1. Department of Radiology, National Defense Medical College , Saitama 3598513, Japan
2. Department of Internal Medicine, National Defense Medical College , Saitama 3598513, Japan
3. Department of Surgery, National Defense Medical College , Saitama 3598513, Japan
4. Department of Basic Pathology, National Defense Medical College , Saitama 3598513, Japan
5. Department of Radiology, Jichi Medical University , Tochigi 3290498, Japan