SIAscopy measures the amount of haemoglobin, melanin and collagen in the stratum corneum, epidermis and dermis to a depth of 2 mm, and identifies whether melanin is present in the epidermis or the dermis. The information is presented as SIAscans, which show how these components vary over the skin.
SIAscopy makes use of the way light interacts with skin – the way it scatters or bounces and the amount absorbed by cells and other structures – and how this varies for different wavelengths or colours of light and is based on Symon Cotton's PhD thesis. Due to the multi-layered structure of the skin, and because the most prominent chromophores have slowly varying spectral properties, it is possible to generate models which can predict the method of light transport within skin. This allows analysis of the skin using broadband spectrophotometric techniques. The device used to capture the information is a SIAscope.
In order to generate the model, simulations are run for hundreds of thousands of different combinations of haemoglobin, melanin, collagen and dermal melanin. The result of each simulation represents how the camera would respond if it was to image the corresponding combination of skin chromophores. This information is stored, and then interrogated during each scan in order to generate SIAscans. Each SIAscan is a bitmap representing the concentration of each chromophore on every pixel.
The example SIAscan shows a melanoma with a series of views of the in-vivo pathology.
SIAscopy is used in the diagnosis of melanoma and also by the cosmetic industry for testing and analyzing products for effects and reactions.
- Cotton S. D (1998) A non-invasive imaging system for assisting in the diagnosis of malignant melanoma. PhD thesis. Birmingham University, UK
- M. MONCRIEFF,S. COTTON, E. CLARIDGE AND P. HALL (2002) Spectrophotometric intracutaneous analysis: a new technique for imaging pigmented skin lesions, British Journal of Dermatology 2002; 146: 448–457.