An apparatus and method for MR imaging in inhomogeneous magnetic fields includes acquisition of a plurality of three-dimensional MR data sets, each data set having a central transmit frequency and a central receive frequency set to a frequency offset that is distinct for each 3D MR data set. The absorbent body has cavities which are essentially cone-shaped and extend at least through part of the absorbent body, said cavities having a tip part and a base, the tip part being located towards or in the liquid permeable surface layer and the base being located away from the liquid permeable surface layer. These preview multicast streams provide pre-recorded content of multicast streams.