1. Department of Radiology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
2. Functional and Molecular Imaging Key Laboratory of Sichuan Province, Chengdu 610000, China
3. College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, China
4. Department of Gastroenterology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, China