1. Department of Radiology, Massachusetts General Hospital, Boston, MA
2. Department of Radiology, University of Ibadan, Ibadan, Nigeria
3. Department of Radiology & Nuclear Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
4. Department of Epidemiology, Erasmus MC University Medical Center, Rotterdam, The Netherlands
5. Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
6. Department of Radiology, University Hospital RWTH Aachen, Aachen, Germany
7. Department of Diagnostic and Interventional Neuroradiology, University Hospital RWTH Aachen, Aachen, Germany