New hand-held scanner could transform cancer and arthritis diagnosis

A new scanner developed by University College London (UCL) researchers can generate highly detailed 3D images of tiny structures inside our bodies in seconds. Using this technology could offer the potential for earlier diagnosis of diseases like arthritis and cancer in a clinical setting for the first time. 

In a study partly funded by Cancer Research UK, the team showed that their hand-held scanners can deliver a photoacoustic image to doctors in real time. This specific type of imaging technology, called photoacoustic tomography (PAT), uses ultrasound waves to visualise subtle changes in veins and arteries.   

Up until now, PAT technology has been too slow to give high-enough quality images to be used by clinicians. Patients would have to stay incredibly still during the scan to ensure that the images wouldn’t be blurred.   

The older PAT scanners took more than 5 minutes to take an image, which can feel quite long when you’re not allowed to move. Because it only takes a few seconds, the new scanner gives doctors much better quality images and is much more suitable for people who are frail or poorly.  

“We’ve come a long way with photoacoustic imaging in recent years, but there were still barriers to using it in the clinic,” said Professor Paul Beard, lead of the Photoacoustic Imaging Group at UCL.  

“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.  

“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.” 

How do PAT scanners work?

Since PAT scanners were developed in 2000, they have been praised as having the potential to revolutionise our understanding of biological processes and improve clinical testing of cancer and other major diseases.   

PAT scanners work by firing very short laser bursts at body tissue. Some of this energy is absorbed, depending on the colour of the target, causing a slight increase in heat and pressure that then generates a faint ultrasound wave containing information about the tissue. This whole process takes place in just a fraction of a second.    

In earlier research, physicists and engineers at UCL (led by Professor Beard) discovered that the ultrasound wave can be detected using light.  

And in the early 2000s they pioneered a system where pulsed laser light absorbed by tissue generated ultrasound waves, which were then detected by ultrasound transducers. This became one of the first systems used in a PAT scanner.

The results revealed tissue structures which had never been seen before. For the first time, scientists had a non-invasive tool for looking at changes in tiny blood vessels which can often be missed by other imaging tests, like MRI scans.   

In this 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. The new PAT scanners can measure the ultrasound at multiple points over the tissue surface at the same time, which reduces the image development time significantly. 

How could this scanner help diagnose cancer?

We’ll need further testing to confirm how well the new scanner works in the clinic, but researchers say it could help doctors diagnose cancer, cardiovascular disease and arthritis. Tumours often have a high amount of small blood vessels that are too small to see with other imaging techniques, but PAT  scans can pick them up.