Cytoarchitecture of the mouse brain by high resolution diffusion magnetic resonance imaging
Cytoarchitecture of the mouse brain by high resolution diffusion magnetic resonance imaging
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DOI：
10.1016/j.neuroimage.2020.116876
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发表时间：
2020-08-01
期刊：
影响因子：
5.7
通讯作者：
Johnson, G. Allan
中科院分区：
文献类型：
--
作者：
Wang, Nian;White, Leonard E.;Johnson, G. Allan
MRI已被广泛用于探测小鼠大脑的神经解剖学，由于有限的空间分辨率和来自水弛豫或扩散特性的各种图像对比度，直接将MRI结果与组织学相关联仍然具有挑战性。磁共振组织学有可能成为缓解这些挑战的不可或缺的研究工具。在本研究中，我们获得了高空间分辨率的MRI数据集，包括25 μm各向同性分辨率的扩散MRI （dMRI）和21.5 μm各向同性分辨率的定量敏感性图谱（QSM），并与常规小鼠脑组织组织学进行了验证。弥散加权图像（dwi）比分数各向异性（FA）图能更好地描绘嗅球皮质层和肾小球。然而，在所有的图像对比中，包括定量敏感性映射（QSM）、T1/T2 *图像和DTI指标，FA地图突出了海马亚区域的独特层流结构，包括海马齿状回和CA区。平均扩散率（MD）和轴向扩散率（AD）与DAPI（0.62和0.71）和NeuN（0.78和0.74）的相关性高于与NF-160（- 0.34和- 0.49）的相关性。FA与DAPI、NeuN和NF-160的相关性分别为0.31、- 0.01和- 0.49。我们的研究结果表明，微观分辨率的MRI为小鼠大脑灰质和白质的精细结构细节表征提供了一个三维、非侵入性和非破坏性的平台。
MRI has been widely used to probe the neuroanatomy of the mouse brain, directly correlating MRI findings to histology is still challenging due to the limited spatial resolution and various image contrasts derived from water relaxation or diffusion properties. Magnetic resonance histology has the potential to become an indispensable research tool to mitigate such challenges. In the present study, we acquired high spatial resolution MRI datasets, including diffusion MRI (dMRI) at 25 μm isotropic resolution and quantitative susceptibility mapping (QSM) at 21.5 μm isotropic resolution to validate with conventional mouse brain histology. Diffusion weighted images (DWIs) show better delineation of cortical layers and glomeruli in the olfactory bulb than fractional anisotropy (FA) maps. However, among all the image contrasts, including quantitative susceptibility mapping (QSM), T1/T2∗ images and DTI metrics, FA maps highlight unique laminar architecture in sub-regions of the hippocampus, including the strata of the dentate gyrus and CA fields of the hippocampus. The mean diffusivity (MD) and axial diffusivity (AD) yield higher correlation with DAPI (0.62 and 0.71) and NeuN (0.78 and 0.74) than with NF-160 (−0.34 and −0.49). The correlations between FA and DAPI, NeuN, and NF-160 are 0.31, −0.01, and −0.49, respectively. Our findings demonstrate that MRI at microscopic resolution deliver a three-dimensional, non-invasive and non-destructive platform for characterization of fine structural detail in both gray matter and white matter of the mouse brain.