1. The First School of Clinical Medicine, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
2. Department of Radiology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, P.R. China
3. Department of Radiology, Huaihai Hospital Affiliated with Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China