Improving RF safety in MRI by modifying the electric field distribution
Date
2011Source Title
2011 XXXth URSI General Assembly and Scientific Symposium
Publisher
IEEE
Language
English
Type
Conference PaperItem Usage Stats
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Abstract
In this work we demonstrate that the radiofrequency (RF) electric field in magnetic resonance imaging (MRI) can be modified in order to enhance patient safety. The heating of metallic devices in MRI is directly related to electric field distribution. On the other hand the MR image homogeneity is related to forward polarized component of the magnetic field (transmit sensitivity). In order to prevent heating, electric field-free zones should be generated in the body without significantly altering the transmit sensitivity. For this purpose the linearly polarized birdcage coil is proposed as a metallic device friendly MRI coil. The zero electric field plane of the linear birdcage coil is coincided with the location of the metallic device and the heating is reduced as shown by simulations and experiments. One disadvantage of this approach is, the linear coils generate twice as much whole body average SAR when compared to quadrature birdcage coils. In order to solve this problem simulations are performed to find electromagnetic field solutions with reduced average SAR and uniform transmit sensitivity. © 2011 IEEE.
Keywords
Electric field distributionsLinearly polarized
Metallic devices
MR images
Patient safety
Polarized components
Radio frequencies
Whole body
Electric fields
Electromagnetic fields
Magnetic fields
Magnetic resonance imaging
Permalink
http://hdl.handle.net/11693/28321Published Version (Please cite this version)
http://dx.doi.org/10.1109/URSIGASS.2011.6051330Collections
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