1. Department of Radiology, Gunma University Hospital, Maebashi, Gunma, Japan
2. Department of Applied Medical Imaging, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
3. Department of Radiology, Saitama Medical Center/Saitama Medical University, Kamoda, Kawagoe, Saitama, Japan
4. Department of Obstetrics and Gynecology, Gunma University Hospital, Maebashi, Gunma, Japan
5. Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan