Could a CT Scan Endanger Your Child?

A routine test may put children at an added and unnecessary risk of cancer.

ByABC News
February 23, 2009, 1:37 PM

Jan. 15, 2008 — -- In the last 30 years, the computerized tomography scan more commonly known as the CT scan has become a valuable study to aid in the diagnosis of illness or trauma. It is estimated that 62 million CT scans per year are performed in the United States, including 4 million on children.

Without a doubt, it's an important and sometimes lifesaving tool. But like most medical technologies, it has the potential to be a double-edged sword. Many parents and some physicians may not be aware of the amount of radiation delivered to a child undergoing a CT scan.

For example, a scan of the head delivers 100 times more radiation than a chest X-ray, and an abdominal scan is equivalent to about 500 chest X-rays!

Compare this to some other well-known procedures that deliver radiation into the body, and you'll see that CT scans come out near the top in terms of radiation exposure. An X-ray of the skull, for example, involves only about 1/25 of the radiation delivered during a typical CT scan.

And a barium swallow a procedure used to screen the upper gastrointestinal tract delivers the radiation equivalent of 150 chest X-rays, which is only a fraction of the amount of radiation delivered during a typical abdominal CT scan.

This high dose of radiation is a potential cause of cancer, especially in children. Young children have many developing cells and growing organs, which makes them more susceptible to radiation injury. Children also have more years of life ahead of them, during which the injury from radiation may later be revealed.

While the benefit of diagnosis is an asset to the physician managing the patient, the potential risks from radiation are a serious concern. History is replete with cancers caused by unnecessary radiation in children. Rates of cancer have been studied on atomic bomb survivors. Based on these studies of radiation exposure, scientists have estimated the risk of cancer to be 1 in 1,200 for brain scans and 1 in 500 for abdominal scans.