1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, Korea.
2. Division of Nephrology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, Korea.
3. Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, Korea.