BACKGROUND: To evaluate the possible association between paediatric head 
computed tomography (CT) examination and increased subsequent risk of malignancy 
and benign brain tumour.
METHODS: In the exposed cohort, 24 418 participants under 18 years of age, who 
underwent head CT examination between 1998 and 2006, were identified from the 
Taiwan National Health Insurance Research Database (NHIRD). Patients were 
followed up until a diagnosis of malignant disease or benign brain tumour, 
withdrawal from the National Health Insurance (NHI) system, or at the end of 
2008.
RESULTS: The overall risk was not significantly different in the two cohorts 
(incidence rate=36.72 per 100 000 person-years in the exposed cohort, 28.48 per 
100 000 person-years in the unexposed cohort, hazard ratio (HR)=1.29, 95% 
confidence interval (CI)=0.90-1.85). The risk of benign brain tumour was 
significantly higher in the exposed cohort than in the unexposed cohort 
(HR=2.97, 95% CI=1.49-5.93). The frequency of CT examination showed strong 
correlation with the subsequent overall risk of malignancy and benign brain 
tumour.
CONCLUSIONS: We found that paediatric head CT examination was associated with an 
increased incidence of benign brain tumour. A large-scale study with longer 
follow-up is necessary to confirm this result.