Size analysis of carboxydextran coated superparamagnetic iron oxide particles used as contrast agents of magnetic resonance imaging

作者：Chen, D X^*; Sun, N; Gu, H C

来源：Journal of Applied Physics, 2009, 106(6): 063906.

DOI：10.1063/1.3211307

• Average particle size
• Commercial products
• Magnetic resonance imaging contrast agents
• Magnetization curves
• Superparamagnetic iron oxides
• Transmission electron microscopy images
• Transverse relaxation rate
• Water suspensions

Superparamagnetic iron oxide particles in commercial products Resovist and SH U555C, used as magnetic resonance imaging contrast agents, are polydispersed and covered with a thick organic coating so that the average particle sizes were reported between 3 and 62 nm with different definitions. It is unclear which size determines the transverse relaxation rate 1/T-2 of water suspensions of such particles. Comparing the measured 1/T-2 and average sizes of different definitions determined from magnetization curve, transmission electron microscopy image, x-ray diffraction, and dynamic light scattering, it is found that the 1/T-2 behavior is basically determined by the diameter of bare single-crystal magnetic particles having the particle-volume-weighted average volume (about 14 or 9 nm for Resovist or SH U555C and is slightly influenced by their thick organic coating. This is explained by the low partial density of the coating substance and the overwhelming water occupation adjacent to magnetic particles.

• 出版日期2009-9-15
• 单位上海交通大学