1.5T磁共振成像系统对人体外周神经刺激研究  

A Peripheral Nerve Stimulation Study for 1.5T Magnetic Resonance Imaging System

作　　者：丁莹[1] 林意群[1] 

机构地区：[1]南方医科大学生物医学工程学院,广东广州510515

出　　处：《中国医学物理学杂志》2008年第4期771-776,共6页Chinese Journal of Medical Physics

摘　　要：医用磁共振成像系统中的时变梯度场对人体外周神经的刺激作用为磁共振扫描带来潜在危险,不容忽视。目的:引入一种新方法预测磁共振成像系统对人体的外周神经刺激。方法:用现今普遍应用于临床的1.5T磁共振成像系统,设计多个不同单梯度轴和多梯度轴组合的测试组,对35名志愿者进行临床实验测试扫描。通过逐步增强梯度线圈的磁场强度直到志愿者发生任何轻微的神经刺激感知来测定每个志愿者的个体刺激域值,最后通过求所有志愿者在所有测试组中的刺激域值的平均值得出系统梯度线圈的刺激域值,将实验数据与新方法中的安全模型计算值进行线性拟合及对比,结果:显示实验值与根据新方法安全模型的计算值具有良好的一致性。结论:虽然安全模型的计算值处于比较保守的水平,但我们认为此方法与其安全模型仍然对预测磁共振成像系统对人体的外周神经刺激有着科学且实用的意义,非常适合应用于实际磁共振产品系统安全测试中。The time varying gradient field of Magnetic Resonance Imaging （MRI） system will result in peripheral nerve stimulation on human bodies. As a result, it will lead to a significant potential risk during the application of MRI system. Objective： Introducing a new method for predicting peripheral nerve stimulations in MRI. Methods： Conducted a clinical investigation in 35 volunteers using a widely clinically applied 1.5 Tesla MRI system. Increased the field strength of gradient coils step by step until slight stimulations had occurred in the test persons. The stimulation thresholds of the gradient coil were determined for all applied pulse forms of the gradients by calculating the mean and the median values for all test persons. Finally we compared the experimental data with the calculated stimulation limits of the SAFE model from the new method and made a linear fit of them. Results： It showed that the calculated values of the SAFE model are in good accordance with the volunteer data and limiting at a slightly conservative level. Conclusion： It＇s believed that the new method for predicting peripheral nerve stimulations in MRI is very sufficient and applicable in the operating of system safety testing in MRI products according to our investigation.

关 键 词：磁共振成像系统 外周神经刺激 刺激域值 梯度组合 安全模型 

分 类 号：R318.6[医药卫生—生物医学工程]