前庭功能的静息态脑功能磁共振成像

目的探讨基于局部一致性(ReHo)、低频振幅(ALFF)和低频振幅分数(fALFF)的静息态脑fMRI技术对于前庭冰水刺激诱导后脑内前庭功能相关区域的BOLD信号变化。方法纳入20名正常志愿者,在10s内将15ml 0℃冰水注入受试者右侧外耳道,采用平面回波序列和32通道头线圈采集受试者的BOLD静息态脑功能成像数据,采用MatLab 7.1和SPM 8进行数据预处理,预处理后的数据采用REST 1.4软件计算获得ReHo、ALFF和fALFF图像。结果ReHo、ALFF和fALFF图像均出现多个脑区激活增加或减低,其中3个参数值增加即激活脑区主要包括岛叶皮层、颞上回、顶下小叶、脑干、海马旁回、小脑半球等,减低即负激活脑区主要包括额上回、额中回、额下回、颞中回、枕下回、楔前叶等。结论人类存在广泛的涉及前庭信息处理的脑皮层及皮层下网络区域,静息态脑功能成像ReHo、ALFF、fALFF分析方法具有较好的一致性,具备定位前庭功能区的潜在能力。     

MR磁化传递对比成像观察新生儿轻度窒息

目的观察MR磁化传递对比(MTC)成像在轻度窒息新生儿中的应用价值。方法对15例轻度窒息新生儿(Apgar评分10分,病例组)及25名正常新生儿(对照组)采集脑常规T1WI、3D-T1WI和T1WI-MTC,计算脑磁化率(MTR),配准于标准新生儿脑模板后行统计分析。采用3dRegAna对病例组MTR与Apgar评分进行回归分析。结果相比对照组,病例组右颞极、左颞下回、左额上回、右缘上回、右眶额皮质、左额中叶、右额中回及左上额叶MTR显著降低;右梭状回、右顶叶下回、右枕中回、右颞中回、右颞下回、右颞上极、右楔叶、右角回、右舌回及右颞上回MTR显著增加。回归分析显示,病例组左中央后回、右颞下叶(前)、右额中回、右颞上极、左眶额皮质及右颞下叶(后)MTR与Apgar评分呈正相关,右壳核、右眶额皮质、左杏仁核、右颞下回、左舌回、右舌回、左颞中回、左枕中回、延髓及右梭状回呈负相关。组间MTR差异有统计学意义、且病例组MTR与Apgar评分呈正相关脑区为右额中叶、右颞极,呈负相关脑区则为右舌叶及右梭状回。结论 MR MTC成像能检出轻度窒息新生儿缺血缺氧脑区;缺血缺氧主要导致新生儿右侧脑损害。     

基于分数低频振幅观察长时程电刺激诱发健康人肢体麻木后脑功能变化

目的 利用静息态功能MRI(rs-fMRI)分数低频振幅（fALFF）观察长时程电刺激（LTES）诱发健康人肢体麻木感后不同脑区功能变化。方法 前瞻性对27名健康人以LTES诱发单侧肢体麻木感,每日1次、每次30 min,持续1周;分别于开始刺激前日及末次刺激次日采集脑rs-fMRI,并于予5 min短时程电刺激后要求受试者采用视觉模拟评分法（VAS）对麻木感进行评分。比较LTES前、后各脑区fALFF,针对存在显著差异脑区分析其fALFF值变化及其差值与VAS评分差值的相关性。结果LTES后双侧顶上小叶、右侧颞中回、左侧海马旁回及右侧缘上回fALFF值降低,而双侧伏隔核、右侧中央后回、左侧小脑及右侧壳核fALFF值升高（P均<0.05）。LTES前、后左侧顶上小叶fALFF差值与VAS评分差值呈负相关（r=-0.422,P=0.029）。结论 LTES所诱发的肢体麻木感涉及感觉运动皮层及情绪等相关脑区,尤以左侧顶上小叶最为重要。     

健康成人膀胱储尿功能的大脑静息态功能网络连接研究

目的:研究采用静息态功能磁共振(rs-fMRI)成像技术分析健康成人膀胱储尿功能的大脑功能网络连接。方法:2014年10月~2016年10月筛选健康受试者44例,其中男19例,女25例,年龄22~50岁,均为右利手。分别在膀胱空虚状态和膀胱充盈状态进行2次rs-fMRI扫描。扫描后通过rs-fMRI分析软件Matlab、SPM8、DPABI等进行处理分析。选取左侧前额叶(X=-39,Y=45,Z=-12);右侧前额叶(X=3,Y=49,Z=40);左侧前扣带回(X=-7,Y=-30,Z=-6);右侧前扣带回(X=9,Y=42,Z=-6);左侧颞叶(X=-33,Y=-51,Z=6);左侧颞上回(X=-57,Y=-18,Z=9)6个种子点,进行全脑功能连接。结果:6个种子的全脑功能连接区域:左侧前额叶,激活区域为双侧岛叶,右侧额下回;抑制区域为左侧海马旁回,左侧枕叶,左侧前额叶。右侧前额叶,抑制区域为左侧岛叶。左侧颞叶,抑制区域为右侧眶额叶。左侧颞上回,激活区域为左侧前额叶,右侧距状回;抑制区域为右侧小脑。左侧颞叶,激活区域为海马旁回;抑制区域为右侧额下回,右侧旁中央小叶。左侧颞上回,激活区域为左侧前额叶,左侧额中回,左侧中央颞叶;抑制区域为右侧岛叶,左侧小脑,左侧颞上回。结论:通过功能连接(functional connectivity,FC)分析发现大脑控尿区域不是某一区域单独完成的,而是广泛的、存在着功能相关性的多个区域共同协调完成的。     

脊髓型多发性硬化患者默认网络及突显网络的功能连接

目的采用独立成分分析(ICA)方法分析脊髓型多发性硬化(SMS)患者脑静息态默认网络(DMN)及突显网络(SN)功能连接(FC)的异常。方法对我院22例SMS患者(SMS组)及22名健康对照者(正常对照组)行静息态fMRI,对所得数据进行ICA分析,并利用SPM8比较两组脑网络FC的差异,同时分析差异脑区的时间序列信号(FC分数)与临床扩展残疾状态量表(EDSS)评分及病程的相关性。结果与正常对照组相比,SMS组DMN的FC减弱的脑区包括双侧内侧额上回、边缘叶及双侧楔叶,FC增强的脑区包括双侧前扣带回、右侧距状皮层;SMS组SN的FC减弱的脑区为双侧内侧扣带回,FC增强的脑区延伸到双侧中央前回、左侧中央后回。两组FC分数与EDSS评分及病程均无相关性(P均0.05)。结论 SMS患者静息态DMN、SN均存在FC异常,可能与继发于脊髓病变的逆行性神经元变性或功能网络重构有关。     

心律失常射频消融术后焦虑状态患者的静息态MRI低频振幅分析

目的采用低频振幅(ALFF)观察心律失常射频消融术后出现焦虑状态患者的全脑功能活动。方法收集符合纳入标准的26例心律失常射频消融术(RFCA)后焦虑状态患者作为RFCA组,纳入同期年龄、性别相匹配的26名健康志愿者作为正常对照组,2组均行fMRI,对2组有差异脑区的ALFF进行双样本t检验,提取有差异的脑区与汉密尔顿焦虑量表评分进行偏相关分析。结果与正常对照组相比,RFCA组左侧颞中回、右侧壳核、左侧杏仁核ALFF增高,左侧前额叶背外侧皮层(DLPFC)、右侧楔前叶、左侧额中叶、右侧枕中叶ALFF减低差异有统计学意义(Alphasim校正,P0.01)。左侧DLPFC的ALFF值与HAMA评分呈负相关(r=-0.872,P=0.013)。结论心律失常射频消融术后焦虑状态患者在静息状态下存在脑功能的异常,ALFF有助于为该疾病的发病机制提供更多证据。     

利用静息态功能磁共振探究颈动脉狭窄患者的认知障碍研究

目的采用静息态功能磁共振成像探讨无症状严重颈动脉狭窄患者产生认知障碍的机制。方法对2016年1月至2018年06月南京大学医学院附属鼓楼医院血管外科收治的21例无症状严重颈动脉狭窄患者和招募的21名健康人为对照组行认知量表评估和静息态磁共振检查,前瞻性分析两组人群的认知水平与影像数据的差异。结果患者组简易精神状态量表(MMSE)和蒙特利尔认知评估量表(MoCA)评分明显低于对照组,差异具有统计学意义(P0.001)。与对照组相比,患者组在右脑内侧额上回处低频振幅(ALFF)水平增加,在舌回处ALFF减少;在左侧额下回低频振幅比率较对照组增加;在颞上回局部一致性(ReHo)值较对照组增加,在右侧枕下回ReHo减少。患者组在右背外侧额上回与后扣带皮层的相关性显著低于对照组。影像学差异和认知评分之间没有显着相关性(P0.05)。结论无症状严重颈动脉狭窄存在不同程度的认知障碍,右内侧额上回、左侧额下回、颞上回、右背外侧额上回在与颈动脉狭窄相关的认知障碍的发生中可能起着重要的作用。     

三叉神经痛患者半月节射频热凝术前后静息态fMRI的变化

目的 利用功能MR研究三叉神经痛患者半月节射频热凝术(PRT)前后脑功能局部一致性(ReHo)变化。方法 对31例接受PRT手术的三叉神经痛患者在术前1周及术后6个月分别进行MR扫描,采集其大脑结构及静息态功能图像;同时记录患者的疼痛视觉模拟量表(VAS)评分、面部麻木程度及患病时间。比较患者手术前后全脑ReHo值出现显著变化的脑区,再将这些脑区的平均ReHo值与临床观察指标进行相关分析。结果 与术前相比,患者术后右侧梭状回(FG)和双侧前扣带回(ACC)的ReHo值显著增高(P均0.05),而左侧顶下小叶(IPL)、右侧距状回、右侧颞中回(MTG)、左侧中央后回(PoCG)以及左侧岛叶的ReHo值显著降低(P均0.05)。左侧PoCG的ReHo值与手术前后VAS评分呈正相关,术前右侧MTG的ReHo值与手术前后VAS的变化值呈负相关。结论 PRT术后多个脑区的Re-Ho出现显著变化,这些区域与痛觉感知、情感表达及情绪体验密切相关,其中左侧PoCG具有作为靶点判断疼痛部位及评估疼痛强度的潜在价值。     

丙泊酚梯度镇静下功能核磁共振全脑功能的次序变化

目的不同剂量的丙泊酚在大脑中的作用部位是不同的,本研究拟动态地观察丙泊酚在脑内的作用途径,进一步探索其镇静机制。方法招募健康志愿者12例,男6例,女6例,年龄18～40岁,BMI 20～25 kg/m~2,ASAⅠ级。在未输注丙泊酚状态下进行一次静息态功能核磁共振(RS-fMRI)扫描,然后设定丙泊酚初始效应室浓度(Ce)为0.5μg/ml,稳定5 min后完成一次RS-fMRI扫描。逐渐以0.5μg/ml的增幅递增,每个Ce下均完成一次RS-fMRI扫描,直到Ramsay评分达到6分。在全脑范围内进行局部一致性(ReHo)的对比分析。结果与清醒时比较,Ce 0.5μg/ml时小脑后叶、舌回、枕叶、颞叶等脑区ReHo值明显增加(P0.05),前扣带回、中央前回、额叶等ReHo值明显降低(P0.05)。与Ce 0.5μg/ml时比较,Ce 1.0μg/ml时额叶等脑区ReHo值明显增加(P0.05),小脑后叶、海马旁回等ReHo值明显降低(P0.05)。与Ce 1.0μg/ml时比较,Ce 1.5μg/ml时楔前叶、前扣带回、枕叶等脑区ReHo值明显增加(P0.05),小脑前叶、梭状回、顶叶等ReHo值明显降低(P0.05)。与Ce 1.5μg/ml时比较,Ce 2.0μg/ml时小脑前叶、小脑后叶、颞叶等脑区ReHo值明显增加(P0.05),楔前叶、额叶、顶叶等ReHo值明显降低(P0.05)。结论丙泊酚的作用部位广泛,包含皮层和皮层下中枢,表现为效应脑区分布和局部脑活动强度的动态变化。小脑、扣带回和楔前叶在丙泊酚镇静加深的过程中起关键作用。     

短暂性脑缺血脑默认状态网络的功能磁共振研究

目的利用fMRI研究TIA患者脑默认状态网络的变化。方法分别采集16例TIA发作间期患者和16名止常对照组静息态fMRI扫描,以扣带回／楔前叶及腹侧扣带前回／内侧前额叶作为种子点,分析与种子点连通的脑区,研究两组间默认状态网络的变化。结果TIA组与正常组具有相似脑默认状态网络,TIA组与正常组比较,ROI功能连接减弱的脑区域包括：扣带前回、楔前叶、前额叶及海马等脑区,功能连接增强的区域主要存在小脑及丘脯。结论TIA患者脑默认状态网络存在异常,扣带回、楔前叶及海马等脑区连通性的减弱反应TIA患者脑DMN失衡,丘脑和小脑的连通性增姒,可能是脑TIA局部脑区功能减弱的补偿及保护性反应。     

青少年肌阵挛性癫痫患者镜像同伦功能连接的初步研究

目的采用镜像同伦连接(VMHC)技术观察青少年肌阵挛性癫痫(JME)患者静息态功能连接的异常改变,以及连接强度与认知间的相关性。方法收集JME患者21例(JME组)及与之匹配的健康志愿者21名(对照组)进行静息态BOLD MR检查。图像数据采用DPABI中DPASFA软件进行预处理,之后采用REST软件进行VMHC分析,提取两组间有差异脑区,并将其与蒙特利尔认知评估量表(MoCa)评分进行相关性分析。结果与对照组比较,JME组的双侧尾状核、丘脑、额中回、额下回及枕中回VMHC值增加(Alphasim校正,P0.01);JME组的双侧尾状核VMHC值与MoCa评分呈正相关(r=0.43,P=0.015)。结论 JME患者静息态下基底核—丘脑—皮层环路中多个脑区间功能连接异常,且双侧尾状核异常可能与认知障碍有关。     

首发抑郁症伴自杀意念患者中缝核功能连接的改变

目的 观察首发抑郁症伴自杀意念（SI）患者中缝核功能连接（FC）改变。方法 前瞻性纳入98例首发抑郁症患者,根据伴SI与否将其分为伴SI组（n=56）与不伴SI组（n=42）;另以47名健康志愿者为对照组。以静息态功能MRI观察背侧中缝核（DRN）、中缝中央核（MRN）与全脑间的FC;比较3组及两两组间FC,分析伴SI组差异脑区FC与临床资料的相关性。结果 相比对照组,伴与不伴SI组DRN与左侧小脑及左侧壳核的FC均降低（P均<0.05）,MRN与右侧颞下回的FC均升高而与左侧额下回、右侧枕上回、左侧顶下小叶及左侧壳核的FC均降低（P均<0.05）;其中,伴SI组DRN与左侧壳核的FC高于不伴SI组（P<0.05）;相比不伴SI组及对照组,伴SI组MRN与右侧中央后回的FC升高（P均<0.05）。伴SI组MRN与左侧壳核的FC与24项汉密尔顿抑郁量表（HAMD-24）体质量得分呈正相关（r_s=0.297,P=0.026）。结论 首发抑郁症伴SI患者中缝核与皮层和皮层下区的FC存在异常改变,且其MRN与左侧壳核的FC与HAMD-24体质量得分呈正相关。     

Brain activity during stimulation of the trigeminal nerve with noxious heat.

OBJECTIVE: The aim of this study was to observe areas of brain activation with painful hot stimulation to the trigeminal nerve. STUDY DESIGN: Nine healthy pain-free women (mean age 26.2 +/- 6.9 yrs) with a natural, regular menstrual cycle participated in the study. Whole-brain functional magnetic resonance imaging (fMRI) data were acquired for each participant on day 2 or 3 after the onset of menses using echo-planar imaging at 1.5T with near-isotropic spatial resolution and a temporal resolution of 4 s. RESULTS: Whole-brain fMRI with a Peltier thermode inside the head coil yielded a feasible imaging protocol with little disturbance from the thermode. Painful thermal stimulation of the left trigeminal system activated discrete brain regions within the insula, cingulate gyrus, thalamus, inferior parietal lobe/postcentral gyrus, right middle and inferior frontal gyri, cuneus, precuneus, and precentral gyrus. CONCLUSION: Painful stimulation of the trigeminal nerve resulted in activation of similar brain areas generally known for pain processing of painful peripheral stimulation.     

Positive evidence against human hippocampal involvement in working memory maintenance of familiar stimuli

Subjects (n = 40) performed a delayed item recognition task for visually presented letters with three set sizes (1, 3 or 6 letters). Accuracy was close to ceiling at all set sizes, so we took set size as a proxy for WM load (i.e. the amount of information being maintained in WM). Functional magnetic resonance imaging (fMRI) signal associated with the delay period increased in a nearly linear fashion with WM load in the left inferior frontal gyrus/anterior insula (possibly Broca's area, BA 44/45), right anterior insula, bilateral caudate, bilateral precentral gyrus (BA 6), bilateral middle frontal gyrus (BA 9/46), bilateral inferior parietal lobule (with foci in both BA 39 and 40), left superior parietal lobule (BA 7), medial frontal gyrus (BA 6), anterior cingulate gyrus (BA 32) and bilateral superior frontal gyrus (BA 8). These results lend support to the idea that at least some of the cortical mechanisms of WM maintenance, potentially rehearsal, exhibit a scaling with WM load. In contrast, the delay-related fMRI signal in hippocampus followed an inverted U-shape, being greatest during the intermediate level of WM load, with relatively lower values at the lowest and highest levels of WM load. This pattern of delay-related fMRI activity, orthogonal to WM load, is seemingly not consonant with a role for hippocampus in WM maintenance of phonologically codable stimuli. This finding could possibly be related more to the general familiarity of the letter stimuli than their phonological codability per se.     

Spontaneous brain activity changes in children with primary monosymptomatic nocturnal enuresis: a resting-state fMRI study

Primary monosymptomatic nocturnal enuresis (PMNE) is a common disorder in school-aged children. However, little is known about resting-state neural function in individuals with PMNE. In this work, resting-state functional magnetic resonance imaging (fMRI) was used to investigate changes in spontaneous brain activity in children with PMNE. We analyzed resting-state fMRI data using statistical parametric mapping (SPM) and a resting-state fMRI data analysis toolkit (REST). Regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) values were calculated to analyze spontaneous brain activity in 16 children with PMNE and 16 healthy controls. Children with PMNE exhibited significant differences in ALFF or ReHo in the left inferior frontal gyrus, medial frontal gyrus (Brodmann area, BA 10), and left midbrain. Abnormalities in BA 10 and the inferior frontal gyrus may affect children's decision-making with regard to voiding; abnormalities in the midbrain in PMNE children may influence the internal signal transmission in their bladder control network. Our data indicate that, in children with PMNE, several brain areas related to the micturate control network undergo developmental delay.     

Cerebral blood flow relationships associated with a difficult tone recognition task in trained normal volunteers

Tone recognition is partially subserved by neural activity in the right frontal and primary auditory cortices. First we determined the brain areas associated with tone perception and recognition. This study then examined how regional cerebral blood flow (rCBF) in these and other brain regions correlates with the behavioral characteristics of a difficult tone recognition task. rCBF changes were assessed using H2(15)O positron emission tomography. Subtraction procedures were used to localize significant change regions and correlational analyses were applied to determine how response times (RT) predicted rCBF patterns. Twelve trained normal volunteers were studied in three conditions: REST, sensory motor control (SMC) and decision (DEC). The SMC-REST contrast revealed bilateral activation of primary auditory cortices, cerebellum and bilateral inferior frontal gyri. DEC-SMC produced significant clusters in the right middle and inferior frontal gyri, insula and claustrum; the anterior cingulate gyrus and supplementary motor area; the left insula/claustrum; and the left cerebellum. Correlational analyses, RT versus rCBF from DEC scans, showed a positive correlation in right inferior and middle frontal cortex; rCBF in bilateral auditory cortices and cerebellum exhibited significant negative correlations with RT These changes suggest that neural activity in the right frontal, superior temporal and cerebellar regions shifts back and forth in magnitude depending on whether tone recognition RT is relatively fast or slow, during a difficult, accurate assessment.      

Blood-oxygenation-level-dependent functional magnetic resonance imaging for evaluating cerebral regions of female sexual arousal response

Objectives. To evaluate, for the first time, the cerebral regions associated with female sexual arousal evoked by visual stimulation using noninvasive blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI).Methods. A total of 6 healthy right-handed female volunteers (mean age 33 years, range 25 to 41) underwent fMRI on a 1.5-T MR scanner, in which the BOLD technique was used to create fMR images reflecting local brain activities. Real-time visual stimulation was performed with alternatively combined erotic and nonerotic films to identify the activated brain regions associated with sexual response. The perceived sexual arousal response was assessed using a scale ranging from 1 (no change) to 5 (maximal increase).Results. The mean score for perceived sexual arousal by erotic visual stimulation was 2.7 on the 5-point scale and was unchanged by nonerotic stimulation. During the visual task, the occipital cortex was activated by both the erotic and the nonerotic films; however, the following cerebral areas were significantly (P <0.05) activated, varying from 4 of 6 to 6 of 6 women: inferior frontal lobe, cingulate gyrus, insula gyrus, corpus callosum, thalamus, caudate nucleus, globus pallidus, and inferior temporal lobe.Conclusions. This study is the first to evaluate noninvasive BOLD-fMRI in identifying cerebral regions associated with sexual arousal response evoked by visual stimulation in women.