1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Seoul 05505, Korea.
2. Asan Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.
3. Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143-0628, USA.
4. Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University College of Medicine, Taoyuan County 333, Taiwan.
5. Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
6. Tri-Service General Hospital and National Defense Medical Center, Taipei 114, Taiwan.