP-AMFPI using models and small scale imaging prototypes. The goal of the proposed work is to develop a practical large area SHARP-AMFPI detector with a distributed resistive interface layer (RIL) to achieve stable and reliable avalanche gain. Our goal will be achieved through the following three specific aims: (1) Develop large area RIL technology to achieve stable avalanche gain in SHARP-AMFPI; (2) Optimize RIL properties to allow integration of HARP with the TFT array, and achieve the desired surface topology and imaging performance; (3) Demonstrate the superior imaging performance and reliability of a practical large area SHARP- AMFPI. Once these aims are accomplished a new AMFPI ready for clinical translation will be resulted, and permit major advancements in the application of x-ray imaging in multimodality clinical applications. PUBLIC HEALTH RELEVANCE: In the proposed work we will develop the next generation x-ray flat-panel detectors for low dose imaging. It will increase the efficiency of x-ray detection in fluoroscopy by up to 5 times while maintaining the capability for dual mode fluoroscopy/radiography operation by virtue of programmable gain.