1. Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, South Korea;
2. Department of Obstetrics and Gynecology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, South Korea;
3. Department of Pathology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, South Korea