Tilted microstrip phased arrays with improved electromagnetic decoupling for ultrahigh-field magnetic resonance imaging.
Tilted microstrip phased arrays with improved electromagnetic decoupling for ultrahigh-field magnetic resonance imaging.
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DOI：
10.1097/md.0000000000000311
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发表时间：
2014-12
期刊：
影响因子：
1.6
通讯作者：
Zhang X
中科院分区：
文献类型：
--
作者：
Pang Y;Wu B;Jiang X;Vigneron DB;Zhang X
在设计用于人体MR成像的专用收发器射频（RF）阵列中的一个技术挑战是如何有效地解耦阵列的谐振元件。在这项工作中，我们提出了一种新的方法，使用倾斜的微带阵列元件，以提高去耦性能和潜在的并行成像能力。为了研究和验证所提出的设计技术，一个8通道的体积阵列与倾斜的直型微带元件的设计，能够在7特斯拉的电磁场的人体成像。通过台架测试和在体MR成像实验，研究了该体收发器阵列中谐振元件之间的电磁解耦行为、射频场对生物样品的穿透能力以及并行成像性能。在这种特殊的倾斜阵元阵列设计中，阵元之间的解耦随着阵元倾斜角度的变化而变化，在一定的倾斜角度下可以实现最佳解耦。使用倾斜体积阵列在7特斯拉下采集体内人膝关节MR图像，以进行方法验证。研究结果表明，在7T场强下，采用倾斜单元法设计微带射频线圈阵列，可以改善阵列单元间的电磁解耦，提高B1场强。
One of the technical challenges in designing a dedicated transceiver radio frequency (RF) array for MR imaging in humans at ultrahigh magnetic fields is how to effectively decouple the resonant elements of the array. In this work, we propose a new approach using tilted microstrip array elements for improving the decoupling performance and potentially parallel imaging capability. To investigate and validate the proposed design technique, an 8-channel volume array with tilted straight-type microstrip elements was designed, capable for human imaging at the ultrahigh field of 7 Tesla. In this volume transceiver array, its electromagnetic decoupling behavior among resonant elements, RF field penetration to biological samples, and parallel imaging performance were studied through bench tests and in vivo MR imaging experiments. In this specific tilted element array design, decoupling among array elements changes with the tilted angle of the elements and the best decoupling can be achieved at certain tilted angle. In vivo human knee MR images were acquired using the tilted volume array at 7 Tesla for method validation. Results of this study demonstrated that the electromagnetic decoupling between array elements and the B1 field strength can be improved by using the tilted element method in microstrip RF coil array designs at the ultrahigh field of 7T.