Jiajun Xie1, Amei Chen1, Zelan Ma2, Xiangdong Xu1, Xinhua Wei3. 1. Department of Radiology, Guangzhou First People's Hospital, #1 Panfu Road, Guangzhou, 510080, Guangdong Province, China. 2. Department of Radiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China. 3. Department of Radiology, Guangzhou First People's Hospital, #1 Panfu Road, Guangzhou, 510080, Guangdong Province, China. eyxinhuawei@scut.edu.cn.