An imaging system having an imaging device for imaging at least a portion of an animal. The imaging device may be of an X-ray computed tomography (CT) type, a positron emission tomography (PET) type, a single-photon emission computed tomography (SPECT) type, or a fluorescence and phosphorescence microscopy (FPM) type. The system also includes: a photon transmitter that transmits photons and that is introducible within the body of an animal at least one imaging photon detector that detects fluorescence excited within the animal by the transmitted photons and an image processor that superimposes an imaging device image and a photon detector image so as to yield a combined image.
