Ward R, et al. – The purpose of the current study was to first determine the radiation dose delivered to children during common radiological investigations using modern equipment and secondly to identify the number of such investigations performed in a cohort of children with cystic fibrosis (CF) to calculate their cumulative radiation exposure. This research provided up–to–date estimations of the radiation exposure when doing common radiological investigations. These doses and the estimates of cumulative radiation exposure in children with CF are lower than previously reported. This reflects the reduced estimated effective dose (EED) related to modern equipment and the use of age–specific scanning protocols.