Overall, CT x-rays will cause 39 cancers in every 10,000 children scanned, and most may be among girls, who appear to be more vulnerable. Children under the age of five years are also at greater risk of developing cancer up to 10 years after a CT scan, say researchers, although the risk may remain for the rest of the person's life.
The cancer risk was highlighted by researchers who examined the medical records of 10.9 million children and adolescents aged up to 19 years, 680,000 of whom had at least one CT scan.
Although the researchers say the risk is small, their discovery does emphasise that CT scans should be used more sparingly and only in cases where it is absolutely necessary.
(Source: British Medical Journal, 2013; 346: f2360).