In nearly all areas of technology our generation is experiencing the phenomena of fast paced innovation and great bursts in development. Besides the completely new techniques, the "experienced user" is astonished when obviously good and appar­ ently matured technology such as the next to last generation of CT equipment undergoes further development, such as is the case with the spiral CT technique. The enormous potential of spiral CT suddenly became apparent, stimulating and giving rise to a wide range of research on its clinical application. Yet again we can see in the field of imaging how great advances in one method competitively affect the range of application in another. Hence it is extremely valuable and necessary to appraise the current situation now. Both physicians - who use the equipment - and the health system and with this the patient - which finances it - have the obligation and the right to permanent optimization of the application strategies of diagnostic procedures. Not least, this symposium also meant to fit the new voice of spiral CT harmo­ niously into the symphonic score of diagnostic procedures. The large radiodiagno­ stic department of the university clinics which has been established at the Neues All­ gemeines Krankenhaus in Vienna, Austria, is proud to have jointly arranged this user symposium with Siemens.