In a method and a magnetic resonance (MR) system and method to generate MR image data of a predetermined volume segment within an examination subject, multiple slices of the volume segment are simultaneously excited by at least one RF excitation pulse, and during the excitation a slice selection gradient is switched. The measurement signals from the multiple slices are acquired with multiple RF reception antennas, at least some of which are spaced along the propagation direction of the slice selection gradient. During the acquisition of the measurement signals the slice selection gradient is switched in order to achieve a spectral separation of the measurement signals of different slices. The MR image data are generated from the measurement signals.