School of Mathematics and Statistics, Shandong Normal University, Jinan, Shandong, 250014, People's Republic of China.
Center for Post-doctoral studies of Management Science and Engineering and also Institute of Data Science and Technology, Shandong Normal University, Jinan, Shandong, 250014, People's Republic of China.
Phys Med Biol. 2020 Nov 17;65(22):225016. doi: 10.1088/1361-6560/abbc4d.
Conventional magnetic resonance electrical impedance tomography (MREIT) reconstruction methods require administration of two linearly independent currents via at least two electrode pairs. This requires long scanning times and inhibits coordination of MREIT measurements with electrical neuromodulation strategies. We sought to develop an isotropic conductivity reconstruction algorithm in MREIT based on a single current injection, both to decrease scanning time by a factor of two and enable MREIT measurements to be conveniently adapted to general transcranial- or implanted-electrode neurostimulation protocols. In this work, we propose and demonstrate an iterative algorithm that extends previously published MREIT work using two-current administration approaches. The proposed algorithm is a single-current adaptation of the harmonic B algorithm. Forward modeling of electric potentials is used to capture changes of conductivity along current directions that would normally be invisible using data from a single-current administration. Computational and experimental results show that the reconstruction algorithm is capable of reconstructing isotropic conductivity images that agree well in terms of L error and structural similarity with exact conductivity distributions or two-current-based MREIT reconstructions. We conclude that it is possible to reconstruct high quality electrical conductivity images using MREIT techniques and one current injection only.
传统的磁共振电阻抗断层成像（MREIT）重建方法需要通过至少两对电极施加两个线性无关的电流。这需要较长的扫描时间，并抑制了 MREIT 测量与电神经调节策略的协调。我们试图开发一种基于单电流注入的各向同性电导率重建算法，以将扫描时间缩短一半，并使 MREIT 测量方便地适应一般的颅外或植入电极神经刺激方案。在这项工作中，我们提出并证明了一种迭代算法，该算法扩展了先前使用双电流给药方法的 MREIT 工作。所提出的算法是双电流给药的谐波 B 算法的单电流自适应。使用电流方向上的电势能正向建模来捕获电导率的变化，这些变化通常使用单电流给药的数据是不可见的。计算和实验结果表明，重建算法能够重建各向同性电导率图像，这些图像在 L 误差和结构相似性方面与精确电导率分布或双电流 MREIT 重建非常吻合。我们得出结论，仅使用 MREIT 技术和一次电流注入即可重建高质量的电导率图像。
