Single Crystalline Micrometric Iron Oxide Particles with Superparamagnetic Behaviour for MRI Apllications

M.L. Kiss, M. Chirita, C.A. Beljung, R. Polanek, C. Savii, A. Ieta, A. Ionut Mihaila Chirita
State University of New York at Oswego, US

Keywords: micrometric iron oxide, superparamagnetic, MRI

Summary:

A major drawback of using metal oxide nanoparticles as contrast agent in MRI is related to their low saturation magnetization mainly due to their particle size. The current works seeks to solve this problem by increasing the number of nanoparticles, of micrometer sized clustered particles. All studies show that to be effective in improving MRI signal, millions of ultrasmall superparamagnetic iron oxide nanoparticles are needed to mark a single cell. Three different samples (three phantoms) were prepared by entering a different number of microparticles in the same volume (1 ml) of ultrasound gel. These samples were placed in the MRI device and subjected to MRI RF signal. The results show artifacts due to the high intensity magnetic response of the particles. In the best obtained image the concentration of microparticles was extremely small. On careful examination, air bubbles can be observed in the gel, which means that there is the concrete possibility that in an appropriate environment and a well-defined concentration, SCMSPIO particles can generate considerable improvement of MRI. For comparison, each image presents an Eppendorf tube containing pure gel and an Eppendorf tube with gadolinium contrast agent.