CAM Study

Project summary

Little is known on large airways mechanics in pediatric lung diseases. Bronchoscopy is considered the gold standard modality to assess the large airways and to their mechanics. However, it is an invasive technique that requires general anesthesia. As an alternative, airway dimensions and even mechanics can be measured by CT scan, but this exposes the child to radiation.To overcome this limitation magnetic resonance imaging (MRI) has been developed by our center for the dynamic cine-assessment of the large airways. The diagnostic performance of cine-MRI has never been compared to bronchoscopy. If cine-MRI proves to be as good as bronchoscopy to diagnose large airways diseases, it will be possible to reduce the number of invasive bronchoscopies.We hypothesize that the new MRI protocol will be sensitive enough to detect changes in large airway dimensions in relation to standardized breathing manoeuvres. To test this hypothesis, the primary objective of this study is to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value of our MRI protocol compared to flexible bronchoscopy, used as reference test. Secondary aims include: 1) assessing concordance between malacia severity, as determined by MRI and bronchoscopy; 2) relationship between severity assessment of MRI and bronchoscopy with pulmonary function tests and respiratory symptoms; and 3) assessing the influence of bronchodilator in airways mechanics.

The new MRI protocol will be sensitive enough to detect abnormal diameter changes (malacia) in relation to standardized breathing manoeuvres.