Résumé
Objective To describe the high-resolution CT(HRCT)findings of arc-welders with early pneumoconiosis and to evaluate manifestation in different course of disease.Methods Seventy-six arc-welders with a one to thirty-eight(mean,14)years history of exposure underwent CT and HRCT scanning.The extent of abnormalities were detected.The relations of age and year history of exposure were analysed in different groups.Results Thirty-eight welders(38/76,50%)showed positive characteristic findings with conventional CT.Predominant thin-section CT findings were poorly-defined centrilobular micronodules(18/76,23.7%),branching linear structure(20/76,26.3%).The mean age in group of branching linear structure[(39±9)years old]was elder than of poorly-defined centrilobular micronodules[(34±7)years old].There was no statistical difference between the two groups(t=-1.648,P＞0.05).The mean length of service at exposure in group of branching linear structure[(15±8)years]was longer than of poorlydefined centrilobular micronodules[(10±5)years].And the significant differences were showed between the two groups in the year history of exposure(t=-2.108,P＜0.05).Conclusions Poorly defined centrilobular micronodules and branching linear structures were the thin-section CT findings most frequently seen in patients with arc-welders'pneumoconiosis and the former may be one early stage characteristic finding of arc-welders'pneumoconiosis.HRCT is useful in achieving more accurate categorization of the parenchymal changes in arc-welders'pneumoconiosis.