OBJECTIVETo evaluate the feasibility of direct digital radiography (DDR) in the diagnosis of asbestosis, and to analyze the difference and similarity between DDR and film-screen radiography (FSR) in terms of the radiographic features of asbestosis.

METHODSA total of 60 cases of asbestosis underwent FSR and DDR of the chest in the same day. The FSR and DDR findings were compared with respect to shapes and profusion of small opacities, pleural abnormality, and diagnostic stages.

RESULTSThe patients showed "s", "t", and "p" small opacities on chest images, with irregular "s" and "t" ones predominating (FSR: 95.0%; DDR: 91.7%). The small opacities were widely distributed in six lung zones, especially in middle and lower zones. The shapes and distribution of small opacities did not differ significantly between FSR and DDR findings (P > 0.05). For all the 60 cases, the two radiographies demonstrated a concordance rate of 64.2% (231/360) for the profusion of small opacities in lung zones (κ = 0.62, 95%CI: 0.54 ∼ 0.69), and for the 43 cases (258 lung zones) who displayed identical small opacity shapes on the two radiographies, the concordance rate was 81.0% (209/258) (κ = 0.79, 95%CI: 0.72 ∼ 0.87). FSR revealed 10 cases (16.7%) of pleural thickening, compared to 12 cases (20.0%) on DDR (P > 0.05). FSR revealed 53 cases (88.3%) of stage I asbestosis and 7 cases (11.7%) of stage II asbestosis, compared to 51 cases (85.0%) and 9 cases (15.0%) on DDR (P > 0.05). There was no significant difference in diagnostic stages between the two radiographies (P > 0.05), demonstrating a concordance rate of 93.3% (56/60) (κ = 0.71, 95%CI: 0.45 ∼ 0.98).

CONCLUSIONDDR is similar to FSR in determining the shapes, distribution, and profusion of small opacities, pleural abnormality, and diagnostic stages.