1. Soonchunhyang University Hospital Seoul
2. Department of radiology, Kyung hee University Hospital at Gangdong
3. department of Radiology, Nowon Eulgi University Hostpial
4. Department of Radiology, Konkuk University Medical center
5. Department of Radiology, CHA Bundang Medical center, Yongin Severance Hospital, Yonsei University College of medicine
6. Department of radiology, Inje University Busan Paik Hospital