3-D Color X-ray Spots Corrosion, Cancer and Contraband

A camera that takes powerful 3-D color x-ray images in near real time and without a synchrotron x-ray source can identify the composition of scanned objects. This capability could significantly improve airport security screening, medical imaging and industrial inspection, among other applications.

Current imaging systems, such as spiral CAT scanners, do not use all the information contained in x-ray beams. The new hyperspectral camera device developed at the University of Manchester, however, uses all wavelengths to give a color x-ray image that provides extra information about the material structure at each voxel — the 3-D equivalent of a pixel. This extra information can be used to fingerprint the material present at each point in a 3-D image.

Scientists at the University of Manchester have developed a camera that can take powerful 3-D color x-ray images in near real time without a synchrotron x-ray source. The camera positively identified liquid in a bottle as iodine. Images courtesy of The University of Manchester.

Rather than mapping several separate images, the new system creates the image in one simple scanning motion, which now takes only several minutes.

This has implications for using the x-ray system for medical applications. “The fact the image can be taken at the same time as using more conventional methods and on the same timescale means more information can be gathered from biopsy samples,” said professor Robert Cernik of the university’s School of Materials. “This will more accurately differentiate between normal and abnormal tissue types, reducing misdiagnosis.”

“The fact that we can now use this technology in a laboratory setting is a substantial step forward,” Cernik said. “When we first developed the idea five years ago, we needed the power of a synchrotron to produce the x-rays. In addition we only had access to silicon-based detectors.” Silicon is a light atom that will not stop the high-energy x-rays that come through large objects.

The device can also identify chemicals and compounds such as cocaine, precious metals, radioactive materials and plastic explosives like semtex, even when they are contained inside a relatively large object like a suitcase. In geophysical exploration, it could be used to quickly analyze the content of core samples taken from bore holes. The method could also be used to image corrosion processes and chemical changes in fabricated parts such as aircraft wings, for example, indicating strain.

The hyperspectral camera can differentiate the materials inside a USB dongle. The various materials inside are highlighted in different colors.

In a recent experiment, the team used the technology to x-ray a USB dongle that controls webcams. They identified the different elements and components inside the dongle by analyzing the energy-sensitive radiographs and fluorescence patterns. The elements were highlighted in different colors to clearly identify them to the systems operator. In this case, the x-ray showed barium, bromine, silver, tin and zirconium.

The team can now achieve the same imaging results with an 80 x 80-pixel cadmium zinc telluride camera that supports real-time hyperspectral x-ray imaging up to very high energies, Cernik said.

He is now seeking industrial partners for collaborative projects to refine the x-ray technology for security, aerospace and medical imaging applications. The team is also close to creating the first color computed tomography scanner, which could advance airport security or drastically improve diagnoses for a range of conditions.

The study appeared in Analyst (doi: 10.1039/C2AN36157D).

For more information, visit: www.manchester.ac.uk