Physicians involved with diagnostic imaging hear a steady stream of fears from patients. When patients learn their diagnostic imaging exams will include radiological imaging, they begin to worry. Everyone knows that radiation is harmful. Right?
Well – not exactly. The radiation used in diagnostic imaging exams is part of the electromagnetic spectrum, a broad range of electromagnetic radiation that includes visible light, radio waves, X-rays, gamma rays, and microwaves. Most of these types of radiation are perfectly harmless. Others may be harmful in high doses.
Many diagnostic imaging procedures, including ultrasound scans and magnetic resonance imaging, use no X-rays or nuclear radiation whatsoever. Other procedures use carefully controlled, clinically safe doses of X-rays or radioactive materials.
Fear of radiation and irresponsible reporting by the media is behind some of the most persistent myths about medical imaging.
Myth 1: CT Scans Increase the Risk of Cancer
CT and CAT scans are composed of many X-ray scans that are combined into three-dimensional images. Getting a CT scan can subject patients to a higher dose of X-rays than they would get from a single conventional X-ray procedure.
If repeated to excess, CT scans could contribute to an increased risk of cancer. However, studies have shown that the risk of cancer from single and even repeated CT scans is very low. In fact, medical experts and regulatory authorities place no recommended limit on the number of CT scans a patient can have. The benefits of provided diagnostic information far outweigh the minimal risk.
Myth 2: Medical Imaging Can Cause Reproductive Problems
Patients worry that X-rays can damage reproductive organs, leaving them sterile or leading to birth defects or other problems.
According to the American College of Radiology and the Radiological Society of North America, however, there have been no instances of reproductive problems related to radiation from diagnostic exams administered to future parents. The dose of radiation from common diagnostic exams is simply too small to cause such problems.
Patients’ fears are fueled when women are advised to wait six to 12 months before becoming pregnant after a radiological exam. This recommendation is usually based on an underlying medical issue that is unrelated to the exam itself. But patients assume that the advice is based on their exposure to radiological diagnostic tests.
Myth 3: Medical Imaging Exams Can Harm Unborn Babies
Some patients worry that radiation can harm fetuses during examinations of pregnant women. This worry is unfounded, however. Most medical imaging exams are safe during pregnancy.
Ultrasound is the most common imaging procedure used during pregnancy, and ultrasound does not expose the mother or baby to harmful radiation. There are no known cases of harm to an unborn baby as a result of this procedure. The same is true of MRIs.
Doctors do ask women if they are pregnant before performing diagnostic imaging tests, but this is merely a precaution. In most cases the radiation exposure to a fetus during an X-ray or CT scan is minimal.
The Bottom Line
It is true that repeated exposure to certain high-radiation procedures can increase lifetime cancer risks very slightly. However, such tests are ordered only when the health benefit of finding and treating a medical disorder outweigh the minimal risks. Radiologists and physicians are trained to evaluate the risks and benefits of every medical procedure, and they have implemented abundant safeguards to ensure that radiological exams and other medical imaging tests are safe.