Enhanced ferrite nanoparticles as MRI contrast agents

Enhanced ferrite nanoparticles are a new class of contrast agents for magnetic resonance imaging (MRI). The enhanced ferrites are synthesized by reverse micelles technique to form iron core and oxide or ferrite shell preventing further oxidation of the nanoparticles. The nanoparticles are further functionalized using dopamine and PEG-600 to increase the solubility of the high magnetic moment nanoparticles. 1H relaxation measurements of aqueous solutions of the nanoparticles were conducted at 2.4 T. The relaxivities r1 and r2, representing the slopes of these curves, are 7.19 and 9.96 s−1 mM−1, respectively. These values should be compared with relaxivities of 4–5 s−1 mM−1 corresponding to commonly used commercial contrast agents in human MR examinations.