1. Department of Obstetrics and Gynecology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Japan
2. Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto 606-8507, Japan
3. Department of Radiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Japan
4. Department of Obstetrics and Gynecology, Japanese Red Cross Wakayama Medical Center, Wakayama 640-8558, Japan
5. Department of Gynecology and Obstetrics, Kyoto University, Kyoto 606-8507, Japan