X-Ray Novel Imaging Optics and Methods

本项目是由以前的两个项目：HL 004606 -24“X射线相衬成像系统”和“HL 006171 -08 X射线微纳光学器件的制作”的组合。2016年，我们发现了一种光学效应，我们称之为通用莫尔效应。这意味着有可能使用纯相移光学元件来成像X射线的折射和散射。这种思路的好处是，它最大限度地减少了成像中的辐射和光子通量的成本，这是人体成像和组织样本显微断层扫描的限制因素。用于这种类型的X射线光学器件的合适材料应该仅具有低原子序数的元素，例如聚合物。我们在一项概念验证研究中表明，3D打印的复合聚合物透镜可以有效地聚焦硬X射线，尽管将这种结构制造成典型病理组织块的大小仍然是一个未解决的问题，特别是在台式设备中使用紧凑的X射线源的形式。然后，我们开始探索其他方法来获得适用于台式系统的X射线相移光学器件。 与此同时，我们的临床合作者向我们展示了除了当前X射线成像中的形态学信息之外，还需要完整组织样本中的分子水平信息。这些信息可以通过X射线衍射获得，我们用它来确定一种罕见遗传疾病中严重组织钙化的化学成分。然后，我们开始研究在实验室环境中获得这两种信息的方法。NIH在使用X射线衍射的结构生物学方面拥有许多世界级的团队。我们计划在这个项目中与其中一位专家Fred Dyda博士进一步合作。 与此同时，我们继续与滑铁卢大学的Pushin博士和NIST中子研究中心的Hussey博士合作，将我们在X射线领域的发展转移到中子成像和干涉测量，因为他们共享一些基本原理和可互换的光学元件。

This project is the combination of two previous projects: HL004606-24 "X-ray phase contrast imaging system" and "HL006171-08 Fabrication of x-ray micro/nano optics". In 2016 we discovered an optics effect which we called the universal moire effect. It meant that it would be possible to use purely phase-shifting optical elements to image the refraction and scattering of x-rays. The benefit of this line of thinking is that it minimizes the cost of radiation and photon flux in imaging, which are limiting factors in human imaging and in micro tomography of tissue samples. Suitable materials for this type of x-ray optics should have only elements of low atomic numbers, such as polymers. We showed in a proof-of-concept study that 3D printed compound polymer lenses effectively focus hard x-rays, although it is still an unsolved problem to fabricate such structures to the size of a typical pathology tissue block, particularly in a form that works with compact x-ray sources in benchtop devices. We then began to explore other ways to obtain x-ray phase-shifting optics that are suitable for benchtop systems. In the meantime, our clinical collaborators showed us the need for molecular-level information in intact tissue samples in addition to the morphological information in current x-ray imaging. Such information can be obtained through x-ray diffraction, which we used to identify the chemical composition of severe tissue calcification in a rare genetic disease. We then began to research ways to obtain both types of information in the laboratory setting. NIH has a number of world-class groups in structural biology using x-ray diffraction. We plan to collaborate further with Dr. Fred Dyda, one of such experts, in this project. At the same time, we continue our collaboration with Dr. Pushin of University of Waterloo and Dr. Hussey of NIST Neutron Research Center, to transfer our development in the x-ray field to neutron imaging and interferometry, since they share some basic principles and interchangeable optical elements.