An analysis of the gradient-induced electric fields and current densities in human models when situated in a hybrid MRI-LINAC system

Liu, Limei, Trakic, Adnan, Sanchez-Lopez, Hector, Liu, Feng and Crozier, Stuart (2014) An analysis of the gradient-induced electric fields and current densities in human models when situated in a hybrid MRI-LINAC system. Physics in Medicine and Biology, 59 1: 233-245. doi:10.1088/0031-9155/59/1/233


Author Liu, Limei
Trakic, Adnan
Sanchez-Lopez, Hector
Liu, Feng
Crozier, Stuart
Title An analysis of the gradient-induced electric fields and current densities in human models when situated in a hybrid MRI-LINAC system
Journal name Physics in Medicine and Biology   Check publisher's open access policy
ISSN 0031-9155
1361-6560
Publication date 2014-01-06
Year available 2013
Sub-type Article (original research)
DOI 10.1088/0031-9155/59/1/233
Volume 59
Issue 1
Start page 233
End page 245
Total pages 13
Place of publication Temple Back, Bristol, United Kingdom
Publisher Institute of Physics Publishing Ltd.
Language eng
Abstract MRI-LINAC is a new image-guided radiotherapy treatment system that combines magnetic resonance imaging (MRI) with a linear accelerator (LINAC) in a single unit. One drawback is that the pulsing of the split gradient coils of the system induces an electric field and currents in the patient which need to be predicted and evaluated for patient safety. In this novel numerical study the in situ electric fields and associated current densities were evaluated inside tissue-accurate male and female human voxel models when a number of different split-geometry gradient coils were operated. The body models were located in the MRI-LINAC system along the axial and radial directions in three different body positions. Each model had a region of interest (ROI) suitable for image-guided radiotherapy. The simulation results show that the amplitudes and distributions of the field and current density induced by different split x-gradient coils were similar with one another in the ROI of the body model, but varied outside of the region. The fields and current densities induced by a split classic coil with the surface unconnected showed the largest deviation from those given by the conventional non-split coils. Another finding indicated that the distributions of the peak current densities varied when the body position, orientation or gender changed, while the peak electric fields mainly occurred in the skin and fat tissues.
Keyword Body model
Gradient induced current density
Gradient induced electric fields
MRI patient safety
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Information Technology and Electrical Engineering Publications
 
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