Abstract

OBJECTIVES
This study was carried out to evaluate manganese exposure marker and the clinical significance of high signal intensity observed on brain magnetic resonance imaging(MRI) in mild steel/arc welders.
METHODS
Brain MRI, blood and urinary manganese concentration measurements, physical and neurologic examinations, questionnaire and biochemistry were performed on 53 mild steel/arc welders(exposed group) and 112 non-manganese handling productive workers(control group). We calculated the pallidal index, the ratio of signal intensity of globus pallidus to subcortical frontal white-matter on sagittal 71-weighted MRI. And we studied the relationships between the pallidal index and other measurements.
RESULTS
In 35(66.3%) exposed workers, high signal intensity were observed on the globus pallidus. Blood and urinary manganese levels were higher in exported group than control group. Pallidal index were significantly correlated with working duration, blood manganese level, urinary manganese level and positive rates of clinical symptoms and signs.
CONCLUSIONS
The results of this study suggests that high signal intensity finding on brain MRI may be considered as useful tool for the evaluation of workers who have manganese exposure.