1. Department of Neurology, Military General Hospital of Beijing PLA, Beijing, China
2. Department of Radiology, Neuroradiology Division, University of Virginia, Charlottesville, VA, USA
3. Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
4. Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
5. Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
6. Department of Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland