Abstract
For small excitation fields in the microtesla (μT) range, the dependency of the magnetic moment of magnetic iron oxide nanoparticles (MNP) on the external field can be regarded as linear. Sensitive superconducting quantum interference devices (SQUIDs) enable the detection of the response of MNP in biological tissue in the pT range. The co-registration of the excitation field is reduced by appropriate geometrical configuration of excitation coil and sensor coil. MNPs in a wide range of mean diameter and distribution parameters can be used for signal generation. The spatial distribution of MNP is reconstructed using data from a parallel multi-sensor and sequential multi-coil arrangement and applying linear estimation techniques. The time delayed response of MNP due to Brownian and Néel relaxation processes represents a specific signal not being influenced by the diamagnetic contribution of water in the tissue. We present the theoretical background and measurement data from different setups that will exemplify the concept.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Hanson, J.D., Hirshman, S.P.: Compact expressions for the Biot-Savart fields of a filamentary segment. Phys. Plasmas 9, 4410 (2002)
Steinhoff, U., Wiekhorst, F., Baumgarten, D., Haueisen, J., Trahms, L.: Imaging of magnetic nanoparticles based on magnetorelaxometry with sequential activation of inhomogeneous magnetization fields. Biomed. Tech. 55(S1(A)), 22–25 (2010)
Wiekhorst, F.: Magnetorelaxometry assisting biomedical applications of magnetic nanoparticles. Pharm. Res. (2012), doi:10.1007/s11095-011-0630-3
Crevecoeur, G., Baumgarten, D., Steinhoff, U., Haueisen, J., Trahms, L., Dupré, L.: Advancements in magnetic nanoparticle reconstruction using sequential activation of excitation coil arrays using magnetorelaxometry. Accepted in IEEE Trans. Mag. (2011)
Sepulveda, N.G., Thomas, I.M., Wikswo Jr., J.P.: Magnetic susceptibility tomography for three-dimensional imaging of diamagnetic and paramagnetic objects. IEEE Trans. Magn. 30, 5062–5069 (1994)
Baumgarten, D., Liehr, M., Wiekhorst, F., Steinhoff, U., Münster, P., Miethe, P., Trahms, L., Haueisen, J.: Magnetic nanoparticle imaging by means of minimum norm estimates from remanence measurements. Med. Biol. Eng. Comp. 46, 1177–1185 (2008)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2012 Springer-Verlag GmbH Berlin Heidelberg
About this paper
Cite this paper
Steinhoff, U. et al. (2012). Spatially Resolved Measurement of Magnetic Nanoparticles Using Inhomogeneous Excitation Fields in the Linear Susceptibility Range (<1mT). In: Buzug, T., Borgert, J. (eds) Magnetic Particle Imaging. Springer Proceedings in Physics, vol 140. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-24133-8_47
Download citation
DOI: https://doi.org/10.1007/978-3-642-24133-8_47
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-24132-1
Online ISBN: 978-3-642-24133-8
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)