1. Department of Radiology, Nagato Memorial Hospital, Saiki 876-0835, Japan
2. Department of Radiology, Faculty of Medicine, Oita University, Yufu 879-5593, Japan
3. Department of Radiology, School of Medicine, Kurume University, Kurume 830-0011, Japan
4. San-Ai Medical Center, Department of Radiology, Oita 870-1151, Japan
5. Department of Radiology, Shin-Beppu Hospital, Beppu 874-8538, Japan
6. Department of Gastroenterology, Shin-Beppu Hospital, Beppu 874-8538, Japan
7. San-Ai Medical Center, Department of Gastroenterology, Oita 870-115, Japan