20 is connected to a speaker 21 for re playing the entered voice command for verification the control computer 17 is also connected to a graphics 22 via a line 23 the graphics processor 22 generates signals for a three dimensional display of the apparatus components on a display 24 for example a plasma display such a three dimensional display is a pseudo 3d illustration with oblique projection and shadowing as shown for example in fig2 the display 24 receives the coordinate values from the control unit 14 via the central control computer 17 and displays the spatial positions of the components such as the x ray tube 1 the imaging system 2 and the patient support 4 relative to each other by means of the signals generated by the graphics processor 22 arrows identified with letters a through n indicate the possible movements of the apparatus components and are indicated in the three dimensional display by voice input of these letters a through n via the microphone 19 the voice processor 18 analyzes the command and generates a control instruction this control instruction is converted back into a voice signal via the circuit 20 for output through the speaker 21 for verification the control instruction is also supplied to the central control computer 17 which simulates a modification of the positions of the components in response thereto as if such movements were actually being made and were being displayed on the basis of the coordinate signals the simulated movement of the apparatus components 1 through 4 is portrayed on the display 24 by entering a stop command by voice the.