[1]Department of Gastroenterology Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou 310009 China;
[2]Department of Gastroenterology Zhuhai People's Hospital Third Affiliated Hospital of Jinan University School of Medicine Zhuhai 519000 China;
[3]Department of Radiology Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou 310009 China;
[4]Department of Ultrasonography Second Affiliated Hospital of Zhejiang University School of Medicme Hangzhou 310009 China;