1. Graduate School of Medical Care and Technology, Teikyo University Hospital, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
2. Central Radiology Division, Teikyo University Hospital, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8606, Japan
3. Department of Radiology, Teikyo University, School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan