1. Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
2. Department of Radiology, New York Presbyterian Hospital, Columbia University Medical Center, 622 W 168th St, New York, NY 10032.
3. Department of Radiology, Shanxi DAYI Hospital, Taiyuan, China.
4. Department of CT, Yancheng Third People's Hospital, Yancheng, China.