1. Department of Radiology, Sendai City Medical Center, 5-22-1, Tsurugaya, Miyagino-ku, Sendai, Miyagi 983-0824, Japan.
2. Department of Radiology, Ishinomaki Red Cross Hospital, Ishinomaki, Miyagi, Japan.
3. Department of Radiology, Sendai Kosei Hospital, Sendai, Miyagi, Japan.
4. Department of Gastroenterology, Sendai City Medical Center, Sendai, Miyagi, Japan.