Department of Radiology;
HunanProvince People's Hospital;
Changsha 410005;
Hunan Province;
China;
Departmentof Radiology;
the Second Xiang-Ya Hospital;
Central SouthUniversity;
Changsha 410005;
Hunan Province;
China;
Department of Pathology;
HunanProvince Children's Hospital;
Changsha 410005;
Hunan Province;
China;
Department of Epidemiology;
Center for DiseaseControl of Hunan Province;
Changsha 410005;
Hunan Province;
China;