Ultrafast laser x-ray in-vivo phase-contrast micro-CT

超快激光 X 射线活体相差显微 CT

• 批准号: 7035529
• 负责人: Andrzej Krol
• 金额: $ 22.62万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7035529
• 关键词: bioimaging /biomedical imaging; computed axial tomography; computer simulation; image enhancement; image processing; laboratory mouse; lasers; mouth neoplasms; phantom model; radiation dosage; technology /technique development; three dimensional imaging /topography

DESCRIPTION (provided by applicant): Emerging photonic technologies, such as ultrafast lasers, provide a new paradigm for overcoming the limitations of traditional biomedical imaging modalities. In this project, we propose to develop in-line x-ray phase-contrast micro-CT system that will utilize an ultrafast laser-based x-ray (ULX) source. This new source produces x-rays through irradiation of a solid target by the laser beam. Any solid (metal or non-metal) can be used as a target. ULX delivers more power in x-rays than a conventional microfocal tube is able to provide, thus allowing for much faster scans. Further, ULX generates narrow x-ray spectra that consist mainly of characteristic lines. These can be easily tailored (by changing laser beam target) to the imaging task. The phase-contrast micro-CT will allow high-resolution measurements of the spatial distribution of the real (x-ray phase-shift) and the imaginary (x-ray absorption) components of the x-ray refractive index in a living animal. This is in contrast to conventional micro-CT, using a microfocal x-ray tube, which can only map 3D distribution of the x-ray absorption coefficient. Therefore, we expect that'opening the new channel of information provided by the x-ray phase-shift 3D mapping, in addition to conventional absorption map measurement, will significantly increase soft tissue low-contrast resolution of micro-CT without any dose increase, thus allowing improved imaging of cancer in small animal models. In due course, this method could be expanded to clinical CT scanners, providing that the high average power ultrafast lasers become available. Compact, robust, ultrafast lasers are commercially available, and their characteristics are rapidly improving. We plan to construct and explore imaging performance of an in vivo in-line x-ray phase-contrast ULX micro-CT system. This goal will be accomplished by completing the following tasks: i) design and optimization via computer simulations of the optimal system geometry and the focal spot size and shape; ii) design and optimization via computer simulations of ULX spectra; iii) experimental implementation and optimization of the selected system design; iv) development of image processing tools for correction, extraction, enhancement, and fusion of the extracted phase-contrast and absorption tomographic data and improved fusion of absorption and phase-contrast images; v) assemble a cone-beam ULX phase-contrast micro-CT system (with optimized geometry, energy, focal spot, and detector) and begin exploration of the imaging performance of the whole system and comparison with conventional micro-CT, using phantoms and in vivo imaging of oral cancer mouse model.

描述（由申请人提供）：新兴的光子技术，如超快激光器，为克服传统生物医学成像模式的局限性提供了新的范例。在这个项目中，我们建议开发在线X射线相衬显微CT系统，将利用超快激光为基础的X射线（ULX）源。这种新光源通过激光束照射固体靶来产生X射线。任何固体（金属或非金属）都可以用作靶。ULX在X射线中提供的功率比传统的微焦管能够提供的功率更大，因此可以实现更快的扫描。此外，ULX产生主要由特征线组成的窄X射线光谱。这些可以很容易地定制（通过改变激光束目标）的成像任务。相衬显微CT将允许高分辨率测量活体动物中X射线折射率的真实的（X射线相移）和虚部（X射线吸收）的空间分布。这与使用微焦点X射线管的常规微CT形成对比，常规微CT只能映射X射线吸收系数的3D分布。因此，我们预计，除了传统的吸收图测量外，通过X射线相移3D映射提供的新信息通道将显着提高微CT的软组织低对比度分辨率，而无需增加任何剂量，从而改善小动物模型中癌症的成像。在适当的时候，这种方法可以扩展到临床CT扫描仪，提供高平均功率超快激光器变得可用。 紧凑、坚固、超快的激光器已经上市，并且其特性正在迅速改善。我们计划构建和探索在体在线X射线相衬ULX微型CT系统的成像性能。这一目标将通过完成以下任务来实现：i）通过计算机模拟最佳系统几何形状以及焦斑尺寸和形状来进行设计和优化; ii）通过计算机模拟ULX光谱来进行设计和优化; iii）所选系统设计的实验实施和优化; iv）开发图像处理工具，用于校正、提取、增强和融合所提取的相衬和吸收断层摄影数据，以及改进吸收和相衬图像的融合; v）组装锥形束ULX相位对比显微CT系统（具有优化的几何形状、能量、焦斑和检测器），并开始探索整个系统的成像性能，并使用口腔癌小鼠模型的体模和体内成像与常规显微CT进行比较。