1. Department of Gastrointestinal Surgery,Yichang Central People's Hospital, The First College of Clinical Medical Science, China Three Gorges University, Yichang, Hubei 443000, P.R. China
2. Department of Radiology, Yichang Central People's Hospital, The First College of Clinical Medical Science, China Three Gorges University, Yichang, Hubei 443000, P.R. China