Katscher Ulrich, Voigt Tobias, Findeklee Christian
Philips Research Europe-Hamburg, Sector Medical Imaging Systems, 22335 Hamburg, Germany.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:3162-4. doi: 10.1109/IEMBS.2009.5334031.
The electrical conductivity of human tissue could be used as an additional diagnostic parameter or might be helpful for the prediction of the local SAR during MR measurements. In this study, the approach "Electric Properties Tomography" (EPT) is applied, which derives the patient's electric conductivity using a standard MR system. To this goal, the spatial transmit sensitivity distribution of the applied RF coil is measured. This sensitivity distribution represents the positive circularly polarized component of the magnetic field. It can be post-processed utilizing Faraday's and Ampere's law, yielding an estimation of the spatial distribution of the patient's electric conductivity. Thus, EPT does not apply externally mounted electrodes, currents, or RF probes. In this study, phantom experiments underline the principle feasibility of EPT. Furthermore, initial conductivity measurements in the brain allow distinguishing cerebro-spinal fluid from the surrounding grey and white matter.
人体组织的电导率可作为一个额外的诊断参数，或者可能有助于在磁共振测量期间预测局部比吸收率。在本研究中，应用了“电特性断层扫描”（EPT）方法，该方法使用标准磁共振系统得出患者的电导率。为实现这一目标，测量了所应用射频线圈的空间发射灵敏度分布。这种灵敏度分布代表磁场的正向圆极化分量。利用法拉第定律和安培定律对其进行后处理，从而得出患者电导率空间分布的估计值。因此，EPT不使用外部安装的电极、电流或射频探头。在本研究中，模型实验证实了EPT的原理可行性。此外，对大脑进行的初始电导率测量能够区分脑脊液与周围的灰质和白质。
