Wang Zhenxiong, Zhang Shun, Liu Chengxia, Yao Yihao, Shi Jingjing, Zhang Ju, Qin Yuanyuan, Zhu Wenzhen
Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan 430030, China.
Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan 430030, China.
Magn Reson Imaging. 2019 Apr;57:28-33. doi: 10.1016/j.mri.2018.10.018. Epub 2018 Oct 29.
To demonstrate the feasibility of the neurite orientation dispersion and density imaging (NODDI) technique in characterizing the microstructural changes in brain tissues during ischemic stroke and to compare its sensitivity with diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI).
Seventy-one patients with hyperacute/acute/subacute ischemic stroke were enrolled in the study. A multishell diffusion magnetic resonance imaging (dMRI) protocol was performed for each subject. Diffusion data were analyzed using the NODDI and diffusional kurtosis estimator toolboxes. Then, NODDI metrics between the lesions and the contralateral tissues were compared to evaluate their values in ischemic stroke. NODDI metrics among different stroke periods and the correlations between NODDI and the duration since stroke onset were analyzed as well. To compare the NODDI's sensitivity with established diffusion techniques, paired t-tests were performed to determine the absolute percentage changes of diffusion metrics between NODDI and DTI/DKI.
Compared with the contralateral tissues, lesions showed significantly increased values of intracellular volume fraction (V) and orientation dispersion index (ODI) and decreased values of isotropic volume fraction (V). ODI value was significantly different among three periods and showed fair to good positive correlation with the duration since stroke onset (R = 0.450). NODDI metrics showed significantly larger absolute percentage changes than that of DTI and DKI (P < 0.05, respectively).
NODDI allowed efficient evaluation of microstructural changes in brain tissues during ischemic stroke and showed increased sensitivity compared with DTI and DKI. The possible biophysical mechanisms underlying ischemia could be further elucidated using this advanced diffusion technique.
证明神经突方向离散度与密度成像（NODDI）技术在表征缺血性脑卒中期间脑组织微观结构变化方面的可行性，并将其敏感性与扩散张量成像（DTI）和扩散峰度成像（DKI）进行比较。
71例超急性/急性/亚急性缺血性脑卒中患者纳入本研究。对每位受试者进行多壳扩散磁共振成像（dMRI）方案。使用NODDI和扩散峰度估计工具箱分析扩散数据。然后，比较病变与对侧组织之间的NODDI指标，以评估其在缺血性脑卒中中的价值。还分析了不同卒中时期的NODDI指标以及NODDI与卒中发作后持续时间之间的相关性。为了将NODDI的敏感性与既定的扩散技术进行比较，进行配对t检验以确定NODDI与DTI/DKI之间扩散指标的绝对百分比变化。
与对侧组织相比，病变显示细胞内体积分数（V）和方向离散度指数（ODI）值显著增加，各向同性体积分数（V）值降低。ODI值在三个时期之间有显著差异，并且与卒中发作后的持续时间呈中等至良好的正相关（R = 0.450）。NODDI指标显示出比DTI和DKI更大的绝对百分比变化（P分别<0.05）。
NODDI能够有效评估缺血性脑卒中期间脑组织的微观结构变化，并且与DTI和DKI相比显示出更高的敏感性。使用这种先进的扩散技术可以进一步阐明缺血潜在的生物物理机制。
