The effect of realistic geometries on the susceptibility-weighted MR signal in white matter.
The effect of realistic geometries on the susceptibility-weighted MR signal in white matter.
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DOI：
10.1002/mrm.26689
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发表时间：
2018-01
影响因子：
3.3
通讯作者：
Miller KL
中科院分区：
文献类型：
--
作者：
Xu T;Foxley S;Kleinnijenhuis M;Chen WC;Miller KL
研究真实显微结构几何形状对白色物质（WM）磁敏感加权MR信号的影响，并应用于脱髓鞘。先前的工作在假设轴突是圆柱形的情况下对磁化率加权信号进行了建模。在这项研究中，我们探讨了这一假设的影响，考虑更现实的几何形状。使用基于文献的包含相关属性的三室WM模型来预测MR信号。有髓鞘的轴突用几种越来越逼真的横截面几何形状建模：嵌套圆，扭曲/椭圆圆，以及从电子显微镜照片中测量的轴突几何形状。从不同的微观结构的几何形状的信号模拟进行了比较，从cuprizone小鼠模型与不同程度的脱髓鞘的测量信号。仿真结果表明，轴突的几何形状影响MR信号。与现实的模型预测显着不同的圆形模型相比，在相同的微观结构组织特性，模拟和不扩散。轴突的几何形状显著影响MR信号。髓鞘敏感性的文献估计，这是基于拟合生物物理模型的MR信号，可能会被偏见的假设的几何形状，将任何衍生的微观结构特性。Magn Reson Med 79：489-500，2018。© 2017国际医学磁共振学会。
To investigate the effect of realistic microstructural geometry on the susceptibility‐weighted MR signal in white matter (WM), with application to demyelination. Previous work has modeled susceptibility‐weighted signals under the assumption that axons are cylindrical. In this study, we explored the implications of this assumption by considering the effect of more realistic geometries. A three‐compartment WM model incorporating relevant properties based on the literature was used to predict the MR signal. Myelinated axons were modeled with several cross‐sectional geometries of increasing realism: nested circles, warped/elliptical circles, and measured axonal geometries from electron micrographs. Signal simulations from the different microstructural geometries were compared with measured signals from a cuprizone mouse model with varying degrees of demyelination. Simulation results suggest that axonal geometry affects the MR signal. Predictions with realistic models were significantly different compared with circular models under the same microstructural tissue properties, for simulations with and without diffusion. The geometry of axons affects the MR signal significantly. Literature estimates of myelin susceptibility, which are based on fitting biophysical models to the MR signal, are likely to be biased by the assumed geometry, as will any derived microstructural properties. Magn Reson Med 79:489–500, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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影响因子：
5.7
作者：
Liu, Chunlei;Li, Wei;Wu, Bing;Jiang, Yi;Johnson, G. Allan
通讯作者：
Johnson, G. Allan
影响因子：
2.5
作者：
MacKay, A;Laule, C;M채dler, B
通讯作者：
M채dler, B
影响因子：
3.3
作者：
CHU, SCK;XU, Y;SPRINGER, CS
通讯作者：
SPRINGER, CS
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：
2.2
作者：
BJORKSTAM, JL;LISTERUD, J;MASSARA, CI
通讯作者：
MASSARA, CI