[1] Guangzhou Med Univ, Affiliated Qingyuan Hosp, Qingyuan Peoples Hosp, Inst Digest Dis, Qingyuan 511518, Peoples R China
[2] Guangzhou Med Univ, Affiliated Qingyuan Hosp, Qingyuan Peoples Hosp, Sch Clin Med 6, Qingyuan 511518, Peoples R China
[3] Guangzhou Med Univ, Affiliated Qingyuan Hosp, Qingyuan Peoples Hosp, Dept Neurosurg, Qingyuan 511518, Peoples R China