Characterization and prediction of gradient acoustic noise in MR imagers
作者:
Robert A. Hedeen,
William A Edelstein,
期刊:
Magnetic Resonance in Medicine
(WILEY Available online 1997)
卷期:
Volume 37,
issue 1
页码: 7-10
ISSN:0740-3194
年代: 1997
DOI:10.1002/mrm.1910370103
出版商: Wiley Subscription Services, Inc., A Wiley Company
关键词: Acoustic;Noise;Gradient;magnetic resonance imaging (MRI)
数据来源: WILEY
摘要:
AbstractGradient acoustic noise has been measured and characterized for an epoxy‐potted, shielded gradient assembly in a 1.5 T MRI system. Noise levels vary by 10 dB or more as a function of longitudinal position in the scanner and reflect the pattern of forces applied to the gradient assembly. The noise level increases slightly (1–3 dB) with a patient in the scanner. The spectrum of the noise is similar (but not identical) to the spectrum of the input signal. A gradient‐pulse‐to‐acoustic‐noise transfer function was obtained by using a white noise voltage input to the gradient system. The transfer function enabled us to accurately predict acoustic noise output for a pulse sequence consisting of a series of trapezoidal pulses on a single axis and for a clinical fast spin echo sequence with gradients present on all
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