Cumulative exposure to ionizing radiation from diagnostic and therapeutic cardiac imaging procedures: a population-based analysis.

OBJECTIVES The purpose of this study was to describe radiation exposure from cardiac imaging procedures over time in a general population. BACKGROUND Cardiac imaging procedures frequently expose patients to ionizing radiation, but their contribution to effective doses of radiation in the general population is unknown. METHODS We used administrative claims to identify cardiac imaging procedures performed from 2005 to 2007 in 952,420 nonelderly insured adults in 5 U.S. health care markets. We estimated 3-year cumulative effective doses of radiation in millisieverts from these procedures We then calculated population-based annual rates of radiation exposure to effective doses < or =3 mSv/year (background level of radiation from natural sources), >3 to 20 mSv/year, or >20 mSv/year (upper annual limit for occupational exposure averaged over 5 years). RESULTS A total of 90,121 (9.5%) individuals underwent at least 1 cardiac imaging procedure using radiation. Among patients who underwent > or =1 cardiac imaging procedures, the mean cumulative effective dose over 3 years was 23.1 mSv (range 1.5 to 543.7 mSv). Myocardial perfusion imaging accounted for 74% of the cumulative effective dose. Overall, 47.8% of cardiac imaging procedures were performed in physician offices; this proportion was higher for myocardial perfusion imaging (74.8%) and cardiac computed tomography studies (76.5%). The annual population-based rate of receiving an effective dose of >3 to 20 mSv/year was 89.0 per 1,000; and 3.3 per 1,000 for cumulative doses >20 mSv/year. Annual effective doses increased with age and were generally higher among men. CONCLUSIONS Cardiac imaging procedures lead to substantial radiation exposure and effective doses for many patients in the U.S.