1. Graduate School of Medical Care and Technology Teikyo University 2‐11‐1 Kaga, Itabashi‐ku Tokyo173‐8605Japan
2. Department of Radiology Teikyo University School of Medicine 2‐11‐1 Kaga, Itabashi‐ku Tokyo173‐8605Japan
3. Central Radiology Division Teikyo University Hospital 2‐11‐1 Kaga, Itabashi‐ku Tokyo173‐8605Japan