The present application is directed to an imaging system having an imaging device for imaging at least a portion of an animal, wherein said imaging device is selected from a group consisting of X-ray computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT), fluorescence and phosphorescence microscopy (FPM), infrared light spectroscopy (IR), Raman spectroscopy, ultrasound and any combination thereof. The system further comprises a photon transmitter of photons, introducible within the body of an animal at least one imaging photon detector located either within or outside said animal, for detecting fluorescence excited within said animal by said transmitted photons and an image processor adapted to superimpose said imaging device image and said photon detector image generating a rendered image of said at least a portion of said animal. Further, the present invention relates to a method of using the system.
