Fig. 2: Resonator tuning principle and results of electromagnetic simulations.

a An illustration of the dielectric resonator prototype for targeted breast MRI at 3 Tesla. Correspondence of the device resonance frequency to the operational frequency of the used 3 Tesla clinical MR system (a vertical dashed black line) is shown with the S₁₁ measurements (blue curve). b, c The gaps between the discs of the resonator are used to tune the resonator to the operating frequency of a particular MR system. That makes the resonator universal. d An RF safety gain map inside the breast in the case of the body birdcage coil used in combination with the ceramic resonator relative to the birdcage coil alone. Different values and colors correspond to different RF safety gain values in different parts of the breast associated with inhomogeneities of root-mean-square value of the transmit RF electromagnetic field. Brown shaded areas show the boundaries of the resonator.