Developing a dual energy x-ray source for low-cost spectral CT

开发用于低成本能谱 CT 的双能 X 射线源

• 批准号: 10610908
• 负责人: OTTO Z ZHOU
• 金额: $ 18.74万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10610908
• 关键词: Algorithms; Anodes; Area; Carbon Nanotubes; Cathodes; Characteristics; Clinical; Data Set; Development; Dose; Effectiveness; Electrodes; Equipment; Excision; Feasibility Studies; Filtration; Goals; Head; Image; Imaging Device; Interventional radiology; Iodine; Limb structure; Measures; Medical Imaging; Metals; Methods; Modeling; Morphologic artifacts; Noise; Patient imaging; Performance; Photons; Production; Productivity; Qualifying; Radiation; Reaction Time; Research; Roentgen Rays; Rotation; Scientist; Source; Specific qualifier value; Spottings; Structure; System; Techniques; Technology; Tissue Differentiation; Translating; Tube; Tungsten; Vacuum; Work; X-Ray Computed Tomography; bone; cone-beam computed tomography; contrast enhanced; cost; design; design and construction; detector; driving force; experience; image guided radiation therapy; improved; maxillofacial; prototype; radiologist; reconstruction; simulation; spectral energy; spectrograph; tomosynthesis; virtual; voltage

ABSTRACT Dual energy computed tomography (DECT) provides significantly more information compared to a regular CT. It is increasingly used for a variety of clinical tasks including tissue differentiation, metal artifact reduction, automatic bone removal, contrast enhancement, and iodine quantification. Although several technologies have been developed for DECT, a major limitation is a significantly increased equipment cost, which has hindered the more widespread clinical use. The goal of this project is to develop a new x-ray source technology to reduce the cost and to enhance the performances of DECT. Specifically, we propose a dual energy x-ray source that emits radiations with two distinct energy spectra with an increased energy separation compared to those obtained by spectral filtration or the rapid kVp switching method alone. This will be accomplished by utilizing two cathode-anode pairs and a voltage divider to reduce the effective voltage of one of the anodes, at a constant applied tube voltage. The radiations from the two anodes are further optimized to reduce the spectral overlap by incorporating two individualized spectral filters. For DECT, x-ray radiation is emitted alternately from the two anodes by selectively activating the corresponding cathode. The carbon nanotube (CNT) field emission cathodes are used to enable rapid switching and intensity modulation of the two beams with micro-second accuracy. The advantages of the proposed source compared the current technologies are: 1) Significantly reduced equipment cost – no rapid kVp switching, energy sensitive detector or two sets of source/detector is required; 2) Increased energy separation and reduced overlap which will lead to an enhanced DECT performance; 3) Independent control of the exposures of the two x-ray beams to minimize image noise; 4) Enabling DE-CBCT imaging in one gantry rotation; and 5) Instantaneous switching of the energy spectrum with micro-second response time resulting in improved accuracy and reliable in the dose profile. This feasibility study will focus on a fixed-anode x-ray source for dual-energy cone-beam CT (DE-CBCT) for maxillofacial and head imaging, the technology developed can be applied to other areas of medical imaging where CBCT is currently deployed such as image guided radiation therapy, interventional radiology and extremity imaging. The approach can also be extended to multi-energy (3 or more) for advanced spectral imaging. It can be used for spatially distributed x-ray source array that emits photons with 2 or more energy spectra from for fixed-gantry dual energy tomosynthesis and CT. The Specific Aims are: 1) Demonstrating the feasibility of a dual energy x-ray source for low-cost DE-CBCT; and 2) Demonstrating DE-CBCT imaging using a prototype dual energy x-ray source.

摘要 与常规CT相比，双能量计算机断层扫描(DECT)提供的信息要多得多 CT.它越来越多地被用于各种临床任务，包括组织分化，金属伪影减少， 自动去骨、对比度增强和碘定量。尽管有几种技术已经 是为DECT开发的，一个主要限制是显著增加的设备成本，这阻碍了 更广泛的临床应用。 该项目的目标是开发一种新的x射线源技术，以降低成本并提高 DECT的表演。具体地说，我们提出了一种双能量x射线源，它发射出两个截然不同的辐射 与通过光谱过滤或快速获得的谱相比，具有更大能量分离的能谱 KVP单独切换方法。这将通过利用两个阴阳极对和一个电压来实现 在恒定施加的管电压下，降低其中一个阳极的有效电压的分流器。辐射 从两个阳极进一步优化，以减少光谱重叠通过结合两个单独的 光谱滤光片。对于DECT，通过选择性地激活两个阳极来交替发射x射线辐射 相应的阴极。碳纳米管(CNT)场发射阴极用于实现快速开关 以及微秒级精度的两束光的强度调制。 与当前的技术相比，提出的源的优点是：1)显著减少 设备成本-不需要快速KVP切换、能量敏感探测器或两套源/探测器；2) 增加能量分离和减少重叠，这将导致增强DECT性能；3) 独立控制两束X射线的曝光，以最大限度地减少图像噪声；4)启用DE-CBCT 一次机架旋转成像；5)微秒量级的瞬时能谱切换 响应时间，从而提高了剂量分布的准确性和可靠性。 这项可行性研究将集中在用于双能锥束CT(DE-CBCT)的固定阳极X射线源 颌面部和头部成像，开发的技术可应用于医学成像的其他领域 目前部署CBCT的地方，如图像引导放射治疗、介入放射学和肢体 成像。该方法还可以扩展到高级光谱成像的多能量(3个或更多)。它可以 用于从FORM发射具有2个或更多能谱的光子的空间分布的x射线源阵列 固定式龙门式双能断层扫描及CT。其具体目的是：1)论证双重制度的可行性 用于低成本DE-CBCT的能量X射线源；以及2)使用DUAL原型演示DE-CBCT成像 能量X射线源。