A new study revealed that CT scans done on kids may make them vulnerable to cancer in the future due to high radiation.

Diana Miglioretti, lead researcher from the University of California Davis, and her team evaluated the medical records of 4,857,736 children below 15 years old who had CT scans anytime from 1996 to 2010. They also measured the radiation dose used during those pediatric scans by getting a sample from 2001 to 2011.

The study aimed to know the frequency of CT scan use, the most common organ subjected for scanning, the most effective radiation dose, and the projected risk to cancer among children when they grow up.

After careful evaluation of all the data gathered, they found out that between the years 1996 and 2005, there were more CT scans performed on children—the frequency is higher from children aged five to 14. The frequency remained stable two years after then started to decline through 2010. This means that there were fewer kids subjected to CT scans now than before.

They also discovered the effective doses differed from 0.03 to 69.2 mSv per scan. An effective dose of over 20 mSv was administered on 14 to 25 percent of the abdomen/pelvis scans, three to eight percent chest scans, and six to 14 percent of spine scans.

Further analysis directed them to another conclusion that girls are more at risk than males in developing cancer. Among CT scans performed for girls, there is a margin of 300 to 390 abdomen/pelvis scans, 330 to 480 chest scans, and 270 to 800 spine scans which were all at risks.

Miglioretti suggested for radiologists to reduce the radiation dose of CT scans administered to children by up to 25 percent to help prevent at least 43 percent of future cancers.

The report was published on the June 10 issue of JAMA Network titled "The Use of Computed Tomography in Pediatrics and the Associated Radiation Exposure and Estimated Cancer Risk."

There were constant debates about giving 20 mSv and higher dose of radiation to children especially in Japan where the Fukushima nuclear disaster occurred. The scientists there had been testing the effects of radiation to children and women and they concluded along with the U.S National Academy of Sciences that such dose may primarily kill women and children due to cancer.