Regional High Iron in the Substantia Nigra Differentiates Parkinson's Disease Patients From Healthy Controls
Regional High Iron in the Substantia Nigra Differentiates Parkinson's Disease Patients From Healthy Controls
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DOI：
10.3389/fnagi.2019.00106
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发表时间：
2019-05-27
影响因子：
4.8
通讯作者：
Haacke, Ewart Mark
中科院分区：
文献类型：
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作者：
Ghassaban, Kiarash;He, Naying;Haacke, Ewart Mark
背景：铁在帕金森病（PD）的病理生理学中是重要的，特别是与黑质（SN）变性相关。磁共振成像（MRI）可用于测量整个脑结构中的铁，但这种方法对铁含量的局部变化不敏感。目的：这项工作的目的是使用定量易感性映射（QSM）和R2* 来定量PD患者和健康对照（HC）的整体和局部脑铁。以确定区域变化是否与临床状况相关，并可用于区分患者和对照组。25例PD和24例HC受试者的易感性和R2* 图由3 T GE扫描仪上收集的数据重建。对于磁化率图，在八个深灰质（DGM）结构上追踪三维感兴趣区域（ROIs），并应用基于年龄的阈值来定义高铁含量区域。相同的多切片ROI也在R2* 标测图上重复。测量了全球和区域高铁（RII）含量沿着的平均易感性值以及全球R2* 值，不仅在两个队列之间进行了比较，而且还与易感性和R2* 基线作为年龄的函数进行了比较。最后，临床特征进行了比较，为那些PD患者躺在上面和下面的95%区域易感性-年龄predictioninterviews.Results：SN是唯一的结构显示显着更高的易感性相比，在PD患者的控制全球（p < 0.01）和区域（p < 0.001）。R2* 值也仅在PD患者的SN中高于健康组群（p < 0.05）。此外，那些异常易感性值高于95%预测区间的患者具有显著更高的联合帕金森病诊断评分。R2* 值有较大的误差，并表现出较大的离散度作为年龄的函数比QSM数据的全球analysis.Conclusion：异常铁沉积在SN，特别是在RII地区，可以作为一个生物标志物，以区分PD患者HC和评估疾病的严重程度，而离散度是显着较小的QSM使用RII铁含量。
Background: Iron is important in the pathophysiology of Parkinson's disease (PD) specifically related to degeneration of the substantia nigra (SN). Magnetic resonance imaging (MRI) can be used to measure brain iron in the entire structure but this approach is insensitive to regional changes in iron content.Objective: The goal of this work was to use quantitative susceptibility mapping (QSM) and R2* to quantify both global and regional brain iron in PD patients and healthy controls (HC) to ascertain if regional changes correlate with clinical conditions and can be used to discriminate patients from controls.Methods: Susceptibility and R2* maps of 25 PD and 24 HC subjects were reconstructed from data collected on a 3T GE scanner. For the susceptibility maps, three-dimensional regions-of-interest (ROIs) were traced on eight deep gray matter (DGM) structures and an age-based threshold was applied to define regions of high iron content. The same multi-slice ROIs were duplicated on the R2* maps as well. Mean susceptibility values of both global and regional high iron (RII) content along with global R2* values were measured and compared not only between the two cohorts, but also to susceptibility and R2* baselines as a function of age. Finally, clinical features were compared for those PD patients lying above and below the upper 95% regional susceptibility-age prediction intervals.Results: The SN was the only structure showing significantly higher susceptibility in PD patients compared to controls globally (p < 0.01) and regionally (p < 0.001). The R2* values were also higher only in the SN of PD patients compared to the healthy cohort (p < 0.05). Furthermore, those patients with abnormal susceptibility values lying above the upper 95% prediction intervals had significantly higher united Parkinson's diagnostic rating scores. R2* values had larger errors and showed larger dispersion as a function of age than QSM data for global analysis while the dispersion was significantly less for QSM using the RII iron content.Conclusion: Abnormal iron deposition in the SN, especially in RII areas, could serve as a biomarker to distinguish PD patients from HC and to assess disease severity.