System design considerations for an x-ray phase-contrast imaging system based on in-line holography

Abstract

Since Roentgen discovered x-ray and performed the first x-ray imaging more than 100 years ago, x-ray imaging has always been based on the biological tissue's differences in x-ray attenuation. However, x-ray-tissue interaction causes x-ray phase changes as well, and the tissue’s differences in phase are about one thousand times larger than their differences in x-ray attenuation. We will present the theoretical foundation and design considerations for clinical x-ray phase-contrast imaging systems based on the x-ray in-line holography. Different from the analysis in literature, we proposed a new formalism for in-line phase-contrast imaging to analyze the effects of four clinically important factors on the phase-contrast. These are the body parts attenuation, the spatial coherence of incident x-ray from an x-ray tube, polychromatic x-ray and radiation dose to patients for clinical applications. We will discuss the phase image-reconstruction based on our new theory for the x-ray in-line holography as well. The theory and image reconstruction algorithms presented in this paper can be applied widely to the diagnostic x-ray imaging applications. The phase-contrast imaging system design guidelines based on the new theory will be discussed and its validation by the computer simulations will be demonstrated.