Disease captured by UCL hand-held 3D photoacoustic scanner. Credit: Dr Nam Huynh.

Researchers believe a new medical imaging device could transform the way in which cancers and arthritis diagnoses are determined.

A new hand-held scanner developed by UCL researchers can generate highly detailed 3D photoacoustic images in just seconds, paving the way for their use in a clinical setting for the first time and offering the potential for earlier disease diagnosis.

In the study the team show their technology can deliver photoacoustic tomography (PAT) imaging scans to doctors in real time, providing them with accurate and intricate images of blood vessels, helping inform patient care.

Photoacoustic tomography imaging uses laser-generated ultrasound waves to visualise subtle changes (an early marker of disease) in the less-than-millimetre-scale veins and arteries up to 15mm deep in human tissues.

However, up until now, existing PAT technology has been too slow to produce high-enough quality 3D images for use by clinicians.

During a PAT scan patients must be completely motionless, meaning any movement during a slower scan can cause images to blur and therefore not guarantee clinically useful images.

The older PAT scanners took more than five minutes to take an image – by reducing that time to a few seconds or less, image quality is much improved and far more suitable for people who are frail or poorly.

Researchers say the new scanner could help to diagnose cancer, cardiovascular disease and arthritis in three to five years’ time, subject to further testing,

Corresponding author Professor Paul Beard, of UCL Medical Physics and Biomedical Engineering and the Wellcome/ EPSRC Centre for Interventional and Surgical Sciences, said: “We’ve come a long way with photoacoustic imaging in recent years, but there were still barriers to using it in the clinic.

“The breakthrough in this study is the acceleration in the time it takes to acquire images, which is between 100 and 1,000 times faster than previous scanners.”

He explained: “This speed avoids motion-induced blurring, providing highly-detailed images of a quality that no other scanner can provide. It also means that rather than taking five minutes or longer, images can be acquired in real time, making it possible to visualise dynamic physiological events.

“These technical advances make the system suitable for clinical use for the first time, allowing us to look at aspects of human biology and disease that we haven’t been able to before.

“Now more research is needed with a larger groups of patients to confirm our findings.”

Beard added that a key potential use for the new scanner was to assess inflammatory arthritis, which requires scanning all 20 finger joints in both hands.

With the new scanner, this can be done in a few minutes – older PAT scanners take nearly an hour, which is too long for elderly, frail patients, he said.

Speed

In the study, the UCL researchers sought to overcome the speed problem by reducing the time needed to acquire images. They achieved this by making innovations in the scanner design and the mathematics used to generate the images.

Unlike earlier PAT scanners, which measured the ultrasound waves at more than 10,000 different points over the tissue surface one at a time, the new scanner detects them at multiple points simultaneously, reducing image acquisition time considerably.

The research team also employed similar mathematical principles to those used in digital image compression.

This enabled high-quality images to be reconstructed from a few thousand (rather than tens of thousands) of measurements of the ultrasound wave, again speeding up image acquisition.

These innovations reduced the imaging time to a few seconds or less than a second, eliminating motion-blur and allowing images of dynamic changes to the tissue to be taken.

The scientists said more research was needed with a larger group of patients to confirm their study’s findings and the extent to which the scanner would be clinically useful in practice.

The study is published in Nature Biomedical Engineering.