Curtin University, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Bentley, WA Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA Australia.
Curtin University, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Bentley, WA Australia.
Neuroscience. 2021 Jul 15;467:218-236. doi: 10.1016/j.neuroscience.2021.05.030. Epub 2021 Jun 2.
Traumatic brain injury (TBI) is a common but heterogeneous injury underpinned by numerous complex and interrelated pathophysiological mechanisms. An essential trace element, iron is abundant within the brain and involved in many fundamental neurobiological processes, including oxygen transportation, oxidative phosphorylation, myelin production and maintenance, as well as neurotransmitter synthesis and metabolism. Excessive levels of iron are neurotoxic and thus iron homeostasis is tightly regulated in the brain, however, many details about the mechanisms by which this is achieved are yet to be elucidated. A key mediator of oxidative stress, mitochondrial dysfunction and neuroinflammatory response, iron dysregulation is an important contributor to secondary injury in TBI. Advances in neuroimaging that leverage magnetic susceptibility properties have enabled increasingly comprehensive investigations into the distribution and behaviour of iron in the brain amongst healthy individuals as well as disease states such as TBI. Quantitative Susceptibility Mapping (QSM) is an advanced neuroimaging technique that promises quantitative estimation of local magnetic susceptibility at the voxel level. In this review, we provide an overview of brain iron and its homeostasis, describe recent advances enabling applications of QSM within the context of TBI and summarise the current state of the literature. Although limited, the emergent research suggests that QSM is a promising neuroimaging technique that can be used to investigate a host of pathophysiological changes that are associated with TBI.
创伤性脑损伤（TBI）是一种常见但异质性的损伤，其基础是许多复杂且相互关联的病理生理机制。铁是一种必需的微量元素，在大脑中含量丰富，参与许多基本的神经生物学过程，包括氧气运输、氧化磷酸化、髓鞘生成和维持，以及神经递质的合成和代谢。过量的铁具有神经毒性，因此大脑中的铁稳态受到严格调节，然而，关于实现这一目标的机制的许多细节仍有待阐明。铁失调是氧化应激、线粒体功能障碍和神经炎症反应的一个关键介质，是 TBI 继发性损伤的一个重要因素。利用磁化率特性的神经影像学进展使人们能够越来越全面地研究健康个体以及 TBI 等疾病状态下大脑中铁的分布和行为。定量磁敏感图（QSM）是一种先进的神经影像学技术，可在体素水平上对局部磁化率进行定量估计。在这篇综述中，我们概述了大脑中的铁及其稳态，描述了最近的进展，使 QSM 在 TBI 背景下的应用成为可能，并总结了目前的文献状况。尽管研究有限，但新兴研究表明，QSM 是一种很有前途的神经影像学技术，可用于研究与 TBI 相关的一系列病理生理变化。
