Tracheomalacia in Adults with Cystic Fibrosis: Determination of Prevalence and Severity with Dynamic Cine CT

Purpose: To determine the prevalence and severity of tracheomalacia in adults with cystic fibrosis (CF) by using dynamic cine multidetector computed tomography (CT) and to correlate these findings with pulmonary function test (PFT) results and the severity of parenchymal lung disease.

Materials and Methods: In this institutional review board-approved HIPAA-compliant study, 40 patients with CF (22 men, 18 women; mean age, 28 years +/- 8 [standard deviation]; age range, 18-54 years) prospectively underwent PFTs, standard thin-section CT, and two dynamic cine multidetector CT acquisitions. Ten control subjects underwent dynamic cine multidetector CT. After standard thin-section CT was completed, dynamic cine multidetector CT was performed during a forced expiratory maneuver and during coughing. Dynamic cine multidetector CT images in nine patients were excluded. Maximal inspiratory, dynamic expiratory, and end-expiratory tracheal luminal areas were compared (Student t test) and correlated (Spearman rank) with PFT results and severity of parenchymal lung disease.

Results: Mean predicted forced expiratory volume in 1 second (FEV(1)) was 70.6% +/- 20.7, and mean Bhalla CT score was 41.8% +/- 13.6. In patients with CF, dynamic cine mean tracheal cross-sectional area reduction was 51.7% +/- 18.4 (range, 9%-89%) for forced expiratory maneuvers and 68.8% +/- 11.7 (range, 18%-88%) for coughing (P = .001). Tracheomalacia was demonstrated in 24 (69%) patients and no control subjects during forced expiratory maneuvers (P = .001) and in 10 (29%) patients and one (10%) control subject during coughing. For end-expiration images, mean tracheal luminal reduction was 16.1% +/- 14.0% ( range, 0.0%-53.0%), with one patient demonstrating tracheal luminal reduction of more than 50%. There was no correlation between tracheal cross-sectional luminal reduction and either predicted FEV(1) or CT Bhalla score.

Conclusion: Tracheomalacia depicted at dynamic cine multidetector CT is a highly prevalent finding in adults with CF. (c) RSNA, 2009