1. Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
2. Department of Maxillofacial Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
3. Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Helsinki Finland
4. Cancer Centre, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
5. Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
6. Department of Otorhinolaryngology–Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland