Figure 7: Small-animal imaging. Multiple imaging modalities are available for small-animal molecular imaging. Shown are views of typical instruments available and illustrative examples of the variety of images that can be obtained with these modalities. A, Coronal whole-body micro-PET image of a rat injected with FDG shows uptake of tracer in tissues that include muscle, heart, and brain and accumulation in bladder owing to renal clearance. B, Coronal micro-CT image of a mouse abdomen after intravenous injection of iodinated contrast medium. C, Coronal micro-SPECT image of mouse abdominal and pelvic regions after injection of technetium 99m–methylene diphosphonate shows spine, pelvis, tail vertebrae, femora, and knee joints owing to accumulation of tracer in bone. D, Optical reflectance fluorescence image of a mouse shows green fluorescent protein fluorescence from the liver, abdomen, spine, and brain. The mouse contains green fluorescent protein–expressing tumor cells that have spread to various sites. (Images courtesy of Dr Hoffman, Anticancer.) E, Coronal T2-weighted micro–MR image of a mouse brain. F, Optical bioluminescence image of a mouse with a subcutaneous xenograft expressing Renilla luciferase in the left shoulder region after injection of the substrate coelenterazine into the tail vein. Images were obtained using a cooled charge-coupled-device camera. The color image of visible light is superimposed on a photographic image of the mouse with a scale in photons per second per square centimeter per steradian (p/s/cm2/sr). (Reprinted, with permission, from reference 2.)