New Method Uses Light to Diagnose Skin -- MEDICA - World Forum for Medicine

With an Optical Coherence Tomography (OCT) device, a beam of white light would be emitted towards the skin. The light is reflected and collected by a detector that translates the information into images. The images are displayed on a computer screen. They show the structure of the skin, and a trained eye will be able to distinguish damaged tissue from healthy tissue.

But, this scenario still lies in the future. Most of the knowledge about OCT is still confined to research laboratories worldwide. Several researchers are focusing on measuring tissue structures, while Trude Stoeren, a research fellow at University of Trondheim (NTNU), is working on collecting information about the tissues' special characteristics.

"In Trondheim we are researching the use of OCT in photodynamic cancer therapy. This method is already being used. Our technology could improve this method," says the physicist.

OCT does not provide sharp and detailed images deeper than a few millimetres, and is therefore best suited to photograph tissues in the upper layers of the skin. However, it is believed that the technique holds a trump card in its hand: Light can easily be transmitted to clinical imaging devices such as microscopes, fibre optic endoscopes, catheters and needles.

This quality presents a whole new world in which doctors can examine everything from blood veins to bladders, researchers hope. Trude Støren concludes: "The excitement of researching new methods is that totally new application may appear”.

With OCT, light is divided into two beams, with one beam directed to a reference mirror and the other to the sample being studied. Both are reflected back to the beam splitter, which sends them to a detector where they interfere with each other. The detector signal is then collected by a computer, which translates the information into pictures that can be interpreted, the researchers explain.; Source: University of Trondheim