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Normalization of Magnetic Field Effects: Towards Quantitative Magnetomotive Ultrasound Imaging

Evertsson, Maria LU ; Cinthio, Magnus LU ; Fredriksson, Sarah; Olsson, Fredrik; Persson, Hans W LU and Jansson, Tomas LU (2012) IEEE International Ultrasonics Symposium (IUS), 2011 In 2011 IEEE International Ultrasonics Symposium (IUS) p.775-778
Abstract
In magnetomotive ultrasound (MMUS) imaging superparamagnetic iron oxide nanoparticles (NP) are used as contrast agents and a time-varying external magnetic field acts to move the particles and thereby the nanoparticle-laden tissue. Recently we proposed a frequency and phase sensitive algorithm to reduce motion artifacts. However, the method is not quantitative as the particle movement induced is dependent not only on the field strength, but also on the field gradient, plus material parameters. Here we assess the measured nanoparticle movement across the image plane in comparison with simulations of the magnetic force, to evaluate the potential for image normalization of magnetic field effects. We found that the movement decreased with... (More)
In magnetomotive ultrasound (MMUS) imaging superparamagnetic iron oxide nanoparticles (NP) are used as contrast agents and a time-varying external magnetic field acts to move the particles and thereby the nanoparticle-laden tissue. Recently we proposed a frequency and phase sensitive algorithm to reduce motion artifacts. However, the method is not quantitative as the particle movement induced is dependent not only on the field strength, but also on the field gradient, plus material parameters. Here we assess the measured nanoparticle movement across the image plane in comparison with simulations of the magnetic force, to evaluate the potential for image normalization of magnetic field effects. We found that the movement decreased with distance to the iron core tip, from which the magnetic field was extending, and approaches zero at the transducer face. This finding did not coincide with the simulation and may make it difficult to enable quantification. The coefficient of variation between measurements on the homogeneous phantom was typically in the order of 15% for all frequencies, indicating the expected accuracy for quantitative measurements. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
multimodal imaging, molecular imaging, contrast agents, magnetic field, normalizations, quantitative measurements
in
2011 IEEE International Ultrasonics Symposium (IUS)
pages
775 - 778
publisher
IEEE--Institute of Electrical and Electronics Engineers Inc.
conference name
IEEE International Ultrasonics Symposium (IUS), 2011
external identifiers
  • WOS:000309918400187
  • Scopus:84869029916
ISBN
978-1-4577-1253-1
DOI
10.1109/ULTSYM.2011.0189
language
English
LU publication?
yes
id
32f81485-e1f8-4a30-ac4f-a94457e32118 (old id 3400384)
date added to LUP
2013-01-30 10:43:53
date last changed
2017-01-01 07:58:53
@inproceedings{32f81485-e1f8-4a30-ac4f-a94457e32118,
  abstract     = {In magnetomotive ultrasound (MMUS) imaging superparamagnetic iron oxide nanoparticles (NP) are used as contrast agents and a time-varying external magnetic field acts to move the particles and thereby the nanoparticle-laden tissue. Recently we proposed a frequency and phase sensitive algorithm to reduce motion artifacts. However, the method is not quantitative as the particle movement induced is dependent not only on the field strength, but also on the field gradient, plus material parameters. Here we assess the measured nanoparticle movement across the image plane in comparison with simulations of the magnetic force, to evaluate the potential for image normalization of magnetic field effects. We found that the movement decreased with distance to the iron core tip, from which the magnetic field was extending, and approaches zero at the transducer face. This finding did not coincide with the simulation and may make it difficult to enable quantification. The coefficient of variation between measurements on the homogeneous phantom was typically in the order of 15% for all frequencies, indicating the expected accuracy for quantitative measurements.},
  author       = {Evertsson, Maria and Cinthio, Magnus and Fredriksson, Sarah and Olsson, Fredrik and Persson, Hans W and Jansson, Tomas},
  booktitle    = {2011 IEEE International Ultrasonics Symposium (IUS)},
  isbn         = {978-1-4577-1253-1},
  keyword      = {multimodal imaging,molecular imaging,contrast agents,magnetic field,normalizations,quantitative measurements},
  language     = {eng},
  pages        = {775--778},
  publisher    = {IEEE--Institute of Electrical and Electronics Engineers Inc.},
  title        = {Normalization of Magnetic Field Effects: Towards Quantitative Magnetomotive Ultrasound Imaging},
  url          = {http://dx.doi.org/10.1109/ULTSYM.2011.0189},
  year         = {2012},
}