Abstract
We investigate the particle size dependence of the relaxivity of hydrogen protons in an aqueous solution of iron oxide (Fe 3O 4) nanoparticles coated in silica for biocompatibility. The T 1 and T 2 relaxation times for various concentrations of silica-coated nanoparticles were determined by a magnetic resonance scanner. We find that the relaxivity increased linearly with increasing particle size. The T 2 relaxivity (R 2) is more than 50 times larger than the T 1 relaxivity (R 1) for the nanoparticle contrast agent, which reflects the fact that the T 2 relaxation is mainly influenced by outer sphere processes. The high R 2/R 1 ratio demonstrates that silica-coated iron oxide nanoparticles may serve as a T 2 contrast agents in magnetic resonance imaging with high efficacy.
Original language | English |
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Pages (from-to) | 969-974 |
Number of pages | 6 |
Journal | Current Applied Physics |
Volume | 12 |
Issue number | 3 |
DOIs | |
State | Published - May 2012 |
Keywords
- Contrast agent
- Iron oxide nanoparticle
- MRI
- Relaxivity
- Silica coating