脑损伤康复的功能性磁共振成像研究现状与进展

脑功能研究是神经科学研究的前沿和热点，越来越受人们关注和重视。自从1991年5月美国麻省总医院的Belliveau等首次利用功能性磁共振成像（functionalmagneticresonanceimaging，fMRI）展示人脑视皮质功能活动以来，fMRI技术很快引起科学家们的极大兴趣。随着这一崭新的医学影像学技术的诞生和不断发展，人们对脑损伤康复的研究已从单一的形态结构学逐步向形态与功能及功能与分子相结合的方向发展。近年来的研究表明，fMRI在脑损伤康复的研究中具有很大的潜力和临床应用价值，为医学影像学在脑科学的研究和临床应用开辟了一个全新的领域，值得我们深入探索。     

7.0T静息态fMRI分析恒河猴脑默认网络

目的 分析健康恒河猴大脑的默认网络（DMN）结构。方法 采用7.0T fMRI获得麻醉状态下健康恒河猴的静息态数据;以DPARSF软件包对猴脑静息态功能像进行预处理,将其配准到恒河猴标准模板112SM-RL-T1;之后利用GIFT软件包对预处理后的功能像数据进行组独立成分分析。结果 本文方法可较准确地对猴脑静息态数据进行预处理,并获得静息态脑网络功能连接图;其中DMN包括位于中线区的后扣带回、前扣带回、内侧顶叶皮质、后压部皮质以及大脑左右半球较为对称的腹侧壁内区域、背侧颞上沟回、颞区、弓状沟回及部分视觉区域等脑区。结论 借助7.0T fMRI,本文证实恒河猴默认网络与人类默认网络在结构上具有相似性,此类模型可辅助进行药理性实验研究以及神经认知类研究。     

组织工程研究中神经细胞的培养

神经科学是现代科学中进展最为迅猛的研究领域之一,神经科学的研究目的在于了解神经系统内分子水平、细胞水平及细胞之间的变化过程,以及这些过程在中枢功能控制系统内的综合作用.神经科学的许多研究,如对神经元、神经细胞膜、神经递质和受体等方面的研究,早己突破形态、生理、生化、药理等学科的界限,出现互相渗透甚至融为一体的现象.神经网络的研究成果更是拓展到生物领域之外,与电子学、信息学等学科交沤渗透.神经科学的快速发展引起了人们对探人脑自身奥秘的极大兴趣,也引起了全球各国政府和有关机构的普遍重视.     

咖啡因对抗睡眠剥夺影响执行控制功能的fMRI研究

目的 研究36 h睡眠剥夺(SD)以及睡眠剥夺并服用咖啡因后脑部功能磁共振成像(fMRI)特点,探讨咖啡因对抗睡眠剥夺对大脑功能影响的可能机制.方法 13名健康男性大学生参加试验.试验采用随机、双盲自身对照设计,对受试者在清醒状态下以及36 h睡眠剥夺并随机服用咖啡因或者安慰剂后进行Go/No-go测验并使用3.0T磁共振仪进行fMRI扫描,3次fMRI扫描之间间隔3周.受试者行为学数据使用SPSS软件处理,fMRI数据使用AFNI软件包进行处理.结果 36 h睡眠剥夺后受试者前额叶皮层显著激活,前扣带回功能活动下降;服用咖啡因后双侧豆状核、丘脑、边缘系统相关脑区激活程度下降.结论 36 h睡眠剥夺可导致执行控制功能的显著下降,前额叶皮质参与功能代偿.咖啡因通过对边缘系统相关区域及纹状体系统活动的抑制来对抗睡眠剥夺对于执行控制功能的影响.     

低剂量水合氯醛镇静对儿童视觉区BOLD-fMRI反应影响的自身对照研究

目的通过自身对照的方法探讨低剂量(30mg/kg)水和氯醛镇静对儿童视觉区BOLD信号反应的影响。方法选取12名健康儿童分别在清醒闭眼和口服水合氯醛(30mg/kg)镇静的状态下行fMRI检查,视觉刺激用2Hz闪烁光,fMRI数据采用SPM2软件进行后处理(ROI),分别计算清醒状态与镇静状态的brodmann(BA)17,18,19区的激活像素数目、HRF峰值信号变化率,进行配对t检验。结果镇静状态视觉区的激活像素显著小于清醒状态。在所检查的12名儿童中,有5名清醒儿童HRF信号变化率为负值。除2名没有进行镇静状态下试验的儿童外,镇静组和非镇静组原始视觉区的激活像素数目和HRF信号变化率未见显著性差异。结论低剂量(30mg/kg)的水合氯醛镇静对儿童原始视觉区fMRI的视觉刺激检查结果无显著影响。     

乙醇气味刺激食蟹猴的脑fMRI

目的 应用3.0T fMRI探讨食蟹猴经乙醇气味刺激引起的脑功能活动。方法 选取健康食蟹猴6只,麻醉后行乙醇气味刺激下的fMRI。采取"静息-刺激-静息"组块设计。刺激组块予乙醇气味刺激,静息组块无气味刺激。BOLD-fMRI扫描128 phase,整个猴脑扫描16层。采用SPM2软件随机效应模式t检验进行组分析。将统计结果覆盖于食蟹猴模板图像上。结果 乙醇气味刺激下,在额叶、颞叶、中央旁小叶、扣带回、豆状核、中央前回分别可以检测到正激活和负激活。结论 海马回钩和眶额回为嗅觉最高级中枢。fMRI可以显示额叶、颞叶的激活。气味刺激引起的中枢反应与中央旁小叶、扣带回、豆状核有密切关系。     

康复治疗在帕金森病治疗中的作用及进展

帕金森病治疗是神经科学研究的一大难题,康复治疗能起到一定的作用,最近有新的康复治疗的方法出现,本文对其进行综述.     

基于数学形态学的功能磁共振信号漂移校正方法

目的 探讨基于数学形态学的功能磁共振信号漂移校正新方法.方法 根据fMRI信号漂移成分的形态特征,采用基于数学形态学的方法校正fMRI信号的基线漂移.结果 应用模拟数据和真实数据测试表明,数学形态学方法能够有效地校正fMRI信号的基线漂移.结论 本研究提出的方法能够同时校正线性和非线性漂移,而不需要任何统计学模型假设.     

利用多层受约束一范数优化检测功能磁共振成像中神经活动

本研究提出利用fMRI中神经信号内在的稀疏性,通过积分器转换,最大期望算法优化对脑fMRI中血流动力学变化建立多层神经信号模型,将检测脑fMRI中神经活动转化为受约束的一范数优化问题.利用空间自适应滤波器,优化结果可以准确地检测出fMRI中神经活动.通过与目前主流检测方法时间聚类分析、最大相关性方法及图模型推理法对比,本文提出的方法能够以较小的计算复杂度得出精确的结果.     

神经科学与疼痛医学

20世纪的最后十年被美国国会确定为“脑的十年” ,由于大量资金和人力的投入 ,神经科学得到了长足的发展。 2 1世纪的头十年又被定为“疼痛研究”的十年。这充分反映出这两个学科在科学发展和社会需求中的重要性。那么这两者之间又有什么联系 ?疼痛属于感知的一种 ,疼痛机制的研究主要在神经科学的框架内进行。因此疼痛医学与神经科学的关系十分密切。神经科学百年发展人类在了解自身脑所走过的漫长道路中 ,诺贝尔生理学或医学奖获得者作出了巨大的贡献。回顾这一过程可以从中看出神经科学发展的轨迹。1.了解神经系统结构 ,为功能研究打下基…     

Robust controlled functional MRI in alert monkeys at high magnetic field: effects of jaw and body movements

The use of functional magnetic resonance imaging (fMRI) in alert non-human primates is of great potential for research in systems neuroscience. It can be combined with invasive techniques and afford better understanding of non-invasively acquired brain imaging signals in humans. However, the difficulties in optimal application of alert monkey fMRI are multi-faceted, especially at high magnetic fields where the effects of motion and of changes in B0 are greatly amplified. To overcome these difficulties, strict behavioral controls and elaborate animal-training are needed. Here, we introduce a number of hardware developments, quantify the effect of movements on fMRI data, and present procedures for animal training and scanning for well-controlled and artifact-reduced alert monkey fMRI at high magnetic field. In particular, we describe systems for monitoring jaw and body movements, and for accurately tracking eye movements. A link between body and jaw movement and MRI image artifacts is established, showing that relying on the immobilization of an animal's head is not sufficient for high-quality imaging. Quantitative analysis showed that body and jaw movement events caused large instabilities in fMRI time series. On average, body movement events caused larger instabilities than jaw movement events. Residual baseline brain image position and signal amplitude shifts were observed after the jaw and body movement events ended. Based on these findings, we introduce a novel behavioral paradigm that relies on training the monkeys to stay still during long trials. A corresponding analysis method discards all data that were not obtained during the movement-free periods. The baseline position and amplitude shifts are overcome by motion correction and trial-by-trial signal normalization. The advantages of the presented method over conventional scanning and analysis are demonstrated with data obtained at 7 T. It is anticipated that the techniques presented here will prove useful for alert monkey fMRI at any magnetic field.     

SPM与AFNI在功能磁共振成像数据处理中的应用与比较

功能磁共振成像(fMRI)在脑功能研究方面应用广泛.目前用于fMRI数据处理与分析的软件很多,以统计参数图(SPM)与功能神经影像分析(AFNI)软件应用最为广泛.本文就SPM和AFNI在fMRI中的应用及二者间的差异作一综述.     

功能MRI：最先进方法的简要回顾和展望

功能MRI(fMRI)起始于20世纪90年代初,它能够敏感地测量由脑激发而引起的血氧浓度变化。在经历了20年的高速发展后,fMRI在大脑研究领域中已经奠定了其不可替代的地位。随着科技的进步,包括硬件、脉冲序列、实验设计以及数据分析方法上的不断更新,fMRI在下一个10年应该会有更广泛的应用。在此文中,针对现状来探讨一下相关的先进技术,例如高清功能成像、脑连接成像、多模成像;并展望将来的发展方向,例如它们在临床医学甚至在社会科学方面的应用。     

How challenges in auditory fMRI led to general advancements for the field

In the early years of fMRI research, the auditory neuroscience community sought to expand its knowledge of the underlying physiology of hearing, while also seeking to come to grips with the inherent acoustic disadvantages of working in the fMRI environment. Early collaborative efforts between prominent auditory research laboratories and prominent fMRI centers led to development of a number of key technical advances that have subsequently been widely used to elucidate principles of auditory neurophysiology. Perhaps the key imaging advance was the simultaneous and parallel development of strategies to use pulse sequences in which the volume acquisitions were "clustered," providing gaps in which stimuli could be presented without direct masking. Such sequences have become widespread in fMRI studies using auditory stimuli and also in a range of translational research domains. This review presents the parallel stories of the people and the auditory neurophysiology research that led to these sequences.     

Functional MRI and the Study of OCD: From Symptom Provocation to Cognitive-Behavioral Probes of Cortico-Striatal Systems and the Amygdala

Functional magnetic resonance imaging (fMRI) first appeared in 1991. Since that time there has been a burgeoning use of the technology by psychiatric researchers and neuroscientists. Our group first used fMRI to study obsessive compulsive disorder (OCD) with a symptom provocation paradigm and then moved to the use of circuitry-specific cognitive-behavioral probes. The techniques we utilized for the symptom provocation study remain valid today, but have been supplemented by a wide array of new tools. Functional MRI continues to be a rapidly developing technology which could become the gold standard for neuroimaging research in psychiatry. With this in mind, this paper focuses on the past, present, and future applications of fMRI to one model illness, namely OCD. We examine the strengths and limitations of our initial OCD symptom provocation study and then evaluate the use of fMRI with cognitive-behavioral probes of cortico-striatal circuitry and limbic (amygdala) circuitry. We conclude with a brief summary of foreseeable developments which will influence the implementation of fMRI for psychiatric neuroscience in general.     

The story of the initial dip in fMRI

Over the past 20 years much attention has been given to characterizing the spatial accuracy of fMRI based signals and to techniques that improve on its co-localization with neuronal activity. While the vast majority of fMRI studies have always used the conventional positive BOLD signal, alternative contrast options have demonstrated superior spatial specificity. One of these options surfaced shortly after the initial BOLD fMRI demonstrations and was motivated by optical imaging studies which revealed an early signal change that was much smaller but spatially more specific than the delayed positive response. This early signal change was attributed to oxygenation changes prior to any subsequent blood flow increases. After observation of this biphasic hemodynamic response in fMRI, because this early response resulted in a small MR signal decrease prior to the onset of the large signal increase, it became known as the "initial dip". While the initial dip in fMRI was subsequently reported by many studies, including those in humans, monkeys, and cats, there were conflicting views about the associated mechanisms and whether it could be generalized across brain regions or species, in addition to whether or not it would prove fruitful for neuroscience. These discrepancies, along with the implications that the initial dip might increase the spatial specificity of BOLD fMRI from 2 to 3mm to something more closely associated with neural activity, resulted in lot of buzz and controversy in the community for many years. In this review, the authors provide an account of the story of the initial dip in MR based functional imaging from the Minnesota perspective, where the first demonstrations, characterizations, and applications of the initial dip commenced.     

功能磁共振成像在针灸机制研究中的应用

目前运用功能磁共振脑成像技术探究针灸机制已经成为一大研究热点,在一些方面取得了明显的进展,其中主要包括探讨穴位、经络与脑功能区的特定联系、针灸镇痛的磁共振脑功能研究、针灸方法和参数对激活脑功能区影响及针灸治疗药物成瘾,但是针灸效应的脑功能成像研究还不够深入,仍需不断的完善和发展.本文对磁功能脑成像技术在探究针灸机制方面的进展进行综述.     

The future of functional MRI in clinical medicine

In the last 20 years or so, functional MRI has matured very rapidly from being an experimental imaging method in the hands of a few labs to being a very widely available and widely used workhorse of cognitive neuroscience and clinical neuroscience research internationally. FMRI studies have had a considerable impact on our understanding of brain system phenotypes of neurological and psychiatric disorders; and some impact already on development of new therapeutics. However, the direct benefit of fMRI to individual patients with brain disorders has so far been minimal. Here I provide a personal perspective on what has already been achieved, and imagine how the further development of fMRI over the medium term might lead to even greater engagement with clinical medicine.     

功能磁共振在神经外科中的应用

功能磁共振(fMRI)是一种被广泛接受的成像手段,近年来已用于多种临床实践中,特别是在指导神经外科手术方面有了很大的进展.本文就fMRI基本原理和技术及其在有效性评估、指导神经外科手术和术后患者随访方面的作用予以综述.     

Quantitative functional MRI: concepts, issues and future challenges

Since its inception 20 years ago, functional magnetic resonance imaging (fMRI) of the human brain based on the blood oxygenation level dependent (BOLD) contrast phenomenon has proliferated and matured. Today it is the predominant functional brain imaging modality with the majority of applications being in basic cognitive neuroscience where it has primarily been used as a tool to localize brain activity. While the magnitude of the BOLD response is often used in these studies as a surrogate for the level of neuronal activity, the link between the two is, in fact, quite indirect. The BOLD response is dependent upon hemodynamic (blood flow and volume) and metabolic (oxygen consumption) responses as well as acquisition details. Furthermore, the relationship between neuronal activity and the hemodynamic response, termed neurovascular coupling, is itself complex and incompletely understood. Quantitative fMRI techniques have therefore been developed to measure the hemodynamic and metabolic responses to modulations in brain activity. These methods have not only helped clarify the behaviour and origins of the BOLD signal under normal physiological conditions but they have also provided a potentially valuable set of tools for exploring pathophysiological conditions. Such quantitative methods will be critical to realize the potential of fMRI in a clinical context, where simple BOLD measurements cannot be uniquely interpreted, and to enhance the power of fMRI in basic neuroscience research. In this article, recent advances in human quantitative fMRI methods are reviewed, outstanding issues discussed and future challenges and opportunities highlighted.