Abstract: An apparatus for transmitting and receiving radiofrequency (RF) signals in a magnetic resonance imaging system for proton and X-nuclear imaging includes at least one radiofrequency (RF) coil and an ultrahigh dielectric constant material incorporated within the at least one RF coil. The permittivity of the ultrahigh dielectric constant material depends on a temperature of the material and is tunable. The apparatus also includes a temperature controller that is thermally coupled to the ultrahigh dielectric constant material. The temperature controller is configured to control a temperature of the ultrahigh dielectric constant material to tune and optimize the permittivity of the ultrahigh dielectric constant material. A chemical structure and composition of the ultrahigh dielectric constant material is selected to control and optimize the permittivity and a dielectric loss of the ultrahigh dielectric constant material and a temperature dependence of the ultrahigh dielectric constant material.

Abstract: A dielectric assembly solid dielectric elements within a liquid or solid matrix material. The dielectric assembly may be manufactured by pressing a dielectric powder to form pressed dielectric elements, sintering the pressed dielectric elements to form the solid dielectric elements, and assembling the solid dielectric elements within the matrix material to form the dielectric assembly. The solid dielectric elements can be specifically oriented (e.g., in one or more tiled layers) or randomly oriented, and the dielectric assemblies can be molded and/or machined into desired 3D geometries. The dielectric assemblies can be relatively large (e.g., >1 mm3) while having bulk dielectric constants higher than conventional slurries and composites formed of dielectric powder in a liquid or solid matrix.

Abstract: An apparatus for transmitting and receiving radiofrequency (RF) signals in a magnetic resonance imaging system for proton and X-nuclear imaging includes at least one radiofrequency (RF) coil and an ultrahigh dielectric constant material incorporated within the at least one RF coil. The permittivity of the ultrahigh dielectric constant material depends on a temperature of the material and is tunable. The apparatus also includes a temperature controller that is thermally coupled to the ultrahigh dielectric constant material. The temperature controller is configured to control a temperature of the ultrahigh dielectric constant material to tune and optimize the permittivity of the ultrahigh dielectric constant material. A chemical structure and composition of the ultrahigh dielectric constant material is selected to control and optimize the permittivity and a dielectric loss of the ultrahigh dielectric constant material and a temperature dependence of the ultrahigh dielectric constant material.