Theoretical analysis of magnetic wall decoupling method for radiative antenna arrays in ultrahigh magnetic field MRI |
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| Authors: | Xinqiang Yan Zhentian Xie Jan Ole Pedersen Xiaoliang Zhang |
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| Affiliation: | 1. State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics Chinese Academy of Sciences, Beijing, China;2. Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China;3. Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing, China;4. Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA;5. Sino‐Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, China;6. UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA |
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| Abstract: | Radiative antenna techniques, e.g., dipole and monopole, have been proposed for radiofrequency (RF) coil array designs in ultrahigh field MRI to obtain stronger B1 field and higher signal‐to‐noise ratio (SNR) gain in the areas deep inside human head or body. It is known that element decoupling performance is crucial to SNR and parallel imaging ability of array coil and has been a challenging issue in radiative antenna array designs for MR imaging. Magnetic wall or induced current elimination (ICE) technique has proven to be a simple and effective way of achieving sufficient decoupling for radiative array coils experimentally. In this study, this decoupling technique for radiative coil array was analyzed theoretically and verified by a simulation study. The decoupling conditions were derived and obtained from the theory. By applying the predicated decoupling conditions, the isolation of two radiative elements could be improved from about ? 8 dB to better than ? 35 dB. The decoupling performance has also been validated by current distribution along the radiative elements and magnetic field profiles in a water phantom. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 45B: 183–190, 2015 |
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| Keywords: | monopole dipole RF coil array magnetic wall ICE decouple simulation ultrahigh field MRI |
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