1. Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
2. Department of Radiology, University Hospital of Geneva, Geneva, Switzerland
3. University Center of Dental Medicine Basel, Center for Dental Imaging, University of Basel, Basel, Switzerland
4. University hospital of Basel, Basel, Switzerland
5. University of Bern, Bern, Switzerland
6. Radiation Protection Division, Federal office of Public Health, Bern, Switzerland
7. HNO-Zentrum, Bern, Switzerland
8. Division of Medical Radiation Physics, Inselspital, Bern, Switzerland
9. Praxisklinik, Basel, Switzerland