Department of Biomedical Engineering, Impedance Imaging Research Center (IIRC), Kyung Hee University, Yongin, Republic of Korea.
Comput Math Methods Med. 2013;2013:704829. doi: 10.1155/2013/704829. Epub 2013 Apr 29.
Magnetic resonance electrical impedance tomography (MREIT) is a new modality capable of imaging the electrical properties of human body using MRI phase information in conjunction with external current injection. Recent in vivo animal and human MREIT studies have revealed unique conductivity contrasts related to different physiological and pathological conditions of tissues or organs. When performing in vivo brain imaging, small imaging currents must be injected so as not to stimulate peripheral nerves in the skin, while delivery of imaging currents to the brain is relatively small due to the skull's low conductivity. As a result, injected imaging currents may induce small phase signals and the overall low phase SNR in brain tissues. In this study, we present numerical simulation results of the use of head MREIT for brain tumor detection. We used a realistic three-dimensional head model to compute signal levels produced as a consequence of a predicted doubling of conductivity occurring within simulated tumorous brain tissues. We determined the feasibility of measuring these changes in a time acceptable to human subjects by adding realistic noise levels measured from a candidate 3 T system. We also reconstructed conductivity contrast images, showing that such conductivity differences can be both detected and imaged.
磁共振电阻抗断层成像（MREIT）是一种新的模态，能够利用 MRI 相位信息结合外部电流注入来对人体的电学特性进行成像。最近的活体动物和人体 MREIT 研究揭示了与组织或器官的不同生理和病理状态相关的独特电导率对比。在进行活体脑部成像时，必须注入小的成像电流，以免刺激皮肤中的外周神经，而由于颅骨的低电导率，向脑部输送成像电流相对较小。因此，注入的成像电流可能会在脑部组织中引起小的相位信号和整体低相位 SNR。在这项研究中，我们展示了使用头部 MREIT 进行脑肿瘤检测的数值模拟结果。我们使用了一个现实的三维头部模型，计算了由于模拟肿瘤性脑组织中电导率预测性翻倍而产生的信号水平。我们通过添加从候选 3T 系统测量的现实噪声水平，确定了在人类受试者可接受的时间内测量这些变化的可行性。我们还重建了电导率对比图像，表明可以检测和成像这些电导率差异。
