Benefits And Risks Of Medical Imaging Tests

There are many types of medical imaging tests that may be prescribed by your physician, depending on your illness and symptoms. Among them might be the common X-rays, including chest and spine; CT or CAT, computed tomography scans and fluoroscopy.

These imaging tests are non-invasive procedures that enable a physician to diagnose diseases and injuries in a non-intrusive way. But patients should understand that some of these tests may involve exposure to ionizing radiation, which can present risks.

Ionizing radiation is a form of energy that acts by removing electrons from atoms and molecules of materials that include air, water and living tissue. An example most well-known to people is the x-ray, which penetrates the body and reveals images of our bones.

When a physician recommends an x-ray or other medical imaging test, you may want to consider:

• The Centers for Disease Control (CDC) suggests that medical imaging tests should be performed only when necessary
• The U.S. Food and Drug Administration (FDA) recommends discussing the benefits and risks of imaging with your physician. 

Typically, according to the CDC, medical imaging tests can help doctors obtain better views of your organs, blood vessels, tissues and bone; may help determine whether surgery is a good treatment option; can help guide medical procedures such as the placement of catheters and stents; may help locate tumors for treatment; locate blood clots or other blockages and help guide options for joint replacement and treatment of fractures. 

Some of the risks from exposure to ionizing radiation, according to the CDC, include:

• A small increase in the likelihood that a person exposed to radiation will develop cancer later in life.
• Health effects that could occur after a large acute exposure to ionizing radiation such as skin reddening and hair loss.
• Possible allergic reactions associated with a contrast dye injected into the veins to better see body structures being examined.

But because these tests may be fairly common, there are suggested ways to reduce exposure to diagnostic ionizing radiation. Physicians and radiation experts can help reduce exposure to, and risk of harm from, diagnostic ionizing radiation by going through a checklist. That includes checking to see if the patient has had a similar test done recently, and that can provide the background information needed without a new test; checking to see if there’s an alternative test that does not use ionizing radiation; instructing that the least amount of radiation needed for a good image is used for the procedure and ensuring protective lead shielding is used to prevent exposing other areas of the body to radiation.

There are also special considerations for pregnant women and children. Typically, the CDC suggests that the risk of an x-ray to a mother and unborn child is small compared to the benefit of the prescribed test. If you are required to have an abdominal x-ray, risks can be reduced by telling the physician if you are pregnant, or think you may become pregnant within a short time-frame. If that is the case, the physician may decide to cancel or postpone the test, or modify it to reduce the level of radiation. 

Special considerations for children include using the lowest exposure setting possible to obtain a good image. Doctors will typically proceed when the medical benefit outweighs the risk, or may use alternative imaging methods such as ultrasound or MRI if possible. MRI, or Magnetic Resonance Imaging, and ultrasound technology do not involve exposure to ionizing radiation.