1. 1 Mazandaran University of Medical Science , Department of Anesthesiology , Sari, Mazandaran , Iran
2. 2 Assistant professor of Neurosurgery, Orthopedic Research Center , Mazandaran University of Medical Science , Sari, Mazandaran , Iran
3. 3 Mazandaran University of Medical Science , Department of Radiology , Sari, Mazandaran , Iran
4. 4 Shahed University of Medical Science , Tehran , Iran