BALTIMORE — CT scans are responsible for 91% of total radiation exposure in pediatric trauma patients, even though only 32% of imaging done in these patients is computed tomography, study results showed.
“If a patient is critical and the imaging study means the difference between life and death, then by all means get [the CT scan]. But there are times when imaging studies are done out of convenience or in place of other imaging modalities [like ultrasound] that could get pictures that are similar without radiation exposure,” said Dr. Marissa A. Brunetti, who is an intensivist at Johns Hopkins Hospital, Baltimore.
In a presentation at the annual meeting of the Pediatric Academic Societies, Dr. Brunetti reported on 729 patients aged 14 years and younger seen in the emergency department at her hospital over a 1-year period. Transfer patients were excluded from the analysis, as were any follow-up imaging studies. In total, 1,457 CT studies and 4,603 radiographic studies were conducted on these patients.
The average radiation dose for each patient was 12.8 millisieverts (mSv), with a high of 73.5 mSv. “The average dose from the environment is about 3 mSv per year, so that's more than four times the annual dose,” Dr. Brunetti said.
Stratified by type of injury, the 178 patients whose trauma resulted from a motor vehicle accident received the greatest radiation exposure, with an average of 18.6 mSv. Pedestrians struck by cars had the second highest level, at 15.6 mSv.
Part of the reason unnecessary imaging studies are done, she said, is that “pediatricians and providers don't know the doses that these images impart.” Education about which studies deliver the highest doses, and emphasis on keeping these studies to a minimum, could lower patients' total radiation exposure.
Another problem lies with transfer patients. Although the study did not look at transfers to the hospital, an audience member pointed out that “there is this idea that my CT scanner is going to be better than the CT that is done in the community hospital,” so patients wind up having studies repeated.
“Especially in the very young with long time horizons, the benefit of additional radiation exposure for diagnostic purposes should be weighed against the long-term risks of additional exposure,” Dr. Brunetti concluded. She had no disclosures in regard to this study.