1,300 Radiation dose, in millirems (mrem), from a single full-body computed tomography (CT) scan

1.5 Miles Distance you’d need to have been from the Hiroshima atomic explosion to receive an equivalent dose

29 Radiation dose, in mrem, from smoking a pack of cigarettes

.08% Increase in risk of death from cancer after a full-body CT scan

3.75% Increase in risk of death from cancer if you receive a full-body CT scan annually starting at age 25

300 Average annual radiation dose from natural sources, in mrem, per person in the U.S.

1 Average annual radiation dose, in mrem, from eating one or two bananas a week

57 MILLION Number of full-body CT scans performed in 2003

$16 BILLION Estimated annual cost of unnecessary diagnostic imaging

7 Percentage of patients informed of the risks of their CT scans

Sources: American College of Radiology, David J. Brenner/Columbia University Medical Center, U.S. Food and Drug Administration, David C. Levin/Thomas Jefferson University Hospital, National Institutes of Health, Nuclear Energy Institute, Yale University School of Medicine