1. ACR White Paper on radiation dose in medicine;Amis;J Am Coll Radiol,2007
2. Computed tomography—an increasing source of radiation exposure;Brenner;New Engl J Med,2007
3. Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 2,2006
4. Royal College of Radiology (RCR). RCR referral guidelines. iRefer: making the best use of clinical radiology. Available at: http://www.rcr.ac.uk/content.aspx?PageID=995 and accessing the guidelines. Available at: http://www.rcr.ac.uk/content.aspx?PageID=2269. Accessed January 20, 2014.
5. ACR. About the ACR Appropriateness Criteria®. Available at: http://www.acr.org/Quality-Safety/Appropriateness-Criteria/About-AC and ACR Appropriateness Criteria® Overview. Available at: http://www.acr.org/∼/media/ACR/Documents/AppCriteria/Overview.pdf. Accessed January 20, 2014.