1. Department of Liver Disease and Digestive Interventional Radiology; Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University; Xi'an China
2. Information Center, School of Stomatology; Fourth Military Medical University; Xi'an China
3. Department of Radiology; Northwestern University; Chicago IL
4. State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases; Xijing Hospital, Fourth Military Medical University; Xi'an China
5. Department of Medical Statistics; Fourth Military Medical University; Xi'an China