Computed tomography in children with cystic fibrosis:: a new way to reduce radiation dose

Aims: To determine whether the monitoring of respiratory disease progression in children with cystic fibrosis ( CF) can be made using six pre- selected computed tomography ( CT) cuts in lieu of the conventional full study. Methods: Forty one lung CT scans from 21 paediatric patients with CF were analysed. The Bhalla and Nathanson scores of the total lung CT and the six pre- selected CT cuts were compared. Results: The Bhalla mean score of the total lung CT evaluated by two radiologists was 5.62. It was 5.36 when just the six pre- selected sections were evaluated. The difference between means was not statistically significant. The Nathanson mean score of the total lung CT evaluated by both radiologists was 66.11; it was 66.51 when just the six pre- selected sections were evaluated. The difference between means was not statistically significant. The mean total radiation dose from a single whole lung CT scan was 716.22 mGy. cm. A dose of 250.66 mGy. cm was estimated if only six sections were used, with a reduction in radiation of about 65%. Conclusion: It is possible to obtain the same radiological information from six pre- selected CT cuts as it is from a full pulmonary CT scan, thereby markedly reducing radiation exposure for children who will require repeat investigations in the future.