BioMedical Engineering Inter-Departmental Program (BME-IDP), University of California Los Angeles, Los Angeles, California, United States.
Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, California, United States.
Sci Rep. 2016 Oct 4;6:34385. doi: 10.1038/srep34385.
Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic fields induced by tDCS currents. This technique is based on Ampere's law and exploits the linear relationship between direct current and induced magnetic fields. Following validation on a phantom with a known path of electric current and induced magnetic field, the proposed MRI technique was applied to a human limb (to demonstrate in-vivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in standard tDCS applications). The results show that the proposed technique detects tDCS induced magnetic fields as small as a nanotesla at millimeter spatial resolution. Through measurements of magnetic fields linearly proportional to the applied tDCS current, our approach opens a new avenue for direct in-vivo visualization of tDCS target engagement.
经颅直流电刺激（tDCS）是一种新兴的非侵入性神经调节技术，它通过头皮上的毫安电流来调节皮质兴奋性。在这里，我们提出了一种新的磁共振成像（MRI）技术，该技术可以检测 tDCS 电流产生的磁场。该技术基于安培定律，并利用直流电流和感应磁场之间的线性关系。在对具有已知电流和感应磁场路径的体模进行验证后，将所提出的 MRI 技术应用于人体肢体（使用简单的生物组织证明体内可行性）和人体头部（在标准 tDCS 应用中证明可行性）。结果表明，所提出的技术可以以毫米空间分辨率检测到小至纳特斯拉的 tDCS 感应磁场。通过测量与施加的 tDCS 电流成正比的磁场，我们的方法为直接在体内可视化 tDCS 目标接触开辟了新途径。
