A TEM resonator system is disclosed comprising at least two TEM resonators (21,31; 22, 32), especially in the form of TEM volume coils, and especially for use in an MR imaging system or apparatus for transmitting RF excitation signals and/or for receiving MR signals into/from an examination object or a part thereof, respectively, wherein the TEM resonators are arranged and displaced along a common longitudinal axis and wherein an intermediate RF shield (4) is positioned in longitudinal direction between the two TEM resonators for at least substantially preventing electromagnetic radiation from emanating from between the first TEM resonator and the second TEM resonator into the surroundings. A PET detector and/or another supplementary element can be placed In the volume between the two TEM resonators.