The present invention provides a hybrid imaging system for imaging a volume of interest of a subject, said hybrid system is characterized by:a. a MRI deviceb. a photon transmitter, introducible within the body of an animalc. at least one imaging photon detector located either within or outside said animal, for detecting fluorescence excited within said animal by said transmitted photons andd. an image processor adapted to superimpose said MRI image and said at least one photon detector image, generating a rendered MRI image of said volume of interest of the subject.The hybrid system is configured to substantially simultaneously acquire MRI image and in vivo fluorescence image.
