Micronodules and emphysema in coal mine dust or silica exposure: relation with lung function

The aim of this study was to investigate the respective effects of micronodules and pulmonary emphysema, detected by computed tomography (CT), on lung function in workers exposed to silica and coal mine dust. Eighty-three subjects exposed to silica (n=35) or to coal mine dust (n=48), without progressive massive fibrosis, were investigated by high-resolution and conventional CT scans to detect micronodules and to quantify pulmonary emphysema by measuring the relative area of the lung with attenuation values lower than -950 Hounsfield units. Sixty-six (54.5%) subjects had evidence of micronodules on CT scans. Smokers had micronodules more rarely than nonsmokers. Significant correlations were found between the forced expiratory volume in one second (FEV(1); % predicted) (r=-0.41, p<0.001), FEV1/vital capacity (VC) (r=-0.61, p<0.001), diffusing capacity of the lung for carbon monoxide (DL,CO) (r=-0.36, p<0.001) and the extent of emphysema. No difference was demonstrated in the linear relationships between the extent of emphysema and the pulmonary function according to the type of exposure or the presence of micronodules on CT scans. This study suggests that micronodules detected by computed tomography have no influence, by themselves, on pulmonary function and that they should only be considered as a marker of exposure.

Bronchioloalveolar carcinoma: computed tomography findings

The aim of the present study was to investigate the appearance of bronchioloalveolar lung carcinoma on computed tomography (CT) scans, and to determine the frequency of signs suggestive of this diagnosis. CT features of 42 cases with pathologically proven bronchioloalveolar carcinoma were retrospectively analysed for pattern, size, location and secondary signs suggesting the diagnosis. Bronchioloalveolar carcinoma had one of the following patterns: solitary nodule or mass (16), lobar consolidation (10), multilobar consolidations (13) and diffuse nodules (3). The 16 solitary nodules or masses ranged in size from 2.0 to 9.4 cm (mean +/- SD 3.75 +/- 1.7 cm). Eleven of the 16 nodules or masses were peripheral and five were central: Eight of the 16 tumours had pleural tags, seven had spiculated margins, and three had bubblelike lucencies. The consolidations were peripherally distributed in 13 out of 23 cases; cystic airspaces were observed in 19 out of 23 consolidations; bulging of interlobar fissures in 8 out of 23; and the angiogram sign in 7 out of 23. In conclusion, computed tomography findings of bronchioloalveolar carcinoma have a wide spectrum, showing typically a peripheral nodule or consolidation. Computed tomography has a role in the diagnosis of nodular localized versus other forms, with subsequent therapeutic and prognostic implications.