[MRI comparison of brain region volumes between welding fumes exposed and non-exposed workers]

Objective: To compare the differences in brain region volumes between workers exposed to welding fume and those not exposed in magnetic resonance imaging (MRI), and to explore the characteristics of brain region volume changes in workers exposed to welding fume, in order to provide imaging-based diagnostic evidence for the neurological damage caused by welding fume. Methods: In July 2024, all workers exposed to welding fume in a certain machinery factory who underwent occupational health examinations at Zibo Occupational Disease Prevention Hospital were selected as the observation group (50 people), and 50 non-dust-exposed workers from the same region were selected using simple random sampling as the control group. Chest computed tomography (CT) examination and high-resolution cranial MRI scans were conducted on the workers, and the volumes of each brain region in MRI were automatically measured using the artificial intelligence-based brain structure analysis workstation. The independent sample t-test was used to compare the volume of the brain region and the percentage of the total intracranial volume between the two groups of workers, and Pearson correlation analysis was used to test the correlation between the volume of brain regions and the percentage of total intracranial volume with the dust exposure years and age. The critical values for abnormality of each indicator were determined based on the receiver operating characteristic (ROC) curve to obtain the binary variable, and the correlation with chest CT abnormalities was analyzed using the Phi coefficient. Results: The volume of the putamen in the observation group was (5.82±0.90) cm(3), and the percentage of the total intracranial volume was (0.39±0.05) %, which were both smaller than those of the control group [ (6.75±0.84) cm(3), (0.45±0.05) %] (t=-5.28, -5.81, P<0.01). The volume of the globus pallidus [ (2.82±0.29) cm(3)] and the percentage[ (0.19±0.01) %] were both smaller than those of the control group[ (3.08±0.32) cm(3), (0.20±0.02) %] (t=-4.21, -4.98, P<0.01). The percentage of the insula in the observation group [ (0.92±0.06) %] was greater than that of the control group[ (0.88±0.06) %] (t=3.26, P<0.01). The volume of the thalamus in the observation group was (15.41±1.46) cm(3), and the percentage was (1.03±0.07) %, which were both greater than those of the control group [ (14.35±1.09) cm(3), (0.95±0.05) %] (t=4.10, 6.18, P<0.01). The volumes or percentages of multiple brain regions such as the cingulate gyrus and globus pallidus in the observation group were negatively correlated with the duration of exposure to welding fume and age (r=-0.46 to -0.29, P<0.05), and the volume or percentage of the ventricles were positively correlated with the duration of exposure to welding fume and age (r=0.45 to 0.54, P<0.01). The percentage of cerebral white matter in the brain of the control group was negatively correlated with age (r=-0.39, P<0.05), and the volume and percentage of the ventricles were positively correlated with age (r=0.33, 0.49, P<0.01). There was no statistical significance in the correlation between the changes in the percentage of the insula, the volume and percentage of the putamen, globus pallidus, and thalamus and chest CT abnormalities in the observation group (P<0.05) . Conclusion: Occupational exposure to welding fume may lead to a reduction in the volume of the putamen and globus pallidus and an increase in the volume of the thalamus, and an increase in the percentage of the insula in workers. However, the changes in brain volume are not significantly correlated with the chest damage caused by welding fume.