University of Texas at Dallas researchers are breathing new life into an old MRI contrast agent by attaching it to a plant virus and wrapping it in a protective chemical cage. MRI is a commonly used medical imaging technology that allows physicians to see soft tissues in the body. Some tissues, like cancer, are better seen when a patient is given a contrast agent, which makes diseased parts of the body show up brightly in an MRI scan. Gassensmith’s research group repurposed the agent by first attaching the ORCA molecules to thousands of docking sites on a tobacco mosaic virus. “The cage and the contrast agent just sort of stick together — they don’t form a chemical bond with one another,” Gassensmith said.