{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T18:09:42Z","timestamp":1779905382914,"version":"3.53.1"},"reference-count":58,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,2,23]],"date-time":"2022-02-23T00:00:00Z","timestamp":1645574400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Health and Welfare of the Republic of Korea","award":["Grant HR14C-0002-010014"],"award-info":[{"award-number":["Grant HR14C-0002-010014"]}]},{"name":"Korea Health Technology R&amp;D Project through the Korea Health Industry Development Institute (KHIDI)","award":["none"],"award-info":[{"award-number":["none"]}]},{"name":"the Brain Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT &amp; Future Planning","award":["NRF-2017M3C7A1047228"],"award-info":[{"award-number":["NRF-2017M3C7A1047228"]}]},{"name":"the Gachon University research fund of 2018","award":["GCU-2018-0673"],"award-info":[{"award-number":["GCU-2018-0673"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Improvements in transmission and reception sensitivities of radiofrequency (RF) coils used in ultra-high field (UHF) magnetic resonance imaging (MRI) are needed to reduce specific absorption rates (SAR) and RF power deposition, albeit without applying high-power RF. Here, we propose a method to simultaneously improve transmission efficiency and reception sensitivity of a band-pass birdcage RF coil (BP-BC RF coil) by combining a multi-channel wireless RF element (MCWE) with a high permittivity material (HPM) in a 7.0 T MRI. Electromagnetic field (EM-field) simulations, performed using two types of phantoms, viz., a cylindrical phantom filled with oil and a human head model, were used to compare the effects of MCWE and HPM on BP-BC RF coils. EM-fields were calculated using the finite difference time-domain (FDTD) method and analyzed using Matlab software. Next, to improve RF transmission efficiency, we compared two HPM structures, namely, a hollow cylinder shape HPM (hcHPM) and segmented cylinder shape HPM (scHPM). The scHPM and MCWE model comprised 16 elements (16-rad BP-BC RF coil) and this coil configuration demonstrated superior RF transmission efficiency and reception sensitivity along with an acceptable SAR. We expect wider clinical application of this combination in 7.0 T MRIs, which were recently approved by the United States Food and Drug Administration.<\/jats:p>","DOI":"10.3390\/s22051741","type":"journal-article","created":{"date-parts":[[2022,2,24]],"date-time":"2022-02-24T00:53:26Z","timestamp":1645664006000},"page":"1741","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["A Comparative Study of Birdcage RF Coil Configurations for Ultra-High Field Magnetic Resonance Imaging"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8454-5002","authenticated-orcid":false,"given":"Jeung-Hoon","family":"Seo","sequence":"first","affiliation":[{"name":"Neuroscience Research Institute, Gachon University, Incheon 21988, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yeji","family":"Han","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Gachon University, Incheon 21936, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7408-8215","authenticated-orcid":false,"given":"Jun-Young","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Neuroscience, College of Medicine, Gachon University, Incheon 21565, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1015","DOI":"10.1016\/j.neuroimage.2011.05.010","article-title":"Clinical fMRI: Evidence for a 7 T benefit over 3 T","volume":"57","author":"Beisteiner","year":"2011","journal-title":"NeuroImage"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1016\/j.neuroimage.2009.05.015","article-title":"fMRI at 1.5, 3 and 7 T: Characterising BOLD signal changes","volume":"47","author":"Francis","year":"2009","journal-title":"NeuroImage"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"20180492","DOI":"10.1259\/bjr.20180492","article-title":"Clinical 7 T MRI: Are we there yet? 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