Oscillating gradient diffusion MRI reveals unique microstructural information in normal and hypoxia-ischemia injured mouse brains.
Oscillating gradient diffusion MRI reveals unique microstructural information in normal and hypoxia-ischemia injured mouse brains.
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DOI：
10.1002/mrm.25441
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发表时间：
2014-11
影响因子：
3.3
通讯作者：
Zhang, Jiangyang
中科院分区：
文献类型：
--
作者：
Wu, Dan;Martin, Lee J.;Northington, Frances J.;Zhang, Jiangyang
我们研究了振荡梯度扩散MRI（dMRI）是否可以提供甲醛固定后和缺氧缺血性（HI）损伤后脑显微结构变化的信息，超出了传统的dMRI。成年小鼠脑的脉冲梯度自旋回波（PGSE）和振荡梯度自旋回波（OGSE）dMRI在体内进行（50-200 Hz，B = 600 mm 2/s），并且在单侧缺氧-缺血后24小时将类似的方案应用于新生小鼠脑。动物用4%多聚甲醛灌注固定，用于离体dMRI和组织学检查。在活体成年小鼠脑中测量的表观扩散系数（ADC）呈现组织依赖性频率依赖性。在高振荡频率（> 100 Hz）下的体内OGSE-ADC图显示成年小鼠小脑中分子层和颗粒细胞层之间存在明显的对比。甲醛固定显着改变了几个脑区的时间扩散光谱。在HI损伤的新生小鼠脑中，与PGSE结果相比，水肿区域的体内ADC测量显示在200 Hz下水肿对比度降低。组织学显示水肿区域有严重的组织肿胀和坏死。结果表明OGSE-dMRI在不同空间尺度上描绘组织微观结构的独特能力。
We investigated whether oscillating gradient diffusion MRI (dMRI) can provide information on brain microstructural changes after formaldehyde fixation and after hypoxic-ischemic (HI) injury beyond that provided by conventional dMRI. Pulsed gradient spin echo (PGSE) and oscillating gradient spin echo (OGSE) dMRI of the adult mouse brain was performed in vivo (50-200 Hz, b = 600 mm2/s), and a similar protocol was applied to neonatal mouse brains at 24 hours after unilateral hypoxia-ischemia. Animals were perfusion fixed with 4% paraformaldehyde for ex vivo dMRI and histology. Apparent diffusion coefficients (ADCs) measured in the live adult mouse brain presented tissue-dependent frequency-dependence. In vivo OGSE-ADC maps at high oscillating frequencies (>100Hz) showed clear contrast between the molecular layer and granule cell layer in the adult mouse cerebellum. Formaldehyde fixation significantly altered the temporal diffusion spectra in several brain regions. In neonatal mouse brains with HI injury, in vivo ADC measurements from edema regions showed diminished edema contrasts at 200 Hz compared to the PGSE results. Histology showed severe tissue swelling and necrosis in the edema regions. The results demonstrate the unique ability of OGSE-dMRI in delineating tissue microstructures at different spatial scales.
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影响因子：
3.3
作者：
Parsons, EC;Does, MD;Gore, JC
通讯作者：
Gore, JC
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3.3
作者：
Does, MD;Parsons, EC;Gore, JC
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3.3
作者：
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