Albumin labeled with Gd-DTPA. An intravascular contrast-enhancing agent for magnetic resonance blood pool and perfusion imaging.

Paramagnetic macromolecules like Gd-DTPA labeled albumin offer certain beneficial features that distinguish them from smaller molecular paramagnetic contrast media, such as Gd-DTPA dimeglumine, which generally distribute in the extracellular fluid space. By joining multiple paramagnets to one large carrier molecule, the molar dose of the agent necessary for image enhancement is reduced, the proton relaxation effectiveness of such macromolecular agents is increased and they may even serve as markers of perfusion and abnormal vascular permeability. The accumulated experimental results with albumin labeled with Gd-DTPA are described.