The highly penetrating nature of X-rays has been utilized in a variety of applications, including non-destructive evaluation, medical imaging, and baggage inspection. The major source of contrast in the existing X-ray imaging techniques originates from the attenuation of X-rays due to Compton scattering and photoelectric absorption. However, using this attenuation contrast, materials with similar atomic numbers cannot be distinguished, and small features yield poor contrast. X-ray phase-contrast imaging (XPCI) is being developed to overcome these limitations. XPCI relies on an alternative image contrast, namely, the electron density of a material; therefore, it can further discriminate materials with similar atomic numbers. This capability is important in imaging different types of soft tissues (e.g., tumors and healthy tissue) and distinguishing improvised homemade explosives from harmless liquids. In collaboration with X-ray physicists and clinicians, we are developing a variety of novel XPCI techniques.

Related publications:

• Sung Y, Segars P, Pan A, Masami A, Sheppard CJ, Gupta R. Realistic wave-optics simulation of X-ray phase-contrast imaging at a human scale. Sci Rep. 2015; 5:12011.
• Sung Y, Gupta R, Nelson B, Leng S, McCollough CH, Graves WS. Phase contrast imaging with a compact X-ray light source: System design. J Med Imag. 2017; 4(4): 043503.

Funding sources: Mayo Clinic-Arizona State University Team Science Grants, National Institutes of Health (subaward from TF Instruments).

Collaborators: Dr. Rajiv Gupta (Massachusetts General Hospital and Harvard Medical School), Dr. William Graves (Arizona State University), Dr. Cynthia McCollough (Mayo Clinic), Dr. Michael Fuller (TF Instruments), Dr. Grant Gullberg (Lawrence Berkeley National Lab.).