Unfortunately, the authors did not optimize their imaging protocols and kept the radiation dose per examination constant, whereas most CF centers have adopted low-dose imaging protocols and systematically lowered the dose during the past 17 years. Therefore, the study must not be regarded as normal practice within most dedicated centers. It may well be that in most centers, the trend in cumulative dose remained constant (or even reduced) as the dose per examination decreased, given technical advances and increased awareness. Additionally, O’Connell et al2 did not adopt pediatric CT scanning protocols that were published many years ago. The dose per CT scan examination used in their center was up to 28.5 times more than what is regarded as state of the art for many years now.3 We urge centers caring for pediatric patients with CF to pay close attention to imaging protocols with respect to the radiation dose administered. Apparently, centers apply up to 28.5 times higher doses than what is, in our opinion, necessary for diagnosis.