LOW-GRADE COAL-WORKERS PNEUMOCONIOSIS - COMPARISON OF CT AND CHEST RADIOGRAPHY

We compared CT with chest radiography (CR) in the assessment of low gr ade coal worker's pneumoconiosis (CWP) in a population of 83 subjects. All subjects had a high-voltage p.a. CR, graded according to the ILO classification between 0/0 and 1/1, a conventional CT (CCT) using cont iguous l-cm-thick sections on the entire thorax and a set of 10 high-r esolution CT (HRCT) images. CR and CT were separately read by consensu s by 2 teams of 2 trained readers. CR were coded 0/0 in 9 subjects; 0/ 1 in 31; 1/0 in 28; 1/1 in 15. Among these groups of patients, microno dules were detected by CT in respectively 2 (22%), 14 (45%), 17 (61%) and 10 (67%) patients. In all groups, micronodules were more often det ected by CT when the opacities detected on CR were scored as rounded ( p, q) than irregular (s, t). Among the patients graded 0/0 or 0/1, CT showed micronodules in 40%. By contrast, among the patients graded 1/0 or 1/1, CT did not show micronodules in 37%, but revealed in numerous patients that opacities detected on CR were related to bronchiectasis and/or emphysema only. Comparative analysis of HRCT and CCT showed th at both techniques are complementary and proved the usefulness of CCT in the detection or confirmation of low profusion of micronodules.