1. Department of Medical Technology, Osaka University Hospital , Suita 5650871 , Japan
2. Department of Radiology, Chiba University Hospital , Chiba 2608677 , Japan
3. Department of Clinical Radiology, Kagawa University Hospital , Kita-gun 7610793 , Japan
4. Department of Radiology, Shimane University Hospital , Izumo 6938501 , Japan
5. Department of Medical Technology, Kochi Medical School Hospital , Nankoku 7830043 , Japan
6. Department of Radiology, Shiga University of Medical Science Hospital , Otsu 5202192 , Japan
7. Department of Radiology, Hirosaki University Hospital , Hirosaki 0368563 , Japan