Radiation from cardiac imaging and procedures may pose cancer risk

Procedures for diagnosing and treating heart disease that use ionizing radiation can potentially damage cells and increase the risk of cancer. Although no single test is likely to be harmful, radiation from cardiac tests, dental x-rays, chest x-rays, mammograms, and tests performed for other reasons can add up, quickly reaching or surpassing the recommended lifetime medical radiation limit of 100 milliSieverts (mSv) set by the American College of Radiology.
There's growing concern about CT scans because the popularity of these tests has exploded, exposing large numbers of people to sometimes substantial doses of radiation.
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
• 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," says Dr. Warren Manning, chief of noninvasive cardiac imaging and testing at Beth Israel Deaconess Medical Center and a professor at Harvard Medical School.
Cardiac tests that pose no radiation risk include ECG, echocardiography, ultrasound, and 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 protocols that allow cardiac CT scans to be performed with one-sixth the conventional radiation dose.