1. Division of Intervention, Department of Radiology, Seoul National University Bundang Hospital, Gyeonggi-do 436-707, Korea.
2. Department of Radiology, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, Seoul 110-744, Korea.
3. Interventional Radiology, Center for Liver Cancer, National Cancer Center, Gyeonggi-do 410-769, Korea.
4. Department of Surgery and Research Institute of Clinical Medicine, Chonbuk National University Hospital, Jeollabuk-do 567-712, Korea.