基于球面测量的磁共振梯度非线性度分析  

Spherical measurement-based analysis of gradient nonlinearity in magnetic resonance imaging

作　　者：杨晓丽 王兆连 王前 张义廷 宋子轩 张玉昌 齐亚飞[4] 马晓鹏 YANG Xiaoli;WANG Zhaolian;WANG Qian;ZHANG Yiting;SONG Zixuan;ZHANG Yuchang;QI Yafei;MA Xiaopeng(Weifang Xinli Superconducting Magnet Technology Co.,Ltd.,Weifang,Shandong 261071,P.R.China;School of Control Science and Engineering,Shandong University,Jinan 250061,P.R.China;Shandong Huate Magnet Technology Co.,Ltd.,Weifang,Shandong 262619,P.R.China;Department of Radiology,Qilu Hospital of Shandong University,Jinan 250012,P.R.China)

机构地区：[1]潍坊新力超导磁电科技有限公司,山东潍坊261071 [2]山东大学控制科学与工程学院,济南250061 [3]山东华特磁电科技股份有限公司,山东潍坊262619 [4]山东大学齐鲁医院放射科,济南250012

出　　处：《生物医学工程学杂志》2025年第1期174-180,共7页Journal of Biomedical Engineering

基　　金：山东省重大科技创新工程项目(2019TSLH0410,2022CXGC010501);泰山产业领军人才工程(tscx202312153)。

摘　　要：梯度场作为磁共振成像(MRI)系统的核心磁场之一,由梯度线圈产生,在磁共振图像空间编码和回波信号的生成中起关键作用。梯度场的均匀性或线性度直接关系到MRI图像的质量和畸变程度。然而,传统的单点测量法在梯度场线性度评估方面准确性不足,难以为图像畸变矫正提供有效参数。本文提出一种基于球面测量的方法,通过在球面上测量磁场分布,进而进行详尽的磁场计算和线性度分析。本研究应用于评估非对称头部梯度线圈的非线性度,显示出较单点测量法更全面和更精确的评估结果。这一进展不仅增强了梯度线圈设计的科学依据,还为MRI图像的畸变矫正提供了更为可靠的参数和方法。The gradient field,one of the core magnetic fields in magnetic resonance imaging(MRI)systems,is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals.The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images.However,traditional point measurement methods lack accuracy in assessing the linearity of gradient fields,making it difficult to provide effective parameters for image distortion correction.This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere,followed by detailed magnetic field calculations and linearity analysis.This study,applied to assess the nonlinearity of asymmetric head gradient coils,demonstrated more comprehensive and precise results compared to point measurement methods.This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.

关 键 词：磁共振成像 梯度线圈 梯度磁场计算 梯度非线性度 

分 类 号：R445.2[医药卫生—影像医学与核医学] TP391.41[医药卫生—诊断学]