An Advanced Technology Flat-Panel Imager for Fluoroscopy

用于荧光检查的先进技术平板成像仪

• 批准号: 7656521
• 负责人: LARRY E ANTONUK
• 金额: $ 135.81万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7656521
• 关键词: Adoption; Algorithms; Amplifiers; Architecture; Area; Behavior; Breast; Cardiac; Charge; Chest; Collaborations; Complex; Computer software; Conceptions; Coupled; Crystallization; Detection; Development; Dose; Evaluation; Exhibits; Film; Fluoroscopy; Frequencies; Goals; Image; Image Enhancement; Imagery; Imaging Techniques; Imaging technology; Individual; Investigation; Lasers; Mammography; Measurement; Mechanics; Medical; Metric; Modeling; Morphologic artifacts; Noise; Patient Care; Patients; Performance; Procedures; Process; Property; Quantitative Evaluations; Radiation; Research; Resolution; Roentgen Rays; Series; Signal Transduction; Silicon; Structure; Study models; System; Systems Analysis; Techniques; Technology; Testing; Thoracic Radiography; Transistors; United States National Institutes of Health; base; clinical application; cone-beam computed tomography; design; detector; digital; expectation; improved; innovation; iterative design; model development; new technology; novel; practical application; programs; prototype; public health relevance; quantum; simulation; statistics; tool

DESCRIPTION (provided by applicant): Extensive research efforts since the 1980s have resulted in the practical introduction of active-matrix flat-panel imagers (AMFPIs) to numerous medical x-ray applications in this decade. These include \ imaging procedures involving cone beam computed tomography (CBCT). While AMFPIs offer many advantages compared to traditional film-screen and x-ray image intensifier systems (XRIIs), the technology nevertheless suffers from several significant limitations. AMFPI image quality degrades at low exposures so that, for example, it cannot match the image quality of XRIIs across the entire fluoroscopic exposure range. Secondly, AMFPIs are subject to image artifacts, originating from the trapping of charge in amorphous materials in the arrays. Such artifacts are particularly prominent when fluoroscopic images are acquired shortly after a large radiographic exposure - a phenomenon called ghosting. Finally, the maximum achievable frame rates of AMFPIs are restrictive. Research leading up to this proposal has identified an innovative, highly promising strategy for overcoming these limitations, involving substitution of the amorphous silicon thin-film transistors (a-Si:H TFTs), used in most conventional AMFPIs, with polycrystalline silicon (poly-Si) TFTs. This allows creation of considerably more sophisticated arrays with in-pixel amplifiers - referred to as an active pixel (AP) architecture. Coupled with the incorporation of novel a-Si:H photodiode structures that are compatible with these more complex pixel circuits, poly-Si AP arrays would overcome the various limitations listed above, while preserving the many favorable properties of conventional AMFPIs. The objectives of the research focus on the development of a series of increasingly higher performance, small area, prototype arrays that exhibit these desirable properties. The objectives are: (1) Development of prototypes with progressively better performance (higher detective quantum efficiency, lower charge trapping effects, higher frame rates) - involving iterative design, fabrication and evaluation of increasingly sophisticated AP prototypes. (2) Quantitative modeling (involving cascaded systems analysis and detailed circuit simulations) to provide guidance in array design and assist in prototype evaluation. (3) Detailed characterization of the properties of individual poly-Si TFTs and other test circuits to support the circuit simulation activities and to provide guidance in improving array performance through improvements to fabrication techniques. (4) Creation of the various tools (mathematical, software, firmware and hardware) required to accomplish the above objectives. The successful conclusion of this research will result in the creation of a technology that offers image quality limited only by the fundamental properties of X rays and x-ray converters, reduces artifacts and increases frame rates. Ultimately, this will improve image quality and/or reduce dose for fluoroscopic procedures, as well as facilitate advanced clinical applications including breast and chest tomosynthesis, and CBCT for breast and angiographic procedures. PUBLIC HEALTH RELEVANCE: The practical application of the novel x-ray imaging technology to be developed in the proposed research will offer significant enhancement of imaging capabilities, ultimately improving patient care in a wide variety of ways. For example, compared to existing x-ray technologies, the new technology will facilitate the realization of higher quality images at very low doses (helping to minimize dose to the patient in fluoroscopic procedures) and enable the visualization of smaller and/or lower contrast features (assisting in the identification of suspicious objects in mammographic examinations). Moreover, it is strongly anticipated that the new technology will enable advanced applications (involving tomosynthesis or cone beam computed tomography techniques for chest and breast imaging) that require rapid acquisition of multiple, high quality images at relatively low doses per image in order to produce three dimensional anatomical views.

描述（由申请人提供）：自 20 世纪 80 年代以来的广泛研究工作已导致有源矩阵平板成像仪 (AMFPIs) 在这十年中实际引入到众多医学 X 射线应用中。这些包括涉及锥形束计算机断层扫描（CBCT）的成像程序。虽然 AMFPI 与传统胶片屏幕和 X 射线图像增强系统 (XRII) 相比具有许多优势，但该技术仍然存在一些重大限制。 AMFPI 图像质量在低曝光下会降低，因此，例如，它无法在整个荧光镜曝光范围内与 XRII 的图像质量相匹配。其次，AMFPI 容易受到图像伪影的影响，这是由于阵列中非晶材料中的电荷俘获造成的。当在大量射线照相曝光后不久获取荧光镜图像时，这种伪影尤其突出 - 这种现象称为重影。最后，AMFPI 可实现的最大帧速率是有限制的。促成该提案的研究已经确定了一种创新的、非常有前途的策略来克服这些限制，包括用多晶硅（多晶硅）替代大多数传统 AMFPI 中使用的非晶硅薄膜晶体管（a-Si:H TFT）硅）TFT。这允许使用像素内放大器创建更加复杂的阵列 - 称为有源像素 (AP) 架构。再加上与这些更复杂的像素电路兼容的新型 a-Si:H 光电二极管结构，多晶硅 AP 阵列将克服上面列出的各种限制，同时保留传统 AMFPI 的许多有利特性。研究的目标集中于开发一系列性能日益提高的小面积原型阵列，以展现这些理想的特性。目标是： (1) 开发性能逐渐更好的原型（更高的探测量子效率、更低的电荷捕获效应、更高的帧速率）——涉及日益复杂的 AP 原型的迭代设计、制造和评估。 (2) 定量建模（涉及级联系统分析和详细电路仿真），为阵列设计提供指导并协助原型评估。 (3) 详细表征各个多晶硅 TFT 和其他测试电路的特性，以支持电路仿真活动并为通过改进制造技术来提高阵列性能提供指导。 (4) 创建实现上述目标所需的各种工具（数学、软件、固件和硬件）。这项研究的成功结束将导致创建一种技术，该技术提供的图像质量仅受 X 射线和 X 射线转换器的基本特性的限制，减少伪影并提高帧速率。最终，这将提高图像质量和/或减少荧光镜检查的剂量，并促进先进的临床应用，包括乳房和胸部断层合成、以及用于乳房和血管造影手术的 CBCT。公共健康相关性：拟议研究中开发的新型 X 射线成像技术的实际应用将显着增强成像能力，最终以多种方式改善患者护理。例如，与现有的 X 射线技术相比，新技术将有助于以极低剂量实现更高质量的图像（有助于最大限度地减少荧光镜检查过程中患者受到的剂量），并实现更小和/或更低对比度特征的可视化（协助识别乳房X光检查中的可疑物体）。此外，人们强烈期望新技术将实现先进的应用（涉及用于胸部和乳腺成像的断层合成或锥形束计算机断层扫描技术），这些应用需要以每张图像相对较低的剂量快速采集多个高质量图像，以便产生三个立体解剖视图。