1. Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, P. R. China
2. Department of Imaging, Weihai Central Hospital, Qingdao University, Weihai, P. R. China
3. Department of Magnetic Resonance Imaging Diagnostic, Qihe County People’s Hospital, Dezhou, P. R. China
4. Department of Otolaryngology, Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, P. R. China