At least a portion of a body (10) of a patient positioned in an examination volume of a MR device (1). A portion of the body (10) is subject to a calibration sequence including RF pulses and switched magnetic field gradients controlled in such a manner that a calibration signal data set is acquired by a multi-point Dixon technique at a first image resolution. Calibration parameters are derived from the calibration signal data set. The MR device (1) is controlled according to the derived calibration parameters. The portion of the body (10) is subject to an imaging sequence including RF pulses and switched magnetic field gradients controlled in such a manner that a diagnostic signal data set is acquired at a second image resolution which is higher than the first image resolution. A diagnostic MR image is reconstructed from the diagnostic signal data set.