Flat-panel x-ray imaging detector with avalanche gain

描述（由申请人提供）：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。提出的探测器采用三个主要组件：一个结构化的碘化铯（CsI）闪烁体，将x射线转换为光子；雪崩非晶硒（a- se）光导体，HARP（高增益雪崩冲击非晶光导体），用于将光学图像转换为充电并提供可编程增益；以及用于以电子方式实时读出图像的大面积有源矩阵（AM）薄膜晶体管（TFT）阵列。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射线成像所需的最低剂量（0.1 <R）产生x射线量子噪声限制图像，实际上每像素只有一个x射线光子。对于高剂量应用（例如放射照相），将降低HARP的增益，以确保宽动态范围而不会使检测器饱和。在我们之前的工作中，我们已经利用模型和小尺度成像原型建立了SHARP-AMFPI所有组件的理论和实验可行性。提出的工作目标是开发具有分布式电阻界面层（RIL）的实用大面积SHARP-AMFPI探测器，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中的稳定雪崩增益；(2)优化RIL性能，使HARP与TFT阵列集成，并获得所需的表面拓扑和成像性能；(3)展示了实用大面积SHARP- AMFPI的优越成像性能和可靠性。一旦这些目标实现，一个新的AMFPI就可以用于临床翻译，并允许x射线成像在多模态临床应用中的应用取得重大进展。

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.