Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Micro-engineered local field control for high-sensitivity multi-spectral MRI



Gary Zabow, Stephen Dodd, John M. Moreland, Alan P. Koretsky


In recent years, biotechnology and biomedical research have benefited from the introduction of a variety of specialized nanoparticles whose well-defined, optically distinguishable signatures enable simultaneous tracking of numerous biological indicators. Unfortunately, equivalent multiplexing capabilities are largely absent in the field of magnetic resonance imaging (MRI). Comparable magnetic-resonance labels have generally been limited to relatively simple chemically synthesized superparamagnetic microparticles that are, to a large extent, indistinguishable from one another. Here we show how it is instead possible to use a top-down microfabrication approach to effectively encode distinguishable spectral signatures into the geometry of magnetic microstructures. Although based on different physical principles from those of optically probed nanoparticles, these geometrically defined magnetic microstructures permit a multiplexing functionality on the magnetic resonance radio-frequency spectrum that is in many ways analogous to that permitted by quantum dots in the optical spectrum. Additionally, [I]in situ[/I] modification of particle geometries may facilitate radio-frequency probing of various local physiological variables.


contrast agent, magnetic resonance imaging, MEMS, micro-engineering, microfabrication, micromagnetics, nuclear magnetic resonance


Zabow, G. , Dodd, S. , Moreland, J. and Koretsky, A. (2008), Micro-engineered local field control for high-sensitivity multi-spectral MRI, Nature, [online], (Accessed May 28, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 19, 2008, Updated February 19, 2017