1. Department of Hepatobiliary and Pancreatic Oncology National Cancer Center Hospital Chuo‐ku Japan
2. Department of Gastroenterology and Hepatology Yokohama City University Hospital Yokohama Japan
3. Department of Diagnostic Radiology National Cancer Center Hospital Chuo‐ku Japan
4. Department of Hepatobiliary and Pancreatic Surgery National Cancer Center Hospital Chuo‐ku Japan