When a patient is suspected of having or already has symptoms of heart disease, diagnostic tests such as computed tomography (CT) angiograms or nuclear stress tests would usually be recommended by his or her doctor.
Being a heart-imaging test, a coronary CT angiogram can find out whether fatty or calcium deposits have built up in the arteries, which supply blood to the heart muscle. On the other hand, nuclear stress tests can determine if there is a lack of blood flow in the heart muscle, which could signal a blockage in a heart artery.
However, in a scientific advisory released on February 2, 2009 in the journal Circulation by the American Heart Association (AHA) suggested that doctors should use these tests carefully and avoid screening their patients regularly for cardiac problems. Doctors are also advised to weigh risks and benefits before recommending to their patients because such low-dose radiation does has the potential to cause cancer.
According to AHA, recommendation for heart scan should not be given to a patient who is at low risk of having heart disease and who has no symptoms of heart disease. Doctors should have careful consideration and send their patients for cardiac imaging only when this would potentially benefit the patients.
Nevertheless, it is not the intention of the AHA to scare the public that these diagnostic tests are dangerous and should not be utilized at all. What they mean is that: use the right tests in the right patient!
Medical imaging techniques represent the biggest source of controllable radiation exposure of Americans, and that is why doctors should be aware of the potential harm from even relatively small doses of radiation
Whenever and wherever possible, doctors should tackle clinical question from their patients without using ionizing radiation. However, once the doctors are certain that ionizing radiation is necessary; they should try every effort to reduce the radiation dose.
In United States, there is no federal regulation of radiation dose, with the exception for mammograms (for breast cancer). It is up to the doctors and medical facilities to determine the appropriate use of the scanning equipment and radiation dose.