© Fotokon/Dreamstime
© Fotokon/Dreamstime

Scientists aim to develop safer X-ray detectors

A novel photonics technology is being developed to produce a set of low radiation, low cost, flat panel X-ray detectors, promising safer diagnosis for patients and less exposure for hospital and dental staff.

The DiCoMo (Direct conversion hybrid-organic X-ray detectors on metal oxide backplane) project also promises this new technology will produce some of the highest resolution images ever seen in single X-ray records or computerised tomography (CT) scans.

High resolution images are seen with direct converters used in mammography, as they use semiconductors that directly convert the X-rays into electrical signals. Indirect converters, on the other hand, use scintillators emitting light upon X-ray irradiation and then converting it into electrical signals by a photodetector. They produce lower radiation doses, but low image quality.

The DiCoMo project is working on combining direct and indirect converters by getting the indirect converter with low radiation output to behave like a direct converter.

Project co-ordinator Dr Sandro Tedde of Siemens Healthineers said they call the process “quasi-direct conversion”.

“X-ray photons,” Tedde said, “are converted first into visible photons and then into electrical charges by an organic photodetector.

“It is a rather complex system in terms of device physics, but it is a rather disruptive approach which is enabled by the versatility of organic semiconductors.”

The DiCoMo’s purported outcome is image quality that rivals a 16 megapixel photograph. Combine that with lower radiation levels and a lower price tag, and it could potentially replace current technology.

Tedde added: “DiCoMo aims to improve the specificity, in our case the resolution, and sensitivity of digital flat panel X-ray detectors, making this device versatile.

“It could be used in medical, veterinary and dental surgeries, as well as be really attractive to customs or the military for scanning relevant material.”

The DiCoMo project began in early 2015 via the European Commission’s Horizon 2020 programme and runs until the end of 2017.