Radiation from Cardiac Imaging Procedures May Pose Cancer Risk

Although no one test is expected to be harmful, radiation from cardiac tests, dental X-rays, chest X-rays, mammograms, and tests performed for other purposes can add up, rapidly reaching or surpassing the recommended lifetime medical radiation limit of 100 milliSieverts (mSv) set by the American College of Radiology (AR; Reston, VA, USA).

There is growing concern about computed tomography (CT) scans because the popularity of these tests has greatly expanded, exposing large numbers of people to at times considerable doses of radiation. Imaging tests that emit ionizing radiation include: chest X-ray: 0.04 mSv; mammogram: 0.07 mSv; calcium scoring test: 1-2 mSv ; cardiac catheterization: 7 mSv ; chest CT: 10 mSv; coronary CT angiogram: 3-14 mSv; radionuclide sestamibi stress test: 10-12 mSv; and radionuclide dual-isotope myocardial perfusion imaging: 25 mSv.

“One or two CT scans over a lifetime is appropriate. But if you have a condition that requires repeated monitoring, a test that does not expose you to ionizing radiation may be preferred,’ stated Dr. Warren Manning, chief of noninvasive cardiac imaging and testing at Beth Israel Deaconess Medical Center (Boston, MA, USA) and a professor at Harvard Medical School (Boston, MA, USA).

Cardiac tests that pose no radiation risk include electrocardiogram (ECG), echocardiography, ultrasound, and magnetic resonance imaging (MRI).

Radiologists in Harvard-affiliated hospitals, as well as those in many other leading medical centers, take precautions to minimize radiation exposure. This includes using regimes that allow cardiac CT scans to be performed with one-sixth the traditional radiation dose.

The report’s findings were published in the July 2012 issue of the Harvard Heart Letter.

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