[Chest computed tomography in children: indications, efficiency and effective dose]

Introduction: New multidetector row computed tomography (CT) has made the imaging of younger children more feasible and extending CT indications to a wide range of pediatric respiratory diseases in the last few years. However, CT is a source of radiation exposure. The aim of this study was to evaluate the main indications and the contribution of chest CT in pediatric pulmonology as well as induced radiation.

Methods: This was an observational, prospective study. Children whose chest CTs were analyzed during multidisciplinary meetings (radiologist, pulmonary pediatrician) were included from November 2009 to April 2010. We collected demographic data, CT results, contribution of CT to diagnosis and management, and radiation doses (dose-length product [DLP] and effective dose). Radiation doses were compared according to the CT scans (Lille University Hospital with 128-slice dual-source CT or Lille University Hospital single-source 64-slice CT, or CT performed outside the university hospital).

Results: One hundred thirty-five patients were included. The mean age was 6.4 years old. The main indications were analysis of bronchial disease (44%), infectious disease (16%), interstitial disease (14%), or a malformation (9%). The aim of CT was diagnosis (61%) or follow-up of previous lung diseases (39%). Diagnosis chest-CT directly contributed to diagnosis in 48% of cases and to treatment in 24%. Follow-up CT contributed to diagnosis in 38% and treatment in 19% of cases. DLP and effective doses were significantly lower for CT performed in the university hospital, especially with the 128-slice CT compared to the others (P<0.001). The effective doses were: 128-slice CT, 0.61 mSv ± 0.32; 64-slice CT, 1.24 mSv ± 0.97; outside university hospital, 2.56 mSv ± 1.98.

Conclusion: This study confirms the role played by chest CT in children, which contributes to diagnosis and management of lung diseases. The main concern of CT application, especially in children, is the radiation burden. Children are more susceptible to the effects of radiation than adults and have a longer life expectancy to develop complications. Both radiologists and pediatricians should be aware of a potential risk and have to conjugate their efforts in reducing this risk. The wide range of radiation doses in this study for the same CT procedures underlines the extensive efforts still needed to limit radiation exposure in children.