Inspiratory and expiratory high-resolution computed tomography (HRCT) in patients with chemical warfare agents exposure

Chemical warfare agents (CWA) including sulfur mustard (SM) were commonly used in Iran-Iraq war. Respiratory problems are the greatest cause of long-term disability among people who had combat exposure to SM. High-resolution computed tomography (HRCT) has been accepted as the imaging modality of choice in these patients. We used expiratory HRCT findings in comparison to inspiratory HRCT for demonstration of pulmonary damage in these patients. HRCT in deep inspiration as well as full expiration was performed in 473 patients with a history of chemical gas exposure during the war and the results were compared. The study was prospective during 1 yr. Of 473 patients, 366 (77.38%) showed normal HRCT in deep inspiration; however, on corresponding expiratory cuts, 263 (71.86%) had abnormalities. The most frequent abnormal finding in expiration was patchy air trapping (77.77%). We conclude that exposure to SM causes pulmonary complications resulting in disability in the affected patients; however, HRCT in inspiration is normal in most of the affected patients. Expiratory HRCT showed patchy air trapping as the most common finding, which is suggestive of small air way diseases such as bronchiolitis obliterans; therefore it is recommended to do HRCT both in deep inspiration and full expiration in patients with a history of CWA exposure.