UCL News


Looking at the body in a whole new light

3 July 2006

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What goes through David Beckham's mind as he lines up to take a free kick? How do babies learn language? How will a tumour respond to treatment? New optical imaging techniques, which go on display at the Royal Society Summer Science Exhibition tonight, could answer these and many other questions about how the human brain works.

The systems, developed at the Biomedical Optics Research Laboratory at UCL Medical Physics & Bioengineering and the Medical Optics Group at the University of Essex, use near infrared light to look inside the body in a new way.

Near infrared spectroscopy is a non-invasive technique which takes advantage of the relative absorption of different wavelengths of light and allows researchers to differentiate between oxygenated arterial blood - which appears red - and venous blood which appears purple/blue. Researchers at the University of Essex are shining near infrared light on the brain and muscles to test the theory that when a footballer visualises taking a free kick, the same blood flow pathways in his mind and body are activated as when he actually takes it.

Optical tomography makes it possible to assess brain function in newborn and premature babies. A device developed at UCL measures the flight times of photons across the head using ultra-short pulses of laser light. The information is then used to reconstruct 3D images of blood volume and oxygenation. The optical images can be used to characterise how the brain develops and to detect abnormalities associated with brain damage.

Photoacoustic imaging allows mapping of tiny blood vessels that proliferate as a tumour grows. By imaging the oxygen levels in these blood vessels it may be possible to help predict how a tumour will respond to treatment. The technique works by firing extremely short laser pulses, which are a few billionths of a second in duration. These generate sound waves in tissue which are then detected at the surface and used to create an image.

Dr Clare Elwell, UCL Medical Physics & Bioengineering, who helped put the exhibit together, said: "The optical systems we are developing are portable and completely safe to use. This means we can cast light on dynamic processes within the body which are difficult to measure with other techniques such as X-rays and magnetic resonance imaging."

The exhibit, entitled 'Shedding light on the human body', will feature at the Royal Society Summer Science Exhibition in London (3-7 July) and at the Glasgow Science Centre (12-14 September).

Image: A baby's brain is examined using optical tomography