A Tracheobronchomalacia : Dynamic Airway Evaluation with Multidetector CT

OBJECTIVE. The objective of our study was to evaluate the role of dynamic inspiratory– expiratory imaging with multidetector CT in patients with suspected tracheobronchomalacia. CONCLUSION. Multidetector CT with inspiratory–expiratory imaging is a promising method in the evaluation of patients with dynamic airway collapse. In our study, the degree of dynamic collapse correlated well with bronchoscopic results. Dynamic expiratory multidetec-tor CT may offer a feasible alternative to bronchoscopy in patients with suspected tracheo-bronchomalacia. lthough tracheobronchomalacia is traditionally viewed as a disease of infants and neonates, recent literature suggests that there is greater recognition of this airway disorder by physicians treating adult patients with respiratory symptoms. Several large studies suggest that the incidence of tracheobronchomalacia is 5–10% in patients presenting with pulmonary complaints and that the incidence increases with advanced age [1, 2]. Equally impressive are recent data that dynamic airway collapse is seen in 10–15% of patients referred to a pulmonologist for evaluation of chronic cough [3]. Although historically diagnosed with cine fluoroscopy [4] and more recently with bronchoscopy, several articles have documented the value of dynamic expiratory CT, and particularly of electron beam CT [5], in the diagnosis of tracheobronchomalacia. Early reports suggest that multidetector CT provides greater anatomic accuracy than conventional single-slice CT [6]. In devising this study, we postulated that the decreased imaging time enabled by multidetector CT would allow volumetric evaluation of the central airways during dynamic expiration, a technique shown to be more sensitive in airway obstruction than conventional end expiratory techniques [7]. This report presents our early experience with the use of multidetector CT in the evaluation of patients with suspected tracheobronchomalacia. Subjects and Methods Thirteen patients with suspected tracheobron-chomalacia were evaluated by multidetector CT. Clinical histories were reviewed in all patients. The patients included seven males and six females who ranged in age from 14 to 88 years (mean age, 49 years). Three patients had a clinical history of asthma, and one patient was a smoker. Six patients were referred with a history of chronic cough, whereas seven patients presented with unexplained dyspnea. Of the 13 patients, 12 underwent pulmonary function testing including flow-volume loops, and six patients underwent correlative fiberoptic bronchoscopy. Chest ra-diographs were available for 12 of the 13 patients. All patients were imaged on a multidetector CT scanner (Picker MX 8000; Marconi Medical Systems , Cleveland, OH). Initial topographic images were obtained first to determine the coverage of the trachea and …