Objective: To assess the accuracy of dynamic expiratory CT for detecting airway malacia using bronchoscopy as the diagnostic “gold standard.”
Materials and methods: A computerized hospital information system was used to retrospectively identify all patients with bronchoscopically proven airway malacia referred for CT airway imaging at our institution during a 19-month period. CT was performed within 1 week of bronchoscopy. All patients were scanned with a standard protocol, including end-inspiratory and dynamic expiratory volumetric imaging, using an eight-detector multislice helical CT scanner. For both CT and bronchoscopy, malacia was defined as ≥ 50% expiratory reduction of the airway lumen. CT and bronchoscopic findings were subsequently jointly reviewed by the radiologist and bronchoscopist for concordance.
Results: Twenty-nine patients (12 men and 17 women; mean age, 60 years; range, 36 to 79 years) comprised the study cohort. CT correctly diagnosed malacia in 28 of 29 patients (97%). The most common presenting symptoms were dyspnea in 20 patients (69%), severe or persistent cough in 16 patients (55%), and recurrent infection in 7 patients (24%). The estimated radiation dose (expressed as dose-length product) for the dual-phase study is 508 mGy-cm, which is comparable to a routine chest CT.
Conclusion: Dynamic expiratory CT is a highly sensitive method for detecting airway malacia and has the potential to serve as an effective, noninvasive test for diagnosing this condition.