April 6, 2011
Doctors are calling for greater caution after a new study found that computed tomography (CT) scans of pediatric patients during emergency room visits has increased dramatically.
Researchers used data from the 1995–2008 National Hospital Ambulatory Medical Care Survey to determine the number of patients under 18 years old who received CT scans during a visit to the emergency room. They found that between 1995 and 2008, the number of children receiving CT scans increased five-fold, from 330,000 to 1.65 million.
The study, entitled “Rising Use of CT in Child Visits to the Emergency Department in the United States, 1995–2008,” appears in the monthly journal Radiology.
Hospitals use CT scans as a diagnostic tool, especially in emergency departments where they need a rapid diagnosis. In the study, the most common complaints necessitating CT scans in children were head injury, abdominal pain and headache.
“We found that abdominal CT imaging went from almost never being used in 1995 to being used in 15 percent to 21 percent of visits in the last four years of the study,” said study author David B. Larson, MD, MBA, Assistant Professor of Radiology at Cincinnati Children’s Hospital Medical Center. “In 1995, abdominal CT took much longer, the resolution was not as good and the research hadn’t been done to support it. By 2008, helical scanning had helped make CT very useful for abdominal imaging. It’s widely available, it’s fast and there are a lot of great reasons to do it, but it does carry a higher radiation dose.”
The radiation from an abdominal CT scan is seven times greater than that of a head CT.
Most children’s CT scans during emergency room visits occur at non-pediatric hospitals. Study authors point out that most radiologists administering and interpreting CT scans are not trained in pediatric radiology. Errors can occur because each CT scan should be tailored to the body size of the child. There is concern that the industry needs better oversight of children’s CT scan procedures and dosages to prevent radiation overdose, as children are especially vulnerable.
“Radiation exposure is a concern in both adults and children,” says the U.S. Food and Drug Administration, who oversees radiation-emitting products. “However, these concerns are greater for children because they are more sensitive to radiation and have a longer life expectancy than adults. As a result, accumulated exposures over a child’s lifetime are more likely to result in an adverse health effect. A child’s smaller size also has an impact on the radiation dose they receive. For example, if a CT scan is performed on a child using the same parameters as those used on an adult, an unnecessarily large dose will be delivered to the child.”
Radiation exposure is cumulative, meaning it builds up with each successive dose over time. Cumulative radiation exposure, including radiation from CT scans, can increase risk of cancer.
“We need to think creatively about how to partner with each other, with ordering clinicians and with CT manufacturers to ensure that all children are scanned only when it is appropriate and with appropriate techniques,” said Dr. Larson.
The Alliance for Radiation Safety in Pediatric Imaging, a consortium of professional societies who are concerned about radiation exposure children receive when undergoing medical imaging procedures, advises parents to ask their child’s doctor if other alternative imaging tests, such as ultrasound or magnetic resonance imaging (MRI), can provide the same information as a CT scan, but without the radiation exposure.