Comparison of chest radiography and high-resolution computed tomography findings in early and low-grade coal worker's pneumoconiosis.

INTRODUCTION: High-resolution computed tomography (HRCT) is more sensitive than chest X-ray (CXR) in the depiction of parenchymal abnormalities. We aimed to present and compare CXR and HRCT findings in coal workers with and without early and low-grade coal worker's pneumoconiosis (CWP).

MATERIALS AND METHODS: 71 coal workers were enrolled in this study. All workers were male. The CXR and HRCT of those workers were obtained and graded by two trained readers. HRCT's were graded according to Hosoda and Shida's Japanese classification. After grading, 67 workers with CXR profusion 0/0-2/2 were included in the study. Four patients with major opacity were excluded. Profusion 0/1 to 1/1 cases were accepted as early and profusion 1/2 and 2/2 cases as low-grade pneumoconiosis.

RESULTS: Discordance between CXR and HRCT was high. Discordance rate was found higher in the early pneumoconiosis cases with negative CXR than low-grade pneumoconiosis (60, 36 and 8%, respectively). When coal miners with normal CXR were evaluated by HRCT, six out of 10 cases were diagnosed as positive. In low-grade pneumoconiosis group, the number of patients with positive CXR but negative HRCT were low in comparison to patients with CXR negative and early pneumoconiosis findings. Most of the CXR category 0 patients (10/16) were diagnosed as category 1 by HRCT. Eleven cases diagnosed as CXR category 1 were diagnosed as category 0 (7/11) and category 2 (4/11) by HRCT. In CXR category 2 (eight cases), there were four cases diagnosed as category 1 by HRCT.

CONCLUSIONS: Discordance between CXR and HRCT was high, especially for CXR negative and early pneumoconiosis cases. The role of CXR in screening coal workers to detect early pneumoconiosis findings should be questioned. We suggest using HRCT as a standard screening method instead of CXR to distinguish between normal and early pneumoconiosis.