article_snippet: The new technique involves firing pulses of light, more of which is absorbed by cancerous cells than by healthy tissue.
article_snippet: The way the cancer cells react to the light means the cancer cells can then be picked up on an ultrasound scan.
article_snippet: an ultrasound scan can show not only if someone has the disease, but also potentially how advanced the disease is.
article_snippet: The way the cancer cells react to the light from the laser beams means the cancer cells can then be picked up on an ultrasound scan .
article_snippet: A CT or MRI scan is performed only if the biopsy suggests there is cancer.
article_snippet: a smear test works on the principle that cancerous tissues (and possibly even pre-cancerous cells) absorbs more light than healthy tissue.
article_snippet: This is because of changes in cancerous tissue such as the formation of new, abnormal blood vessels and fewer collagen fibres (a tough, connective tissue).
article_snippet: The cancerous tissue can then be picked up on an ultrasound scan because the extra energy absorbed from the light is converted into heat, which causes the cells to expand and affects the way soundwaves bounce back to the scanner, creating an image of the cells with cancerous changes.
article_snippet: This is because the more advanced the disease, the greater the amount of light and energy absorbed by the cells; these areas then look even more pronounced on a scan.
article_snippet: The technique has so far been tested on tissue samples from 30 women — some with cancer and some who were healthy — which showed that it can distinguish between the two.
article_snippet: The study is published in Biomedical Optics Express, the journal of the Optical Society of America.
article_snippet: The same technology is also being investigated for detecting and monitoring other cancers, including breast and skin.
highlights_snippet: Cancerous tissue can be picked up on an ultrasound scan because of laser .