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Microfabricated high‐moment micrometer‐sized MRI contrast agents
Author(s) -
Zabow Gary,
Dodd Stephen J.,
Shapiro Erik,
Moreland John,
Koretsky Alan P.
Publication year - 2011
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.22647
Subject(s) - microfabrication , micrometer , materials science , tracking (education) , contrast (vision) , superparamagnetism , nanotechnology , signal (programming language) , nuclear magnetic resonance , biomedical engineering , computer science , magnetic field , optics , physics , magnetization , artificial intelligence , medicine , psychology , pedagogy , alternative medicine , pathology , quantum mechanics , fabrication , programming language
Abstract While chemically synthesized superparamagnetic microparticles have enabled much new research based on MRI tracking of magnetically labeled cells, signal‐to‐noise levels still limit the potential range of applications. Here it is shown how, through top‐down microfabrication, contrast agent relaxivity can be increased several‐fold, which should extend the sensitivity of such cell‐tracking studies. Microfabricated agents can benefit from both higher magnetic moments and higher uniformity than their chemically synthesized counterparts, implying increased label visibility and more quantitative image analyses. To assess the performance of microfabricated micrometer‐sized contrast agent particles, analytic models and numerical simulations are developed and tested against new microfabricated agents described in this article, as well as against results of previous imaging studies of traditional chemically synthesized microparticle agents. Experimental data showing signal effects of 500‐nm thick, 2‐μm diameter, gold‐coated iron and gold‐coated nickel disks verify the simulations. Additionally, it is suggested that measures of location better than the pixel resolution can be obtained and that these are aided using well‐defined contrast agent particles achievable through microfabrication techniques. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.