论文标题
将白质微观结构的效果纳入了前体小鼠脑中磁敏感性的估计
Incorporating the effect of white matter microstructure in the estimation of magnetic susceptibility in ex-vivo mouse brain
论文作者
论文摘要
在生物组织中诱导的微观磁场变化的准确估计对于映射健康和疾病的组织组成可能是有价值的。在这里，我们提出了定量易感映射（QSM）的扩展，以通过使用我们先前呈现的模型为具有任意取向的固体圆柱体来解释局部白质（WM）磁性微观结构，以描述同心圆柱体的轴突。通过计算机模拟，我们发现与QSM相比，我们的模型改善了易感性估计，并且易感性张量成像（STI）基本上受到了介镜频率贡献的未指定的结构各向异性的偏见，这表明观察到的STI张量可能无法表示易启动性各向异性各向异性。在超高场上获得的小鼠大脑中的实验表明，由于WM微观结构是实质性的，因此介质贡献。与标准QSM相比，WM的估计易感性值又将估计的易感性值最高为25％。我们的工作强调了微观结构场的影响如何影响易感性估计，并且在成像各向异性组织（如脑WM）时不应忽略。
Accurate estimation of microscopic magnetic field variations induced in biological tissue can be valuable for mapping tissue composition in health and disease. Here, we present an extension to Quantitative susceptibility mapping (QSM) to account for local white matter (WM) magnetic microstructure by using our previously presented model for solid cylinders with arbitrary orientations to describe axons in terms of concentric cylinders. Through computer simulations, we find that our model improves susceptibility estimation compared to QSM, and Susceptibility Tensor Imaging (STI) are substantially biased by the unaccounted-for structural anisotropy due to the mesoscopic frequency contribution, indicating the observed STI tensor might not represent susceptibility anisotropy as expected. Experiments in mouse brains acquired at ultrahigh field shows the mesoscopic contribution due to WM microstructure to be substantial. This in turn changed estimated susceptibility values up to 25% root-mean-squared-difference in WM compared to standard QSM. Our work underscores how microstructural field effects impact susceptibility estimates, and should not be neglected when imaging anisotropic tissue such as brain WM.
