摘要 |
<p>Novel MRI contrast agents that comprise one or more metal-ion chelates in juxtaposition with one or more free-radical nitroxide compounds in a polymeric or oligomeric molecule. Both the chelate units and the free radical units may, independently, be inside the main chain of the polymer or in a side chain of the linkage portion of the polymer. The number of combined units of chelates and free radicals in the polymer or oligomer is at least two.</p> |