How to identify high radiation burden from computed tomography: an example in obese children

Background: Radiation burden from the use of computed tomography (CT) imaging may not be evenly distributed. We tested whether overweight and obese children receive higher radiation burden from CT imaging.

Methods: An automated software tool (DoseWizard) assessed patient-level radiation dose from CT and merged results with clinical data from the electronic health record. CT scans of the head, chest, and abdomen/pelvis (A/P) performed at our institution from January 2013 to August 2015 on patients aged <16 y were processed using this software. Patients were categorized as overweight/obese if they had a body mass index (BMI) greater than the 85th percentile for age. Radiation exposures were compared between groups. Higher dose CT scans were identified as having a radiation dose in the top decile. Multivariate analysis identified factors associated with high-dose CT scans.

Results: About 7212 CT scans were included. Overweight/obese patients received similar radiation dose for head CT as compared with normal weight patients (1.51 versus 1.49 mSv, P = 0.04) but higher radiation dose for chest (1.14 versus 0.81 mSv, P < 0.001) and A/P (1.97 versus 1.43 mSv, P < 0.001). In multivariable regression models, being overweight/obese increased the odds of a higher dose chest CT (odds ratio 2.24, P < 0.001) and A/P CT (odds ratio 7.24, P < 0.001).

Conclusions: Overweight and obese children receive higher radiation burden from CT imaging and are one group that deserves consideration of dose monitoring. This software tool can be used to measure changes in radiation exposure and run clinical decision support in future studies targeting high radiation exposure to children.