Determining an outer contour during MR imaging

A magnetic resonance tomography unit and a method is provided in which a patient couch may be moved in relation to the longitudinal direction into the patient tunnel in the transversal direction into a left-hand side extreme position and an opposite-lying right-hand side extreme position. Using an image acquisition facility in the left-hand side extreme position a right-hand side part is acquired and in the right-hand side extreme position a left-hand side part of the outer contour of the predetermined object is acquired. Using the image acquisition facility, the outer contour of the object is subsequently created from the left-hand side part of the outer contour and also from the right-hand side part of the outer contour.