A targeted contrast agent for magnetic resonance imaging of thrombus: Implications of spatial resolution

✍ Scribed by L.O. Johansson; A. Bjørnerud; H.K Ahlström; D.L. Ladd; D.K. Fujii

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 158 KB
• Volume: 13
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.1086

✦ Synopsis

Abstract

A preparation of ultra‐small superparamagnetic iron oxide (USPIO) particles coupled to an RGD peptide (RGD‐USPIO) was investigated as an MR contrast agent, targeted to activated platelets, in both ex vivo and in vivo thrombus models. Thrombus visualization ex vivo was compared using RGD‐USPIO and a non‐targeted UPSIO. The influence of thrombus visualization on thrombus exposure time to RGD‐USPIO (ex vivo) and on the spatial resolution of the MR image (ex vivo and in vivo) was assessed. RGD‐USPIO resulted in better thrombus visualization than non‐targeted USPIO ex vivo, and maximum enhancement was achieved after approximately one hour exposure time of the thrombus to RGD‐USPIO. The ability to visualize the clots was highly dependent on the spatial resolution of the image. In vivo, an in‐plane resolution of less than 0.2 × 0.2 mm^2^ was required for good clot visualization after contrast enhancement. It is concluded that the achievable resolution and sensitivity is a potential limitation to the usefulness of active vascular targeting in MRI. J. Magn. Reson. Imaging 2001;13:615–618. © 2001 Wiley‐Liss, Inc.