阿茲海默症的大腦結構功能耦合性：擴散與功能核磁共振影像整合

Structure-Function Coupling of the Brain in Alzheimer's Disease: Integration of Diffusion and Functional Magnetic Resonance Images

劉慧敏(HUEI-MIN LIU)

指導教授 ： 羅畯義

中原大學/工學院/生物醫學工程學系/碩士(2024年)

https://doi.org/10.6840/cycu202400181

摘要

阿茲海默症為一種大腦的神經退化性疾病，主要表現為認知或記憶功能等障礙，並伴隨大腦結構的萎縮。先前，已有許多文獻指出透過擴散磁振造影可評估該病症所導致的腦白質結構異常資訊，以及使用功能磁振造影觀察到特定腦區活化異常的情況，然而，目前對於共同探討同一大腦區域結構與功能的整合型研究仍然甚少，並且在阿茲海默症的結論並不一致，無法顯示結構與功能表現上兩者之異常關聯性。本論文主要目的為通過觀察阿茲海默症患者大腦白質的神經結構連接性與活化情況，以深入理解該疾病對於神經功能上的異常影響與白質結構和功能之間的關聯性。
本研究利用擴散權重影像和功能磁振影像分別進行擴散張量與功能相關性張量的重建，以獲取白質結構與神經束功能活化之資訊。接著，透過歐基里德距離度量和非等向性指標，評估兩者張量於同一體素中的相似度，即結構與神經功能走向的一致性，並比較患者與健康受試者之間的差異。最後，分析患者的張量相似度與臨床診斷數據之間的偏相關性。
在張量相似度的比較中，阿茲海默症患者相較於健康受試者的特定大腦區域功能活化降低，而在多個區域的張量相似度與記憶和認知能力之臨床測驗分數具有顯著性相關，與先前文獻中的研究結果一致，顯示大腦結構和功能之間的異常與臨床症狀有著密切的關聯性。
總體而言，本研究整合兩種張量評估腦白質結構和功能之連接性，深入探討阿茲海默症對於大腦神經活化的異常情形，擴展腦功能與記憶和認知能力的理解，為日後臨床研究提供了更加微觀的資訊，有助於未來更有效地解析疾病的發病機制，並為不同患者個體化治療方案。

關鍵字

阿茲海默症 ； 靜息狀態 ； 核磁共振影像 ； 擴散張量 ； 功能相關性張量 ； 結構與功能耦合

並列摘要

Alzheimer's disease, a cerebral neurodegenerative disorder, manifests primarily as cognitive and memory impairments with associated brain structural atrophy. While previous literature has extensively utilized diffusion magnetic resonance imaging (MRI) to assess white matter structural abnormalities associated with the disease and functional MRI to observe abnormal activations in specific brain regions, integrated studies examining both structural and functional abnormalities within the same brain regions remain limited. Additionally, conclusions regarding Alzheimer's disease have been inconsistent, failing to demonstrate a clear correlation between structural and functional aberrations. The main objective of this thesis is to deepen our understanding of the abnormal neurological effects of the disease and the relationship between white matter structure and function by observing the neural connectivity and activation patterns of Alzheimer's disease patients' brain white matter.
In this study, diffusion-weighted imaging and functional magnetic resonance imaging were used to reconstruct diffusion tensors and functional connectivity tensors, respectively, to acquire information on white matter structure and neural bundle functional activation. Subsequently, the similarity between the two tensors within the same voxel, indicating the consistency between structural and neural functional trends, was evaluated using Euclidean distance metrics and anisotropy indices, and the differences between patients and healthy controls were compared. Finally, the partial correlation between patients' tensor similarity and clinical diagnostic data was analyzed.
In comparing tensor similarity, Alzheimer's disease patients exhibited reduced functional activations in specific brain regions compared to healthy controls, and tensor similarity in multiple regions showed significant correlations with memory and cognitive ability clinical test scores. These findings are consistent with previous research, indicating a close association between abnormal brain structure and function and clinical symptoms.
Overall, this study integrates two tensor evaluations of brain white matter structure and function connectivity, delving into the abnormal neural activations in Alzheimer's disease, expanding our understanding of brain function and memory and cognitive abilities, and providing more microscopic information for future clinical research, aiding in more effectively deciphering the pathogenesis of the disease and tailoring personalized treatment plans for individual patients.

並列關鍵字

Alzheimer's disease ； resting state ； magnetic resonance image ； diffusion tensor ； functional correlation tensor ； coupling of structural and functional

參考文獻

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