Toward high relaxivity and high stability in Gd MRI agents

NUCL 99

Kenneth N. Raymond, raymond@socrates.berkeley.edu1, Eric J. Werner, ejwerner@berkeley.edu2, and Christoph J. Jocher, jocher@berkeley.edu2. (1) Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460, (2) Department of Chemistry, University of California, Berkeley, CA 94720
Gadolinium chelates are the standard commercial MRI contrast agents. However, their relaxivity is only 1 to 10 % what is theoretically possible. For further improvement as many coordinated water molecules as possible are needed, yet complex stability must be maintained to minimize in vivo toxicity. In addition, the water exchange rate and rotational correlation time must be optimized. These parameters limit relaxivity in current commercial poly(amino-carboxylate) complexes and present challenging problems of fundamental coordination chemistry. A series of Gd(III) complexes based on hydroxypyridinone and terephthalamide has been prepared. These complexes are stable and have substantially higher relaxivity than most clinically used agents. The fast water exchange rate and relaxivity at several field strengths have been studied. The feasibility of using these chelates as contrast agents is enhanced by their excellent selectivity for Gd(III) binding and low anion affinities. New developments will be presented.

 

Recent Advances in Molecular Imaging
1:25 PM-5:00 PM, Wednesday, 13 September 2006 Moscone Center -- Room 272, Oral

Division of Nuclear Chemistry & Technology

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006