Described embodiments include a system, apparatus, and method. A system includes an array of at least two groups of at least two artificially structured electromagnetic unit cells. Each group includes a controllable amplifier responsive to a B1 localization control signal and configured to amplify a received pulse of radiofrequency electromagnetic waves. Each group includes an electromagnetic wave conducting structure configured to deliver an amplified pulse of radiofrequency electromagnetic waves to the at least two artificially structured electromagnetic unit cells. The at least two artificially structured electromagnetic unit cells are configured to transform the incident amplified pulse into a pulse of radiofrequency magnetic field B1 orientated transverse to a segment of the z-axis. A control circuit selects an arbitrary examination segment transverse to the z-axis responsive to data indicative of a transverse slice selected for examination, and generates the B1 localization control signal defining an amplification state assigned to each group.