Researchers at University College London are about to build a potentially practical new type of X-ray machine that detects and makes images by analyzing diffraction patterns rather than absorption.
From The Engineer Online:
‘With a conventional X-ray, what you read on the detector are the photons that have not been absorbed by the material in their way,’ said Dr Robert Speller, professor of physics and head of the radiation group at UCL.
‘In an application such as mammography the difference between absorption by material that is normal and that which is not normal is very small — in the order of a few per cent.
‘Therefore, radiologists struggle to see small features in the breast. It is a very challenging area of work with well-documented limitations.’
Rather than measuring the degree of absorption, known as the attenuation coefficient, the XPCI (extremely high potential, X-ray phase contrast imaging) technique looks at the photons’ refractive index data; in other words, how much they are deviated by the material as they pass through.
More at the The Engineer…
An article by Professor Robert D Speller and Dr Alessandro Olivo, of the Medical Physics & Bioengineering Dept. University College London, in European Hospital magazine: XPCi…
Here’s an overview of phase contrast imaging from UCL…