[1] Qingdao Univ, Dept Radiol, Affiliated Hosp, Qingdao, Shandong, Peoples R China
[2] PLA Rocket Force, Dept Radiol, Gen Hosp, Beijing, Peoples R China
[3] Qingdao Univ, Dept Urol, Affiliated Hosp, Qingdao, Shandong, Peoples R China
[4] Qingdao Univ, Dept Pediat Surg, Affiliated Hosp, Qingdao, Shandong, Peoples R China