Comparison of dendrimer-based macromolecular contrast agents for dynamic micro-magnetic resonance lymphangiography

✍ Scribed by Hisataka Kobayashi; Satomi Kawamoto; Peter L. Choyke; Noriko Sato; Michael V. Knopp; Robert A. Star; Thomas A. Waldmann; Yutaka Tagaya; Martin W. Brechbiel

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 563 KB
• Volume: 50
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.10583

✦ Synopsis

Abstract

Few methods are currently available to visualize the entire lymphatic system. A method known as micro‐magnetic resonance lymphangiography (MRL), which employs a dendrimer‐based MRI contrast agent (PAMAM‐G8) and a clinical‐grade 1.5T MRI instrument, was recently developed for use in mice. In the present study, three dendrimer‐based MRI contrast agents (PAMAM‐G8, DAB‐G5, and PAMAM‐G4) with different pharmacokinetic characteristics were compared to determine the best reagent to visualize the lymphatic system under physiological or pathological conditions. In addition, two established MRI contrast agents (Gadomer‐17 and Gd‐[DTPA]‐dimeglumine (Magnevist)) were used as control agents. In experiments with mice, most of the deep lymphatic system was visualized by micro‐MRL with all agents except Gd‐[DTPA]‐dimeglumine. PAMAM‐G8 was best for visualizing lymphatic vessels, whereas DAB‐G5 was better for visualizing lymph nodes. PAMAM‐G4 was intermediate in character between PAMAM‐G8 and DAB‐G5, except in exhibiting a low background signal (especially in the liver). The lymphatic system was not clearly visualized with Gd‐[DTPA]‐dimeglumine; however, the lymph nodes were visualized with Gadomer‐17, although not as well as with dendrimer‐based agents. In conclusion, DAB‐G5 and PAMAM‐G4 can be used to identify lymph nodes and lymphatic vessels, respectively. Their rapid excretion makes these compounds potentially attractive for human use. Magn Reson Med 50:758–766, 2003. Published 2003 Wiley‐Liss, Inc.