Canadian researchers have created new tools to reduce the number of unnecessary computed tomography (CT) scans performed on children each year – rules they hope will become standard across the country.
The number of children who undergo CT scans after suffering minor head injuries has risen dramatically in recent years, though there’s little evidence to show the need for such tests in a majority of patients.
It’s a trend that has led to growing concern in the medical community over children being unnecessarily exposed to levels of radiation that could increase their risk of developing cancer.
“These things have crept into practice without a really good look at them,” said Martin Osmond, chief executive officer and scientific director of the Children’s Hospital of Eastern Ontario Research Institute. “We can’t continue to CT scan more and more children, because it could result in a public health problem later on.”
In a study published yesterday in the Canadian Medical Association Journal, Dr. Osmond and colleagues laid out a set of risk factors that signal a child could have a brain injury. By following the guidelines, doctors could help ensure children who are in danger get help quickly – and prevent others being needlessly exposed to radiation, the study said.
One CT scan emits 300 to 600 times the radiation of a single chest X-ray, which is why an increasing number of doctors and other health-care professionals are concerned about the over-use of scans in patients, particularly kids, who may be more vulnerable to the effects.
There are currently no nationally accepted, evidence-based rules to help hospitals determine which patients need a CT scan. As a result, many children who hit their head or suffer some other type of minor head injury may undergo one due to parental pressure or a doctor’s desire to play it safe, Dr. Osmond said.
Performing CT scans has also become increasingly efficient in recent years, which could be contributing to the surge, he added. Previous research has shown the use of CT scans for minor head injury in children increased to 53 per cent of cases in 2005 from 15 per cent in 1995.
“You tend to err on the side of caution, and the question is how far do you err on the side of caution?” said Dr. Osmond, who is also an emergency room physician and associate professor of pediatrics at the University of Ottawa. “Without reliable guidelines, sometimes I think the envelope just gets pushed.”
But research also shows the additional use hasn’t resulted in better treatment.
A “small but important” number of life-threatening brain injuries in children are missed by CT scans, the study said, and only a small percentage of other brain injuries are visible on the test. At the same time, the overwhelming majority of children with a minor head injury don’t require urgent medical attention, it said.
The new rules, dubbed the Canadian Assessment of Tomography for Childhood Injury, or CATCH, were developed after researchers looked at the cases of nearly 4,000 patients (from 10 pediatric teaching hospitals in Canada) who suffered minor head injuries from 2001 to 2005.
All patients included in the study met certain criteria, such as loss of consciousness, amnesia, vomiting – or persistent irritability in children under 2.
Researchers identified four high-risk factors that signal a child may need neurosurgical intervention, including a headache that grows worse and suspicion of an open-skull fracture.
They also determined three medium-risk factors, including suspected fracture at the base of the skull, that signal the possibility of a brain injury that could be seen on a CT scan.
Researchers found the two sets of risk factors were highly accurate in predicting whether children would need medical intervention or had a brain injury.
Before the rules become standard across Canada, researchers will apply them in 5,000 new patients to ensure they’re effective in a real-time setting.
