X-Ray Novel Imaging Optics and Methods

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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.