Comparison of Chest HRCT in Inspiration and Expiration of patients with Chemical Gas Exposure

Background/Objectives: Chemical weapon agents (CWA) including Sulfur Mustard (SM), were com-monly used in the Iran-Iraq war and pulmonary complications are known to occur in over half of the exposed patients. Previous studies showed that HRCT in inspiration was normal in most of the patients. In this study comparison between the HRCT findings in deep inspiration and full expiration was carried out. Materials and Method: HRCT in deep inspiration and full expiration in 473 patients with history of chemi-cal gas exposure during the war was performed and the results were compared. The study was prospective during one year since 1382 to 1383. Results: In our study, 366 patients (77%) showed normal HRCT in deep inspiration, however in corre-sponding expiration cuts, 54% showed abnormal findings, from which, patchy air trapping was the most common (78%). Other findings in our study were pulmonary fibrotic changes (30%), emphysema (19%), and bronchiectasis (10%). Conclusion: Exposure to SM has pulmonary compli-cations and results in disability in the affected pa-tients. HRCT is normal only in inspiration in most of the affected patients; expiratory HRCT showed patchy air trapping as the most common finding which is suggestive of bronchiolitis obliterans. There-fore, HRCT should be advised to be done both in deep inspiration and full expiration in patients with history of CWA exposure.