Comparison of high-resolution computerized tomography with film-screen radiography for the evaluation of opacity and the recognition of coal workers' pneumoconiosis.

OBJECTIVES Current diagnostic standards of pneumoconiosis, which is the most serious occupational disease in China, are based on film-screen radiography (FSR). However, parenchymal structure overlap limits the sensitivity of FSR in the clinic. High-resolution computerized tomography (HRCT) has the advantage of identifying nodular pulmonary parenchymal changes. In this study, we aimed to compare HRCT and FSR for recognition of the profusion of small opacities, opacity shape and opacity coalescence in coal miners with or without radiographic evidence of coal workers' pneumoconiosis (CWP) and evaluate the possible role of HRCT in CWP diagnosis. METHODS There were 96 coal miners with radiographic evidence of CWP, 67 coal miners without CWP and 37 healthy controls in this study. FSR and HRCT images for all subjects were interpreted separately by three readers. Crude agreement and Kappa values were calculated to evaluate the agreement between the two methods. RESULTS The overall agreement for CWP evaluation was good (crude agreement rate=87.1%, κ=0.72, 95% CI: 0.62-0.83) between FSR and HRCT in all coal miners. The sensitivity of HRCT for CWP diagnosis was 96.9% (93/96). We observed that 18 of the 67 (26.9%) miners negative for CWP by FSR were classified as category 1 by HRCT according to the lung parenchyma profusion category system reported by Bérgin et al. The difference in the profusion scores between CWP subjects and healthy controls for HRCT scans were statistically significantly higher than those for FSR. CONCLUSIONS HRCT was more sensitive than FSR in recognition of the profusion of small opacities among coal miners. More research is needed to evaluate the role of HRCT in early diagnosis of CWP.