A method for acquiring raw data for generating image data of a target organ via a magnetic resonance system is described. In an embodiment, test raw data is initially acquired from a measurement region including at least the target organ using a plurality of magnetic resonance coils. Test image data is reconstructed from the test raw data. Furthermore, a mask defining the position and the dimensions of the target organ is generated using the reconstructed test image data. The magnetic resonance coils, to be used for the image acquisition, are then selected. This takes place on the basis of intensity values from a region covered by the mask and intensity values of a measurement region lying outside of the mask. Finally, the measurement is performed by acquiring raw data via the selected magnetic resonance coils. Furthermore, a device for acquiring raw data for generating image data is also described.