Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study.
Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study.
复制标题
DOI：
10.1016/j.neuroimage.2012.05.049
复制
发表时间：
2012-09
期刊：
影响因子：
5.7
通讯作者：
Reichenbach, Juergen R.
中科院分区：
文献类型：
--
作者：
Langkammer, Christian;Schweser, Ferdinand;Krebs, Nikolaus;Deistung, Andreas;Goessler, Walter;Scheurer, Eva;Sommer, Karsten;Reishofer, Gernot;Yen, Kathrin;Fazekas, Franz;Ropele, Stefan;Reichenbach, Juergen R.
定量磁化率成像（QSM）是一种利用梯度回波磁共振相位图像确定体内组织体磁化率分布的新技术。人们通常认为顺磁性铁是灰质易感性变化的主要来源，因为许多研究已经报道了磁化率与体内脑铁浓度的合理相关性。然而，所有这些研究都没有进行直接比较，而是使用Hallgren和Sourander（1958）的标志性研究报告中假定的铁浓度进行分析。因此，QSM在多大程度上可以可靠地评估脑铁水平尚不完全清楚。为了提供这些信息，我们利用MRI和电感耦合等离子体质谱研究了13名受试者死后未固定（原位）大脑的大组织磁化率与脑铁浓度的关系。化学测定的铁浓度与体磁化率在灰质结构中存在很强的线性相关性（r = 0.84, p < 0.001），而在白质中相关系数要低得多（r = 0.27, p < 0.001）。整体线性相关性的斜率与铁蛋白磁性的理论考虑一致，支持大脑中的大多数铁与铁蛋白结合。综上所述，铁是深灰质磁化率的主要来源，可以用QSM来评估。在白质区域，QSM对铁浓度的估计不太准确，也更复杂，因为反磁性髓鞘神经元纤维的抵消作用会混淆解释。脑铁浓度与体磁化率相关。铁是灰质组织磁化率的主要因素。铁与易感性在WM中相关性较弱，提示髓磷脂的作用。
Quantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variations in gray matter as many studies have reported a reasonable correlation of magnetic susceptibility with brain iron concentrations in vivo. Instead of performing direct comparisons, however, all these studies used the putative iron concentrations reported in the hallmark study by Hallgren and Sourander (1958) for their analysis. Consequently, the extent to which QSM can serve to reliably assess brain iron levels is not yet fully clear. To provide such information we investigated the relation between bulk tissue magnetic susceptibility and brain iron concentration in unfixed (in situ) post mortem brains of 13 subjects using MRI and inductively coupled plasma mass spectrometry. A strong linear correlation between chemically determined iron concentration and bulk magnetic susceptibility was found in gray matter structures (r = 0.84, p < 0.001), whereas the correlation coefficient was much lower in white matter (r = 0.27, p < 0.001). The slope of the overall linear correlation was consistent with theoretical considerations of the magnetism of ferritin supporting that most of the iron in the brain is bound to ferritin proteins. In conclusion, iron is the dominant source of magnetic susceptibility in deep gray matter and can be assessed with QSM. In white matter regions the estimation of iron concentrations by QSM is less accurate and more complex because the counteracting contribution from diamagnetic myelinated neuronal fibers confounds the interpretation. ► Brain iron concentration correlates with bulk magnetic susceptibility. ► Iron is the dominant contributor to magnetic susceptibility in gray matter tissue. ► Iron and susceptibility are weaker correlated in WM, indicating effects of myelin.
登录
查看更多内容
影响因子：
3.3
作者：
Liu, Tian;Liu, Jing;Wang, Yi
通讯作者：
Wang, Yi
影响因子：
2.5
作者：
Petridou, Natalia;Schaefer, Andreas;Bowtell, Richard
通讯作者：
Bowtell, Richard
DOI：
10.1073/pnas.0910222107
发表时间：
2010-03-16
影响因子：
11.1
作者：
Lee, Jongho;Shmueli, Karin;Duyn, Jeff H.
通讯作者：
Duyn, Jeff H.
影响因子：
19.7
作者：
Aquino, Domenico;Bizzi, Alberto;Chiapparini, Luisa
通讯作者：
Chiapparini, Luisa
影响因子：
3.3
作者：
Deistung, Andreas;Rauscher, Alexander;Reichenbach, Juergen R.
通讯作者：
Reichenbach, Juergen R.