The Findings of HRCT of the Lung in Chemical Warfare Veterans with Previous Sulfur Mustard (SM) Gas Exposure

"nIntroduction: To identify the findings of High-Resolution Computed Tomography (HRCT) of the lung in chemical warfare veterans with previous sulfur mustard (SM) gas exposure. "nMaterials and Methods: 93 patients were studied prospectively 22 years after exposure. Demographic and clinical data were recorded. HRCT of the lung was performed during expiration and was reported double blinded by two radiologists. HRCT findings include air trapping, mosaic attenuation, ground glass attenuation, nodules, signet ring, fibrosis, bronchial wall thickening, bronchodilation, tree in bud, interlobular wall thickening, bulla, cavity, air consolidation, honey comb and mediastinal and pleural abnormalities that were analyzed. Final diagnosis was identified according to HRCT findings. The relation between HRCT findings, final diagnosis and the distribution of the abnormalities with duration after exposure were evaluated. Distribution of each finding was also evaluated. "nb The most frequent HRCT finding was air trapping (56.7%). Other common findings were mosaic attenuation (35.1%), ground glass attenuation (20.6%), nodules (17.5%), signet ring (15.5%) and fibrosis(12.4%). Distribution of the abnormalities were mostly local (79.4%) and bilateral (73%). Abnormalities were mostly in the lower lobe (61.3%). No significant correlation was found between the HRCT findings and the duration after exposure or distribution of the abnormalities. The respiratory complications diagnosed according to HRCT included bronchiolitis obliterans (43%), chronic obstructive pulmonary disease (COPD) (27.9%), asthma (23.6%), bronchiectasis (13.9%), interstitial lung disease (ILD) (9.6%). All abnormalities were seen more frequently in patients with lesser duration of exposure.( P-value < 0.05). "nConclusion: Focal bilateral air trapping was the most common finding seen in expiratory HRCT in this study, and it is highly suggestive of bronchiolitis obliterance (BO). BO can be a late complication of SM exposure. Keywords: Chemical Warfare Veterans, High-Resolution Computed Tomography (HRCT), Sulfur mustard (SM) Gas, Air Trapping, Mosaic Attenuation, Bronchiolitis Obliterance(BO)