1. Department of Radiology, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan
2. Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan
3. Department of Laboratory Medicine, Diagnostic Ultrasound Division, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan
4. Department of Radiology, Maruyama Memorial General Hospital, 2-10-5 Hon-cho, Iwatsuki-ku, Saitama 339-8521, Japan