Direct MRI detection of neuronal magnetic fields in the brain: theoretical modeling.
Direct MRI detection of neuronal magnetic fields in the brain: theoretical modeling.
复制标题
大脑神经元磁场的直接 MRI 检测：理论模型。
DOI：
10.1016/j.neuroimage.2005.12.041
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Xiong,Jinhu
中科院分区：
文献类型：
--
作者：
Xue,Yiqun;Gao,Jia-Hong;Xiong,Jinhu
Whether MRI can be used for direct detection of neuronal activity is a matter of debate. Controversial theoretical and experimental results have been reported. Here, we present an improved current-dipole model to compute magnetic field generated by neural firing and to calculate MRI signal changes resulting from the neuronal magnetic field (NMF). Each dendrite or each unmyelinated axon was modeled as a modified current-dipole. NMF were estimated based on a synchronized activity of multiple neurons. Sensitivity of using phase and magnitude MRI to measure effects of NMF was evaluated. Our results show that NMF can potentially generate up to a few percent changes in MRI magnitude signals. Phases of MRI signal tend to be destructively added and are insensitive to NMF in the activated region when the distribution of the activated dendrites is symmetrical. Phases could be detected when the distribution of the activated dendrites is asymmetrical and on some neighboring voxels. Our modeling implies that direct MRI detection of neuronal activity is possible.
