The microbubbles help to make the images produced by an ultrasound scan much clearer.

This may be particularly relevant for detecting small lesions where other imaging techniques are relatively unsuccessful Professor David Cosgrove

This should make it easier for doctors to use the scans to identify cancerous tumours.

The principle underlying this new technology is that microbubbles resonate under an ultrasound beam.

The pressure changes produced by the sound wave cause the tiny gas filled bubbles to contract and expand rapidly.

The bubbles also vibrate particularly strongly at the high frequencies used for diagnostic ultrasound.

This makes them several thousand times more reflective than normal body tissue, and means that they show up very clearly on ultrasound scans.

Liver research

Researchers at Hammersmith Hospital have exploited the procedure with particular success in the liver - which displays a strong affinity for taking up the microbubbles.

The additional clarity provided by the bubbles has meant that tumours within the liver are immediately visible as defects.

Researcher Professor David Cosgrove said: "Early studies suggest that both the sensitivity and specificity of ultrasound to cancerous tumours is substantially increased using this technique.

"This may be particularly relevant for detecting small lesions where other imaging techniques are relatively unsuccessful."

Professor Cosgrove said the technology was also being used to distinguish between different types of liver disease and the diagnosis of cirrhosis.

"This is especially encouraging since traditional imaging techniques can be unhelpful and patients often require a biopsy."