针刺大鼠后三里穴脑fMRI成像的初步研究

目的：探讨针刺大鼠的功能性磁共振(fMRI)成像的动物实验方法。方法：利用4．7T磁共振对9例雄性SD大鼠行针刺右侧后三里穴及穴旁的fMRI成像，采用统计参数图(SPM)软件进行统计学处理。结果：针刺大鼠右侧后三里穴可以引起下丘脑外侧区、下丘脑前区、下丘脑腹内侧等脑区MRI信号增加(P=0．001)；两组第Ⅰ、第Ⅱ感觉运动皮质和尾壳核的MRI信号均增加，穴位组在P=0．001水平检出，穴旁组则在P=0．01或者P=0．05水平检出。结论：针刺大鼠后三里穴可引起下丘脑外侧区、下丘脑前区、下丘脑腹内侧区和丘脑室旁核等脑区MRI信号增加。fMRI是在活体动物实验中研究针刺中枢机制的可行方法之一。     

Regional variability of cerebral blood oxygenation response to hypercapnia

In functional magnetic resonance imaging studies changes in blood oxygenation level-dependent (BOLD) signal intensities during task activation are related to multiple physiological parameters such as cerebral blood flow, volume, and oxidative metabolism, as well as to the regional microvascular anatomy. Consequently, the magnitude of activation-induced BOLD signal changes may vary regionally and between subjects. The aim of this study was to use a uniform global stimulus such as hypercapnia to quantitatively investigate the regional BOLD response in the human brain. In 10 healthy volunteers, T2*-weighted gradient echo images were acquired for a total dynamic scanning time of 9 min during alternating periods of breath holding for 30 s after expiration and self-paced normal breathing for 60 s. Hypercapnia-induced BOLD signal changes in the sensorimotor cortex, frontal cortex, basal ganglia, visual cortex, and cerebellum were significantly different (P < 0.001) and varied from 1.8 to 5.1%. The highest BOLD signal changes were found in the cerebellum and visual cortex, whereas the lowest BOLD signal increase was observed in the frontal cortex. These results demonstrate a regional dependence of the BOLD signal changes during breath hold-induced hypercapnia, indirectly supporting the notion of regional different sensitivities of BOLD responses to task activation.     

鞍旁常见占位性病变的MRI诊断

目的：探讨鞍旁常见占位性病变的MRI特点与诊断价值。资料与方法：回顾分析28例鞍旁常见占位性病变的MRI特点，其中海绵状血管瘤7例，脑膜瘤12例，神经鞘瘤5例，表皮样囊肿4例。结果：海绵状血管瘤呈长T1长T2信号；增强扫描非常显著均匀强化。脑膜瘤多呈等T1等T2信号，部分病灶T2WI周边呈等信号，内见片状低信号；增强扫描均明显均匀强化，可出现“脑膜尾征”。神经鞘瘤呈稍长T1长T2信号, 呈哑铃形跨中后颅凹，多发生囊变；增强扫描明显环形强化。表皮样囊肿平扫信号表现多样性，增强后不强化。结论：鞍旁常见占位性病变有其典型的MRI特点，MRI很大程度可做出正确的定性诊断。     

不同年龄健康成人大脑皮层厚度差异

目的 观察不同年龄健康成人大脑皮层厚度的差异。方法 对134名健康成人，包括青年组（18~44岁）54名、中年组（45~59岁）40名及老年组（≥60岁）40名采集脑结构MR T1WI。采用FreeSurfer 6.0软件对图像进行基于表面的形态测量学分析，观察左、右侧大脑皮层厚度与年龄的相关性；比较3组间左、右侧大脑皮层厚度的差异，并对组间皮层厚度存在差异的脑区进行图形可视化。结果 左、右侧大脑皮层厚度均随年龄增长而下降（r=－0.57、－0.52，P均<0.01）。3组间左、右侧大脑皮层厚度总体差异有统计学意义（F=70.20，P<0.01），两两比较差异均有统计学意义（P均<0.01）。中年组20个脑区团簇皮层厚度较青年组变薄，老年组7个脑区团簇皮层厚度较中年组变薄，老年组29个脑区团簇皮层厚度较青年组变薄。结论 健康成人大脑皮层厚度随年龄增长而变薄。     

Functional connectivity of the visual cortex differentiates anxiety comorbidity from episodic migraineurs without aura

BackgroundMigraine is a common neurological disease that is often accompanied by psychiatric comorbidities. However, the relationship between abnormal brain function and psychiatric comorbidities in migraine patients remains largely unclear. Therefore, the present study sought to explore the correlations between the resting-state functional deficits and psychiatric comorbidities in migraine without aura (MwoA) patients.MethodsResting-state functional magnetic resonance images were obtained. In addition, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) values were obtained. Thereafter regional abnormalities in MwoA patients with and without anxiety (MwoA-A and MwoA-OA) were chosen as seeds to conduct functional connectivity (FC) analysis.ResultsCompared to the healthy controls (HCs), the MwoA-A and MwoA-OA patients had abnormal ALFF and ReHo values in the right lingual gyrus (LG). They also had abnormal FC of the right LG with the ipsilateral superior frontal gyrus (SFG) and middle cingulate cortex (MCC). Additionally, the MwoA-A patients showed higher ReHo values in the left posterior intraparietal sulcus (pIPS) and abnormal FC of the right LG with ipsilateral pIPS and primary visual cortex, compared to the MwoA-OA patients. Moreover, the MwoA-OA patients showed an increase in the FC with the right posterior cingulate cortex/precuneus (PCC/PCUN), left middle frontal gyrus (MFG) and left inferior temporal gyrus (ITG) relative to the HCs. Furthermore, the ALFF values of the right LG positively were correlated with anxiety scores in MwoA-A patients. The abnormal LG-related FCs with the PCC/PCUN, MFG and ITG were negatively associated with the frequency of headaches in MwoA-OA patients.ConclusionsThis study identified abnormal visual FC along with other core networks differentiating anxiety comorbidity from MwoA. This may therefore enhance the understanding of the neuropsychological basis of psychiatric comorbidities and provide novel insights that may help in the discovery of new marks or even treatment targets.     

A polymorphism in the serotonin transporter gene regulatory region and frequency of migraine attacks

BACKGROUND: The serotonergic system has been thought to play an important part in the pathophysiology of migraine. OBJECTIVE: To study an association between the polymorphism of serotonin (5-hydroxytryptamine [5-HT]) transporter gene-linked polymorphic region (5-HTTLPR) and migraine. Method.-We compared 151 patients with migraine with 190 healthy unrelated control subjects. The 5-HTTLPR polymorphism was detected using polymerase chain reaction. Migraine patients were interviewed regarding attack frequency in the last 6 months. RESULTS: We denoted the products of the 484-base pair (bp) fragments as the short (s) and those of 528 bp as the long (l) allele according to the previously reported manner. Migraine patients with s/s genotype were compared with those with l/s and l/l genotype. We did not find significant differences in the genotype and allele frequencies of 5-HTTLPR between patients with migraine and control subjects. Among patients with migraine, those with s/s type had significantly more frequent attacks than those with the l/s or l/l type. CONCLUSIONS: This polymorphism does not appear to be involved in a genetic predisposition to the disease but may affect the frequency of attacks in patients with migraine. These findings may contribute to our understanding of factors that influence the clinical severity of migraine.     

Functional anatomy of visual search: regional segregations within the frontal eye fields and effective connectivity of the superior colliculus

The ability to find targets embedded within complex visual environments requires the dynamic programming of visuomotor search behaviors. Functional magnetic resonance imaging was used to image subjects while they visually searched for targets embedded among foils. Visuomotor search activated the posterior parietal cortex and the frontal eye fields. Both regions showed a greater number of activated voxels on the right, consistent with the known pattern of right hemispheric dominance for spatial attention. The superior colliculus showed prominent activation in the search versus eye movement contrast, demonstrating, for the first time in humans, activation of this region specifically related to an exploratory attentional contingency. An analysis of effective connectivity demonstrated that the search-dependent variance in the activity of the superior colliculus was significantly influenced by the activity in a network of cortical regions including the right frontal eye fields and bilateral parietal and occipital cortices. These experiments also revealed the presence of a mosaic of activated sites within the frontal eye field region wherein saccadic eye movements, covert shifts of attention, and visuomotor search elicited overlapping but not identical zones of activation. In contrast to the existing literature on functional imaging, which has focused on covert shifts of spatial attention, this study helps to characterize the functional anatomy of overt spatial exploration.     

不同测量者和不同大小兴趣区正常脑组织ADC值测量的差异

目的:观察不同测量者用不同大小的兴趣区测量正常人脑组织不同解剖部位的平均表观弥散系数(ADC)值是否存在差异。方法:60例MR检查正常的健康自愿者行弥散加权成像。两个测量者分别用两个兴趣区[(15±3)mm2和(35±4)mm2]在ADC图上测量脑内不同解剖部位(半卵圆中心、额叶白质、尾状核头、壳核、丘脑、胼胝体膝、胼胝体压部、内囊后肢、桥脑及侧脑室体部)的ADC值。结果:脑实质的平均ADC值范围为(0.668±0.06)×10-3~(0.803±0.02)×10-3mm2/s,侧脑室体部的平均ADC值为(2.968±0.05)×10-3mm2/s。不同测量者之间在半卵圆中心、额叶白质、胼胝体膝、内囊后肢、桥脑测得的ADC值有显著性差异,对胼胝体膝、内囊后肢、桥脑不同兴趣区的ADC值测量有显著性差异。结论:由于不同测量者和不同兴趣区对脑内一些结构的ADC值测量的差异性,对脑内某些区域用ADC值评价病理改变并不可靠。     

脑型肝豆状核变性脑皮层及皮层下核团体积的磁共振研究

目的探索脑型肝豆状核变性患者脑灰质的损害。材料与方法采集30例初发且未经治疗的脑型肝豆状核变性患者脑3D T1WI图像,利用FSL软件,运用基于体素的形态学测量(voxel_based morphometry,VBM)对脑皮层及深部核团的体积进行分析。30名健康志愿者作为对照组,采用单因素方差分析对双侧脑叶灰质及深部核团统计分析。结果脑型肝豆状核变性患者与对照组相比,各脑区皮质萎缩率及两侧脑叶比较如下,小脑:左侧(16.48%)<右侧(16.54%),P>0.05;额叶:左侧(23.6%)>右侧(19.5%),P<0.001;颞叶:左侧(16.9%)<右侧(25.4%),P<0.001;顶叶:左侧(15.5%)<右侧(16.1%),P<0.05;枕叶:左侧(21.0%)<右侧(27.2%),P<0.001;岛叶:左侧(58.7%)>右侧(49.2%),P<0.001。脑干和深部核团(杏仁核除外)体积均显著萎缩,萎缩率依次为伏隔核>壳核>苍白球>丘脑>尾状核>脑干,但左、右两侧各核团萎缩率无显著性差异。结论脑型肝豆状核变性可引起脑皮层广泛而非对称性损害及深部核团对称性损害。     

局灶性脑损害患者视觉注意环路的小世界网络属性分析

摘要 目的：探讨局灶性脑损害患者视觉注意网络的连通性及其小世界特征。 方法：对2例局灶性后顶叶损害、2例背外侧前额叶损害、2例颞叶损害（其中1例为手术前后）和1例锥体束损害患者进行静息态fMRI检测,然后进行功能网络建立和小世界属性分析。 结果：所有局灶性脑损害患者的脑功能网络在给定阈值范围（0.05—0.5）内都具有小世界属性。局灶性后顶叶、背外侧前额叶、颞叶和锥体束损害患者之间,Gamma系数差异（P<0.05）和Sigma系数差异（P<0.01）均具有显著性意义。 结论：小世界网络分析为视觉注意网络的连通性研究提供了一个非常有价值的方法。我们推测,小世界网络检测方法应该可以作为局灶性脑损害神经功能损害的影像学生物标记。     

急性和亚急性脑挫伤后脑血容量变化的脑灌注MR研究

目的:评价灌注加权成像(PWI)对急性及亚急性脑挫伤的价值,确定PWI能否检出脑挫伤病人的局部脑血容量(rCBV)下降。材料和方法:对30例急性和亚急性脑挫伤病人和10例健康自愿者行常规MRI和PWI检查,计算病人脑挫伤和脑挫伤周围区与对侧正常表现白质(NAWM)的rCBV比值、双侧NAWM的rCBV比值以及正常对照组双侧额顶区rCBV的比值。伤后6个月应用格拉斯哥预后评级(GOS)对病人进行评分。结果:所有病例的脑挫伤区rCBV都有下降(0.42±0.02,P<0.001);急性期脑挫伤周围区与对侧NAWM的rCBV比值升高(2.12±0.07,P<0.001);10例双侧NAWM的rCBV比值在正常对照组范围之外病人的临床预后较差。结论:PWI是评价急性和亚急性脑挫伤rCBV变化的有效手段;双侧NAWM的rCBV比值异常可能预示着临床预后较差。     

静脉栓塞继发脑梗死的MRI影像诊断

目的:研究静脉栓塞继发脑梗死的MRI影像诊断及其临床应用价值。方法:对14例经脑血管造影及临床治疗有效证实的静脉栓塞继发脑梗死的MRI影像进行了回顾性分析。男6例,女8例,年龄21~65岁,平均43岁。全部行头颅MRI平扫检查,其中10例行磁共振静脉血管造影(MRV)检查,5例行Gd-DTPA增强扫描。结果:14例中脑梗死发生于额叶6例,顶叶4例,颞叶3例,岛叶1例,小脑1例,发生于基底节、丘脑累及中脑、胼胝体1例。脑梗死发生于双侧脑内的8例,单侧6例。静脉栓塞部位14例中10例为上矢状窦(其中6例同时合并横窦或乙状窦或直窦栓塞),1例直窦及左横窦,1例左侧横窦及乙状窦,2例皮层大脑浅静脉,其中梗死内伴出血10例。5例静脉注射Gd-DTPA后增强扫描,3例无强化,2例病灶内出现不规则类环形强化,其中有大脑镰、小脑幕脑膜增厚强化的2例。10例MRV均显示栓塞的静脉血流信号丢失或缺损,以及周围异常静脉侧支和其他引流静脉异常扩张。结论:静脉栓塞继发脑梗死的MRI影像表现具有一定的特征性,对静脉栓塞的诊断和治疗非常重要,其继发的脑梗死又是评估静脉栓塞的脑实质病变严重程度和观察临床治疗效果的一项重要指标。     

Brain imaging and the effects of caffeine and nicotine

Caffeine and nicotine are the most common psychostimulant drugs used worldwide. Structural neuroimaging findings associated with caffeine and nicotine consumption are limited and primarily reflect the putative relationship between smoking and white matter hyperintensities (WMH), a finding that warrants further appraisal of its clinical implications. The application of newer brain imaging modalities that measure subtle haemodynamic changes or tissue-based chemistry in order to better elucidate brain functional processes, including mechanisms underlying addiction to nicotine and caffeine and the brain functional consequences, provide intriguing findings. Potential influences of caffeine and nicotine on the functional contrast, or metabolic response, to neural activation also necessitates the careful appraisal of the effects that these commonly used drugs may have on the results of functional imaging.     

针刺对脑梗死后痉挛期患者脑功能重塑作用的功能磁共振成像研究

目的:观察健康人及脑梗死后左侧偏瘫患者执行左侧上肢运动及针刺左侧阳陵泉穴后的激活区分布特点,初步探讨脑梗死后痉挛期脑功能重塑的特点及针刺阳陵泉对其影响的机制。方法:观察8例健康人及5例脑梗死后左侧偏瘫患者。试验1:分别对正常组及偏瘫组进行左侧上肢运动。试验2:分别对正常组及偏瘫组针刺左侧阳陵泉穴。两个试验均采用组块设计模式,运用BOLD-f MRI技术及Brain Voyager软件分析方法显示激活情况。结果:正常组执行运动任务出现右侧初级感觉运动皮质及双侧小脑的明显激活;正常组针刺左侧阳陵泉穴出现左侧小脑、两侧中央后回和顶下小叶的激活;偏瘫组执行运动任务,双侧大脑皮质均有明显激活,包括双侧初级感觉运动皮质(SM1)、运动前区(PMC)和次级运动区(PPC)、双侧丘脑、小脑蚓部、双侧小脑、右侧岛叶、壳核,以及健侧苍白球;偏瘫组针刺左侧阳陵泉穴出现中脑、左侧大脑皮质的运动前区和次级运动区的激活。结论:脑梗死后痉挛期脑功能重塑的机制在于通过功能区的转移和次级功能区的功能代偿,而针刺阳陵泉穴主要作用于锥体外系,通过调节中枢神经递质的释放,缓解痉挛状态。     

Neural correlates of spontaneous direction reversals in ambiguous apparent visual motion

Looking at bistable visual stimuli, the observer experiences striking transitions between two competing percepts while the physical stimulus remains the same. Using functional imaging techniques, it is therefore possible to isolate neural correlates of perceptual changes that are independent of the low-level aspects of the stimulus. Previous experiments have demonstrated distributed activations in human extrastriate visual cortex related to switches between competing percepts. Here we asked where extrastriate responses still occur with a bistable stimulus that minimizes the cognitive difference between the two percepts. We used the "spinning wheel illusion," a bistable apparent motion stimulus of which both possible percepts correspond to the same object, share the same center, and are perceived as identically patterned stimuli moving at the same speed and changing only in direction. Using functional magnetic resonance imaging, we analyzed the spatial distribution of event-related activations occurring during spontaneous reversals of perceived direction of motion. In accordance with earlier neuroimaging findings for bistable percepts, we observed event-related activations in several frontal and parietal areas, including the superior parietal cortex bilaterally, the right inferior parietal cortex, and the premotor and inferior frontal cortex of both hemispheres. Furthermore, we found bilateral activations in the occipitotemporal junction (hMT+/V5) and in the lateral occipital sulcus ("KO") posterior to hMT+/V5, but not in areas of the "ventral stream" of cortical visual processing. Our data suggest that, while a frontoparietal network subserves more general aspects in bistable visual perception, the activations in functionally specialized extrastriate visual cortex are highly category- or attribute-specific.     

东西方人大脑皮层结构偏侧化的差异

目的 探讨不同年龄中国汉族人（东方人）与高加索白人（西方人）大脑皮层结构偏侧化的差异。方法 采集不同年龄段（青年组和老年组各30名）中国汉族人和高加索人的T1WI脑结构像，采用脑网络组图谱"Brainnetome Atlas"对大脑皮层进行精细化分区，计算各脑区大脑皮层表面积、皮层厚度及皮层平均曲率的偏侧化系数，并比较东西方人群的差异。结果 东西方青年组及老年组被试者皮层表面积、皮层厚度以及平均曲率呈现出偏侧化现象，大脑皮层表面积偏侧化的脑区数目均高于皮层厚度和平均曲率。东西方老年组出现大脑偏侧化的脑区数目少于青年组，但青年组与老年组间偏侧化系数无明显差异。东西方大脑偏侧化出现显著性差异的脑区主要集中在Brodmann分区的BA45、BA13、BA9和BA14等脑区（FDR校正，P均<0.05）。结论 东西方人群出现偏侧化差异的脑区主要集中在与语言、记忆、面孔识别等认知加工活动相关的脑区。     

手运动相关脑功能皮层功能磁共振成像原理及临床应用

脑功能磁共振成像在脑的功能研究和神经外科手术制订上应用广泛.运动皮层在个体内定位稳定,手运动的复杂程度、频率、强度及单双侧不同,参与研究者的年龄和利手不同,都可激活不同的脑功能皮层;手运动区已成功用于各运动区外科手术前的定位,对探讨疾病的发生发展,神经损伤后的修复及脑功能皮层病变的摘除手术有重要意义.     

视觉皮层对视觉刺激反应的研究———脑功能磁共振成像及磁共振波谱的联合应用

目的对视觉中枢进行BOLD-f MRI及MRS综合应用的研究。方法10例健康受试者,男7例,女3例,年龄26~45岁(平均33岁),常规头颅磁共振检查未发现颅内病变。所有受试者均接受一次f MRI及两次MRS检查。f MRI检查采用组块化设计,活动期通过Goggle系统给予以10Hz闪烁的黑白棋盘格刺激,静息期给予黑屏刺激。f MRI检查结束后,利用MR扫描仪上所带RTIP软件找出兴奋灶的层面,然后在这个层面中进行MRS检查。在第一次MRS检查中,给予黑屏刺激。在第二次MRS检查中给予受试者和f MRI检查中相同的黑白棋盘格刺激。f MRI数据使用SPM99处理,MRS数据使用Functool2处理。结果在f MRI实验中,双侧枕叶有较明显的激活,双侧距状回则更加明显,激活最强点位于右侧距状回。MRS实验中,可发现给予视觉刺激后NAA峰高有一定程度的增高,Cho峰高有一定程度的降低,所以在距状回层面,双侧枕叶发现较明显的NAA/Cho增高区。刺激前后NAA/Cho增加54.28%(2.103±0.014versus3.200±0.061,P0.05,配对t检验)。而且f MRI所得兴奋区与MRS所得NAA/Cho增加区基本吻合。结论视皮层的功能磁共振及磁共振波谱联合研究是可行的,其二者所得结果有一定的相关性和一致性。     

Dissociation of Frontal and Cerebellar Activity in a Cognitive Task: Evidence for a Distinction between Selection and Search

Human brain imaging studies have found that increases in functional activation in left-frontal cortex during cognitive tasks are often accompanied by similar increases in right-cerebellar regions. The present study used functional magnetic resonance imaging (fMRI) to investigate the distinctive contributions of these regions using a word stem completion task. Stems with many possible completions (MANY condition) were alternately presented with stems that had few possible completions (FEW condition), and subjects were asked to covertly complete each stem with a word and press a response switch for each successful completion. Prominent increases in activation in the MANY, relative to the FEW, condition were observed in the left middle frontal gyrus (Brodmann areas 9/10) and left caudate nucleus. In contrast, portions of the right-cerebellar hemisphere (posterior quadrangular lobule and superior semilunar lobule) and cerebellar vermis exhibited increases in the FEW, relative to the MANY, condition. This double dissociation suggests that the frontal and cerebellar regions make distinctive contributions to cognitive performance, with left-frontal (and striatal) activations reflecting response selection, which increases in difficulty when there are many appropriate responses, and right-cerebellar activation reflecting the search for responses, which increases in difficulty when even a single appropriate response is hard to retrieve.