Simulation study of noise reduction methods for a split MRI system using a finite element method

Wang, Y., Liu, F. and Crozier, S. (2015) Simulation study of noise reduction methods for a split MRI system using a finite element method. Medical Physics, 42 12: 7122-7131. doi:10.1118/1.4935864


Author Wang, Y.
Liu, F.
Crozier, S.
Title Simulation study of noise reduction methods for a split MRI system using a finite element method
Journal name Medical Physics   Check publisher's open access policy
ISSN 0094-2405
1522-8541
Publication date 2015-12-01
Sub-type Article (original research)
DOI 10.1118/1.4935864
Open Access Status Not Open Access
Volume 42
Issue 12
Start page 7122
End page 7131
Total pages 10
Place of publication Melville, NY, United States
Publisher A I P Publishing
Collection year 2016
Language eng
Formatted abstract
Purpose: To evaluate the acoustic noise levels induced by the split-gradient coils of a MRI-LINAC system, and also propose a scheme for acoustic noise reduction.

Methods: A finite element (FE)modeling method was used to simulate the acoustic environment of a MRI-LINAC system. By optimizing mounting supports between the split gradient assembly and the main magnet, the authors first altered the vibration modes of the acoustic system, smoothed the acoustic frequency responses, and relocated the acoustic field distribution in the central gap, cylindrical tunnels, and outside of the central gap. The acoustic noise was further reduced by means of applying damping treatment on the surfaces of the split-gradient assembly.

Results: Compared with conventional bolts that were placed at the ends, when the near supports were fixed and the far adjustable supports were 40 cm away from the further (here near and far are relative to the central gap) ends of the split-gradient assembly, the overall average sound pressure level (SPL) reductions were about 6.3–9.9 dB both inside and outside the central gap for the transverse and longitudinal coils. After applying damping treatment, the average SPLs inside the central gap and outside it were further reduced by 8.5–12.5 and 6.3–8.8 dB for the transverse coils and longitudinal coils, respectively.

Conclusions: The authors’ FE results showed that, for the cases of transverse coil and longitudinal coil switching, the overall average-SPL reduction quantities amounted to around 20 dB by applying the proposed noise reduction scheme, resulting in lower SPLs than the human hearing threshold.
Keyword Damping
FEM
MRI
MRI-LINAC
Noise
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Information Technology and Electrical Engineering Publications
 
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