1. Unscear 2008 Sources and effects of ionizing radiation. Available via www.unscear.org/docs/reports/2008/09-86753_Report_2008_Annex_A.pdf . Accessed 10 Jan 2011
2. Mettler FA, Thomadsen BR, Bhargavan M et al (2008) Medical radiation exposure in the US in 2006: preliminary results. Health Phys 95:502–507
3. You JJ, Alter DA, Iron K et al (2007) Diagnostic Services in Ontario: Descriptive analysis and Juristictional Review. ICES Investigative Report. Institute for Clinical Evaluation Sciences, Toronto, Canada
4. Department of Health (2010) Total number of imaging and radiodiagnostic examinations or tests, by imaging modality, England, 1995–96 to 2009–10. Available via www.dh.gov.uk/en/Publicationsandstatistics/Statistics/Performancedataandstatistics/HospitalActivityStatistics/DH_077487 . Accessed 05 April 2011
5. Tsushima Y, Taketomi-Takahashi A, Takei H et al (2010) Radiation exposure from CT examinations in Japan. BMC Med Imaging 10:1–8