Monsivais Humberto, Dydak Ulrike
School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA.
Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Toxics. 2025 Feb 25;13(3):157. doi: 10.3390/toxics13030157.
Chronic overexposure to manganese (Mn) can occur in occupational settings, such as welding, leading to increased Mn levels in the brain. Excess brain Mn accumulation may result in neurotoxicity, which is characterized by Parkinsonian-like symptoms including motor and cognitive dysfunctions. In this work, we demonstrate a novel methodology for personalized diagnosis and spatial characterization of abnormal Magnetic Resonance Imaging R1 (R1 = 1/T1) relaxation rates arising from excessive Mn accumulation in welders' brains. Utilizing voxel-wise population-derived norms based on a frequency age-matched non-exposed group (n = 25), we demonstrate the ability to conduct subject-specific assessments and mapping of Mn exposure using MRI relaxometry. Our results show elevated R1 in multiple brain regions in individual welders, but also extreme between-subject variability in Mn accumulation, debasing the concept that high exposures correlate with uniformly high Mn deposition in the brain. Consequently, the presented personalized methodology serves as a counterpart to group-based comparison, which allows for understanding the level of individual exposure and the toxicokinetics of Mn accumulation. This work lays a foundation for improved occupational health assessments and preventive measures against neurotoxic metal exposure.
长期过度接触锰（Mn）可能发生在职业环境中，如焊接，这会导致大脑中锰含量升高。大脑中过量的锰积累可能会导致神经毒性，其特征是出现类似帕金森氏症的症状，包括运动和认知功能障碍。在这项研究中，我们展示了一种新颖的方法，用于对焊工大脑中因过量锰积累而产生的异常磁共振成像R1（R1 = 1/T1）弛豫率进行个性化诊断和空间表征。利用基于频率年龄匹配的未接触组（n = 25）的体素级人群衍生标准，我们展示了使用MRI弛豫测量法进行个体特异性评估和锰暴露映射的能力。我们的结果显示，个体焊工的多个脑区R1升高，但锰积累在个体之间也存在极大差异，这削弱了高暴露与大脑中锰沉积均匀高度相关的概念。因此，所提出的个性化方法可作为基于群体比较的补充，有助于了解个体暴露水平和锰积累的毒代动力学。这项工作为改进职业健康评估和针对神经毒性金属暴露的预防措施奠定了基础。
