1. Praxis für Rheumatologie, Köln-Rodenkirchen, Germany;
2. Department of Radiology, Neuroradiology, Sonography and Nuclear Medicine, Trier, Germany;
3. Department of Radiology, University Hospital of Bonn, Bonn, Germany;
4. Department of Oncology, Hematology and Rheumatology, University Hospital of Bonn, Bonn, Germany;
5. Schmerzklinik Basel, Basel, Switzerland