Various embodiments relate to a method for the movement-averaged attenuation correction of positron emission tomography data based on magnetic resonance tomography data. In at least one embodiment, the method includes capturing of multiple MRT data respectively in different phases of a cycle of an anatomical disposition of an investigation subject. The method furthermore includes respectively for each of the plurality of MRT data: determination of a value of an attenuation parameter via segmentation and averaging of the determined values of the attenuation parameter in order to obtain an averaged value of the attenuation parameter. The method furthermore includes the execution of attenuation correction of the PET data based on the averaged value of the attenuation parameter.
