1. Course of Radiological Technology, Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
2. Department of Radiation Biology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
3. Department of Radiology, Sendai Kousei Hospital, Sendai 980-0873, Japan
4. Department of Radiation Disaster Medicine, International Research Institute of Disaster Science, Tohoku University, Sendai 980-0845, Japan
5. Department of Cardiovascular Medicine, Sendai Kousei Hospital, Sendai 980-0873, Japan