Effective Doses in Radiology and Diagnostic Nuclear Medicine: A Catalog 1 Fred A. Mettler, Jr, MD, MPH Walter Huda, PhD Terry T. Yoshizumi, PhD Mahadevappa Mahesh, MS, PhD Medical uses of radiation have grown very rapidly over the past decade, and, as of 2007, medical uses represent the largest source of exposure to the U.S. population. Most physicians have difficulty assessing the magnitude of expo- sure or potential risk. Effective dose provides an approxi- mate indicator of potential detriment from ionizing radia- tion and should be used as one parameter in evaluating the appropriateness of examinations involving ionizing radia- tion. The purpose of this review is to provide a compilation of effective doses for radiologic and nuclear medicine pro- cedures. Standard radiographic examinations have aver- age effective doses that vary by over a factor of 1000 (0.01–10 mSv). Computed tomographic examinations tend to be in a more narrow range but have relatively high average effective doses (approximately 2–20 mSv), and average effective doses for interventional procedures usu- ally range from 5–70 mSv. Average effective dose for most nuclear medicine procedures varies between 0.3 and 20 mSv. These doses can be compared with the average annual effective dose from background radiation of about 3 mSv.  RSNA, 2008 1 From the Department of Radiology and Nuclear Medi- cine, New Mexico Veterans Administration Healthcare System, 1501 San Pedro Blvd, Albuquerque, NM 87108 (F.A.M.); Department of Radiology, Medical University of South Carolina, Charleston, SC (W.H.); Department of Ra- diology, Duke University Medical Center, Durham, NC (T.T.Y.); and The Russell H. Morgan Department of Radi- ology and Radiological Sciences, Johns Hopkins Medical Institutions, Baltimore, Md (M.M.). Received August 17, 2007; revision requested October 2; revision received October 29; accepted December 11; final version ac- cepted January 28, 2008. Address correspondence to F.A.M. (e-mail: fmettler@salud.unm.edu ).  RSNA, 2008 ORIGINAL RESEARCH  SPECIAL REPORT 254 Radiology: Volume 248: Number 1—July 2008 Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, use the Radiology Reprints form at the end of this article.