Investigation of magnetic properties of various complexes prepared as contrast agents for MRI

WOS: 000261711400063In this study, the relaxivities of various ferri-ferro and superparamagnetic particles in human serum and deionized water were determined by using MRI system operating at 1.5 T. For this purpose, the spin-lattice (1/T-1) and spin-spin (1/T-2) relaxation rates in serum and deionized water were measured versus increasing concentrations of the DyPO4, 5Fe(2)O(3)3Gd(2)O(3) + dextran, 5Fe(2)O(3)3Gd(2)O(3) + CMC, 5Fe(2)O(3)3Gd(2)O(3). The longitudinal relaxivity (r(1)) and transverse relaxivity (r(2)) of proton were determined from the slopes of fits between the relaxation rates and concentrations. T-1 and T-2 times in serum were decreased due to increased concentrations of the ions added to samples. The r(2)/r(1) values for ions added to serum ranged from 1 to 4, whereas the r(2)/r(1) for the ions added to water changed between 0.57 and 1 except that for 5Fe(2)O(3)3Gd(2)O(3). PRRE (proton relaxation rate enhancement) data reveals that, the ions added to serum are not bound to the proteins. The present results suggest that chemical compounds of iron oxide studied may have a potential that can be used as an alternative superparamagnetic MRI contrast agent. (C) 2008 Elsevier B.V. All rights reserved.Research Foundation of Ege UniversityEge University [2003/FEN/01]We are grateful to Prof. Dr. Muruvvet Yurdakoc and Research Assistant Yoldas Seki (Faculty of Science, Department of Chemistry, Dokuz Eylul University) for assistance in the preparation of samples. In addition, we thank Prof. Dr. Ali Yilmaz (Faculty of Science, Department of Physics, Dicle University) for his helpful advice.; This work was partially supported by the Research Foundation of Ege University, Grant No. 2003/FEN/01