Active-passive gradient shielding for MRI acoustic noise reduction
Active-passive gradient shielding for MRI acoustic noise reduction
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DOI：
10.1002/mrm.20472
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发表时间：
2005-05-01
影响因子：
3.3
通讯作者：
Mallick, JA
中科院分区：
文献类型：
--
作者：
Edelstein, WA;Kidane, TK;Mallick, JA
磁共振成像噪声的一个重要来源——磁体低温恒温器温孔振动是由涡流引起的——可以通过安装在隔振真空封闭屏蔽梯度装置外部的被动金属屏蔽来减轻。z梯度的有限元计算表明，在梯度组件上包裹2 mm厚的Cu层可以减少热膛中的机械功率沉积，并使热膛噪声产生降低约25 dB。消除作为主要噪声源的导电热孔和其他磁性部件，可以开发出真正安静、功能齐全、噪音水平低于70 dB的MRI系统。(c) 2005 Wiley-Liss, Inc。
An important source of MRI acoustic noise-magnet cryostat warm-bore vibrations caused by eddy-current-induced forces-can be mitigated by a passive metal shield mounted on the outside of a vibration-isolated, vacuum-enclosed shielded gradient set. Finite-element (FE) calculations for a z-gradient indicate that a 2-mm-thick Cu layer wrapped on the gradient assembly can decrease mechanical power deposition in the warm bore and reduce warm-bore acoustic noise production by about 25 dB. Eliminating the conducting warm bore and other magnet parts as significant acoustic noise sources could lead to the development of truly quiet, fully functioning MRI systems with noise levels below 70 dB. (c) 2005 Wiley-Liss, Inc.