1. Physiology Research Center, Iran University of Medical Sciences, Tehran 14496-14535, Iran
2. Faculty of Medicine, Guilan University of Medical Sciences, Rasht 41937-13111, Iran
3. Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj 66186-34683, Iran
4. Radiology Department, Tabriz University of Medical Sciences, Tabriz 51656-65931, Iran
5. School of Medicine, Tehran University of Medical Sciences, Tehran 14167-53955, Iran
6. Department of Radiology and Neurology, Heersink School of Medicine, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USA