1. Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Korea.
2. Division of Cardiology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 135-720, Korea.
3. Healthcare Sector, Siemens AG, Erlangen D-91052, Germany.
4. Siemens Ltd., Seoul 120-837, Korea.