1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, Korea.
2. Endocrinology Division & Thyroid Disease Center, Arcispedale Santa Maria Nuova 42123, Reggio Emilia, Italy.
3. Diagnostic Imaging and Interventional Radiology Department, Ospedale Regina Apostolorum 00041, Albano Laziale-Rome, Italy.
4. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea.
5. Department of Radiology, Human Medical Imaging and Intervention Center, Seoul 137-902, Korea.