Swiss boffins polish X-ray specs

Researchers at the Paul Scherrer Institute and the Ecole Polytechnique Fédérale de Lausanne have produced highly sensitive dark-field x-ray images at wavelengths typically used in medical and industrial imaging equipment.

Dark-field images provide more detail than ordinary x-ray radiographs, and could be used to diagnose the onset of diseases including osteoporosis, breast cancer and Alzheimer's.

The technology could also be used to identify explosives in luggage, or pinpoint hairline cracks or corrosion in structures.

Traditional x-ray images show a simple absorption contrast, but dark-field images capture the scattering of the radiation within the material itself, exposing subtle inner changes in bone, soft tissue or alloys.

Dark-field x-ray imaging had required sophisticated optics and could only be produced at facilities like the Paul Scherrer Institute's 300m diameter synchrotron.

However, with the new nanostructured gratings, dark-field images could soon be produced using ordinary x-ray equipment already in place in hospitals and airports around the world.

"Researchers have been working on dark-field x-ray images for many years," said Franz Pfeiffer, a professor at the Ecole Polytechnique Fédérale de Lausanne and researcher at the Paul Scherrer Institute.

"Up until now these images have only been possible using sophisticated crystal optical elements."

Co-researcher Christian David added: "Our new technique uses novel x-ray optical components that permit the use of a broad energy spectrum, including the standard range of energies in traditional x-ray equipment.

"This opens up the possibility for adapting current imaging equipment to include dark-field imaging."