1. Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
2. Department of Neurosurgery, Shiqianxian People's Hospital, Guizhou 555100, P.R. China
3. Department of Radiology, Suzhou Guangji Hospital, Suzhou, Jiangsu 215006, P.R. China