UCL News


UCL in the News: Laser scanner gives 3D view inside tumours

14 December 2007

David Robson, NewScientist.


Existing ultrasound scanners capture images by aiming high-frequency sound waves at the body. These waves reflect whenever the density of tissue changes, for example at the boundary between muscle and bone. The resulting "echoes" are then used to create a picture.

Such scanners … produce only low-contrast images of the inside of a tumour, because the density of blood vessels is similar to that of the surrounding tissue.

Paul Beard [UCL Medical Physics & Bioengineering] and colleagues have now developed a high-resolution photoacoustic tomography scanner that offers a solution.

This shoots very short pulses of non-harmful near-infrared laser light at a tumour. As the light is absorbed by tissue, the cells heat up and expand very slightly, creating an ultrasound wave that can then be detected by a sensor. …

"It's very scalable," Beard told New Scientist. "Our scanner is best suited to providing high-resolutions images at a short range, but the technique could be used to image tumours a few centimetres into the breast." …

In order to convert the reflected ultrasound into a high-resolution 3D image the team had to create a new ultrasound sensor as well. …