Although manganese (Mn) is a trace metal essential for humans, chronic exposure to Mn can cause accumulation of this metal ion in the brain leading to an increased risk of neurological and neurobehavioral health effects. This is a concern for welders exposed to Mn through welding fumes. While brain Mn accumulation in occupational settings has mostly been reported in the basal ganglia, several imaging studies also revealed elevated Mn in other brain areas. Since Mn functions as a magnetic resonance imaging (MRI) T1 contrast agent, we developed a whole-brain MRI approach to map in vivo Mn deposition differences in the brains of non-exposed factory controls and exposed welders. This is a cross-sectional analysis of 23 non-exposed factory controls and 36 exposed full-time welders from the same truck manufacturer. We collected high-resolution 3D MRIs of brain anatomy and R1 relaxation maps to identify regional differences using voxel-based quantification (VBQ) and statistical parametric mapping. Furthermore, we investigated the associations between excess Mn deposition and neuropsychological and motor test performance. Our results indicate that: (1) Using whole-brain MRI relaxometry methods we can generate excess Mn deposition maps in vivo, (2) excess Mn accumulation due to occupational exposure occurs beyond the basal ganglia in cortical areas associated with motor and cognitive functions, (3) Mn likely diffuses along white matter tracts in the brain, and (4) Mn deposition in specific brain regions is associated with exposure (cerebellum and frontal cortex) and motor metrics (cerebellum and hippocampus).

虽然锰 (Mn) 是人类必需的微量金属，但长期接触锰会导致这种金属离子在大脑中积累，从而增加神经和神经行为健康影响的风险。这是通过焊接烟雾接触锰的焊工所关心的问题。虽然职业环境中大脑锰的积累主要发生在基底神经节，但一些影像学研究也显示大脑其他区域的锰含量升高。由于锰作为磁共振成像 (MRI) T1 造影剂，我们开发了一种全脑 MRI 方法来绘制未暴露的工厂控制人员和暴露的焊工大脑中体内锰沉积的差异。这是对来自同一卡车制造商的 23 名非暴露工厂控制人员和 36 名暴露全职焊工的横截面分析。我们收集了大脑解剖结构的高分辨率 3D MRI 和 R1 松弛图，以使用基于体素的量化 (VBQ) 和统计参数映射来识别区域差异。此外，我们研究了过量的锰沉积与神经心理和运动测试表现之间的关联。我们的结果表明：（1）使用全脑 MRI 松弛测量方法，我们可以在体内生成过量的锰沉积图，（2）由于职业暴露而导致的过量锰积累发生在与运动和认知功能相关的皮质区域的基底神经节之外， (3) 锰可能沿着大脑中的白质束扩散，(4) 特定大脑区域的锰沉积与暴露（小脑和额叶皮层）和运动指标（小脑和海马）有关。