1. Division of Legal Medicine, Department of Community Preventive Medicine, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata 951-8510, Japan
2. Center of Cause of Death Investigation, Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8510, Japan
3. Department of Radiological Technology, Graduate School of Health Sciences, Niigata University, Niigata 951-8518, Japan