Radiographic and pathologic correlation of coal workers' pneumoconiosis

The relationships between chest radiographs (CXR) and corresponding pathology were investigated in 430 autopsied coal miners from West Virginia. Whole-lung sections were reviewed and graded on four-point severity scales for the following lesions of coal workers' pneumoconiosis (CWP): macules, micro- and macronodules (small and large fibrotic nodules), and progressive massive fibrosis (PMF). Antemortem CXR were classified by three B readers using the 1971 International Labor Office (ILO) U/C classification (6). On pathologic examination, 96% of miners had macules, 70% micronodules, 45% macronodules, 15% silicosis, and 28% PMF. By CXR, 69% of the miners had small, rounded opacity profusions of category > or = 0/1. Data analysis revealed increasing odds that small opacities of category > or = 0/1 would be detected with increasing grade of nodules. Profusion category 0/0 was often reported for cases with macules of mild to moderate grade and mild levels of micronodules. Overall, q-type opacities were associated with macules and micronodules, whereas the large r-type opacities were associated with macronodules. By CXR, large opacities showed good correlation with pathologic PMF. However, about one-third of cases identified as having large opacities by CXR were not substantiated as PMF by pathology. One-fourth of these cases could be explained by lung lesions such as Caplan's nodules, tuberculosis scars, and tumors. Similarly, 22% of cases classified as PMF on pathology had no large opacities by CXR. In half of these cases, the radiologists had noted other abnormalities (cancer, tuberculosis) by CXR as large opacities. Overall, the study showed good agreement (Somer's d = 0.64) between the predicted probabilities and observed responses of a profusion category > or = 0/1 for pathologic CWP lesions. However, the study also showed that CXR were insensitive for detecting minimal CWP lesions, and were unreliable indicators in the presence of concomitant pulmonary pathology.