Washington: A new laser-based tool has been developed by scientists which, they claim, can assist doctors in better diagnosis of melanoma. It is the most lethal form of skin cancer that kills thousands of people every year.

The tool has been developed by a team at the Duke University in the US. It produces high-resolution images by pumping small amounts of energy into skin cells and help pinpoint rogue cells.

Thomas Matthews, who helped develop the new two-laser microscopy technique at Duke, said the new tool allowed scientists to identify substantial chemical differences between cancerous and healthy skin tissues.

For the study, which has been published in journal Science Translational Medicine, the Duke team imaged 42 skin slices with the new tool. Images showed that melanomas tend to have more eumelanin, a kind of skin pigment, than healthy tissue.

Using the amount of eumelanin as a diagnostic criterion, the team used the tool to correctly identify all 11 melanoma samples in the study.

The method will be further tested using thousands of archived skin slices. Studying old samples will verify whether the new technique can identify changes in moles that eventually become cancerous.

Even if the technique proves, on a large scale, to be 50 per cent more precise than a biopsy, it would prevent about 100,000 false melanoma diagnoses, said Warren S Warren, of Duke's Centre for Molecular and Biomolecular Imaging.