• 文献检索
  • 文档翻译
  • 深度研究
  • 学术资讯
  • Suppr Zotero 插件Zotero 插件
  • 邀请有礼
  • 套餐&价格
  • 历史记录
应用&插件
Suppr Zotero 插件Zotero 插件浏览器插件Mac 客户端Windows 客户端微信小程序
定价
高级版会员购买积分包购买API积分包
服务
文献检索文档翻译深度研究API 文档MCP 服务
关于我们
关于 Suppr公司介绍联系我们用户协议隐私条款
关注我们

Suppr 超能文献

核心技术专利：CN118964589B侵权必究
粤ICP备2023148730 号-1Suppr @ 2026

文献检索

告别复杂PubMed语法，用中文像聊天一样搜索，搜遍4000万医学文献。AI智能推荐，让科研检索更轻松。

立即免费搜索

文件翻译

保留排版，准确专业，支持PDF/Word/PPT等文件格式，支持 12+语言互译。

免费翻译文档

深度研究

AI帮你快速写综述，25分钟生成高质量综述，智能提取关键信息，辅助科研写作。

立即免费体验

用于减少7T射频线圈屏蔽上产生的涡流的射频和准静态场模拟的双重优化方法。

Dual optimization method of radiofrequency and quasistatic field simulations for reduction of eddy currents generated on 7T radiofrequency coil shielding.

作者信息

Zhao Yujuan, Zhao Tiejun, Raval Shailesh B, Krishnamurthy Narayanan, Zheng Hai, Harris Chad T, Handler William B, Chronik Blaine A, Ibrahim Tamer S

机构信息

Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

Siemens Medical Solutions, Pittsburgh, Pennsylvania, USA.

出版信息

Magn Reson Med. 2015 Nov;74(5):1461-9. doi: 10.1002/mrm.25424. Epub 2014 Nov 3.

DOI:10.1002/mrm.25424
PMID:25367703
原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4515214/
Abstract

PURPOSE

To optimize the design of radiofrequency (RF) shielding of transmit coils at 7T and reduce eddy currents generated on the RF shielding when imaging with rapid gradient waveforms.

METHODS

One set of a four-element, 2 × 2 Tic-Tac-Toe head coil structure was selected and constructed to study eddy currents on the RF coil shielding. The generated eddy currents were quantitatively studied in the time and frequency domains. The RF characteristics were studied using the finite difference time domain method. Five different kinds of RF shielding were tested on a 7T MRI scanner with phantoms and in vivo human subjects.

RESULTS

The eddy current simulation method was verified by the measurement results. Eddy currents induced by solid/intact and simple-structured slotted RF shielding significantly distorted the gradient fields. Echo-planar images, B1+ maps, and S matrix measurements verified that the proposed slot pattern suppressed the eddy currents while maintaining the RF characteristics of the transmit coil.

CONCLUSION

The presented dual-optimization method could be used to design RF shielding and reduce the gradient field-induced eddy currents while maintaining the RF characteristics of the transmit coil.

摘要

目的

优化7T时发射线圈的射频（RF）屏蔽设计，并减少在使用快速梯度波形成像时RF屏蔽上产生的涡流。

方法

选择并构建一组四元2×2 Tic-Tac-Toe头部线圈结构，以研究RF线圈屏蔽上的涡流。在时域和频域中对产生的涡流进行定量研究。使用时域有限差分法研究RF特性。在7T MRI扫描仪上使用体模和体内人体受试者测试了五种不同类型的RF屏蔽。

结果

测量结果验证了涡流模拟方法。由实心/完整和结构简单的开槽RF屏蔽感应的涡流显著扭曲了梯度场。回波平面图像、B1+图和S矩阵测量结果证实，所提出的槽型在保持发射线圈RF特性的同时抑制了涡流。

结论

所提出的双重优化方法可用于设计RF屏蔽，并在保持发射线圈RF特性的同时减少梯度场感应的涡流。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/80240acdcb0b/nihms621635f6.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/6dcf38fe4b0f/nihms621635f1.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/bc64728d5ca7/nihms621635f2.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/bba68d37a812/nihms621635f3.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/3a0f5359dd20/nihms621635f4.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/78f9f5d9a727/nihms621635f5.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/80240acdcb0b/nihms621635f6.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/6dcf38fe4b0f/nihms621635f1.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/bc64728d5ca7/nihms621635f2.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/bba68d37a812/nihms621635f3.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/3a0f5359dd20/nihms621635f4.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/78f9f5d9a727/nihms621635f5.jpg
https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b05a/4515214/80240acdcb0b/nihms621635f6.jpg

相似文献

1
Dual optimization method of radiofrequency and quasistatic field simulations for reduction of eddy currents generated on 7T radiofrequency coil shielding.用于减少7T射频线圈屏蔽上产生的涡流的射频和准静态场模拟的双重优化方法。
Magn Reson Med. 2015 Nov;74(5):1461-9. doi: 10.1002/mrm.25424. Epub 2014 Nov 3.
2
Characterization and reduction of gradient-induced eddy currents in the RF shield of a TEM resonator.TEM 谐振器射频屏蔽中梯度感应涡流的表征与抑制
Magn Reson Med. 2002 Aug;48(2):404-7. doi: 10.1002/mrm.10226.
3
Low eddy current RF shielding enclosure designs for 3T MR applications.用于 3TMR 应用的低涡流射频屏蔽外壳设计。
Magn Reson Med. 2018 Mar;79(3):1745-1752. doi: 10.1002/mrm.26766. Epub 2017 Jun 6.
4
Characterization methods for comprehensive evaluations of shielding materials used in an MRI.用于 MRI 的屏蔽材料的综合评估的表征方法。
Med Phys. 2018 Apr;45(4):1415-1424. doi: 10.1002/mp.12762. Epub 2018 Feb 26.
5
An Asymmetric Birdcage Coil for Small-animal MR Imaging at 7T.一种用于7T小动物磁共振成像的非对称鸟笼线圈。
Magn Reson Med Sci. 2017 Jul 10;16(3):253-258. doi: 10.2463/mrms.tn.2016-0149. Epub 2016 Sep 30.
6
Development of a new RF coil and gamma-ray radiation shielding assembly for improved MR image quality in SPECT/MRI.开发一种新的射频线圈和伽马射线辐射屏蔽组件，以提高 SPECT/MRI 中的磁共振图像质量。
Phys Med Biol. 2010 May 7;55(9):2495-504. doi: 10.1088/0031-9155/55/9/005. Epub 2010 Apr 6.
7
Longitudinal gradient coil optimization in the presence of transient eddy currents.存在瞬态涡流时的纵向梯度线圈优化
Magn Reson Med. 2007 Jun;57(6):1119-30. doi: 10.1002/mrm.21243.
8
RF shielding designs for birdcage coils for preclinical MRI at 9.4 T.9.4T 临床前 MRI 用鸟笼线圈的射频屏蔽设计。
Magn Reson Imaging. 2022 Dec;94:1-6. doi: 10.1016/j.mri.2022.08.018. Epub 2022 Sep 6.
9
Parallel transmit excitation at 1.5 T based on the minimization of a driving function for device heating.基于使设备发热的驱动函数最小化的1.5T并行发射激励
Med Phys. 2015 Jan;42(1):359-71. doi: 10.1118/1.4903894.
10
Design of a parallel transmit head coil at 7T with magnetic wall distributed filters.设计一种 7T 磁共振的平行发射头部线圈，采用磁墙分布式滤波器。
IEEE Trans Med Imaging. 2015 Apr;34(4):836-45. doi: 10.1109/TMI.2014.2370533. Epub 2014 Nov 13.

引用本文的文献

1
Improved 7 Tesla transmit field homogeneity with reduced electromagnetic power deposition using coupled Tic Tac Toe antennas.使用耦合的井字天线提高7特斯拉发射场均匀性并降低电磁功率沉积。
Sci Rep. 2021 Feb 9;11(1):3370. doi: 10.1038/s41598-020-79807-9.
2
Computational and experimental evaluation of the Tic-Tac-Toe RF coil for 7 Tesla MRI.7T MRI 中 Tic-Tac-Toe 射频线圈的计算与实验评估。
PLoS One. 2019 Jan 10;14(1):e0209663. doi: 10.1371/journal.pone.0209663. eCollection 2019.
3
In-vivo and numerical analysis of the eigenmodes produced by a multi-level Tic-Tac-Toe head transmit array for 7 Tesla MRI.

本文引用的文献

1
Skin and proximity effects in the conductors of split gradient coils for a hybrid Linac-MRI scanner.用于混合直线加速器 - 磁共振成像扫描仪的分裂梯度线圈导体中的趋肤效应和邻近效应。
J Magn Reson. 2014 May;242:86-94. doi: 10.1016/j.jmr.2014.02.002. Epub 2014 Feb 12.
2
Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla.采用双侧线圈在7特斯拉进行乳腺磁共振成像及具有稳健脂肪抑制的T1加权采集：图像评估及与3特斯拉的比较
Eur Radiol. 2013 Nov;23(11):2969-78. doi: 10.1007/s00330-013-2972-1. Epub 2013 Jul 30.
3
Multilayer integral method for simulation of eddy currents in thin volumes of arbitrary geometry produced by MRI gradient coils.
体内和数值分析 7T MRI 中多级 Tic-Tac-Toe 头传输阵列产生的本征模。
PLoS One. 2018 Nov 27;13(11):e0206127. doi: 10.1371/journal.pone.0206127. eCollection 2018.
4
A new RF transmit coil for foot and ankle imaging at 7T MRI.一种用于7T磁共振成像的足部和踝关节成像的新型射频发射线圈。
Magn Reson Imaging. 2018 Jan;45:1-6. doi: 10.1016/j.mri.2017.09.005. Epub 2017 Sep 8.
5
Development of a 7 T RF coil system for breast imaging.用于乳腺成像的7T射频线圈系统的研发。
NMR Biomed. 2017 Jan;30(1). doi: 10.1002/nbm.3664. Epub 2016 Nov 11.
6
Ultra-high-field RF coil development for evaluating upper extremity imaging applications.用于评估上肢成像应用的超高场射频线圈开发。
NMR Biomed. 2016 Dec;29(12):1768-1779. doi: 10.1002/nbm.3582. Epub 2016 Nov 3.
用于模拟MRI梯度线圈产生的任意几何形状薄体积中涡电流的多层积分方法。
Magn Reson Med. 2014 May;71(5):1912-22. doi: 10.1002/mrm.24819. Epub 2013 Jul 1.
4
Application and experimental validation of an integral method for simulation of gradient-induced eddy currents on conducting surfaces during magnetic resonance imaging.应用和实验验证用于模拟磁共振成像过程中导体内表面梯度感应涡流的积分方法。
Phys Med Biol. 2013 Jun 21;58(12):4367-79. doi: 10.1088/0031-9155/58/12/4367. Epub 2013 Jun 5.
5
A broadside-split-ring resonator-based coil for MRI at 7 T.一种基于宽边分裂环谐振器的 7T MRI 线圈。
IEEE Trans Med Imaging. 2013 Jun;32(6):1081-4. doi: 10.1109/TMI.2013.2253488. Epub 2013 Mar 20.
6
Prospective and retrospective high order eddy current mitigation for diffusion weighted echo planar imaging.前瞻性和回顾性高阶涡流缓解在扩散加权回波平面成像中的应用。
Magn Reson Med. 2013 Nov;70(5):1293-305. doi: 10.1002/mrm.24589. Epub 2013 Jan 16.
7
12-channel receive array with a volume transmit coil for hand/wrist imaging at 7 T.用于 7T 手部/腕部成像的 12 通道接收阵列和容积发射线圈。
J Magn Reson Imaging. 2013 Jul;38(1):238-44. doi: 10.1002/jmri.23883. Epub 2012 Dec 13.
8
Design and evaluation of a detunable water-based quadrature HEM11 mode dielectric resonator as a new type of volume coil for high field MRI.一种可调谐水基正交 HEM11 模式介质谐振器的设计与评估，作为一种新型高场 MRI 体线圈。
Magn Reson Med. 2012 Oct;68(4):1325-31. doi: 10.1002/mrm.24451. Epub 2012 Aug 6.
9
Design of a nested eight-channel sodium and four-channel proton coil for 7T knee imaging.设计嵌套式八通道钠离子和四通道质子线圈，用于 7T 膝关节成像。
Magn Reson Med. 2013 Jul;70(1):259-68. doi: 10.1002/mrm.24432. Epub 2012 Aug 8.
10
Parallel transmission RF pulse design for eddy current correction at ultra high field.用于超高场涡流校正的并行传输 RF 脉冲设计。
J Magn Reson. 2012 Aug;221:139-46. doi: 10.1016/j.jmr.2012.03.017. Epub 2012 Mar 28.