Microscopic X-ray Luminescence Computed Tomography

 描述(申请人提供)：X射线发光计算机断层扫描(XLCT)是一种新兴的成像方式，其中X射线光子激发纳米磷光体发射光学光子，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DIE组织中的目标，通过在重建算法中引入X射线束的大小和位置来克服光学散射。我们已经建立了XLCT成像原型系统，通过该系统，我们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射线发光计算机层析成像(MicroXLCT)，它使用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，但由于准直器吸收了大部分X射线光子，微XLCT存在X射线利用率低的问题。在这个方案中，我们的目标是提高X射线光子的利用效率，并通过在X射线管上安装多毛细光学透镜来获得更精细的X射线束。X射线光子的利用效率将提高50倍以上，这将大大减少测量时间，使系统更加实用。更细的X射线束将使成像的空间分辨率提高到100微米以下。我们将通过体模和安乐死小鼠的实验来优化和评估微XLCT的性能。这笔小额赠款将主要支持购买这种带有多毛细管透镜的特殊X射线管和人力成本。成像系统中的其他主要部件，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，已经在我的实验室中用于这个项目。因此，我们相信拟议的项目非常适合NIH R03拨款，并将通过为分子成像界提供一个强大而可行的成像工具而具有很高的意义。

 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.