Application of a capacitively-loaded split-ring metamaterial lens in a 0.3 T magnetic resonance imaging system

In this work, it is demonstrated that metamaterial lenses can help to increase the signal-to-noise ratio of magnetic resonance imaging coils in low-field magnetic resonance imaging systems. In low-field magnetic resonance imaging systems, the dominant source of noise in the signal-to-noise ratio comes from the metallization of the coil and the noise sample or tissue is negligible, unlike high-field magnetic resonance imaging systems. A metamaterial lens consisting of a three-dimensional array of capacitively loaded split rings was fabricated and tested on a 0.3 T MRI system. The experiment was performed for a configuration in which the metamaterial lens is far enough from the coil so that the additional losses that can be introduced into the coil by the metamaterial lens are also negligible, as are the tissue losses.