Open AccessNMR relaxation and magnetic properties of superparamagnetic nanoworms
Author(s) -
Gossuin Yves,
Disch Sabrina,
Vuong Quoc L.,
Gillis Pierre,
Hermann Raphaël P.,
Park JiHo,
Sailor Michael J.
Publication year - 2010
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.387
Subject(s) - superparamagnetism , maghemite , relaxation (psychology) , nuclear magnetic resonance , magnetization , materials science , saturation (graph theory) , magnetic resonance imaging , relaxometry , magnetic nanoparticles , magnetic field , chemical physics , nanoparticle , nanotechnology , condensed matter physics , chemistry , physics , spin echo , medicine , radiology , quantum mechanics , mathematics , combinatorics
Maghemite particles are used as T 2 contrast agents for magnetic resonance imaging, especially for molecular and cellular imaging. Linear clusters of particles – called nanoworms – were recently developed to enhance the targeting efficiency. In this work, the magnetic and NMR relaxation properties of these nanoworms are studied at multiple magnetic fields. After the usual saturation at 0.5 T, the magnetization of the worms is still increasing, which results in an appreciable increase of the transverse relaxivity at high magnetic fields. The obtained relaxivities are typical of superparamagnetic particles of iron oxide (SPIOs). The transverse relaxation of the worms is clearly more efficient than for the isolated grains, which is confirmed by computer simulations. At high field, the longitudinal relaxation of the worms is less pronounced than for the grains, as expected for SPIOs. The nanoworms thus constitute a promising T 2 agent for cellular and molecular imaging. Copyright © 2010 John Wiley & Sons, Ltd.