HIGH-RESOLUTION CT IN SIMPLE COAL-WORKERS PNEUMOCONIOSIS - LACK OF CORRELATION WITH PULMONARY-FUNCTION TESTS AND ARTERIAL BLOOD-GAS VALUES

We examined 21 miners by means of standard chest radiography, high-res olution computerized tomography (HRCT), pulmonary function tests, and resting arterial blood gas levels. Using the ILO/UC classification of pneumoconiosis, 7 miners had category 1/0 or 2/1 simple coal workers' pneumoconiosis (CWP). By HRCT, nodules were identified in 12 miners; 4 of 9 were classified as category 0/0 CWP; 2 of 5, 0/1 CWP; 5 of 6, 1/ 0 CWP; and 1 of 1, 2/1 CWP by chest radiograph. Focal emphysema was id entified by HRCT in 7 miners; 4 of 9 were classified as 0/0 CWP; 2 of 5, 0/1 CWP; and 1 of 6, 1/0 CWP by standard chest radiography. Four mi ners with definite nodules confirmed by HRCT had focal emphysema, whil e three without nodules had focal emphysema. Pulmonary function testin g was not different between miners with or without CWP by standard che st radiography, nor was it different between miners with or without de finite nodules evidenced by HRCT. No difference in resting oxygenation was found between any group of miners. The presence of focal emphysem a confirmed by HRCT did not significantly affect pulmonary function te sts on resting arterial blood gas values. There was, however, a signif icantly lower FEV1 and mean forced expiratory flow during the middle h alf of forced vital capacity with lifetime nonsmoking miners. The pres ence of CWP on chest radiography was significantly correlated with smo king cigarettes but not the years of mining. The presence of nodules o n HRCT approached a significant correlation with cigarette smoking, bu t focal emphysema did not. For detecting evidence of coal dust accumul ation in lung parenchyma and identifying focal emphysema, HRCT was mor e sensitive than standard chest radiography. However, despite earlier detection of parenchymal abnormalities, abnormal pulmonary function at tributable to coal dust could not be identified.