Jan. 3, 2011 -- The average child in the U.S. will have around seven medical imaging tests involving radiation by the time he or she reaches the age of 18, a new study suggests.
Researchers examined diagnostic imaging data over three years for more than 355,000 children enrolled with a leading health care provider across five large markets in the U.S.
Published online today in the Archives of Pediatric and Adolescent Medicine, the analysis revealed that:
- 42% of the children had at least one imaging procedure involving radiation from January 2005 through December 2007.
- About 12% of scans involved computed tomography (CT), which delivers much higher doses or radiation than conventional X-rays.
- About 1 in 4 children had two or more imaging tests involving radiation during the three-year period and about 1 in 7 children had three or more tests.
Radiation Risk Poorly Understood
Based on these numbers, the researchers estimate that the average child will have more than seven imaging tests involving radiation by their late teens.
While the cancer risk, if any, associated with these tests may never be fully understood, pediatrician and study researcher Adam L. Dorfman, MD, of the University of Michigan, says the hazards of radiation may be greater for children than adults.
“We know that exposure to radiation is additive over a lifetime,” he tells WebMD. “And we know that kids are more susceptible to the adverse effects of a given amount of radiation than adults.”
The vast majority (85%) of imaging procedures performed in the study involved conventional X-rays, which deliver much lower radiation doses than CT.
But about 8% of children in the study received one or more CT scan during the three-year period.
Studies suggest the use of CT scans in pediatric hospitals is declining, due in part to efforts aimed at encouraging practitioners to use the imaging procedure in children only when absolutely necessary.
These efforts include the Image Gently initiative from the Alliance for Radiation Safety in Pediatric Imaging initiative, chaired by Cincinnati Children’s Hospital radiologist Marilyn J. Goske, MD.
The initiative includes the Society for Pediatric Radiology and more than 33 other groups representing more than 500,000 health care professionals.
Group Aims to Educate Doctors, Parents
In addition to educating doctors and encouraging pediatric-specific CT scanning with reduced radiation doses, a goal is to educate parents about diagnostic imaging, Goske tells WebMD.
“Having a record of what test was done and when and where it was done can result in fewer repeat procedures,” Goske says.
The group’s mission is to promote optimal scanning strategies for children, she says. These strategies include:
- Imaging only when there is a clear medical benefit.
- Using the lowest amount of radiation for adequate imaging, determined by the child’s size.
- Image only the areas indicated.
- Avoiding multiple scans.
- Using diagnostic procedures that don’t expose children to ionizing radiation, including MRI and ultrasound, when appropriate.