SWAD: Large-Area Photon Counting X-Ray Imager using Amorphous Selenium

SWAD：使用非晶硒的大面积光子计数 X 射线成像仪

• 批准号: 10380628
• 负责人: Amirhossein Goldan
• 金额: $ 39.4万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10380628
• 关键词: Area; Breast Microcalcification; Charge; Deposition; Development; Digital Radiography; Dose; Film; Geometry; Glass; Goals; Image; Mammary Gland Parenchyma; Mammography; Measures; Memory; Morphologic artifacts; Motion; Noise; Output; Patients; Performance; Photons; Physiologic pulse; Process; Resolution; Roentgen Rays; Screening for cancer; Selenium; Shapes; Silicon; Structure; System; Technology; Testing; Thinness; Time; Transistors; Weight; Work; X-Ray Computed Tomography; X-Ray Medical Imaging; base; breast imaging; clinical application; clinical translation; cone-beam computed tomography; contrast enhanced; cost; cost effective; design; detector; digital; experience; imager; next generation; photon-counting detector; prototype; quantum; radiological imaging; sensor; spectrograph; technological innovation; tomosynthesis

Abstract The field of medical x-ray imaging experienced a "digital revolution" in the early 2000s, with the spreading of digital radiography systems which are based on active matrix at panel imagers (AMFPI). Since then we have seen rapid development and clinical translation of large-area AMFPI based on amorphous silicon active matrix technology. However they have one major difficulty to overcome: producing x-ray quantum noise limited images at very low dose. Advanced applications of AMFPI, including tomosynthesis and cone-beam computed tomography have fueled the development of the next generation detectors, mainly in the ability of AMFPI to generate high quality images that are quantum noise limited and free from artifacts at low x-ray exposures and high frame rates. An alternative approach is to operate the detector in pulse mode for photon counting which provides higher dose efficiency through efficient noise rejection, quantum-noise limited performance, and optimal energy weighting. Photon counting systems are also not susceptible to memory artifacts. While the development of photon counting detector for computed tomography has been very promising, no commercial photon counting 2D sensors exists for radiography or mammography due to the simultaneous requirement for both high resolution and large area. Our hypothesis is that a direct-conversion amorphous selenium detector with unipolar time-differential (UTD) charge sensing and avalanche gain can yield a cost-effective and large-area photon counting imager with spectroscopic capabilities. The true impact of photon counting is to provide hyperspectral imaging (via multi-energy thresholding) to enable widespread application of contrast enhanced (CE) breast imaging with rapid acquisition and without motion artifacts (via simultaneous acquisition of high energy and low images during a single x-ray exposure). The objective of this proposal is therefore to fabricate and test a prototype photon counting imager using the proposed eld-Shaping multi-Well Avalanche Detector (SWAD). Conceptually the proposed SWAD imager employs four major components: (1) a photon counting chip, (2) multi-well pixel geometry, (3) amorphous selenium (a-Se) photoconductor deposited over the multi-well substrate for UTD charge sensing and avalanche gain, and finally (4) an image acquisition circuit board where the SWAD chip will be connected to. We expect to show that the proposed photon counting SWAD imager has quantum-noise-limited performance, high spectral sensitivity for energy weighting, and high frame-rates. Successful development of SWAD will lead to the first ever cost-effective and large-area photon counting detector for x-ray imaging. Although this is seemingly a high cost proposal, the technological innovation we develop will lead to the widespread clinical application of a more efficient and lower dose contrast-enhanced cancer screening system for mammography.

抽象的 医疗X射线成像领域在2000年代初期经历了一场“数字革命”，其中 基于面板成像仪（AMFPI）的主动矩阵的数字X线照相系统的传播。 从那以后，我们看到了基于无定形硅活性基质技术的大面积AMFPI的快速发展和临床翻译。但是，他们有一个主要的困难要克服：生产 X射线量子噪声限制非常低剂量的图像。 AMFPI的高级应用，包括断层合成和锥形束计算机断层扫描，促进了下一代的发展 检测器，主要是AMFPI产生量子噪声的高质量图像的能力 并且没有低X射线暴露和高框架速率的人工制品。另一种方法是操作 光子计数脉冲模式下的检测器，通过有效地提供较高剂量效率 噪声排斥，量子噪声有限的性能和最佳的能量加权。光子计数 系统也不容易受到记忆工件的影响。虽然用于计算层析成像的光子计数检测器的开发非常有前途，但没有商业光子计数2D传感器 由于同时需要两个高分辨率，因此存在X线摄影或乳房X线摄影 和大面积。我们的假设是直接转化为单极的无定形硒检测器 时间差异（UTD）电荷感应和雪崩增益可以产生成本效益的大面积光子 用光谱功能计数成像仪。光子计数的真正影响是提供高光谱成像（通过多能阈值），以实现对比度的广泛应用 （CE）乳房成像，并没有运动伪影（通过同时获得） 单X射线暴露期间的高能量和低图像）。因此，该提议的目的是 使用拟议的ELD成型多孔制造和测试原型光子计数成像仪 雪崩探测器（SWAD）。从概念上讲，拟议的SWAD成像仪采用四个主要组成部分： （1）光子计数芯片，（2）多孔像素几何形状，（3）无定形硒（A-SE）光电导体 沉积在多孔基板上，用于UTD电荷感应和雪崩增益，最后（4） 图像采集电路板将在其中连接到SWAD芯片。我们希望证明 提出的光子计数SWAD成像仪具有量子噪声限制的性能，对能量加权的高光谱灵敏度和高框架速率。 SWAD的成功发展将导致有史以来第一个 X射线成像的成本效益和大面积光子计数检测器。虽然这似乎是 高成本提案，我们开发的技术创新将导致广泛的临床应用 乳房X线摄影的更有效，较低剂量增强的癌症筛查系统。