1. Department of Legal Medicine; Graduate School of Medicine; Chiba University; 1-8-1 Inohana, Chuo-ku Chiba 260-8670 Japan
2. Department of Public Health; Graduate School of Medicine; Chiba University; 1-8-1 Inohana, Chuo-ku Chiba 260-8670 Japan
3. Department of Radiology; Chiba University; 1-8-1 Inohana, Chuo-ku Chiba 260-8670 Japan