Tabletop x-ray ghost imaging with ultra-low radiation

Computational ghost imaging, in which an image is retrieved from a known patterned field that illuminates an object and the total transmitted intensity therefrom, has seen great advances on account of its advantages and potential applications at all wavelengths. However, even though lensless x-ray ghost imaging was anticipated more than a decade ago, its development has been hampered due to the lack of suitable optics. The image quality is proportional to the total flux in conventional projection x-ray imaging, but high photon energy could severely damage the object being imaged, so decreasing the radiation dose while maintaining image quality is a fundamental problem. Using a simple tabletop x-ray source, we have successfully realized ghost imaging of planar and natural objects with a much higher contrast-to-noise ratio compared to projection x-ray imaging at the same low-radiation dose. Ultra-low-flux imaging has been achieved, and thus radiation damage of biological specimens could be greatly reduced with this new technique.