Radiographic Appearances of Small Opacities and Their Correlation with Pathology Grading of Macules, Nodules and Dust Burden in the Lungs

Radiographic appearances of small opacities were correlated with pathological assessments of whole lung sections in a series of autopsy cases from southern West Virginia. The results revealed correlations between the radiographic and pathologic data, mainly between micro- and macro-nodules and X-ray category (Pearson correlations close to 0.5), but reveal that moderate to severe pathologic abnormality has to be present before radiographic detection is at all certain. The presence of macules tended to be associated with the smallest radiographic opacities (type p), while nodules were often manifested as type q or r. Macule profusion was related to overall levels of total retained dust, while nodules and X-ray category were associated with both coal and silica fractions of the retained dust weights. Weight-for-weight, silica dust was 20 times more important than coal dust in the latter relationship.