In a magnetic resonance (MR) apparatus and a method for operation thereof, the radio-frequency (RF) resonator of the scanner of the apparatus fed from a single RF source and is operated, during a total scan duration for acquiring MR scan data from a subject, so as to excite nuclear spins in the subject with respective RF fields having different B1+ field profiles that are radiated at respectively different times during the acquisition of the scan data. The scan data acquired during the scan thus are produced from MR signals caused by nuclear spins excited by at least two different B1+ field profiles. The scan can be used to acquire MR data for MR fingerprinting.