Wei-Zhong Zhou1, Lin-Bo Zhao1, Sheng Liu2, Hai-Bin Shi1. 1. From the Radiology Department, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. 2. From the Radiology Department, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. liusheng@njmu.edu.cn.