多模态MRI技术和数值模拟技术用于脑血流灌注研究进展

脑血管疾病发病机制复杂,包括脑实质损伤、脑血流和脑脊液循环异常等。MRI脑血流灌注成像可评估脑结构和功能,结合数值模拟技术及流体间的差异,更准确地描述脑的病理变化。本文就多模态MRI技术结合数值模拟对脑血管疾病的脑血流灌注研究进展进行综述。     

弱视磁共振成像研究进展

弱视长久以来被认为是一种皮质疾病,而非单纯眼部疾病,其发病机制仍未完全明确。磁共振成像(MRI)已广泛应用于神经科学研究,以评估疾病所致脑结构和功能的变化。利用MRI,研究人员可以非侵入性地检查视觉传入减少对整个视觉通路的影响,包括外侧膝状核、纹状体和纹外皮层。本文旨在综述应用MRI研究弱视的结构、化学和功能的影响。结构MRI已显示出在视觉和非视觉区域,弱视患者在灰质和白质密度存在明显的异常,枕叶与其他脑叶的网络连接也存在有异常。功能核MRI研究也为视觉丧失后整个视觉通路功能变化提供了广泛的证据。磁共振波谱成像(MRS)也在弱视中得到更多的应用。在未来,MRI很可能在评估弱视对视觉通路的影响以及病情如何进展方面发挥重要作用。     

基于多模态MRI在帕金森病冻结步态的研究进展

冻结步态（freezing of gait, FOG）是一种可见于帕金森病中晚期患者的阵发性步态障碍,极大地影响了患者的生活质量,但针对其发病机制以及病程中脑结构功能变化至今尚无明确的阐述。近年来以扩散张量成像（diffusion tensor imaging,DTI）、三维T1加权成像（3D T1-weighted imaging, 3D-T1WI）和功能MRI(functional MRI, fMRI)为主的多模态MRI技术广泛运用于神经性疾病发病机制的探究,为探索FOG的深层机制提供了新思路。近年来研究显示,视觉、运动和认知网络的改变与FOG的发生紧密相关。笔者旨在通过查阅分析近年国内外相关文献,对多模态MRI探索帕金森病FOG患者脑结构和功能变化的研究进行综述,讨论当前FOG研究仍值得商榷之处,为今后通过多模态MRI更全面解释其发病机制提供新的思路。     

脑卒中后抑郁的MR研究进展

卒中后抑郁（PSD）为脑卒中患者常见的非躯体障碍,其发病机制尚未明确。脑PSD可降低卒中患者生存质量和社会功能,缩短患者寿命。随着影像学技术的发展,MRI新技术和计算机辅助全脑MRI图像分析法已广泛应用于脑的结构、功能及代谢变化等领域,有助于研究者从多角度探讨脑PSD的危险因素和相关机制。本文对MR技术在脑PSD的研究进展进行综述。     

原发性三叉神经痛的MRI研究进展

原发性三叉神经痛(primary trigeminal neuralgia,PTN),是一种临床常见的颅神经疾病,其特点为三叉神经分布区内反复发作的短暂性剧痛。迄今其病因及发病机制并不完全清楚。PTN的结构性MRI能显示三叉神经微观改变及其与周围成分的结构关系,可助于探索病因、辅助诊断、指导治疗;其功能性MRI能反映相应脑区功能与代谢变化,可为探索PTN的病因及发病机制等提供重要信息。本文就PTN的脑影像学研究及其进展进行综述。     

脑小血管病的研究进展

脑小血管病是一组随着年龄增长而逐渐增加的疾病,可以导致卒中、认知功能障碍等,目前尚无预防及治疗措施来改善这种情况。近年来随着MRI的发展,脑小血管病检出率逐渐增高。本文就该病的发病机制、神经影像学与认知功能的研究进展进行综述,以期为脑小血管病的早期诊治提供有益参考。     

多模态影像学研究帕金森病伴左旋多巴诱导异动症进展

帕金森病(PD)是常见神经退行性疾病;左旋多巴诱导异动症(LID)是PD患者长期服用左旋多巴药物所致常见致残性运动并发症。MR结构成像、功能MRI及PET显像可观察LID患者脑结构、功能及代谢改变,为阐述脑相关发病机制提供多模态影像学依据,有助于临床早期诊断。本文就多模态影像学研究PD伴LID进展进行综述。     

功能MRI揭示抑郁症脑结构及功能变化的应用及展望

抑郁症是由多种因素导致的心境障碍性疾病,主要表现为情绪低落,悲观,严重者甚至会有自杀倾向。有研究发现抑郁症与脑部某些神经联系减低及神经递质减少有关。随着功能MRI的发展,越来越多的人将功能MRI用于抑郁症的研究,以期阐明其发病机制。与传统的成像方式相比,它能反应脑白质微结构的变化并将相应脑区的功能状态影像化,有利于更加直观地分析研究脑结构与功能之间的关系。     

负荷心肌MRI灌注成像在冠心病中应用的研究进展

冠心病发病率、病死率均居心血管疾病首位,其发病与冠状动脉狭窄有关,早期诊断具有重要意义。心脏MRI是评价心脏结构和功能的金标准,但常规心脏MRI无法显示早期隐匿性冠心病患者的异常心肌储备功能。负荷心肌MRI灌注成像在评估心肌缺血、心肌储备功能方面有明显优势。本文就负荷心肌MRI灌注成像诊断冠状动脉疾病的负荷方式、图像特征、诊断效能及在冠心病预后评估中应用的研究进展作一综述。     

动脉自旋标记成像用于轻度认知障碍研究进展

轻度认知障碍（MCI）是阿尔茨海默病（AD）的前驱期，对其发病机制尚不明确。脑血流量是衡量脑功能的重要指标，各种原因致局部脑血流量（rCBF）减低而损伤大脑。动脉自旋标记（ASL）MRI是通过磁化标记动脉血中氢质子作为内源性示踪剂测量rCBF的成像技术。本研究针对ASL成像在早期诊断MCI、监测疾病进展及评估疗效中的研究进展进行综述。     

Chronic fatigue syndrome—aetiological aspects

The chronic fatigue syndrome (CFS) has been intensively studied over the last 40 years, but no conclusions have yet been agreed as to its cause. Most cases nowadays are sporadic. In the established chronic condition there are no consistently abnormal physical signs or abnormalities on laboratory investigation. Many physicians remain convinced that the symptoms are psychological rather than physical in origin. This view is reinforced by the emotional way in which many patients present themselves. The overlap of symptoms between CFS and depression remains a source of confusion and difficulty. But even if all CFS patients were rediagnosed as depressives, this would not negate the possibility of an underlying organic cause for the condition, in view of the growing evidence that depression itself has a physical cause and responds best to physical treatments. There is some evidence both for active viral infection and for an immunological disorder in the CFS. Many observations suggest that the syndrome could derive from residual damage to the reticular activating system (RAS) of the upper brain stem and/or to its cortical projections. Such damage could be produced by a previous viral infection, leaving functional defects unaccompanied by any gross histological changes. In animal experiments activation of the RAS can change sleep state and activate or stimulate cortical functions. RAS lesions can produce somnolence and apathy. Studies by modern imaging techniques have not been entirely consistent, but many magnetic resonance imaging (MRI) studies already suggest that small discrete patchy brain stem and subcortical lesions can often be seen in CFS. Regional blood flow studies by single photon-emission computerized tomography (SPECT) have been more consistent. They have revealed blood flow reductions in many regions, especially in the hind brain. Similar lesions have been reported after poliomyelitis and in multiple sclerosis—in both of which conditions chronic fatigue is characteristically present. In the well-known post-polio fatigue syndrome, lesions predominate in the RAS of the brain stem. If similar underlying lesions in the RAS can eventually be identified in CFS, the therapeutic target for CFS would be better defined than it is at present. A number of logical approaches to treatment can already be envisaged.     

功能MRI研究特发性耳鸣机制进展

特发性耳鸣是临床最常见耳鸣类型，指患者在无外界刺激情况下自觉耳内或颅内鸣响；因其发病原因及机制尚不明了，亦无特效治疗方法。功能MRI(fMRI)现已逐渐用于研究耳鸣患者大脑结构和功能变化，在研究耳鸣的中枢机制中发挥重要作用。本文就fMRI研究特发性耳鸣机制进展进行综述。     

基于MRI影像组学和机器学习诊断抑郁症研究进展

抑郁症为常见神经心理疾病,目前尚无客观诊断标准。MRI可提供脑结构、白质纤维束完整性及静息态和任务态下脑功能等多方面信息;MRI影像组学和机器学习(ML)有助于建立个体化诊断抑郁症模型。本文对基于MRI影像组学及ML诊断抑郁症研究进展进行综述。     

Low-resolution electromagnetic brain tomography (LORETA) of monozygotic twins discordant for chronic fatigue syndrome

BACKGROUND: Previous work using quantified EEG has suggested that brain activity in individuals with chronic fatigue syndrome (CFS) and normal persons differs. Our objective was to investigate if specific frequency band-pass regions and spatial locations are associated with CFS using low-resolution electromagnetic brain tomography (LORETA). METHODS: We conducted a co-twin control study of 17 pairs of monozygotic twins where 1 twin met criteria for CFS and the co-twin was healthy. Twins underwent an extensive battery of tests including a structured psychiatric interview and a quantified EEG. Eyes closed EEG frequency-domain analysis was computed and the entire brain volume was compared of the CFS and healthy twins using a multiple comparison procedure. RESULTS: Compared with their healthy co-twins, twins with CFS differed in current source density. The CFS twins had higher delta in the left uncus and parahippocampal gyrus and higher theta in the cingulate gyrus and right superior frontal gyrus. CONCLUSIONS: These findings suggest that neurophysiological activity in specific areas of the brain may differentiate individuals with CFS from those in good health. The study corroborates that slowing of the deeper structures of the limbic system is associated with affect. It also supports the neurobiological model that the right forebrain is associated with sympathetic activity and the left forebrain with the effective management of energy. These preliminary findings await replication.     

慢性疲劳综合征患者外周血单个核细胞中转化生长因子β1 mRNA及雌二醇受体β野生型mRNA的表达水平

目的 探讨慢性疲劳综合征(CFS)患者外周血单个核细胞(PBMCs)中转化生长因子β1(TGF-β1)mRNA及雌二醇受体p野生型(ERβwt)mRNA表达及其与CFS的发病关系.方法 用实时荧光定量逆转录(FQ-RT)-PCR检测63例CFS患者、50例其他疾病患者(疾病对照组)、50名健康体检者(健康对照组)外周血PBMCs中TGF-β1 mRNA和ERβwt mRNA的表达水平和含量.以△Ct=Ct(待测基因)-Ct(内参基因)来比较基因表达水平的变化.结果 CFS患者TGF-β1 mRNA表达水平(△Ct=3.27±0.58)明显高于健康对照组(△Ct=4.37±1.00,t=7.02,P<0.01)和疾病对照组(△Ct=4.54±1.05,t=8.11,P<0.01).CFS患者ERβwt mRNA表达水平(△Ct=9.34±0.92)明显低于健康对照组(△Ct=7.10±0.48,t=15.47,P<0.01)与疾病对照组(△Ct=7.12±0.47,t=15.44,P<0.01);结论CFS患者TGF-β1 mRNA表达水平显著高于健康人和疾病对照组;CFS患者ERβwtmRNA表达水平显著低于健康人和疾病对照组,TGF-β1 mRNA和ERβwt mRNA的表达可能参与了CFS的发病过程.     

PET研究慢性疲劳综合征中枢机制现状

慢性疲劳综合征(CFS)与中枢系统功能异常密切相关,常伴认知困难、焦虑抑郁及痛觉改变等,目前尚无特异性诊断方法。PET可为研究CFS中枢系统异常提供重要参考依据。本文就PET研究CFS中枢机制现状进行综述。     

一体化PET/MR评估脑血流量的研究进展

一体化PET/MR技术具有一次扫描可同时获得PET和MRI图像的独特优势,目前已逐步应用于临床。准确定量分析脑血流量（CBF）对研究脑血管病、脑肿瘤、癫痫等脑部重大疾病的发病机制及临床转归具有重要价值。一体化PET/MR可实现无创、简便、准确获得动脉输入函数,从而精准定量CBF。本文对一体化PET/MR评估CBF的研究进展进行综述。     

功能MRI在肝性脑病诊断和研究中的进展

肝性脑病是由急、慢性肝功能障碍或门—体分流引起的神经精神综合征,可导致不同程度精神异常,影响患者生活质量。近年来,MR功能成像技术飞速发展,可无创显示大脑结构及代谢功能变化,为早期发现、诊断肝性脑病及治疗监测提供依据。本文对功能MRI在肝性脑病诊断和研究中的进展进行综述。