CT gantry with grating interferometer for dark-field imaging of a phantom human chest.
### Human-scale dark-field computed tomography
To produce 3D images of animal tissues, X-ray computed tomography (CT) infers contrast solely from differences in how X-rays are attenuated as they pass through tissues. Some wave aspects of X-rays, such as refraction and small-angle scattering, also contain useful diagnostic information, but technical challenges have impeded these properties from being exploited for human-scale imaging. Manuel Viermetz, Nikolai Gustschin, et al. describe a human-sized prototype that integrates a Talbot-Lau interferometer into a clinical CT gantry to glean previously unresolvable tissue microstructure from small-angle X-ray scattering, an approach termed dark-field CT. To address the sensitivity requirements for medical applications, the authors fabricated optical gratings fine-tuned with a custom analysis technique ensuring that the gratings are of sufficient qualit