Abstract: Methods, systems, and techniques for a field modification device for modifying a transmission field (Tx) and/or a receive field (Rx) used by an MR system are provided. The field modification device comprises a plurality of resonator elements being inducible by the transmission field and/or the receive field to resonate, thereby modifying the transmission field and/or the receive field, respectively, wherein a respective resonance frequency and/or resonance phase of a respective resonator element and/or of a respective group of resonator elements is individually controllable. The field modification device further comprises a device controller configured to individually control the respective resonance frequency and/or resonance phase of the respective resonator element and/or of the respective group of resonator elements .

Abstract: An article having a metal substrate and a channel in the metal substrate which is partly or completely open to the surface, wherein the cross section of the channel has a local width maximum (5) between the channel base (7) and the contact plane (1), measured parallel to the contact plane and at right angles to the longitudinal channel axis in the section perpendicular to the surface. (FIG.