New type of nanocrystals to enable safer medical imaging

29 October 2018 (Last Updated October 29th, 2018 10:19)

Researchers from the National University of Singapore (NUS) have discovered that use of a new type of nanocrystals may enable safer and cost-effective medical imaging approaches such as X-ray and computerised tomography (CT).

New type of nanocrystals to enable safer medical imaging
New perovskite nanocrystals (in the bottles) are highly sensitive to X-ray irradiation. Credit: National University of Singapore.

Researchers from the National University of Singapore (NUS) have discovered that use of a new type of nanocrystals may enable safer and more cost-effective medical imaging approaches such as X-ray and computerised tomography (CT).

The team of chemists from the NUS Faculty of Science’s Chemistry department, in alliance with researchers from Australia, China, Hong Kong, Italy, Saudi Arabia, and the US, has developed lead halide perovskite nanocrystals with high sensitivity to X-ray irradiation.

These nanocrystals were then embedded into flat-panel X-ray imagers to create a new detector that possessed the capability to detect X-rays at a radiation dose nearly 400 times lower than that used in existing medical diagnostics.

“The new nanocrystals detect and convert small doses of X-ray photons and into visible light, providing a cost-effective scintillator material alternative.”

In comparison to the inorganic crystals used in traditional X-ray devices, the new technology is also said to be cheaper.

Chemistry department professor Liu Xiaogang said: “Our technology uses a much lower radiation dose to deliver higher resolution images, and it can also be used for rapid, real-time X-ray imaging.

“It shows great promise in revolutionising imaging technology for the medical and electronics industries. For patients, this means lower cost of X-ray imaging and less radiation risk.”

X-ray imaging technology involves the conversion of high-energy X-ray photons to visible luminescence, and the inorganic crystals used in standard machines are expensive. Their low light emission conversion efficiency also requires a high X-ray dose to ensure effective imaging.

The new nanocrystals detect and convert small doses of X-ray photons and into visible light, providing a cost-effective scintillator material alternative.

During the testing phase, the researchers replaced scintillators of commercial flat-panel X-ray imaging systems with the new nanocrystals and found that higher resolution images could be achieved with lower radiation exposure.

Chemistry department research fellow Chen Qiushui said: “Our experiments showed that using this approach, X-ray images can be directly recorded using low-cost, widely available digital cameras, or even using cameras of mobile phones. This was not achievable using conventional bulky scintillators.

“In addition, we have also demonstrated that the nanocrystal scintillators can be used to examine the internal structures of electronic circuit boards. This offers a cheaper and highly sensitive alternative to current technology.”

Currently, the team is working to further test the new approach for longer times, and at different temperatures and humidity levels.