Figure 1From: The American College of Radiology white paper on radiation dose in medicine:deep impact on the practice of cardiovascular imagingMedical and natural sources of radiation. Modified from ref 1, and updated with 2006 data from ref. 3. The effective dose of 1 mSv is equivalent to 50 chest x-rays. The per-head dose of ionizing radiation from clinical imaging exams in the United States increased almost 600 percent from 1980 to 2006.Back to article page