By Shashi Ranganath, MD
When your children are sick or injured, nothing is more important than getting them well. And sometimes that requires diagnostic testing. The use of computed tomography (CT) scans, which combine a series of X-rays taken from many angles with computer processing to produce detailed cross-sectional images, has increased tenfold since 1980, according to the National Cancer Institute – primarily because these scans, first developed in the 1970s, are quick, accurate, and non-invasive. Today, about 5 to 9 million CT scans are performed annually on children in the United States.
The most common reason for a doctor to recommend a CT scan for a baby or child is to evaluate a head injury or abdominal pain, but these scans can also be used to diagnose cancers, blood clots, infections, fractures, and internal injuries. In some situations, such as finding a malignant tumor before it’s had a chance to spread, a CT scan can even save a child’s life.
While CT scans have many benefits, they also come with potential risks because they expose patients to several hundred times more radiation than an X-ray. This creates some unique considerations for children.
“Kids are growing, and their tissue is more sensitive,” explains Shashi Ranganath, MD, a pediatric radiologist and Assistant Regional Medical Director of Imaging Services at Mid-Atlantic Permanente Medical Group (MAPMG). “Moreover, the effects of radiation are cumulative; the radiation your child receives today will be with him or her forever.”
In addition, if the CT scan settings are not adjusted for the child’s size, he or she may receive a higher radiation dose than truly necessary. Together, these factors can raise concerns for parents and healthcare providers, since exposure to radiation may increase the risk of developing a radiation-related cancer.
How can parents get their children the diagnostic imaging they need while minimizing risk? Fortunately, there are ways to minimize your child’s exposure to radiation without forgoing the benefit of this powerful tool when it’s truly needed.
First, before consenting to a CT scan for your child, ask your doctor about using alternative forms of imaging that do not involve radiation. “As a pediatric radiologist, I always first try to answer questions with an MRI or an ultrasound when possible,” says Dr. Ranganath. “If I can’t, then I consider a CT scan.” Rather than producing radiation, ultrasound uses sound waves and MRIs use radio waves to create an image.
Fortunately, it’s common for emergency departments to be equipped with pediatric dose protocols for CT scans; if your child lands in the ED, you can confirm that with the doctors or technologists there. If your child needs a CT scan outside of an ED, locate an imaging center that adjusts its scanning methods for children. Many facilities, like those operated by Kaiser Permanente in the Mid-Atlantic States, have specific protocols for kids, including low-dose CT scanning equipment. “Our scanners have built-in protocols with a type of software that allows us to make adjustments to the scanner according to the age and size of the child,” says Dr. Ranganath. Depending on the scan being performed, these scanners can reduce the dose for a baby or child by as much as half of what an adult would receive.
Additionally, the CT technologists Dr. Ranganath works with try to scan only the part of the body that needs to be examined. For example, if a child has abdominal pain and doctors suspect appendicitis, the radiologist can scan just the lower abdomen and pelvis and exclude the lower chest and upper abdomen, thereby lowering the radiation dose.
“Radiologists then save the dose information for each scan, so that they can track how much radiation each child has been exposed to and use that information when considering a scan in the future,” says Dr. Ranganath.
It’s important to remember that while no amount of radiation is considered absolutely safe, the absolute cancer risks associated with CT scans are small. And, as always, talk to your physician. “CT is such a great technique,” she says. “We just need to minimize the risks for kids whenever possible.”