Researchers have a new warning about the use of CT scans for children.
A study in the journal "The Lancet" found radiation exposure from two to three CT scans of the head during childhood can triple the risk of developing brain cancer or leukemia.
Researchers note that newer scanners expose children to less radiation, but they say there is still cause for concern.
"There is a small but real risk of cancer from these CT scans that needs to be weighed against the benefits of CT scans," said Doctor Andrew Einstein of Columbia University Medical Center.
The FDA advises parents to question their doctor about whether a scan is needed.
The American College of Radiology says radiation fears should not prevent parents from getting necessary scans for their children.