High-resolution Computed Tomography Findings in Arc-welders

Background:

Welding work is associated with exposure to various fumes and gases that are potentially harmful to the respiratory system. Objective: To describe high-resolution computed tomography (HRCT) findings in arc-welders.

Materials and Methods:

The study involved 36 arc-welders and 26 officers as the control group. Arc-welders with a history of 2-to-3O years’ exposure and control subjects underwent HRCT scanning. The welders were grouped according to their smoking habits (smokers, n=14; non-smokers, n=22). HRCT findings of both groups were compared.

Results:

Predominant HRCT findings in the arc-welders were poorly-defined centrilobular micronodules (31/36, 86.1%) and branching linear structures (17/36, 47.2%). Poorly-de­fined centrilobular micronodules were found in 12 (85.7%) patients in the smokers subgroup, and 19 (86.4%) patients in the non-smokers subgroup. The branching linear structures were found in 7 (50.0%) patients in the smokers subgroup, and 10 (45.5%) patients in the non-smokers subgroup. Ground-glass pattern was not observed in either of the two subgroups. Moreover, no difference was found in CT abnormalities between these two subgroups. In the control group, poorly-defined centrilobular micronodules were found in 14 (53.8%) subjects, but branching linear structures and ground-glass pattern were not observed. Differences in CT abnormalities were significant between arc-welders and controls (p=0.005). There was no signifi­cant relationship between pulmonary function tests and spread of mi­cronodules (FEV^/o r=-0.10, p=0.6; FVC% r =-0.08, p=0.6) and welding duration (FEV/% r =-0.09, p=0.6; FVC% r =-0.21, p=0.2).

Conclusion:

Poorly-defined centrilobular micronodules and branching linear structures were the most frequently seen HRCT abnormalities in arc-welders. Occurrence of these similar findings less frequently and intensely in non-smoker control subjects requires the investigation of other potentially causative inhalants.