[Cheng, Guanxun; Xiang, Yonghua] Southern Med Univ, Nanfang Hosp, Dept Radiol, Guangzhou, Guangdong, Peoples R China.
[Jin, Ke; Xiang, Yonghua] Univ South China, Hunan Childrens Hosp, Dept Radiol, Changsha, Hunan, Peoples R China.
[Zhang, Xuehua] Univ South China, Hunan Childrens Hosp, Dept Ultrasound, Changsha, Hunan, Peoples R China.
[Yang, Yuan] Cent S Univ, Dept Hlth Stat, Xiangya Hosp 2, Changsha, Hunan, Peoples R China.