Use of a contrast agent for magnetic resonance imaging of endoleaks

The present invention relates to the use of an agent for the preparation of a diagnostic agent for contrast-enhanced diagnostic MR imaging of endoleak. In particular, the present invention relates to the use of a contrast agent for the visualizing of endoleak via MR imaging, e.g. after endovascular aneurysm repair. The use of an agent is disclosed, said agent comprising: iv. an image-enhancing moiety (IEM), v. a plasma protein binding moiety (PPBM), and vi. a blood half-life extending moiety (BHEM), the agent demonstrating at least about 10% binding to plasma proteins, measured in plasma, and, in a rat plasma pharmacokinetic experiment, an area under the plasma concentration versus time curve from 0 to 10 minutes, which is at least about 20% greater than observed for the combination of the IEM and the PPBM alone without the BHEM; wherein said agent is used for the manufacture of a pharmaceutical contrast agent for diagnostic MR imaging of endoleak.