Molecular Optical Imaging with Radioactive Probes

BACKGROUND: Optical imaging (OI) techniques such as bioluminescence and fluorescence imaging have been widely used to track diseases in a non-invasive manner within living subjects. These techniques generally require bioluminescent and fluorescent probes. Here we demonstrate the feasibility of using radioactive probes for in vivo molecular OI. METHODOLOGY/PRINCIPAL FINDINGS: By taking the advantages of low energy window of light (1.2–3.1 eV, 400–1000 nm) resulting from radiation, radionuclides that emit charged particles such as β(+) and β(−) can be successfully imaged with an OI instrument. In vivo optical images can be obtained for several radioactive probes including 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG), Na(18)F, Na(131)I, (90)YCl(3) and a (90)Y labeled peptide that specifically target tumors. CONCLUSIONS/SIGNIFICANCE: These studies demonstrate generalizability of radioactive OI technique. It provides a new molecular imaging strategy and will likely have significant impact on both small animal and clinical imaging.