Microscopic X-ray Luminescence Computed Tomography

 描述（由申请人提供）： X射线发光计算机断层扫描（XLCT）是一种新兴的成像模式，其中X射线光子激发纳米荧光粉发射光子，测量光子用于光学成像。XLCT结合了光学成像的高测量灵敏度和X射线成像的高空间分辨率。对于组织中的目标，通过将X射线束的大小和位置引入重建算法来克服光学散射。我们建立了一个XLCT成像的原型系统，我们已经证明了成像分辨率与深度无关。为了进一步提高空间分辨率，我们提出了显微X射线发光计算机断层扫描（microXLCT），其中我们使用精细准直器形成直径小于100微米的X射线束。虽然我们得到了有希望的初步结果，但microXLCT的X射线利用效率较低，因为准直器吸收了大部分X射线光子。在该方案中，我们的目标是通过使用安装在X射线管上的多毛细管光学透镜来提高X射线光子利用效率并具有更精细的X射线束。X射线光子利用效率将提高50倍以上，这将大大减少测量时间，使系统更加实用。更精细的X射线束将提高成像空间分辨率至小于100微米。我们将通过体模和安乐死小鼠实验优化和评价microXLCT性能。这笔小额赠款将主要用于支持购买这种带有多毛细管透镜的特定X射线管和劳动力成本。成像系统中的其他主要组件，例如带冷却系统的电子倍增电荷耦合器件（EMCCD）相机，带安全联锁的X射线屏蔽柜和X射线探测器，都已在我的实验室中提供。因此，我们相信，拟议的项目符合NIH R03基金非常好，也将通过提供一个强大的和可行的成像工具的分子成像社区具有很高的意义。

 DESCRIPTION (provided by applicant): X-ray luminescence computed tomography (XLCT) is an emerging imaging modality, in which x-ray photons excite nanophosphors to emit optical photons that are measured for optical imaging. XLCT combines the high measurement sensitivity of optical imaging and the high spatial resolution of x-ray imaging. For targets in dee tissues, the optical scattering is overcome by introducing x-ray beam size and location into the reconstruction algorithm. We have built an XLCT imaging prototype system, by which we have demonstrated that the imaging resolution is independent of the depth. To further improve the spatial resolution, we have proposed the microscopic x-ray luminescence computed tomography (microXLCT), in which we used fine collimators to form x-ray beams with diameter less than 100 micrometer. While we got promising preliminary results, the microXLCT suffers from low x-ray utilization efficiency as collimator absorbs most x-ray photons. In this proposal, we aim to improve the x-ray photon utilization efficiency and to have a finer x-ray beam by using a polycapillary optic lens mounted on an x-ray tube. The x-ray photon utilization efficiency will be improved by more than 50 times, which will reduce the measurement time substantially to make the system more practical. The finer x-ray beam will improve the imaging spatial resolution to be less than 100 micrometer. We will optimize and evaluate the microXLCT performance with phantom and euthanized mice experiments. This small grant will mainly support the purchase of this specific x-ray tube with the polycapillary lens and labor cost. Other major components in the imaging system, such as an electron multiplying charge coupled device (EMCCD) camera with a cooling system, an x-ray shielding cabinet with safety interlock, and x-ray detector, are already available in my lab for this project. Thus we believe the proposed project fits an NIH R03 grant very well and will also have high significance by providing a powerful and feasible imaging tool for the molecular imaging community.