Expiratory CT Scans For Small Airway Disease

Purpose: To detennine the relative utility of expiratory CT scans for small airway diseases. Materials And Methods: Thuity one small airway patients, veiified by clinical and pulmonaiy functional tests, underwent inspiratoiy and expiratory CT scans. The 12 healthy controls were nonsmokers, with nonnal plain chest film and pulmonary functional tests results. Cross-sectional lung area reduction score(CLARS), Lung density attenuation value(LDAV) and Pixel index(PI) of 31 patients and 12 healthy controls were calculate& Both groups underwent HRCT which consisted of inspiratoiy scans and expimtoiy scans at 3-4cm intervals from aortic arch to the diaphragm The CT indices (CLAPS, LDAV, PI)were then correlated with the results of the functional tests results(FEF2575, Vmax5O, Vmax2S). Results: The means of CLAPS of the patients group and control group were 25 and 48 respectively. The means of LDAV of 25 patients and 12 healthy controls were 79HU and 186HU respectively These two indices of the group of patients were obviously lower than the control. At end expiratory phase, the P1 of the group of patients was 11.36%, and higher than the contml. Expimtory air trapping was seen in 13(42%) of 31 patients. In 12 healthy controls, Expiratomy air trapping was never seen. CLAPS, LDAV, PIe have significant correlations with the results of the PETs indexes(FEFsm.. VmaxSON Vmax2S) respectively. Conclusion: The small airway disease patients can be diagnosed and quantilied by expiratory CT scans, which seems to be a promising method.