caa a22 4500 605545200 CHVBK 20210128100935.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00723-014-0612-9 doi (NATIONALLICENCE)springer-10.1007/s00723-014-0612-9 Design and Test of Magnetic Wall Decoupling for Dipole Transmit/Receive Array for MR Imaging at the Ultrahigh Field of 7T [Elektronische Daten] [Xinqiang Yan, Xiaoliang Zhang, Long Wei, Rong Xue] Radio-frequency coil arrays using dipole antenna technique have been recently applied for ultrahigh field magnetic resonance (MR) imaging to obtain the better signal-noise-ratio (SNR) gain at the deep area of human tissues. However, the unique structure of dipole antennas makes it challenging to achieve sufficient electromagnetic decoupling among the dipole antenna elements. Currently, there is no decoupling methods proposed for dipole antenna arrays in MR imaging. The recently developed magnetic wall (MW) or induced current elimination decoupling technique has demonstrated its feasibility and robustness in designing microstrip transmission line arrays, L/C loop arrays and monopole arrays. In this study, we aim to investigate the possibility and performance of MW decoupling technique in dipole arrays for MR imaging at the ultrahigh field of 7T. To achieve this goal, a two-channel MW decoupled dipole array was designed, constructed and analyzed experimentally through bench test and MR imaging. Electromagnetic isolation between the two dipole elements was improved from about −3.6dB (without any decoupling treatments) to −16.5dB by using the MW decoupling method. MR images acquired from a water phantom using the MW decoupled dipole array and the geometry factor maps were measured, calculated and compared with those acquired using the dipole array without decoupling treatments. The MW decoupled dipole array demonstrated well-defined image profiles from each element and had better geometry factor over the array without decoupling treatments. The experimental results indicate that the MW decoupling technique might be a promising solution to reducing the electromagnetic coupling of dipole arrays in ultrahigh field MRI, consequently improving their performance in SNR and parallel imaging. Springer-Verlag Wien, 2014 Yan Xinqiang State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Bldg. 11, 15 Datun Road, Chaoyang District, 100101, Beijing, China aut Zhang Xiaoliang Department of Radiology and Biomedical Imaging, University of California San Francisco, Byers Hall, Room 102, 1700 4th ST, 94158-2330, San Francisco, CA, USA aut Wei Long Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, China aut Xue Rong State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Bldg. 11, 15 Datun Road, Chaoyang District, 100101, Beijing, China aut Applied Magnetic Resonance Springer Vienna 46/1(2015-01-01), 59-66 0937-9347 46:1<59 2015 46 723 https://doi.org/10.1007/s00723-014-0612-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00723-014-0612-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yan Xinqiang State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Bldg. 11, 15 Datun Road, Chaoyang District, 100101, Beijing, China aut NATIONALLICENCE 700 1- Zhang Xiaoliang Department of Radiology and Biomedical Imaging, University of California San Francisco, Byers Hall, Room 102, 1700 4th ST, 94158-2330, San Francisco, CA, USA aut NATIONALLICENCE 700 1- Wei Long Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, China aut NATIONALLICENCE 700 1- Xue Rong State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Bldg. 11, 15 Datun Road, Chaoyang District, 100101, Beijing, China aut NATIONALLICENCE 773 0- Applied Magnetic Resonance Springer Vienna 46/1(2015-01-01), 59-66 0937-9347 46:1<59 2015 46 723