1. Department of Radiology, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang 10326, Korea.
2. Department of Radiology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul 07985, Korea.
3. Department of Radiology, Gachon University Gil Medical Center, Gachon University, Incheon 21565, Korea.