Polymeric gadolinium chelate magnetic resonance imaging contrast agents: Design, synthesis, and properties

We have synthesized and evaluated five series of polymeric gadolinium chela tes which are of interest as potential MRI blood pool contrast agents. The polymers were designed so that important physical properties including mole cular weight, relaxivity, metal content, viscosity, and chelate stability c ould be varied. We have shown that, by selecting polymers of the appropriat e MW, extended blood pool retention can be achieved. In addition, relaxivit y can be manipulated by changing the polymer rigidity, metal content affect ed by monomer selection, viscosity by polymer shape, and chelate stability by chelator selection.