[Principles of optical and fluorescence mediated tomography in turbid media]

Three-dimensional, tomographic imaging of biological tissues by means of visible light is becoming increasingly important. Current progress in the mathematical-physical modelling of photon propagation in scattering media allows spatially-resolved reconstructions of optical parameters with common computing hardware. Especially in the field of molecular imaging, optical tomography promises a transfer of knowledge from successful in vitro assays (as evaluated by fluorescence microscopy) to in vivo imaging of living animals. In the latter case, spatial resolution is not as critical as the ability to quantify the concentration of fluorescence-labelled probes, a task not solvable by the use of common planar imaging techniques. In this article, the theoretical foundations of optical tomography are introduced along with some examples of applications.