Skin deep details

A new optical method that can image subsurface structures under skin has been demonstrated by scientists at the

(NIST) and the

.

The method relies on differences in the way surface and subsurface features of various materials scatter light. It was demonstrated with small pieces of pigskin and inorganic materials but might eventually prove useful for imaging living tissues to help diagnose or determine the extent of various types of skin cancers.

The imaging process involves illuminating a sample with polarised light, which has its electric field oriented in a particular direction, and using a digital camera with a rotating polarisation filter to image the light scattered from the sample.

Researchers manipulated the polarisation to minimise light scattered from the rough skin surface, and positioned the light source in multiple locations to separate out, and delete, light scattered more than one time from deeper sample layers. By using certain polarisation settings and combining two images made with the light source in different positions, they generated a processed image that reveals significant subsurface structure.