Differentiating between subcortical ischemic vascular disease (SIVD), Alzheimer's disease (AD), and normal cognition (NC) remains a challenge, and reliable neuroimaging biomarkers are needed. The current study, therefore, investigated the discriminative ability of diffusion kurtosis imaging (DKI) metrics in segregated thalamic regions and compare with diffusion tensor imaging (DTI) metrics. Twenty‐three SIVD patients, 30 AD patients, and 24 NC participants underwent brain magnetic resonance imaging. The DKI metrics including mean kurtosis (MK), axial kurtosis (K_axial) and radial kurtosis (K_radial) and the DTI metrics including diffusivity and fractional anisotropy (FA) were measured within the whole thalamus and segregated thalamic subregions. Strategic correlations by group, thalamo‐frontal connectivity, and canonical discriminant analysis (CDA) were used to demonstrate the discriminative ability of DKI for SIVD, AD, and NC. Whole and segregated thalamus analysis suggested that DKI metrics are less affected by white matter hyperintensities compared to DTI metrics. Segregated thalamic analysis showed that MK and K_radial were notably different between SIVD and AD/NC. The correlation analysis between K_axial and MK showed a nonsignificant relationship in SIVD group, a trend of negative relationship in AD group, and a significant positive relationship in NC group. A wider spatial distribution of thalamo‐frontal connectivity differences across groups was shown by MK compared to FA. CDA showed a discriminant power of 97.4% correct classification using all DKI metrics. Our findings support that DKI metrics could be more sensitive than DTI metrics to reflect microstructural changes within the gray matter, hence providing complementary information for currently outlined pathogenesis of SIVD and AD.

中文翻译：

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通过分离丘脑区域的扩散峰度成像区分皮质下缺血性血管疾病和阿尔茨海默病

区分皮层下缺血性血管疾病 (SIVD)、阿尔茨海默病 (AD) 和正常认知 (NC) 仍然是一个挑战，需要可靠的神经影像学生物标志物。因此，目前的研究调查了扩散峰度成像 (DKI) 指标在分离的丘脑区域中的判别能力，并与扩散张量成像 (DTI) 指标进行了比较。23 名 SIVD 患者、30 名 AD 患者和 24 名 NC 参与者接受了脑磁共振成像。DKI指标包括平均峰度（MK）、轴向峰度（K_轴）和径向峰度（K_径向）) 和包括扩散率和分数各向异性 (FA) 在内的 DTI 指标是在整个丘脑和分离的丘脑亚区域内测量的。使用按组、丘脑-额叶连接和典型判别分析 (CDA) 的战略相关性来证明 DKI 对 SIVD、AD 和 NC 的判别能力。整体和分离的丘脑分析表明，与 DTI 指标相比，DKI 指标受白质高信号的影响较小。分离的丘脑分析表明，在 SIVD 和 AD/NC 之间，MK 和K_{径向显着不同。}K_轴之间的相关性分析MK在SIVD组呈不显着相关，在AD组呈负相关趋势，在NC组呈显着正相关。与 FA 相比，MK 显示了跨组丘脑-额叶连接差异的更广泛的空间分布。CDA 显示使用所有 DKI 指标的 97.4% 正确分类的判别力。我们的研究结果支持 DKI 指标可能比 DTI 指标更敏感，以反映灰质内的微观结构变化，因此为目前概述的 SIVD 和 AD 发病机制提供补充信息。