Rietsch Stefan H G, Quick Harald H, Orzada Stephan
Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen 45141, Germany and High Field and Hybrid MR Imaging, University Hospital Essen, Essen 45147, Germany.
Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen 45141, Germany.
Med Phys. 2015 Aug;42(8):4542-52. doi: 10.1118/1.4923177.
In this work, the transmit performance and interelement coupling characteristics of radio frequency (RF) antenna microstrip line elements are examined in simulations and measurements.
The initial point of the simulations is a microstrip line element loaded with a phantom. Meander structures are then introduced at the end of the element. The size of the meanders is increased in fixed steps and the magnetic field is optimized. In continuative simulations, the coupling between identical elements is evaluated for different element spacing and loading conditions. Verification of the simulation results is accomplished in measurements of the coupling between two identical elements for four different meander sizes. Image acquisition on a 7 T magnetic resonance imaging (MRI) system provides qualitative and quantitative comparisons to confirm the simulation results.
Simulations point out an optimum range of meander sizes concerning coupling in all chosen geometric setups. Coupling measurement results are in good agreement with the simulations. Qualitative and quantitative comparisons of the acquired MRI images substantiate the coupling results.
The coupling between coil elements in RF antenna arrays consisting of the investigated element types can be optimized under consideration of the central magnetic field strength or efficiency depending on the desired application.
在本研究中，通过模拟和测量来研究射频（RF）天线微带线元件的传输性能和元件间耦合特性。
模拟的起始点是加载了体模的微带线元件。然后在元件末端引入曲折结构。以固定步长增加曲折的尺寸并优化磁场。在后续模拟中，针对不同的元件间距和加载条件评估相同元件之间的耦合。通过测量四种不同曲折尺寸的两个相同元件之间的耦合来验证模拟结果。在7T磁共振成像（MRI）系统上进行图像采集，以提供定性和定量比较，从而确认模拟结果。
模拟指出了在所有选定几何设置中关于耦合的曲折尺寸的最佳范围。耦合测量结果与模拟结果高度吻合。所采集MRI图像的定性和定量比较证实了耦合结果。
根据期望的应用，在考虑中心磁场强度或效率的情况下，可以优化由所研究元件类型组成的RF天线阵列中线圈元件之间的耦合。
