Detection of weak magnetic fields induced by electrical currents with MRI: theoretical and practical limits of sensitivity.
Detection of weak magnetic fields induced by electrical currents with MRI: theoretical and practical limits of sensitivity.
复制标题
用 MRI 检测电流感应的弱磁场：灵敏度的理论和实际极限。
DOI：
10.2463/mrms.3.159
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Ueno
中科院分区：
文献类型：
--
作者：
T. Hatada;M. Sekino;S. Ueno
磁共振成像(MRI)检测神经元电活动引起的弱磁场是一种潜在的脑功能成像的有效方法。在这项研究中，我们比较了柱状体模探测弱磁场的理论和实际灵敏度极限。根据磁共振图像中的信号和噪声强度估计了灵敏度的理论极限。灵敏度的理论极限约为10(-8)T，实际极限是理论极限的10倍。定量评估了理论灵敏度极限与采集参数的关系，如重复时间(TR)、回波时间(TE)、像素数和光谱宽度。结果表明，T(E)/T2*存在一个最佳值。
Detection of weak magnetic fields induced by neuronal electrical activities with magnetic resonance imaging (MRI) is a potentially effective method for functional imaging of the brain. In this study, we compared the theoretical and practical limits of sensitivity for detecting weak magnetic fields with a columnar phantom. The theoretical limit of sensitivity was estimated from signal and noise intensities in magnetic resonance images. The theoretical limit of sensitivity was approximately 10(-8)T. The practical limit was 10 times the theoretical limit. The dependence of the theoretical limit of sensitivity on acquisition parameters, such as the repetition time (TR), echo time (TE), number of pixels, and spectral width, was quantitatively evaluated. The results indicated the existence of an optimal value in T(E)/T2*.