A simplified, semi-quantitative structural lung disease computed tomography outcome during quiet breathing in infants with cystic fibrosis.

Chest tomography (CT) using the controlled ventilation technique (CTCV) is a sensitive method to detect features of lung cystic fibrosis (CF) disease in infants with CF. However, this technique needs sedation and is not easily applied for the clinician who may need, in the follow-up, to evaluate more precisely lung disease in infants with CF. Thus, our study aims to evaluate if CT assessment of lung disease, without the need of sedation, during quiet breathing, using a semi-quantitative scoring system, is reproducible and may discriminate infants with CF from control infants at an early stage of the lung disease. 39 infants with CF underwent a first CT at 10.3 [9.4, 11.4] weeks of age. Among them, 33 underwent a second CT at 56.1 [53.1, 59.6] weeks of age. CF scoring images of the different scanner variables, i.e. bronchial wall thickening, bronchiectasis, mucus plugging and air trapping were compared to CT scoring obtained in 2 different groups of control infants of similar age without lung disease. Among all the constituents of the scoring, air trapping is the only parameter discriminating infants with CF from control infants at both ages in our study (p≤0.01). Moreover, air trapping explains 90% of the total score variability with r2=0.89 with a good concordance after re-scoring in blind, 6months apart, by the same operator for both infant populations: ICC=0.98 [0.97, 0.99]. In this study, we propose that CT during quiet breathing could be a useful clinical tool to evaluate the early presence of gas trapping in infants with CF.