1. Department of Imaging, Jiaozhou Central Hospital, Qingdao 266300, China
2. Anorectal Department, Rizhao Hospital of TCM, Rizhao 276800, China
3. Department of Gastroenterology, The Affiliated Qingdao Central Hospital of Qingdao University, The Second Affiliated Hospital of Medical College of Qingdao University, Qingdao 266042, Shandong, China
4. Department of General Surgery (I), Qingdao Hospital of Traditional Chinese Medicine, Qingdao Hiser Hospital Affiliated to Qingdao University, Qingdao 266033, China