1. Department of Radiology, Peking University People’s Hospital, Beijing, China
2. Department of Radiology, Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
3. Department of Colorectal Surgery, Gansu Provincial Hospital, Lanzhou, Gansu, China
4. Department of Gastrointestinal Surgery, West China Hospital of Sichuan University, Chengdu, China