Adrian Sarapata MSc, Presenter: Nothing to Disclose

Michael Chabior, Abstract Co-Author: Nothing to Disclose

Dan Stutman PhD, Abstract Co-Author: Nothing to Disclose

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

Grating based X-ray phase contrast imaging can work with conventional X-ray tubes and provides complementary information about the specimen. The technique has been proven to provide higher soft tissue contrast in comparison to conventional attenuation-based imaging. The essential next step is to get the X-ray energy up to clinically relevant levels. Our goals are to open possibilities for imaging of thick human body parts with bones as well as reduce the radiation dose.

A Talbot-Lau grating interferometer with 3 gratings was used at the designed energy of 45 keV. X-ray photons were generated by an X-ray tube with a molybdenum target operated at 75 kVp. Grating structures of an absorption grating had 150 micrometers in height. The system was operated at the normal incidence angle of the gratings. Several biological samples were measured to demonstrate the capabilities of the system; among others, a 4.5 mm thick sample submerged in 8 cm thick water bath. The soft tissue contrast and image quality of CT scan images were compared with soft tissue phantom results obtained with a glancing-angle grating interferometer, which have been published elsewhere.  

The CT scans show improved soft tissue contrast in comparison with the absorption based images. At this Compton effect-dominated energy range the phase contrast images are still superior to the absorption based images. But a system with high fringe visibility and high angular sensitivity should be considered for clinical applications, because of the biggest difference in soft tissue contrast between phase contrast and absorption based images. 

Grating-based X-ray phase contrast imaging can be successfully used with an X-ray spectrum of 45 keV mean energy. Phase contrast images provide higher soft tissue contrast than absorption based images, even from a not perfectly optimized system. This shows huge potential of high energy grating-based X-ray phase contrast imaging for clinical applications. 

The study represents an important step towards clinical implementation of grating-based X-ray phase contrast imaging, as it demonstrates the possibility of the technique to be used at clinically relevant X-ray energies.

Sarapata, A, Chabior, M, Stutman, D, Pfeiffer, F, Taking Grating-based X-ray Phase Contrast Imaging to Clinically Relevant X-ray Energies.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016745.html