1. Hokkaido University of Science, Radiological Technology, Sapporo, Hokkaido, Japan.
2. Obihiro Kosei Hospital, Radiological Technology, Obihiro, Hokkaido, Japan.
3. Hokkaido University, Health Sciences, Sapporo, Hokkaido, Japan.
4. Institute for Health Economics and Policy, Tokyo, Japan.
5. Mayo Clinic Department of Health Sciences Research, Rochester, Minnesota.