Academic achievement after a CT examination toward the head in childhood: Follow up of a randomized controlled trial

by Elina Salonen, Robert Bujila, Jean-Luc af Geijerstam, Håkan Nyman, Olof Flodmark, Peter Aspelin, Magnus Kaijser

Increasing use of CT examinations has led to concerns of possible negative cognitive effects for children. The objective of this study is to examine if the ionizing radiation dose from a CT head scan at the age of 6–16 years affects academic performance and high school eligibility at the end of compulsory school.

A total of 832 children, 535 boys and 297 girls, from a previous trial where CT head scan was randomized on patients presenting with mild traumatic brain injury, were followed. Age at inclusion was 6–16 years (mean of 12.1), age at follow up 15–18 years (mean of 16.0), and time between injury and follow up one week up to 10 years (mean of 3.9). Participants’ radiation exposure status was linked with the total grade score, grades in mathematics and the Swedish language, eligibility for high school at the end of compulsory school, previously measured GOSE-score, and their mothers’ education level. The Chi-Square Test, Student’s t-Test and factorial logistics were used to analyze data.

Although estimates of school grades and high school eligibility were generally higher for the unexposed, the results showed no statistically significant differences between the exposed and unexposed participants in any of the aforementioned variables.

Any effect on high school eligibility and school grades from a CT head scan at the age of 6–16 years is too small to be detected in a study of more than 800 patients, half of whom were randomly assigned to CT head scan exposure.