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Full-Text Articles in Medicine and Health Sciences
Phase Imaging Using Focusing Polycapillary Optics, Sajid Bashir
Phase Imaging Using Focusing Polycapillary Optics, Sajid Bashir
Legacy Theses & Dissertations (2009 - 2024)
The interaction of X rays in diagnostic energy range with soft tissues can be described by Compton scattering and by the complex refractive index, which together characterize the attenuation properties of the tissue and the phase imparted to X rays passing through it. Many soft tissues exhibit extremely similar attenuation, so that their discrimination using conventional radiography, which generates contrast in an image through differential attenuation, is challenging. However, these tissues will impart phase differences significantly greater than attenuation differences to the X rays passing through them, so that phase-contrast imaging techniques can enable their discrimination.
Grid-Based Fourier Transform Phase Contrast Imaging, Sajjad Tahir
Grid-Based Fourier Transform Phase Contrast Imaging, Sajjad Tahir
Legacy Theses & Dissertations (2009 - 2024)
Low contrast in x-ray attenuation imaging between different materials of low electron density is a limitation of traditional x-ray radiography. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One recently developed phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a technique recently demonstrated by Bennett et al.1 …