The radiation from CT scans can increase a child's risk of brain cancer and leukemia, a study finds, with risk increasing along with the amount of radiation. The radiation in two or three CT scans triples brain cancer risk for a kid under 15, while five to 10 scans is enough to triple the risk of leukemia, NPR reports. While those numbers sound big, however, they only amount to "one excess brain tumor and one leukemia per 10,000 head CT scans," a researcher says.
"There was debate about whether the risks were real, and this study shows pretty unequivocally that they are," an expert tells ABC News. But CT scans can still be well worth it, researchers say. "Providing the scan is clinically justified and performed properly with a child size dose of radiation, the benefits should easily outweigh the risks." The scans are used increasingly often, with some 4 million kids a year receiving them, the New York Times notes. But a third of those may not be needed; radiation-free MRIs and ultrasounds could be a better bet.