1. Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, Beijing, 100730 China.
2. Department of Rheumatology, Peking Union Medical College Hospital, Beijing, China.
3. Department of Diagnostic and Interventional Radiology, University of Leipzig Medical Center, Leipzig, Germany.
4. Department of Radiology, Charité, Universitaetsmedizin Berlin, corporate member of Freie Universitaet Berlin, Humboldt-Universitaet zu Berlin, and Berlin Institute of Health, Berlin, Germany.
5. Department of Gastroenterology, Peking Union Medical College Hospital, Beijing, China.