Human X-ray dark-field prototype chest scanner.

(A) The X-ray chest scanner combines a three-grating arrangement (with an oblong active area) with a continuous line-scanning approach, with the purpose of imaging an entire human thorax. By scanning the active area over the field of view, every pixel is sampled at various phases of the Moiré pattern, allowing retrieval of attenuation, differential-phase, and dark-field information. In order to simulate in-vivo conditions and demonstrate clinical relevance of the presented results, tracheal intubation was performed on the deceased body and the lungs were inflated at 23 mbar during measurement. (B) X-ray dark-field contrast is generated by ultra small-angle scattering for instance at air-tissue interfaces of lung alveoli. Scattering causes blurring (red) of the initially well-delimited (black) intensity pattern generated by G1 resulting in a reduction of the measured visibility. Note that several slit sources contribute to the intensity value at any specific location in front of G2. For sake of simplicity, only a few rays passing trough one G1 slot are shown for illustrational purposes.