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1980年代以来的广泛研究工作导致实际引入了活跃的马trix扁平面板成像器（AMFPIS），以在这十年中介绍许多医疗X射线应用。其中包括涉及锥形束计算机断层扫描（CBCT）的\成像程序。与传统的胶片屏幕和X射线图像增强器系统（XRIIS）相比，AMFPI提供了许多优势，但该技术仍然受到了一些重大限制。 AMFPI图像质量在低暴露率下降低，因此，例如，它不能匹配整个荧光镜暴露范围内XRII的图像质量。其次，AMFPI受图像伪影的约束，源自阵列中无定形材料中电荷的捕获。当大量射线照相暴露后不久获得荧光镜图像时，这种伪影特别突出 - 一种称为hothing的现象。最后，AMFPI的最大可实现帧速率是限制性的。提出该提案的研究已经确定了一种创新的，高度有希望的策略来克服这些局限性，涉及在大多数常规AMFPIS中替代无定形的硅薄膜晶体管（A-SI：H TFTS），该策略在大多数传统的AMFPIS中使用，与多晶硅烷硅（Poly-Si）（Poly-SI）TFTS一起使用。这允许使用像素内放大器（称为Active Pixel（AP）体系结构）创建相当复杂的数组。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，Poly-Si AP阵列将克服上述各种局限性，同时保留常规AMFPIS的许多有利性能。研究的目标集中在开发一系列表现出这些理想特性的一系列越来越高的性能，小面积，原型阵列。目标是：（1）开发具有更好性能的原型（较高的侦探量子效率，较低的电荷陷阱效应，较高的帧速率） - 涉及迭代设计，制造和评估日益复杂的AP原型。 （2）定量建模（涉及级联系统分析和详细的电路模拟），以提供阵列设计的指导并协助原型评估。 （3）详细表征单个聚-SI TFT和其他测试电路的性质，以支持电路模拟活动，并通过改进制造技术来改善阵列性能。 （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）。这项研究的成功结论将导致创建一项技术，该技术仅受X射线和X射线转换器的基本属性限制的图像质量限制，从而降低了工件并提高框架速率。最终，这将改善图像质量和/或减少荧光镜检查的剂量，并促进乳房和胸部间隔（包括乳房和血管造影程序）的晚期临床应用。公共卫生相关性：在拟议的研究中开发的新型X射线成像技术的实际应用将提供显着增强成像功能，最终以各种方式改善患者护理。例如，与现有的X射线技术相比，新技术将有助于以非常低剂量的质量图像实现（有助于最大程度地减少荧光镜检查中的患者剂量），并能够可视化较小和/或较低的对比度（有助于在乳腺检查中鉴定可疑对象检查）。此外，人们强烈预料，新技术将实现高级应用（涉及用于胸部和乳房成像的锥束计算机断层扫描技术），需要快速获取以相对较低剂量的多种剂量以相对较低的剂量以产生三维解剖学视图。