阿尔茨海默病的影像学研究进展

Research advances in the imaging findings of Alzheimer’s disease

阿尔茨海默病(AD)是一种起病隐匿的进行性发展的神经系统退行性疾病,临床上以记忆减退、人格和行为障碍、认知功能和精神障碍等表现为特征,并伴有神经炎性斑块和神经原纤维缠结的典型病理学改变。目前临床常用的计算机断层扫描和磁共振成像等结构影像学技术,仅能发现出现了脑组织结构改变的AD患者,但无法实现疾病的早期和超早期诊断。功能影像学和分子影像学分别能从功能水平和分子水平评估AD的发展进程和变化,功能影像学技术包括CT灌注成像、功能磁共振成像和动脉自旋标记等,通过检测局部脑组织血流灌注的变化来评价大脑活动和功能的改变,对诊断临床前AD有着指示性作用。分子影像学技术包括正电子发射断层扫描、单光子发射计算机断层扫描、磁共振波谱成像等,在确定AD标志性生物靶点的基础上,开发出相应的放射性示踪剂,识别和结合AD特征性病理分子,从细胞层面的病理变化实现AD早期发现。相比于结构和功能影像学,分子影像学技术对AD早期发现、分级评估、治疗效果预测有着更大的作用,为阐明发病机制、研发药物新靶点提供了全新的技术路径。该文概述了AD各类影像学技术的最新研究进展,分析了相关技术的临床和科研价值,并评价不同技术的优缺点,并浅谈了未来的展望与挑战。

Alzheimer’s disease(AD) is a progressive neurological degenerative disease with an insidious onset and has the clinical features of memory loss, personality and behavioral disorders, cognitive impairment, and mental disorders, as well as the typical pathological changes of neuroinflammatory plaques and neuronal fibrillary tangles. At present, the structural imaging techniques commonly used in clinical practice, such as computed tomography and magnetic resonance imaging, can only find AD patients with structural changes of brain tissue and cannot realize the early and super-early diagnosis of the disease. Functional imaging and molecular imaging can assess the progression and changes of AD respectively from the functional and molecular levels. Functional imaging techniques include CT perfusion imaging, functional magnetic resonance imaging, and arterial spin labeling and have an indicative role in the diagnosis of preclinical AD by detecting the changes in local cerebral blood perfusion to evaluate the change of brain activity and function. Molecular imaging techniques include positron emission tomography, single-photon emission computed tomography, and magnetic resonance spectrum imaging, and based on the identification of AD biomarkers, corresponding radioactive tracers are developed to identify and combine the characteristic pathological molecules of AD, so as to realize the early identification of AD from the pathological changes of cells. Compared with structural and functional imaging techniques, molecular imaging techniques have a greater role in the early identification, grading assessment, and treatment outcome prediction of AD and provide new technical paths for the clarification of pathogenesis and the development of new drug targets. This article summarizes the latest research advances in various imaging techniques for AD, analyzes the clinical and scientific research value of related techniques, evaluates the advantages and disadvantages of different techniques, and discusses future prospects and challenges.[Journal of International Neurology and Neurosurgery, 2022, 49(5): 60-66]