Nav: Home

Invention by NUS chemists opens the door to safer and less expensive X-ray imaging

October 25, 2018

Medical imaging, such as X-ray or computerised tomography (CT), may soon be cheaper and safer, thanks to a recent discovery made by chemists from the National University of Singapore (NUS).

Professor Liu Xiaogang and his team from the Department of Chemistry under the NUS Faculty of Science had developed novel lead halide perovskite nanocrystals that are highly sensitive to X-ray irradiation. By incorporating these nanocrystals into flat-panel X-ray imagers, the team developed a new type of detector that could sense X-rays at a radiation dose about 400 times lower than the standard dose used in current medical diagnostics. These nanocrystals are also cheaper than the inorganic crystals used in conventional X-ray imaging machines.

"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," said Prof Liu.

The team's research breakthrough was the result of a collaborative effort with researchers from Australia, China, Hong Kong, Italy, Saudi Arabia, Singapore and the United States. It was first published in the online edition of Nature on 27 August 2018, and a patent for this novel technology has been filed.

Nanocrystals light the way for better imaging

X-ray imaging technology has been widely used for many applications since the 1890s. Among its many uses are medical diagnostics, homeland security, national defence, advanced manufacturing, nuclear technology, and environmental monitoring.

A crucial part of X-ray imaging technology is scintillation, which is the conversion of high-energy X-ray photons to visible luminescence. Most scintillator materials used in conventional imaging devices comprise expensive and large inorganic crystals that have low light emission conversion efficiency. Hence, they will need a high dose of X-rays for effective imaging. Conventional scintillators are also usually produced using a solid-growth method at a high temperature, making it difficult to fabricate thin, large and uniform scintillator films.

To overcome the limitations of current scintillator materials, Prof Liu and his team developed novel lead halide perovskite nanocrystals as an alternative scintillator material. From their experiments, the team found that their nanocrystals can detect small doses of X-ray photons and convert them into visible light. They can also be tuned to light up, or scintillate, in different colours in response to the X-rays they absorb. With these properties, these nanocrystals could achieve higher resolution X-ray imaging with lower radiation exposure.

To test the application of the lead halide perovskite nanocrystals in X-ray imaging technology, the team replaced the scintillators of commercial flat-panel X-ray imagers with their nanocrystals.

"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," explained Dr Chen Qiushui, a Research Fellow with the NUS Department of Chemistry and the first author of the study.

Using nanocrystals as scintillator materials could also lower the cost of X-ray imaging as these nanocrystals can be produced using simpler, less expensive processes and at a relatively low temperature.

Prof Liu elaborated, "Our creation of perovskite nanocrystal scintillators has significant implications for many fields of research and opens the door to new applications. We hope that this new class of high performance X-ray scintillator can better meet tomorrow's increasingly diversified needs."

Next steps and commercialisation opportunities

To validate the performance of their invention, the NUS scientists will be testing their abilities of the nanocrystals for longer times, and at different temperatures and humidity levels. The team is also looking to collaborate with industry partners to commercialise their novel imaging technique.
-end-


National University of Singapore

Related Radiation Dose Articles:

Large nuclear cardiology laboratory slashes radiation dose by 60 percent in 8 years
A large nuclear cardiology laboratory has slashed its average radiation dose by 60 percent in eight years, according to new research presented today at ICNC 2017 and published in JACC: Cardiovascular Imaging.
Giving a single, high dose of radiation directly to the site of a prostate tumor is safe
Doctors have found that treating prostate cancer with a single, high dose of radiation delivered precisely to the site of the tumor results in good quality of life and fewer trips to the hospital, with adverse side effects that are no worse than if the radiation treatment had been given in several lower doses.
Fear of diagnostic low-dose radiation exposure is overstated, experts assert
In an article published in the January 2017 issue of The Journal of Nuclear Medicine, researchers assert that exposure to medical radiation does not increase a person's risk of getting cancer.
Ancient supernovae buffeted Earth's biology with radiation dose, researcher says
Ancient supernovae likely exposed biology on our planet to a long-lasting gust of cosmic radiation, which also affected the atmosphere.
AJR opinion piece considers managing the radiation dose while communicating the risk
Despite evidence that low doses of ionizing radiation associated with imaging are not dangerous, the medical community is frequently faced with the challenge of communicating the risk and managing the dose.
Study shows multiple-dose, targeted radiation more effective for treating pituitary tumors
A recent patient study at Houston Methodist Hospital proved that multiple small doses of highly focused radiation therapy is safer and more effective than a single larger dose of radiation at destroying pituitary gland tumors.
New clues about the risk of cancer from low-dose radiation
Berkeley Lab scientists studied mice and found their risk of mammary cancer from low-dose radiation depends a great deal on their genetic makeup.
ASU embarks on $9 million next phase of an effort to assess an absorbed radiation dose
Arizona State University's Biodesign Institute announced today it is entering a new, $9 million phase of a multi-million, multi-institutional development project to produce a diagnostic test to measure rapidly an individual's level of absorption of ionizing radiation in the event of an unplanned radiological or nuclear event.
Iterative reconstruction techniques reduce radiation dose for pediatric brain CT
Estimated radiation doses are substantially lower for pediatric CT exams of the brain that used an adaptive statistical iterative reconstruction technique (ASIR) compared to those that did not use ASIR.
Special journal issue focuses on radiation dose optimization
To be published online Monday, Mar. 3, a special issue of the Journal of the American College of Radiology focuses on improving the safety of computed tomography exams through careful radiation dose optimization.

Related Radiation Dose Reading:

Low Dose Radiation: The History of the U.S. Department of Energy Research Program
by Antone L Brooks (Author)

Handbook of Treatment Planning in Radiation Oncology, Second Edition
by Gregory Videtic MD CM FRCPC (Editor), Neil Woody MD (Editor), Andrew Vassil MD (Editor)

Permissible Dose: A History of Radiation Protection in the Twentieth Century
by J. Samuel Walker (Author)

Ethics for Radiation Protection in Medicine (Series in Medical Physics and Biomedical Engineering)
by Jim Malone (Author), Friedo Zölzer (Author), Gaston Meskens (Author), Christina Skourou (Author)

Introduction to Megavoltage X-Ray Dose Computation Algorithms (Series in Medical Physics and Biomedical Engineering)
by Jerry Battista (Editor)

MDCT Physics: The Basics: Technology, Image Quality and Radiation Dose
by Mahadevappa Mahesh MS PhD (Author)

Advanced and Emerging Technologies in Radiation Oncology Physics (Series in Medical Physics and Biomedical Engineering)
by Siyong Kim (Editor), John W. Wong (Editor)

Designing Spacecraft and Mission Operations Plans to Meet Flight Crew Radiation Dose Requirements: Why is this an "Epic Challenge" for Long-Term Manned Interplanetary Flight
by Steven Kootnz (Author), NASA Technical Reports Server (NTRS) (Creator)

Radiation Dose Assessment for Ionizing and Ultraviolet Radiation
by Hussain ali al-jobouri (Author), Fala Hatem Taha (Author)

Handbook of Radiation Doses in Nuclear Medicine and Diagnostic X-Ray
by James G. Kereiakes (Author), Marvin Rosenstein (Author)

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".