Simulation verification of SNR and parallel imaging improvements by ICE-decoupled loop array in MRI.
Simulation verification of SNR and parallel imaging improvements by ICE-decoupled loop array in MRI.
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DOI：
10.1007/s00723-016-0764-x
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发表时间：
2016-04
影响因子：
1
通讯作者：
Zhang X
中科院分区：
文献类型：
--
作者：
Yan X;Cao Z;Zhang X
具有感应电流消除（ICE）或磁壁解耦方法的发射/接收L/C环形阵列已经显示出高信噪比（SNR）和用于在双磁场下进行MR成像的优异并行成像能力，例如，7 T.在这项研究中，我们的目标是数值分析的八通道ICE去耦环阵列在7 T的性能。三维（3-D）电磁（EM）和射频（RF）电路联合仿真方法。通过优化所有线圈元件的S参数，获得所有电容的值。电磁仿真准确地模拟了线圈结构、体模和激励。所有线圈元件都匹配到50欧姆，任何两个线圈元件之间的隔离度都更好，为−15 dB。模拟得到的S参数与实验结果吻合较好，说明模拟结果是可靠的。与传统的电容去耦阵列相比，由于去耦环的屏蔽作用，ICE去耦阵列在成像对象的外围区域具有更高的灵敏度。接收灵敏度的提高导致了ICE去耦阵列的信号强度和SNR的改善。
Transmit/receive L/C loop arrays with the induced current elimination (ICE) or magnetic wall decoupling method has shown high signal-to-noise (SNR) and excellent parallel imaging ability for MR imaging at ultrahigh fields, e.g., 7 T. In this study, we aim to numerically analyze the performance of an eight-channel ICE-decoupled loop array at 7 T. Three dimensional (3-D) electromagnetic (EM) and radiofrequency (RF) circuit co-simulation approach was employed. The values of all capacitors were obtained by optimizing the S-parameters of all coil elements. The EM simulation accurately modeled the coil structure, the phantom and the excitation. All coil elements were well matched to 50 ohm and the isolation between any two coil elements was better −15 dB. The simulated S parameters were exactly similar with the experimental results, indicating the simulation results were reliable. Compared with the conventional capacitively decoupled array, the ICE-decoupled array had higher sensitivity at the peripheral areas of the image subjects due to the shielding effect of the decoupling loops. The increased receive sensitivity resulted in an improvement of signal intensity and SNR for the ICE-decoupled array.