1. Department of Radiology, Severance Hospital Stroke Center, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Neurology, Keimyung University School of Medicine, Daegu, Korea.
3. Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Neurology, Severance Hospital Stroke Center, Yonsei University College of Medicine, Seoul, Korea.