1. An apparatus for combined magnetic resonance tomography and positron emission tomography imaging, comprising: a structurally integrated imaging unit including, a single patient table, a magnetic resonance imaging scanner configured to record, from an examination region, MRT image data of a person under examination, a positron emission tomography scanner configured to record, from the examination region, PET image data of the person under examination, an additional scanning unit, configured to scan an area of the person under examination and based on the scanning, to determine a contour of the person under examination for the area, and a processor configured to, determine a location of structures that attenuate a PET signal based on the determined contour and the MRT image data, and carry out an absorption correction of the recorded PET image data from the examination region of the person under examination based on the determined location of the structures.