To traverse the chasm from in vitro therapeutic studies to clinical applications in translational research, animal models that mimic various human diseases are employed to evaluate the ecacy of new therapeutics. Such evaluations in animal models require various imaging and histochemical methods. For conventional histochemical or immunohistochemical analysis, animals are sacriced at multiple time points prior to performing tissue sectioning and staining to visualize the location of certain molecules or cells. To reduce experimental variability, number of animals required, and the duration and cost of animal studies, noninvasive imaging modalities have been developed that allow researchers to follow disease progression by monitoring events repeatedly in the same living animals.