  Developments in metamaterials and related structures such as metasurfaces
have opened up new possibilities in designing materials and devices with unique
properties. The main progress related to electromagnetic waves applications was
done in optical and microwave spectra. Here we report about a new hybrid
metasurface structure, comprising a two-dimensional metamaterial surface and a
very high permittivity dielectric substrate that was designed to enhance the
performance of an ultra-high field MRI scanner. This new flexible and compact
resonant structure is the first one which can be integrated into a
multi-element close-fitting receive coil array used for all clinical MRI. We
successfully demonstrated the operation of the metasurface in acquiring vivo
human brain images and spectra with enhanced local sensitivity on a commercial
7 Tesla system. These experimental findings prove the feasibility of real
clinical applications of metasurfaces in MRI.
