Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
GE Healthcare, Beijing, China.
J Magn Reson Imaging. 2019 Sep;50(3):889-898. doi: 10.1002/jmri.26687. Epub 2019 Feb 19.
Diffusion-tensor-imaging (DTI) is sensitive in detecting white matter changes in type-2 diabetes mellitus (T2DM). However, DTI indices can be affected by either neurite density or spatial variation. A novel diffusion MRI technique, termed neurite orientation dispersion and density imaging (NODDI), can provide distinct indices of fiber density and dispersion.
To characterize brain microstructural alterations in T2DM patients with mild cognitive impairment (MCI) using the NODDI model.
Cross-sectional.
Twenty T2DM patients with (DM-MCI group), 18 age- and gender-matched T2DM patients with normal cognition (DM-NC group), and 28 euglycemic healthy controls (HC).
FIELD STRENGTH/SEQUENCE: 3T/NODDI.
Diffusion data were analyzed using tract-based-spatial-statistics (TBSS) analysis in white matter and voxel-based analysis in both white and gray matter. NODDI indices, including intracellular volume fraction (Vic) and orientation dispersion index (ODI), were estimated from multiple regions and compared among these groups.
Differences between groups were compared by Student's t-test, Pearson chi-square test, or analysis of variance when appropriate. Correlation analyses were performed to investigate the relationship between NODDI variables and clinical measurements.
Whole-brain TBSS revealed that 2.29% and 2.02% of the white matter regions exhibited decreased fractional anisotropy and Vic, respectively, between the DM-NC and HC, while considerably larger white matter areas showed decreased fractional anisotropy (38.38%) and Vic (34.64%) between the DM-MCI and HC (Student's t-test, P < 0.05). However, the angular variation of neurites, characterized by ODI, exhibited very little (0.1%, P < 0.05) or no difference (P > 0.05) between either the DM-MCI or DM-NC groups and HC. Decreased Vic values in the genu of the corpus callosum (R = 0.580, 0.551 and 0.586, P < 0.01) and thalamus (R = 0.570, 0.616, and 0.595, P < 0.05) correlated with glycosylated hemoglobin A1c level, disease duration, and neuropsychological scores, respectively.
T2DM patients with cognitive decline had reduced Vic, which indicated decreased density of axons and dendrites. NODDI might be able to help probe microstructural changes in white and gray matter and provide information on diabetic encephalopathy, including those with cognitive impairment.
1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:889-898.
扩散张量成像（DTI）在检测 2 型糖尿病（T2DM）患者的白质变化方面很敏感。然而，DTI 指数可能受到神经丝密度或空间变化的影响。一种新的扩散 MRI 技术，称为神经丝取向弥散和密度成像（NODDI），可以提供纤维密度和弥散的独特指数。
使用 NODDI 模型描述 T2DM 合并轻度认知障碍（MCI）患者的脑微观结构改变。
横断面。
20 例 T2DM 合并 MCI 患者（DM-MCI 组）、18 例年龄和性别匹配的 T2DM 合并认知正常患者（DM-NC 组）和 28 例血糖正常的健康对照者（HC）。
场强/序列：3T/NODDI。
使用基于束的空间统计学（TBSS）分析对白质进行弥散数据分析，并对白质和灰质进行体素分析。从多个区域估计 NODDI 指数，包括细胞内容积分数（Vic）和取向弥散指数（ODI），并在这些组之间进行比较。
通过学生 t 检验、Pearson 卡方检验或适当的方差分析比较组间差异。进行相关性分析，以研究 NODDI 变量与临床测量值之间的关系。
全脑 TBSS 显示，DM-NC 与 HC 相比，有 2.29%和 2.02%的白质区域的各向异性分数和 Vic 分别降低，而 DM-MCI 与 HC 相比，有相当大的白质区域的各向异性分数（38.38%）和 Vic（34.64%）降低（学生 t 检验，P<0.05）。然而，神经丝的角度变化，用 ODI 表示，在 DM-MCI 或 DM-NC 组与 HC 之间几乎没有（0.1%，P<0.05）或没有差异（P>0.05）。胼胝体膝部（R=0.580、0.551 和 0.586，P<0.01）和丘脑（R=0.570、0.616 和 0.595，P<0.05）的 Vic 值降低与糖化血红蛋白 A1c 水平、疾病持续时间和神经心理学评分相关。
认知能力下降的 T2DM 患者 Vic 值降低，提示轴突和树突密度降低。NODDI 可能有助于探测白质和灰质的微观结构变化，并提供有关糖尿病性脑病的信息，包括认知障碍患者。
1 技术功效：阶段 2 J. Magn. Reson. Imaging 2019;50:889-898.
