1. Institute for Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany
2. Department of Cardiology and Pulmonology, University Medical Center Göttingen, Göttingen, Germany
3. Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
4. Harvard Medical School, Boston, MA, USA
5. Clinic of Gastroenterology, Gastrointestinal Oncology and Endocrinology, University Medical Center Göttingen, Göttingen, Germany