Correlative Imaging with Multi-energy X-ray Tomography

简介：福特博士的研究实验室建立在临床前肺部微型计算机断层扫描（micro-CT）成像的强大背景之上，开发了多能量对比增强微型CT成像方案，使用碘和氙作为造影剂，分别可视化血管和气道。 我们还在加拿大光源同步加速器设施（CLS）的生物医学光束线（BMIT）上开发了新的成像技术，包括氙的第一个K边缘减法（KES）成像和第一个使用啮齿动物呼吸信号的图像，以触发在指定的呼吸阶段的图像采集。我们的微CT技术和BMIT光束线将使啮齿动物器官和组织的结构，生理和功能的体内定量分析成为可能。 目标：比较显微CT和同步加速器研究的3D X射线图像与光学技术，包括2D共聚焦显微镜和3D光学投影断层扫描（OPT）。 在微型CT和同步加速器图像中进行的测量提供了有关活体动物内器官结构和功能的信息。 对于光学技术，器官被切片以提供关于器官或组织内细胞的结构和功能的信息。 方法：我们将在不同的成像技术下引入造影剂或染色来显示相同的器官特征。 对于体内成像，我们分别使用碘和氙来可视化血管和空气空间;这两种材料在微型CT和KES同步加速器成像中都是可见的。 为了关联X射线和光学技术，可能的造影剂候选物包括金和银纳米颗粒以及CdSe/ZnS量子点。 我们预计所有这些材料将在同步加速器和微型计算机断层扫描图像中可见。 银纳米颗粒和量子点都已被确立为光学标记物。 同步辐射成像将在CLS同步加速器设施使用一种新的光谱KES技术。 UBC高通量表型基因组学中心（CHTP）有两台微型CT扫描仪，适用于活体啮齿动物和切除的器官和组织成像。 CHTP还包含一台光学投影断层扫描仪，可生成荧光标记组织的3D光学图像或自体荧光图像，以及一台具有多个激光源的白色激光共聚焦显微镜。 影响：该计划的新奇包括同步图像采集与生理信号在BMIT光束线，并使用世界范围内独特的光谱KES技术。 使用同步加速器将实现非常精确的测量，将与体内微型CT、离体微型CT、OPT和显微镜进行比较。总之，这些测量提供了器官功能的更完整的图像，或识别器官功能不正常的区域。

INTRODUCTION: Dr. Ford's research lab has built upon a strong background in preclinical micro-computed tomography (micro-CT) imaging of the lung to develop multi-energy contrast-enhanced micro-CT imaging protocols using iodine and xenon as contrast agents to visualize the blood vessels and airways respectively. We have also developed new imaging techniques on the biomedical beam line (BMIT) of the Canadian Light Source Synchrotron facility (CLS), including the first K-edge subtraction (KES) imaging of xenon and the first images using the respiratory signal from the rodent to trigger image acquisition during a specified respiratory phase. Our techniques for micro-CT and on the BMIT beam line will enable in vivo quantitative analysis of structure, physiology and function in rodent organs and tissues. PROGRAM GOAL: To compare 3D x-ray images from micro-CT and synchrotron studies with optical techniques, including 2D confocal microscopy and 3D optical projection tomography (OPT). The measurements performed in the micro-CT and synchrotron images provide information about the organ structure and function within a living animal. For the optical techniques, the organs are sectioned to give information about the structure and function of the cells within the organ or tissue. METHODS: We will introduce contrast media or staining to visualize the same organ features under different imaging techniques. For in vivo imaging, we are using iodine and xenon to visualize the blood vessels and air spaces respectively; both of these materials are visible in the micro-CT and in KES synchrotron imaging. To correlate x-ray and optical techniques, possible contrast agent candidates include gold and silver nanoparticles and CdSe/ZnS quantum dots. We expect all of these materials will be visible in the synchrotron and micro-computed tomography images. Both the silver nanoparticles and quantum dots have been established as optical markers. Synchrotron imaging will be performed at the CLS synchrotron facility using a novel spectral KES technique. The UBC Centre for High-Throughput Phenogenomics (CHTP) has two micro-CT scanners suitable for imaging live rodents and excised organs and tissues. The CHTP also houses an optical projection tomography machine that produces 3D optical images of fluorescently labeled tissues or auto fluorescence images and a white light laser confocal microscope with multiple laser sources. IMPACT: The novelty of this program includes synchronizing the image acquisition with physiological signals at the BMIT beam line and using a world-wide unique spectral KES technique. Using the synchrotron will enable very accurate measurements that will be compared with in vivo micro-CT, ex vivo micro-CT, OPT and microscopy. Together, these measurements provide a more complete picture of how the organ functions or identify regions of the organ that are not functioning properly.