Abstracted from USA Today

Each year, about 1.6 million children in the USA get CT scans to the head and abdomen - and about 1,500 of those will die later in life of radiation-induced cancer.

What's more, CT or computed tomography scans given to kids are typically calibrated for adults, so children absorb two to six times the radiation needed to produce clear images. Radiologists could turn down the X-rays without losing quality, and thus expose the children to less potentially cancer-causing radiation.

These doses are much larger than the sorts of doses that people at Three Mile Island were getting. Most people there got a tenth or a hundredth of the dose of a CT.

Doctors use CT scans on children to search for cancers and ailments such as appendicitis and kidney stones. There's a huge number of people who don't just receive one scan.

About 11% of the CT scans at his center are done in children under 15, and they get 70% of the total radiation dose given to patients. Children have more rapidly dividing cells than adults, which are more susceptible to radiation damage. Children also will live long enough for cancers to develop.

The breast dose from a CT scan of the chest is somewhere between 10 and 20 mammograms. You'd want to think long and hard about giving your young daughter 10 to 20 mammograms unless she really needs it.

CT scans are used in about 4% of medical X-ray examinations, but it contributes to an estimated 40% of the total radiation dose to the population.

American Journal of Roentgenology 2001:176;303-306