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.

摘要 医学X射线成像领域在21世纪初经历了一场“数字革命”， 基于有源矩阵平板成像器（AMFPI）的数字X射线摄影系统的推广。 从那时起，我们看到了基于非晶硅有源矩阵技术的大面积AMFPI的快速发展和临床应用。然而，他们有一个主要的困难要克服：生产 在非常低的剂量下X射线量子噪声限制图像。AMFPI的先进应用，包括断层合成和锥形束计算机断层扫描，推动了下一代的发展 探测器，主要是AMFPI生成量子噪声限制的高质量图像的能力 并且在低X射线曝光和高帧速率下没有伪像。另一种方法是操作 用于光子计数的脉冲模式的探测器，其通过有效的 噪声抑制、量子噪声限制性能和最佳能量加权。光子计数 系统也不易受存储器伪像的影响。虽然用于计算机断层扫描的光子计数探测器的开发已经非常有前途，但是没有商业光子计数2D传感器 由于同时需要高分辨率和高分辨率， 和大面积。我们的假设是， 时间差分（UTD）电荷感测和雪崩增益可以产生具有成本效益和大面积的光子 具有光谱能力的计数成像仪。光子计数的真正影响是提供高光谱成像（通过多能量阈值），以实现对比度增强成像的广泛应用。 (CE)具有快速采集和无运动伪影的乳房成像（通过同时采集 在单次X射线曝光期间的高能量和低图像）。因此，本建议的目的是 使用所提出的eld-Shaping多阱制造和测试光子计数成像仪原型 雪崩探测器（SWAD）。从概念上讲，所提出的SWAD成像仪采用四个主要部件： (1)光子计数芯片，（2）多阱像素几何结构，（3）非晶硒（a-Se）光电导体 沉积在多阱衬底上，用于UTD电荷感测和雪崩增益，以及最后（4） 图像采集电路板，SWAD芯片将连接到该电路板。我们希望证明， 所提出的光子计数SWAD成像器具有量子噪声限制性能、用于能量加权的高光谱灵敏度和高帧速率。SWAD的成功开发将导致有史以来第一次 用于X射线成像的具有成本效益的大面积光子计数探测器。虽然这似乎是一个 高成本的建议，我们开发的技术创新将导致广泛的临床应用 一个更有效和更低剂量的对比增强乳腺癌筛查系统。