According to the invention, a mobile signal pick-up means (11) of a diagnostics installation comprises a radiation receiver (12) for generating electrical signals dependent on the radiation shadow of a transirradiated subject, an image acquisition system (15), a calculating and storage unit (21), a display (22) as well as a communication means. A stationary evaluation means (5, 6, 7, 8) comprising a communication means is provided. The communication means are implemented as bidirectional communication means and serve for the signal transmission between the mobile signal pick-up means (11) and the stationary evaluation means (5, 6, 7, 8).