CAT scans of the head triple a child’s risk for brain cancer. That’s the word from across the Pond where British researchers recently reported the findings of a twenty-year study in the medical journal Lancet. The report has caused quite a stir here in the U.S. because in many hospitals, CAT scans of the head are a rite of passage following a severe head injury.

This is not the case in most pediatric facilities. Emergency pediatricians have long-recognized the potential danger of radiation exposure and have questioned the usefulness of universal CAT scans for all kids presenting with significant head injury. Instead, they take a close look at the mechanism of injury, explore other historical details of the incident, including immediate and subsequent symptoms, perform detailed physical and neurological examinations, and often opt for a period of observation before deciding if a CAT scan is really necessary.

So why aren’t all doctors following the same protocol and limiting a child’s exposure to CAT scan radiation? Well, some docs don’t see as many kids, so it’s difficult for them to get a feel for what REALLY needs a CAT scan and what doesn’t. Plus, when a kid comes in with a history of brief loss of consciousness and is still acting a little funny and the parents (and lawyers) are looking over his shoulder, it’s comforting for the doctor to send your child straight to the CAT scanner. After all, nobody wants to miss a skull fracture or a brain bleed.

And can you blame him? Of course not… unless your child ends up with a brain tumor!

But should that really be a concern?

The authors of the study did some fancy calculations and they say, following a single CAT scan of the head, the absolute risk of developing brain cancer is 1 in 10,000. Let’s compare that to some other risks we know. According to the National Safety Council, the lifetime risk of dying in a car accident is 1 in 368. For drowning, it’s 1 in 1000, and for dying in a plane crash, it’s 1 in 7000.

Of course, we ride in cars, swim in pools, and fly in planes all the time. Why? Because the enjoyment and convenience of these activities outweighs the risk.

But what about CAT scans? We know they are safer than cars and swimming pools and airplanes, but does their benefit outweigh the risk?

That depends.

It depends on your child’s specific injury and physical exam findings. It depends on your doctor’s confidence level. And it depends on your own peace of mind and definition of acceptable risk.

In the end, what should you do?

I’d suggest listening to the person in the white lab coat standing on the other side of your child’s bed. Don’t demand a CAT scan and don’t refuse one. Instead, ask about the risks and benefits of getting the scan. Sure, you may get a funny look, but trust me… deep down, your doc will be glad you asked!

Dr. Mike Patrick is an emergency medicine physician and Medical Director of Interactive Media for Nationwide Children’s Hospital. Each week, Dr. Mike 

presents news parents can use, answers listener questions, and interviews pediatric experts on PediaCast: a pediatric podcast for parents.