In This Issue : vimarsana.com
In This Issue
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 quality and contain few defects. The system also incorporates new data-processing algorithms that minimize artifacts due to vibrations caused by the rotating CT gantry. The authors demonstrated the method by producing images of a phantom human-sized thorax that were reconstructed from a single rotation scan lasting 1 second. According to the authors, the protype offers a viable approach for using dark-field CT in clinical settings. T.J.
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Moon. Image credit: NASA/Nancy Neal Jones/Goddard Space Flight Center.
### Volatile elements in the Moon
The origin of volatile elements, such as water, in the Earth–Moon system is a matter of debate. The Moon’s low levels of volatile elements compared with Earth may be the result of the Giant Impact event, thought to have formed the Moon following the collision of a Mars-sized body called Theia with the proto-Earth. Lars …
### 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 quality and contain few defects. The system also incorporates new data-processing algorithms that minimize artifacts due to vibrations caused by the rotating CT gantry. The authors demonstrated the method by producing images of a phantom human-sized thorax that were reconstructed from a single rotation scan lasting 1 second. According to the authors, the protype offers a viable approach for using dark-field CT in clinical settings. T.J.
Read online
Moon. Image credit: NASA/Nancy Neal Jones/Goddard Space Flight Center.
### Volatile elements in the Moon
The origin of volatile elements, such as water, in the Earth–Moon system is a matter of debate. The Moon’s low levels of volatile elements compared with Earth may be the result of the Giant Impact event, thought to have formed the Moon following the collision of a Mars-sized body called Theia with the proto-Earth. Lars …
Related Keywords
La Paz, Bolivia, United States, United Kingdom, Lahore, Punjab, Pakistan, Ethiopia, North Sea, Oceans General, Oceans, Britain, America, Nikolai Gustschin, Marte Sodeland, Addis Ababa, Pierre Justeau, Katharina Dulias, John Wilkinson, Lars Borg, M George Foody, Atlantic Ocean, Manuel Viermetz, Martin Richards, Ceiridwen Edwards, , Giant Impact, Solar System, Saharan Africa, South Asia, South America, Global South, North America, Orkney Islands, Bronze Age, Iron Age,