Magnetic Resonance Imaging (MRI) is a noninvasive imaging technique that provides multidimensional images of the soft tissues of the body. This imaging technique has proven to be an excellent diagnostic and experimental tool for the detection of pathologic alterations in soft tissues, as well as an adjunct screening method for following the genesis, progression, or regression of chemically induced lesions in the same live animal. Future applications of MRI technology in small animals include MRI microscopy, mapping of vascular or circulatory alterations, measurement of perfusion and diffusion rates of body fluids, and acquisition of cell metabolic states in combination with Nuclear Magnetic Resonance (NMR) spectroscopy, all of which will contribute immensely to the advancement of toxicologic and biomolecular research.