18F-FDG SPECT/CT脑显像诊断老年性痴呆初步应用

目的探讨老年性痴呆（AD）的^18F—FDGSPECT／CT显像图特点。方法10例AD患者、10例血管性痴呆（VD）患者及20例正常对照行^18F—FDGSPECT／CT脑显像。患者禁食6h以上，戴眼罩安静休息20min后肘静脉注射^18F—FDG185—296MBq，60min后开始SPECT和X线CT透射扫描。先进行X线透射扫描，CT连续采集10min，然后进行符合线路PET连续采集30min。透射和发射图像进行衰减校正和叠代重建（COSEM），得到横断面、冠状面、矢状面及其CT与SPECT的融合图像。半定量分析取横断面图像，在双侧顶叶、颢叶、额叶和小脑划取感兴趣区（ROI），并获取单位像素放射性计数。将各脑叶分别与同侧小脑进行比较，即可得放射性摄取比值（Rcl／cb）。结果对10例患者、10例VD患者和20例正常对照的^18F-FDG显像图进行X线衰减校正前后比较和与CT扫描图的同机图像融合。结果表明，经过X线衰减校正后的^18F—FDG正电子图像比校正前的图像明显清晰，校正后的图像由发散、模糊变为细腻、清晰。融合后的图像与融合前的图像比较，在解剖学定位方面有了很大的改善，特别表现在大脑的沟回、基底节的辨认方面。在10例AD患者中，图像呈双侧颞叶、额叶或顶叶对称性放射性摄取减低者8例，占80％。图像呈单侧额叶或顶叶放射性减低者2例，占20％。在10例VD患者中，图像均呈多发性非对称性放射性稀疏区，且部位可位于基底节、丘脑或脑皮质区。AD组双侧顶叶、额叶和颞叶与同侧小脑的放射性摄取比值（Rcl／cb）明显低于正常对照组（P〈0．01）。结论AD患者的特征性^18F—FDG显像图改变对于AD的诊断及与VD的鉴别诊断有十分重要的临床意义。     

PET脑显像及其他显像技术在放射性脑损伤诊断的对比性研究

目的探讨18F-脱氧葡萄糖(FDG)正电子发射型计算机断层显影(PET)脑显像和其他医学影像方法对早期诊断放射性脑损伤的价值,以达到预防、减少脑放射损伤的目的. 方法静脉注射18F-FDG后行脑显像,获得横断面、冠状面、矢状面断层显像.所有病人均进行CT检查. 结果 20例正常人脑PET显像图像可见大脑皮质各叶、基底神经节、丘脑及小脑放射性分布均匀对称.12例完成头颈部恶性肿瘤放疗后有临床症状者均检出不同程度局灶性脑组织葡萄糖代谢下降,显像阳性率100%;其中10例鼻咽癌放疗后PET结果提示放射脑损伤病灶共23处,最常见于颞叶病灶13处、脑干4处、小脑 4处以及顶叶2处.2例脑胶质细胞瘤放疗病人,PET结果提示病灶:顶叶2处、颞叶1处、枕叶1处.12例放疗后病人CT检查仅10例提示放射性脑损伤. 结论 PET脑显像能准确、早期诊断脑放射损伤,是头颈部恶性肿瘤肿瘤放疗后的非常重要的监测手段 .     

磁刺激穴位对大脑功能网络的影响

基于复杂网络理论,研究磁刺激穴位时大脑功能连接的变化情况.利用互相关和互信息方法,分析了7名被试内关穴磁刺激前、刺激中、刺激后同步脑电信号的通道间关联特性,构建了大脑功能网络,并利用复杂网络分析方法对其进行了中心化程度评价,分析了几种状态下的关键脑区.结果表明:1 Hz刺激与刺激前相比,顶叶内部、顶叶与中央区节点间的关联程度发生了统一增强,额叶与枕叶、额叶与顶枕叶节点间的关联程度发生了统一减弱;3 Hz刺激与刺激前相比,统一增强的区域集中在额叶内部、中央区内部、额叶与中央区、额叶与顶叶、额叶与颞叶、中央区与颞叶、中央区与顶叶节点之间.度值较大的节点主要分布在额叶和中央区,介数值较大的节点主要分布在顶叶、中央区以及顶枕区.此研究有助于揭示磁刺激穴位对大脑功能网络的影响.     

PET脑显像及其他显像技术在放射性脑损伤诊断的对比性研究

目的 探讨^18F－脱氧葡萄糖（FDG）正电子发射型计算机断层显影（PET）脑显像和其他医学影像方法对早期诊断放射性脑损伤的价值，以达到预防、减少脑放射损伤的目的。方法 静脉注射^18F-FDG后行脑显像，获得横断面、冠状面、矢状面断层显像。所有病人均进行CT检查。结果 20例正常人脑PET显像图像可见大脑皮质各叶、基底神经节、丘脑及小脑放射性分布均匀对称。12例完成头颈部恶性肿瘤放疗后有临床症状者均检出不同程度局灶性脑组织葡萄糖代谢下降，显像阳性率100％；其中10例鼻咽癌放疗后PET结果提示放射脑损伤病灶共23处，最常见于颞叶病灶13处、脑干4处、小脑4处以及顶叶2处。2例脑胶质细胞瘤放疗病人，PET结果提示病灶：顶叶2处、颞叶1处、枕叶1处。12例放疗后病人CT检查仅10例提示放射性脑损伤。结论 PET脑显像能准确、早期诊断脑放射损伤，是头颈部恶性肿瘤肿瘤放疗后的非常重要的监测手段。     

基于功能连接算法的斜视性弱视儿童静息态功能磁共振成像的研究

目的探索斜视性弱视儿童脑功能区及其功能连接的改变,揭示斜视性弱视的发生与脑功能改变的相关性。方法在静息态下采集22位斜视性弱视儿童和10名健康儿童脑功能磁共振图像,利用DPARSF软件计算全脑与ROI功能区的连接系数,并应用t检验对实验组和健康对照组进行组内和组间功能连接系数分析。结果发现斜视性弱视儿童部分脑功能连接低于正常对照组的相应脑区连接,这些功能区主要分布于枕叶、颞叶、小脑后叶、顶叶、额叶、扣带回等脑区。结论基于静息态的f MRI的脑功能连接算法可以反映斜视性弱视儿童视皮层的变化和多脑区神经活动的变化。     

阴性精神分裂症患者局部脑血流与威斯康星卡片分类测验的相关分析

目的：为探讨阴性精神分裂症患者脑结构与认知功能缺陷的关系。方法：运用单光子发射计算机断层扫描（ＳＰＥＣＴ），测定了１２例阴性精神分裂症患者在安静状态与威斯康星卡片分类测验的负荷状态下的局部脑血流。结果：在安静状态下阴性精神分裂症病人的脑局部放射性分布是对称的，但在威斯康星卡片分类测验的刺激状态下左、右侧额叶的局部脑放射性计数是不对称的。结论：提示精神分裂症的阴性症状与左侧额叶的功能状态有关。     

健康成年人脑葡萄糖代谢性别差异的SPM分析

目的: 采用统计参数图(SPM)法分析健康成年人安静状态下大脑葡萄糖代谢水平的性别差异。方法: 对306例健康成年人进行静息状态下的¹⁸氟-脱氧葡萄糖(¹⁸F-FDG) 正电子发射型计算机断层(PET) 脑显像。采用SPM 5软件将男性组(n=218)和女性组(n=88)PET脑显像数据进行基于体素水平的图像分析。男、女性之间脑代谢水平进行两独立样本t检验,获得有差异区域的Talairach坐标值,并查出各坐标所对应的脑功能区。结果: 女性组总体脑葡萄糖代谢水平较男性组高。男性组脑葡萄糖代谢水平较女性组增高的脑区为右额叶旁中央小叶,而较女性组减低的脑区为左扣带后回、右颞叶中央后回、左额叶中央前回和右额叶上回。 结论: 安静状态下健康成年人脑葡萄糖代谢水平存在明显的性别差异。     

基于纤维束的空间统计方式的复发缓解型多发性硬化患者磁共振扩散张量成像与正常人对照

目的:利用基于纤维束的空间统计(TBSS)方式结合磁共振扩散张量成像技术(DTI)综合评价DTI对复发缓解型多发性硬化(RRMS)患者全脑白质微结构改变与正常人的对比,并探讨其应用价值。方法:实验组和对照组均进行全脑轴位常规扫描及DTI扫描,数据进行TBSS后处理,生成三维平均各向异性系数纤维骨架并进行非参数统计比较。结果:RRMS患者全脑双侧额叶、颞叶、顶叶及枕叶脑白质区域纤维素呈广泛性各向异性系数值减低、平均扩散率值升高,差异有统计学意义(P0.05)。结论:RRMS患者双侧额叶、颞叶、顶叶及枕叶脑白质区存在广泛的脑白质损伤,TBSS后处理方法能较为准确地定位和定量监测、评估及发现RRMS病灶。     

膝骨性关节炎患者慢性疼痛静息态脑功能局部一致性研究

目的探讨膝骨性关节炎(KOA)慢性疼痛患者静息状态下脑功能活动改变情况。方法采用局部一致性(ReHo)分析方法分析21例KOA患者(KOA组)和21例健康人群(HC组)静息状态下脑功能活动差异。结果与HC组相比,KOA组患者双侧额叶、顶叶、颞叶、小脑、边缘系统及静息状态默认网络分布区ReHo值广泛异常。结论慢性疼痛疾病患者的脑功能异常除了包括了疼痛信息的处理,更是一种皮层广泛参与的情绪功能异常、认知功能损害的病理状态。     

20Hz体感振动刺激对脑电特征影响研究

体感振动能够刺激人的体表感觉区,这种刺激传输到躯体感觉神经,进而影响大脑皮层中央后回及中央旁小叶后部的躯体感觉中枢,从而改变大脑功能状态。本研究旨在通过脑电检测方法,研究体感振动对大脑功能状态的影响。分别对12名受试者进行了20Hz体感振动刺激实验,采用相对功率变化率、Lempel-Ziv复杂度和基于互信息的脑网络等方法。结果发现,20Hz振动使得左前额区及左前颞区的脑电信号产生频率跟随响应;而脑网络分析表明:20Hz体感振动刺激使大脑右半脑区的额叶、中央叶、顶叶、颞叶、枕叶之间的信息流传递加强,大脑皮层趋于兴奋。因此,利用20Hz体感振动刺激调节大脑功能状态具有一定可行性。     

SPECT显像在NPC放疗后所致脑损伤中的初步应用

目的 评价单光子发射型电子计算机断层（ＳＰＥＣＴ）脑血流灌注显像在鼻咽癌（ＮＰＣ）放射治疗后放射性脑损伤中的临床价值。方法 采用ＳＰＥＣＴ脑血流灌注显像检查,对１６例鼻咽癌放射治疗后有放射性脑损伤症状的患者和８例示经放疗的鼻咽癌患者作半定时分析对测量结果作统计学分析。１６例放射性脑损伤患者同期做电子计算机体层检查（ＣＴ）对比。结果 １６例有放射性脑损伤症状的鼻咽癌患者双侧颞叶局部脑血流灌注（ｒＣＢＦ）在横断面层面－放射性曲线相应部位上可见局部放射性下降峰或曲线变窄小,峰值降低,其曲线局部下降峰值与鼻咽癌放疗效量的生物效应剂量（ＢＥＤ）值呈正相关（ｒ＝０．８９７６,Ｐ〈０．０１）。８例未经放疗的鼻咽癌患者,在横断面图像上其双侧颞叶局部脑血流灌注的层面－放射性曲线大致呈正态分布曲线,未见异常的局部下降峰或曲线变窄小     

Study of the influence of electroconvulsive therapy on the regional cerebral blood flow by HMPAO-SPECT.

STUDY OBJECTIVE: The aim of this preliminary study is to investigate the regional blood flow in response to ECT (electroconvulsive therapy) and to identify any responsive-pattern to the treatment. METHODS: STUDY DESIGN: Single longitudinal prospective study of cohorts. SUBJECTS: For this preliminary study ten patients, female sex, mean age 70.8 years with major mood disorder (CID-10 investigation criteria) were studied after signature consent. INTERVENTIONS: The intervention consisted in the administration of bilateral brief pulse ECT three times a week, during 6 to 12 sessions according to the standards of the Psychiatric Department of the Santiago Hospital in Victoria. MEASUREMENT: Clinical evaluation of depression was evaluated by Hamilton Depression Scale, Montgomery and Asberg Scale, Newcastle Scale and regional cerebral blood flow (rCBF) using the HMPAO-SPECT. RESULTS: The pattern of distribution on the regional cerebral flow during the ECT showed changes from the basal pattern in all patients. All patients had a relative increased perfusion of the temporal lobes and basal ganglia. Other changes from the basal study were areas of decreased perfusion of the occipital lobe (6 patients) and parietal lobe (3 patients). CONCLUSIONS: Brain perfusion SPECT study of the patients with major depression shows changes during ECT. Further analysis are needed to understand the relationship between mechanisms of treatment and recovery in affective illness.     

Perfusion scanning using 99mTc-HMPAO detects early cerebrovascular changes in the diabetic rat

Background

^99mTc-HMPAO is a well-established isotope useful in the detection of regional cerebral blood flow. Diabetes gives rise to arterial atherosclerotic changes that can lead to significant end organ dysfunction, prominently affecting perfusion to the heart, kidneys, eyes and brain. In the current study, we investigated the role of ^99mTc-HMPAO cerebral perfusion scans in detecting early vascular changes in the diabetic brain.

Methods

Cerebral perfusion studies were performed on both control and streptozotocin-(STZ) induced diabetic male Wistar rats. Rat brain imaging using a gamma camera was performed for each group 0.5, 2, 4, and 24 hours post ^99mTc-HMPAO injection. Data processing for each cerebral perfusion scan was performed by drawing a region of interest (ROI) circumferentially around the brain (B). Background (BKG) due to signal from the soft tissue of each rat was subtracted. Brain ^99mTc-HMPAO uptake minus background counts (net brain counts; NBC) were then compared between the two groups.

Results

The NBC (mean ± SD) for the STZ group were statistically significantly higher (p = 0.0004) than those of the control group at each of the time points studied.

Conclusion

^99mTc-HMPAO brain scan may be useful in the detection of early atherosclerotic changes in the diabetic rat brain.     

全脑容积灌注动脉自旋标记成像用于缺血性脑血管疾病的初步研究

目的 探讨全脑容积灌注动脉自旋标记成像（3DASL）应用于缺血性脑血管病诊断中的可行性和价值.方法 实验1：全部患者（对照组30例、脑栓塞组20例）行头部MRI增强检查,加扫3DASL及动态磁敏感对比增强（DSC）序列.对照组计算3DASL及DSC得到的大脑左右半球半卵圆中心镜像感兴趣区（ROI）的脑血流量（CBF）比,脑栓塞组计算2种方法得到的病灶区域与对侧镜像ROI的CBF比,配对分析数据.实验2：急性及亚急性脑栓塞组和短暂脑缺血发作（TIA）组患者各30例,全部行常规头部MRI检查,加扫3DASL序列,对比分析弥散成像（DWI）及3DASL 2种技术显示病变的阳性率及面积大小.结果 实验1：2种灌注方法获得了一致的灌注结果.对照组左右侧镜像ROI的CBF比值：3DASL为1.02±0.18,DSC为1.06±0.24,2者间差异无统计学意义（P＞0.05）;脑栓塞组病灶区域与对侧镜像ROI的CBF比值：3DASL为0.50±0.12,DSC为0.48±0.18,2者间差异无统计学意义（P＞0.05）.实验2：急性及亚急性脑栓塞的检出率：DWI和3DASL均为100％.同一病例相同病变显示面积的大小：SDwI＜S3DASL,n=22; SDW1≈S3DASL,n=8;SDWI＞S3DASL,n=0.TIA的检出率：DWI为0％,3DASL为70％.结论 3DASL和DSC相比,测量脑血流量有相似的敏感性,且具有三维成像扫描范围广、无需注射对比剂和可重复性强等优势.3DASL较DWI有更高的TIA阳性检出率,有助于TIA的早期诊断,全面准确地评估缺血半暗带及急性缺血性脑血管病的血流灌注情况,可作为急诊检查方法之一,为临床治疗提供科学依据.     

Acute effect of intranasal estrogen on cerebral and cerebellar perfusion in postmenopausal women

OBJECTIVES: Estrogen action in the brain influences many neurochemical processes. The aim of the study was to evaluate the acute effect of intranasal 17beta-estradiol on cerebral and cerebellar perfusion in postmenopausal women. METHODS: The study group included 24 healthy postmenopausal women who had been in natural menopause for at least 1 year (mean age: 47.38+/-5.9 years). We conducted an experimental, randomized, placebo-controlled, cross-over, double-blind study. Cerebral and cerebellar perfusion was measured after placebo (saline serum physiologic) or intranasal 17beta-estradiol administration by Single Photon Emission Computed Tomography (SPECT) using technetium-99m-hexamethylpropylene amine oxime (Tc99m-HMPAO). Regions of interest (ROIs) were drawn manually. Cerebral and cerebellar perfusions were calculated for each ROI using average number of counts per pixel. Semiquantitative analysis was performed in bilateral frontal, temporal, parietal and occipital lobes, thalamus, putamen, hippocampus, amygdala, caudate nuclei, cerebellar region, anterior/posterior of cingulate gyrus and pons. RESULTS: After intranasal 17beta-estradiol administration, SPECT study revealed significant increases in cerebral and cerebellar perfusion compared to placebo measurements in all studied slices (p<0.05). There was a positive correlation between serum estrogen levels after 17beta-estradiol and cerebral and cerebellar perfusion. CONCLUSIONS: Administration of single dose intranasal 17beta-estradiol increases cerebral and cerebellar perfusions in healthy postmenopausal women.     

糖尿病视网膜病变患者自发活动性异常的脑区与MoCA的相关性研究

目的 基于静息态功能磁共振局部一致性技术探讨糖尿病视网膜病变患者局部脑区一致性的改变及与认知关系.方法 选择27例糖尿病视网膜病变(DR)及与之年龄、性别、受教育年限相匹配的单纯糖尿病(N-DR)患者27例,均进行实验室检查、蒙特利尔量表(MoCA)检测及头颅磁共振扫描.利用多元回归分析及Pearson回归分析观察临床变量与活动性异常活动脑区ReHo值之间的关系.结果 相对于N-DR,DR患者在左小脑后叶、右额叶/额中回/内侧回、右枕叶/楔叶/距状回、左颞叶/上/中回、右边缘叶/后扣带回、左顶叶/中央后回ReHo值降低;在左额叶/眶部额上回、左顶叶/楔前叶ReHo值增强.而且MoCA量表评分与颞叶及楔前叶异常活动的脑区存在相关性.降低的枕叶距状回及颞叶中回与糖化血红蛋白呈负相关,增强的眶额叶与糖化血红蛋白呈正相关.结论 糖尿病视网膜病变患者存在多个脑区活动性异常的表现,且这些局部异常活动的脑区与认知功能及糖化血红蛋白存在相关.     

The segmented regional volumes of the cerebrum and cerebellum in boys with Tourette syndrome

Neuropathological deficits are an etiological factor in Tourette syndrome (TS), and implicate a network linking the basal ganglia and the cerebrum, not a particular single brain region. In this study, the volumes of 20 cerebral and cerebellar regions and their symmetries were measured in normal boys and TS boys by brain magnetic resonance imaging. Brain magnetic resonance images were obtained prospectively in 19 boys with TS and 17 age-matched normal control boys. Cerebral and cerebellar regions were segmented to gray and white fractions using algorithm for semi-automated fuzzy tissue segmentation. The frontal, parietal, temporal, and the occipital lobes and the cerebellum were defined using the semiautomated Talairach atlas-based parcellation method. Boys with TS had smaller total brain volumes than control subjects. In the gray matter, although the smaller brain volume was taken into account, TS boys had a smaller right frontal lobe and a larger left frontal lobe and increased normal asymmetry (left>right). In addition, TS boys had more frontal lobe white matter. There were no significant differences in regions of interest of the parietal, temporal, or the occipital lobes or the cerebellum. These findings suggest that boys with TS may have neuropathological abnormalities in the gray and the white matter of the frontal lobe.     

Effects of sympathetic nerves on cerebral blood flow in awake dogs.

Although cerebral blood vessels are densely innervated by sympathetic nerve fibers, the functional significance of the nerves is controversial. Because previous studies have been primarily performed in anesthetized animals, it is possible that failure to observe prominent neural control of the cerebral circulation was secondary to anesthetic-induced depression of the sympathetic nervous system. Therefore, we studied sympathetic control of the cerebral circulation in 11 awake chronically instrumented dogs. Total and regional cerebral blood flow was measured with 15-micrometer microspheres at control blood pressure and during three levels of progressive hemorrhagic hypotension. Sympathetic nerves had only a small effect (11% decrease; P less than 0.05) on flow to the cerebrum during moderate hypotension (mean arterial pressure 49 +/- 2 mmHg). Also, during severe hypotension, there was a bilateral redistribution of brain blood flow that tended to preserve flow to the medulla. Although these studies suggest that sympathetic nerves have a definite constrictor effect on cerebral vessels, the data support the concept that the functional importance of sympathetic nerves to cerebral vessels is limited.     

Comparison of regional vasomotor responses to acetazolamide and CO2 in rabbit cerebrum and cerebellum, measured by a hydrogen clearance method

AIM: Many investigators have proved the usefulness of acetazolamide provocation and the carbon dioxide test for assessment of the local cerebrovascular reactivity by measurement of the regional cerebral blood flow in patients with occlusive cerebrovascular disease. Data originating from a comparison of these two different vasomotor stimuli as concerns the differences in sensitivity to them in various parts of the central nervous system are scarce. Our aim was to compare the cerebral blood flow responses to hypercapnic and acetazolamide stimuli in different brain regions. METHODS: The cerebral blood flow was measured in the cerebrum (cortex and caudate nucleus) and cerebellum (cortex), as measured by a hydrogen clearance method in anaesthetized, artificially ventilated rabbits. RESULTS: In normocapnia, the cerebral blood flow values in the cerebrum and the cerebellum differed significantly. The cerebral blood flow responses to both vasodilatory stimuli were to be significantly higher in the cerebrum than in the cerebellum, but the relative increases, i.e. the mean relative reactivities, were similar in the different regions measured. CONCLUSION: The regional dissimilarity might explain to some extent the different sensitivities of the various brain areas to sudden blood pressure changes (infarction or haemorrhage). The results further suggest that heterogeneity in cerebrovascular reactivity should be considered in the assessment of vasoreactivity in patients with occlusive cerebrovascular disease. Since the comparison of the carbon dioxide and acetazolamide-induced cerebrovascular reactivities revealed a strong linear relationship, it was concluded that acetazolamide provocation is equivalent to the carbon dioxide test in the evaluation of cerebrovascular reactivity.     

阻塞性睡眠呼吸暂停的脑血流灌注成像研究进展

阻塞性睡眠呼吸暂停（OSA）是一种常见的睡眠呼吸障碍,可致局部脑血流量改变,脑血流灌注成像对于评估OSA严重程度及预后进展具有重要意义。目前应用于评估OSA患者脑血流灌注的成像技术主要包括单光子发射计算机断层显像、磁共振脑血流灌注成像等。本研究旨在对脑血流灌注成像技术在OSA的研究进展进行综述,客观分析各脑血流灌注技术的优势和局限,以期提高各技术在OSA的早期筛查、评价疾病严重程度以及预后进展的临床适用性,并展望未来研究方向和提出目前潜在的挑战。