Flat-panel x-ray imaging detector with avalanche gain

描述(申请人提供)：本提案的目标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，以满足先进的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。该探测器使用三个主要组件：用于将X射线转换为光子的结构碘化铯(CSI)闪烁体；用于将光学图像转换为电荷并提供可编程增益的雪崩非晶Se(a-Se)光导体；以及用于实时电子读出图像的大面积有源矩阵(AM)薄膜晶体管(TFT)阵列。建议的探测器已命名为SHARP-AMFPI(闪烁器-HARP有源矩阵平板成像器)。它能够以X射线成像所期望的最低剂量(0.1和lt；R)产生X射线量子噪声有限的图像，这实际上是每个像素只有一个X射线光子。对于高剂量应用(如射线照相)，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。在我们之前的工作中，我们已经利用模型和小规模成像原型建立了夏普-AMFPI所有组件的理论和实验可行性。这项工作的目标是开发一种实用的大面积SHARP-AMFPI探测器，该探测器具有分布式电阻界面层(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的稳定雪崩增益；(2)优化RIL特性，以实现HARP与TFT阵列的集成，并实现所需的表面拓扑和成像性能；(3)展示实用的大面积SHARP-AMFP的卓越成像性能和可靠性。一旦这些目标实现，将产生一个新的AMFPI，为临床翻译做好准备，并使X射线成像在多模式临床应用中的应用取得重大进展。 与公共健康相关：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。它将把透视中的X射线检测效率提高5倍，同时通过可编程增益保持双模透视/射线照相操作的能力。

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.