Acquired tracheomalacia: Detection by expiratory CT scan

Purpose: The put-pose of this work was to determine whether cross-sectional area and coronal and sagittal diameter measurements of the trachea between inspiration and end-expiration on CT are significantly different between p atients with acquired tracheomalacia and those without this condition. Method: Inspiratory and end-expiratory CT scans of the trachea of 23 normal patients and 10 patients with acquired tracheomalacia were analyzed. Perce nt changes in cross-sectional area, coronal, and sagittal diameters were ca lculated. Results: For patients with tracheomalacia, mean percent changes in the uppe r and middle trachea between inspiration and expiration were 49 and 44% : m ean changes in the coronal and sagittal diameters in the upper and middle t racheal were 4 and 10% and 39 and 54%, respectively. Control group mean per cent changes in the upper and middle tracheal area were 12 and 14%, respect ively, and mean changes in the coronal and sagittal diameters in the upper and middle trachea were 4 and 4% and 11 and 13%, respectively. Significant differences were calculated for changes in cross-sectional area and sagitta l diameter between groups (p < 10(-5)). Based on receiver operator curve an alysis, a > 18% change in the upper trachea and 28% change in the midtrache a between inspiration and expiration were observed: the probability of trac heomalacia was 89-100%. The probability of tracheomalacia was > 89%, especi ally if the change in sagittal diameter was > 28%. Conclusion: By measuring changes in tracheal cross-sectional area and sagit tal diameters between inspiratory and end-expiratory CT, a significant diff erence can be identified between normal patients and those with acquired tr acheomalacia.