In 2012 and 2013 we discovered a form of x-ray white-light interferometry, and based on it a type of x-ray phase contrast imaging method capable of detecting the refractive bending of x-rays at sub-nanoradian resolution with broadband x-ray sources. We invented a way to retrieve the phase information without the need for mechanical scanning, and an adaptive image reconstruction algorithm to suit future application environments outside the ideal laboratory setting. These methods are further developed and optimized, on the path towards realizing the benefit x-ray phase-contrast imaging in clinical applications. In 2014 we discovered a wave phenomenon which we named the phase moire effect. This effect allowed us to realize x-ray white-light interferometry in a benchtop system with conventional x-ray tubes. The benchtop system is called a polychromatic far-field interferometer (PFI). In collaboration with Dr. Priya Bhandarkar of Walter Reed NMMC we demonstrated its extraordinary sensitivity at low radiation dose levels compared to a clinical mammography scan. We also gained a thorough understanding of the physical mechanism through comprehensive theoretical and numerical analysis and comparison with experimental measurements. This understanding helps with future designs of new imaging methods. The central hardware necessary for the new imaging method is hard x-ray diffraction gratings of 200 nm periods. They are developed in another project of our laboratory in collaboration with NIST.
| George, Alex; Chen, Peter Y; Morales-Martinez, Alejandro et al. (2017) Geometric calibration and correction for a lens-coupled detector in x-ray phase-contrast imaging. J Med Imaging (Bellingham) 4:013507 |
| Miao, Houxun; Panna, Alireza; Gomella, Andrew A et al. (2016) A Universal Moiré Effect and Application in X-Ray Phase-Contrast Imaging. Nat Phys 12:830-834 |
| Miao, Houxun; Chen, Lei; Mirzaeimoghri, Mona et al. (2016) Cryogenic Etching of High Aspect Ratio 400 nm Pitch Silicon Gratings. J Microelectromech Syst 25:963-967 |
| Miao, Houxun; Gomella, Andrew A; Harmon, Katherine J et al. (2015) Enhancing Tabletop X-Ray Phase Contrast Imaging with Nano-Fabrication. Sci Rep 5:13581 |
| Nayak, Krishna S; Nielsen, Jon-Fredrik; Bernstein, Matt A et al. (2015) Cardiovascular magnetic resonance phase contrast imaging. J Cardiovasc Magn Reson 17:71 |
| Harmon, Katherine J; Miao, Houxun; Gomella, Andrew A et al. (2015) Motionless electromagnetic phase stepping versus mechanical phase stepping in x-ray phase-contrast imaging with a compact source. Phys Med Biol 60:3031-43 |
| Harmon, Katherine J; Bennett, Eric E; Gomella, Andrew A et al. (2014) Efficient decoding of 2D structured illumination with linear phase stepping in X-ray phase contrast and dark-field imaging. PLoS One 9:e87127 |
| Wen, Han; Gomella, Andrew A; Patel, Ajay et al. (2014) Boosting phase contrast with a grating Bonse-Hart interferometer of 200 nanometre grating period. Philos Trans A Math Phys Eng Sci 372:20130028 |
| Miao, Houxun; Gomella, Andrew A; Chedid, Nicholas et al. (2014) Fabrication of 200 nm period hard X-ray phase gratings. Nano Lett 14:3453-8 |
| Wen, Han; Wolfe, Douglas E; Gomella, Andrew A et al. (2013) Interferometric hard x-ray phase contrast imaging at 204 nm grating period. Rev Sci Instrum 84:013706 |
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