Shchelokova, Alena VSlobozhanyuk, Alexey Pde Bruin, PaulZivkovic, IrenaKallos, EfthymiosBelov, Pavel AWebb, Andrew2018-01-192018-01-191090-7807http://hdl.handle.net/1885/139483In this work, we experimentally demonstrate an increase in the local transmit efficiency of a 1.5 T MRI scanner by using a metasurface formed by an array of brass wires embedded in a high permittivity low loss medium. Placement of such a structure inside the scanner results in strong coupling of the radiofrequency field produced by the body coil with the lowest frequency electromagnetic eigenmode of the metasurface. This leads to spatial redistribution of the near fields with enhancement of the local magnetic field and an increase in the transmit efficiency per square root maximum specific absorption rate in the region-of-interest. We have investigated this structure in vivo and achieved a factor of 3.3 enhancement in the local radiofrequency transmit efficiency.The numerical calculations were supported by the Russian Science Foundation (Project No. 15-19-20054). Experimental studies were supported by the Ministry of Education and Science of the Russian Federation (Zadanie No. 3.2465.2017/4.6) and partially by the European Research Council Advanced Grant number 670629 (A.W.) and Medical Wireless Sensing Ltd.application/pdf© 2017 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).implantmetasurfacespecific absorption ratetransmit efficiency2018-0110.1016/j.jmr.2017.11.013