The diethylenetriaminepentaacetic acid-chelate contains five acetate moieties linked by a molecular backbone, which bind a metallic ion complex. This chemical bonding solves the problem of toxicity of, e.g. Gadolinium, because DTPA complexes are very stable.
DTPA is used together with technetium-99m as a nuclear imaging radiopharmaceutical and with gadolinium as a MR contrast medium. DTPA chelates undergo renal glomerular filtration and can be used to quantify it. DTPA is also used as a decontamination agent in individuals who have ingested radioactive materials.

Short name: Gd-DTPA-PEG, generic name: Gd-DTPA-PEG polymers, chemical compound: Gadolinium DTPA polyethylene glycol, central moiety: Gd2+, relaxivity: r1=6.0, B0=1.0 T
A substance under development (preclin.) as an intravascular MRI contrast agent for MR angiography and capillary permeability detection.

Short name: PLLGd-DTPA, generic name: (Gd-DTPA)n-polylysine, chemical compound: Gd-DTPA poly(L-lysine-Gd-diethylenetriamine-N,N,N',N'',N''-pentaacetic acid), central moiety: Gd2+, relaxivity: r1=13.1, B0=0.23T
A polymeric MRI contrast agent under development (preclin., Bayer Schering Pharma AG, Berlin, Germany) with advantages in both MRA and in the differential diagnosis of tumors, particularly in perfusion studies of the myocardium and potential in MR lung perfusion. Dozens of the relatively small molecule Gd-DTPA is bound covalently to polylysine, a large molecular weight backbone. The stable, highly water-soluble agent does not diffuse through the endothelium of the vascular system; it is subject to renal elimination.

Short name: Gd-DTPA mesoporphyrin, generic name: gadophrin, central moiety: Gd2+
Gd-DTPA mesoporphyrin is a substance under development (Bayer Schering Pharma AG) as a positive enhancing myocardium- and necrosis- targeted MRI contrast agent.

See also Metalloporphyrins and Necrosis Avid Contrast Agent.

Short name:(Gd-DTPA)n-dextran, central moiety: Gd2+
Gd-DTPA labeled dextran is a substance that has been tested as a blood pool agent (intravascular MRI contrast agent). Dextran is a polysaccharide and has labeled with 15 Gd-DTPA moieties a higher T1 relaxivity than unbound Gd-DTPA, compared with a high safety level.

See also Intravascular Contrast Agents, Blood Pool Agents.