1. Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
2. The School of Clinical Medicine, Fujian Medical University, Fuzhou, China
3. Endoscopy Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
4. Department of Ultrasound, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China