Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan; Department of Neuropsychiatry, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8576, Japan.
Department of Psychiatry, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan; Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan.
J Affect Disord. 2019 May 15;251:231-234. doi: 10.1016/j.jad.2019.03.068. Epub 2019 Mar 22.
Diffusional kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) are new diffusional magnetic resonance imaging (dMRI) techniques to clarify the characterization of neural tissues in the human brain. In this study, we evaluated the structural changes of the cerebrum in patients with bipolar disorder (BD) by these dMRI techniques.
Thirty-one Japanese patients with BD (male/female: 14/17; 29 out of 31 patients were right-handed; mean age: 39.5 ± 9.3) and 28 healthy, right-handed Japanese subjects underwent 3-Tesla dMRI. We compared the dMRI metrics between the 2 groups and examined the relationships among the metrics.
The majority of the participants in this study were medicated with antidepressants and antipsychotics. Further studies with drug-free participants will be needed before any conclusions can be drawn regarding microstructural changes in BD.
The BD patients showed significantly reduced mean kurtosis in right inferior front-occipital fasciculus and right posterior cingulate cortex (PCC), and neurite density indices in the right -PCC, compared with the controls. As for the orientation dispersion index, we detected significant decrease in the left hippocampal region of BD patients.
Using the new dMRI techniques, we observed disease-related alterations in the inferior front-occipital fasciculus, PCC, and hippocampal regions which play important roles in BD. These results may indicate that NODDI and DKI are useful to detect changes in the microstructural tissue organization in BD. It is anticipated that these techniques will be adopted as the mainstream methods for neuroimaging study.
扩散峰度成像（DKI）和神经纤维各向异性分布和密度成像（NODDI）是两种新的磁共振扩散成像（dMRI）技术，用于阐明人脑神经组织的特征。本研究通过这些 dMRI 技术评估双相情感障碍（BD）患者大脑的结构变化。
31 名日本 BD 患者（男/女：14/17；31 名患者中有 29 名右利手；平均年龄：39.5±9.3）和 28 名健康右利手日本对照者接受 3.0T dMRI 检查。我们比较了两组间的 dMRI 指标，并探讨了这些指标之间的关系。
本研究的大多数参与者都服用了抗抑郁药和抗精神病药。在得出关于 BD 患者微观结构变化的任何结论之前，还需要对无药物治疗的参与者进行进一步的研究。
BD 患者右侧下额枕束和右侧后扣带回皮层的平均峰度以及右侧 -PCC 的神经纤维密度指数明显低于对照组。对于各向异性弥散指数，我们发现 BD 患者左侧海马区域的明显下降。
使用新的 dMRI 技术，我们观察到与疾病相关的下额枕束、后扣带回皮层和海马区域的改变，这些区域在 BD 中起着重要作用。这些结果可能表明 NODDI 和 DKI 可用于检测 BD 患者的微观结构组织变化。预计这些技术将被用作神经影像学研究的主流方法。
