In a magnetic resonance (MR) apparatus and an operating method therefor, MR data are acquired from a patient using an MR sequence wherein, after at least one excitation pulse, multiple refocusing pulses are radiated during a readout period. The respective strengths of the refocusing pulses proceed according to a first flip-angle variation over time that is defined so as to minimize the SAR of the patient. A multislice imaging technique is used for simultaneous excitation and readout of at least two slices of a slice group of the patient, and flip-angle variations, which differ from the first variation, are selected in order to further reduce the SAR of the patient, compared with the use of identical flip-angle variations.