[Near-infrared rays in tissue diagnosis]

The application of Near-Infrared Radiation provides the physician with a method of reaching a specific and non-invasive examination of internal body parts: Without addition of a contrast medium, the distributions of local haematocrit, namely the structures of mainly subcutaneous blood vessels, can be shown with continuity and good definition in the regions of focus (NIR-Microangiopathy, especially for peripheral body sections). This paper introduced a transmission method able to penetrate even thick sections (> 30 mm). A new, simple method to evaluate reflected NIR parts permits a non-invasive and exact localization of inhomogeneities in organic substances of certain consistency (for instance milk and blood) up to depth of 20 mm.