Pulmonary abnormalities in ankylosing spondilitis -: Inspiratory and expiratory high-resolution CT findings in 17 patients

Objective: The purpose of this study was to evaluate pulmonary manifestations of ankylosing spondylitis on inspiratory and expiratory high resolution CT. Material and Methods: The study included 17 patients ranging from 40 to 62 years in age. Fifteen patients were male, and 8 were smokers. All patients underwent chest radiography and high-resolution CT. High-resolution CT was obtained using 1 or 2 mm collimation scans at 10-mm intervals at the end of maximal inspiration and at 3 cm intervals at the end of maximal expiration. Results: Pulmonary abnormalities were evident on chest radiography in 2 patients and on CT in 15 patients. The abnormalities on CT included evidence of airway disease in 14 (82%), interstitial abnormalities in 11 (65%), and emphysema in 6 (35%) patients. Airway abnormalities included bronchial wall thickening in 7 (41%), mosaic perfusion in 3 (18%), centrilobular nodules in 3, bronchiolectasis in 2, and air trapping on expiratory CT in 7 (41%) patients. Interstitial abnormalities included parenchymal bands in 7 (41%), intralobular linear opacities (n = 2), and 1 patient each with irregular thickening of interlobular septa, subpleuraI lines, and honeycombing. Conclusion: The majority of patients with ankylosing spondylitis have airway and interstitial abnormalities evident on high-resolution CT. These abnormalities are usually mild and therefore seldom evident on the chest radiograph.