Bronchiolitis obliterans syndrome in lung transplant recipients: correlation of computed tomography findings with bronchiolitis obliterans syndrome stage

The purpose of this study was to correlate the extent of computed tomographic (CT) findings with the severity of respiratory dysfunction in lung transplant recipients with bronchiolitis obliterans syndrome (BOS). Eighty-nine conventional and 61 thin-section CT scans performed in 44 transplant recipients (17 bilateral, 27 single) with BOS were reviewed for mosaic attenuation, degree of bronchial dilation, bronchial thickening, central and peripheral bronchiectasis, mucus plugging, and air trapping. Findings on conventional and thin-section CT scans were correlated with BOS stage for bilateral and single-lung transplant recipients. In bilateral-lung recipients, a significant correlation existed, although weak, between BOS stage and findings of degree of bronchial dilation (P < 0.01), bronchial wall thickening (P = 0.01), peripheral bronchiectasis (P = 0.01), and mosaic attenuation (P = 0.01) on conventional CT; and bronchial wall thickening (P = 0.01) and mosaic attenuation (P = 0.03) on thin-section CT. In single-lung recipients, BOS stage correlated only with the finding of central bronchiectasis (P = 0.02) on conventional CT scans. No correlation was found between the extent of air trapping and BOS stage in either single- or bilateral-lung transplant recipients. CT findings are relatively poor indices of airflow obstruction in lung transplant recipients with BOS, particularly in those with single-lung transplants for emphysema.