Phase contrast X-ray imaging

Richard Lanza

The basic principle of x-ray imaging; relying solely on the difference in absorption as the source of contrast, has remained essentially unchanged since 1895 when Wilhelm Conrad Röntgen coined the word “x-rays.” Whether done with film or with digital methods, the fundamental limitation of current x-ray technology is the tradeoff between contrast and dose. Phase contrast x-ray imaging uses the wave nature of x-rays to form images based on small differences in the x-ray refractive index of materials. As a result, images created by this method may be formed even for materials that cannot easily be imaged or distinguished conventionally. Development of a practical phase contrast technology would enable more clearly distinguishable images at a lower dose.

This project proposes a new approach to phase contrast x-ray imaging to improve both medical procedures as well as security screening. For medical imaging, particularly in mammography, the technology could enhance the contrast of images while reducing the dose of the patient. For security screening, the approach could help airport security screeners distinguish between explosives and benign materials in passenger luggage.