1. A phantom device for use with a low-level light imaging system, the phantom device comprising: a body including one or more surfaces and an optically selective material designed to at least partially resemble the optical behavior of mammalian tissue; and a low intensity light source disposed within the body and configured to emit light from within the body, through the optically selective material and to the one or more surfaces, wherein the light source is configured to emit a photon flux in the range of about 10 4 to about 10 13 photons/second.