PORTLAND, Ore. Today's "dark-field" X-ray machines are too expensive for routine use. For instance, the Paul Scherrer Institute (PSI) uses its $200 million, 300-meter diameter synchrotron to take dark-field X-rays.
Now, researchers at the Ecole Polytechnique Fdrale de Lausanne (EPFL, Switzerland) have crafted a nanoscale diffraction grating that could be retrofitted into existing X-ray machines, enabling health-care providers to also take dark-field X-rays.
"Until now, dark-field X-ray images have only been possible using sophisticated crystal optics," said EPFL professor Franz Pfeiffer.
Beside significant medical benefits, a nanoscale retrofit to current X-ray machines could also enable better security scanners. PSI claims dark-field X-rays can help identify explosives in hand luggage, spot hairline cracks and corrosion in bridges and airplane wings as well as aid in the early diagnose of osteoporosis, breast cancer and Alzheimer's disease.
|Dark-field X-ray (left) shows much more detail than the traditional X-ray (right).|
Dark-field X-ray images span the gamut from pure white to darkest black, and a detailed inspection reveals much higher resolution and the ability to see the fine structures inside objects. Dark-field X-rays retrieve not just the directly reflected beam, but its scattered components after they bounce around inside a structure to reveal hidden details.
"Our new technique uses novel X-ray optical components in the form of nanostructured gratings," said PSI researcher Christian David. "This opens up the possibility for adapting current imaging equipment to include dark-field imaging."
By collaborating with the Center for Biomedical Imaging, a joint development effort with the University of Lausanne and the University of Geneva, the researchers now hope to take their invention out of the lab to develop an add-on optical grating that could be added to existing medical X-ray machines over the next few years.