多系统萎缩不同亚型间的临床特征及脑葡萄糖代谢差异分析

目的分析多系统萎缩-帕金森亚型和多系统萎缩-小脑共济失调亚型患者的临床特征以及18氟-脱氧葡萄糖正电子发射断层(l8F-FDG PET)显像的特征差异。方法收集8例多系统萎缩-帕金森亚型患者和17例多系统萎缩-小脑共济失调亚型患者的临床资料,回顾性分析包括统一帕金森病评定量表-运动部分(UPDRS Ⅲ)评分和Hoehn-Yahr分级的运动症状评估,认知功能、抑郁、嗅觉、快速眼动期睡眠行为紊乱等非运动症状评估,以及基于l8F-FDG PET脑葡萄糖代谢显像的特征差异。结果多系统萎缩-帕金森亚型与多系统萎缩-小脑共济失调亚型患者UPDRS Ⅲ评分(P=0.004)及Hoehn-Yahr分级(P<0.001)比较,差异有统计学意义,而非运动症状组间比较,差异无统计学意义(P>0.05)。多系统萎缩-帕金森亚型在基底节(尤其是后壳核)脑葡萄糖代谢(P<0.001)、小脑及顶枕叶呈低代谢,多系统萎缩-小脑共济失调亚型基底节脑葡萄糖代谢未见减低,仅在小脑和枕叶呈低代谢。结论多系统萎缩的临床特征异质性大,l8F-FDG PET脑葡萄糖代谢显像特征差异可为深入研究多系统萎缩的发病机制、开发更精准治疗奠定基础。     

致死性家族性失眠患者脑葡萄糖代谢分析

目的 研究致死性家族性失眠(fatal familial insomnia,FFI)患者脑葡萄糖代谢变化特征.方法 对病程分别为2个月的患者1和6个月的患者2以及20名健康对照者进行18F-脱氧葡萄糖(18F-fluorodeoxyglucose,18F-FDG)PET静态显像.采用视觉分析的方法判断2例患者脑代谢改变情况,然后利用统计参数图分析方法对每例患者和与其年龄相匹配的10名健康对照者进行组间分析,判断其代谢改变特征.结果 与10名年龄相匹配的健康对照组相比,患者1表现为明显的丘脑、顶叶、尾状核、后扣带回和前额叶的代谢减低(t＞2.82,P＜0.01).患者2表现为明显的丘脑、顶叶、后扣带回和前额叶的代谢减低,其代谢减低的范围和程度明显大于患者1(t＞2.82,P＜0.01),并伴有颞叶和枕叶代谢减低(t＞2.82,P＜0.01).结论 FFI患者脑葡萄糖代谢改变主要为双侧丘脑和大脑皮质代谢减低,大脑皮质所累及的范围和程度随病程发展而增大.18F-FDG PET显像对FFI的诊断和鉴别诊断具有一定的参考价值.     

Resolving metabolic abnormalities in a case of pure alexia

We report resolving metabolic abnormalities corresponding to clinical improvement in a patient with pure alexia secondary to acute cerebral infarction. Local cerebral glucose metabolism (lCMRgl) was measured with positron emission tomography (PET) using 18F-fluorodeoxyglucose (18F-FDG) close to ictus and 4 1/2 months later. Serial CTs and a subsequent MRI demonstrated small, unchanging left-hemispheric lesions involving the area of the lateral geniculate body and the splenium of the corpus callosum. PET demonstrated the evolution of the metabolic abnormality resulting from intrahemispheric (lateral geniculate) and interhemispheric (splenium) disconnection in the absence of occipital lobe infarction. This case illustrates that cerebral disconnection can result in the syndrome of pure alexia. The factors accounting for focal hypometabolism in the absence of cerebral infarction are discussed.     

18F-FDG PET/CT脑显像评价认知障碍患者中的脑小血管病变对皮层功能的影响

目的 探讨18氟代脱氧葡萄糖（18F-fluorodeoxyglucose,18F-FDG）正电子发射断层成像/计算机断层扫
描（positron emission tomography/computed tomography,PET/CT）脑显像评价认知障碍患者中的脑小血
管病变对皮层功能的影响。
方法 本研究为回顾性研究,纳入2009年1月～2010年12月北京协和医院PET中心行18F-FDG PET/CT
脑显像且颅脑磁共振成像（magnetic resonance imaging,MRI）提示存在小血管病变的认知障碍患者21例,
其中临床诊断血管性痴呆（vascular dementia,VaD）10例,阿尔茨海默病（Alzheimer’s disease,AD）或混
合型痴呆（mixed dementia,MD）11例。首先目测两组患者的18F-FDG PET/CT脑显像皮层及皮层下核团代
谢减低特点,并结合颅脑MRI判断病变血管对脑代谢的影响。使用NeuroQ软件和Scenium软件对18F-FDG
PET/CT脑图像在像素基础上进行定量分析比较两组患者的皮层代谢情况。
结果 通过目测和NeuroQ软件分析发现VaD组患者18F-FDG PET/CT脑显像图像特点为无规律,不对
称皮层或皮层下核团代谢减低,其中额叶皮层代谢减低范围最广,程度最重。结合颅脑MRI改变,考
虑皮层和皮层下核团代谢减低主要为小血管病变引起。AD或MD组患者脑代谢均呈现双侧颞顶叶代谢
减低,其中8例出现皮层代谢减低不对称表现,6例出现基底节丘脑不对称代谢减低表现,与典型AD
的表现不符,结合颅脑MRI表现,考虑为病变血管所致,小血管病变可能导致相应皮层代谢减低。通
过定量分析发现两组患者的SUV比值在左右顶叶、内外颞叶和枕叶差异具有显著性。
结论 18F-FDG PET/CT脑显像作为功能影像可以推断小血管病变与皮层及皮层下核团代谢的关系。     

阿尔茨海默病~(18)F-FDG PET显像诊断的研究

目的 探讨阿尔茨海默病（AD）脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描（18F-FDG PET）显像的影像学特征和PET诊断标准。方法 静脉注射18F-FDG后行脑断层显像,检查13例 AD、13例非AD痴呆及13例正常人。获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值（Rcl/cb）,进行半定量分析,并与MR进行对照。结果AD患者PET异常率为100％,MR异常者占10/13。PET显像特征:①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例（9/13）;②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例（3/13）;③双顶叶对称性代谢降低1例（1/13）。12例（12/13）非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13。结论 在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD。PET对AD早期诊断及鉴别诊断具有临床意义。     

Comparison of brain MRI and 18F-FDG PET in the differential diagnosis of multiple system atrophy from Parkinson's disease.

To investigate the diagnostic value of brain magnetic resonance image (MRI) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) in the differentiation of multiple system atrophy (MSA) from Parkinson's disease (PD). Thirty-five patients with MSA (23 MSA-P and 12 MSA-C) and 17 patients with PD were included in this study. Overall correct diagnosis rates between clinical and imaging diagnosis among MSA-P, MSA-C, and PD patients were 80% for visual MRI analysis, 88.5% for visual (18)F-FDG PET analysis, and 84.3% for SPM-supported analysis of (18)F-FDG PET. The sensitivity of brain MRI, and visual and SPM analysis of (18)F-FDG PET in differentiating MSA from PD was 72.7%, 90.9%, and 95.5%, respectively, the specificity was 100% for each imaging analysis, the positive predictive value was 100% for each imaging analysis, and the negative predictive value was 60%, 81.8%, and 90%, respectively. Our results suggest that brain MRI and (18)F-FDG PET are diagnostically useful in differentiating MSA (MSA-P and MSA-C) from PD, and indicate that (18)F-FDG PET has a tendency toward higher sensitivity compared to brain MRI, but a larger longitudinal study including pathological data will be required to confirm our findings.     

Differentiating multiple system atrophy from Parkinson's disease: contribution of striatal and midbrain MRI volumetry and multi-tracer PET imaging

OBJECTIVES: The differential diagnosis between typical idiopathic Parkinson's disease (PD) and the striatonigral variant of multiple system atrophy (MSA-P) is often difficult because of the presence of signs and symptoms common to both forms of parkinsonism, particularly at symptom onset. This study investigated striatal and midbrain findings in MSA-P and PD patients in comparison with normal controls with the use of positron emission tomography (PET) and three dimensional magnetic resonance imaging (3D MRI) based volumetry to increase the differential diagnostic accuracy between both disease entities. METHODS: Nine patients with MSA-P, 24 patients with PD, and seven healthy controls were studied by MRI and PET with 6-[(18)F]-fluoro-L-dopa (FDOPA), [(18)F]fluoro-deoxyglucose (FDG), and 11-C-Raclopride (RACLO). Striatal and extrastriatal volumes of interest (VOI) were calculated on the basis of the individual MRI data. The PET data were transferred to the VOI datasets and subsequently analysed. RESULTS: MSA-P differed significantly from PD patients in terms of decreased putaminal volume, glucose metabolism, and postsynaptic D2 receptor density. The striatal FDOPA uptake was equally impaired in both conditions. Neither MRI volumetry nor PET imaging of the midbrain region further contributed to the differential diagnosis between PD and MSA-P. CONCLUSIONS: The extent and spatial distribution of functional and morphological changes in the striatum permit the differentiation of MSA-P from PD. Both, multi-tracer PET and 3D MRI based volumetry, may be considered equivalent in the assessment of different striatal abnormality in both disease entities. In contrast, MRI and PET imaging of the midbrain does not provide a further gain in diagnostic accuracy.     

Motor correlates of occipital glucose hypometabolism in Parkinson's disease without dementia

OBJECTIVE: To determine whether occipital reduction in regional cerebral glucose metabolism in PD reflects retinal versus nigrostriatal dopaminergic degeneration. We hypothesized that occipital glucose metabolic reduction should be symmetric if parkinsonian retinopathy is responsible for the reduction. METHODS: PD patients without dementia (n = 29; age 63 +/- 10 years) and normal controls (n = 27; age 60 +/- 12 years) underwent [18F]fluorodeoxyglucose PET imaging. Regional cerebral glucose metabolic rates were assessed quantitatively. RESULTS: When compared with normal controls, PD patients showed most severe glucose metabolic reduction in the primary visual cortex (mean -15%, p < 0.001). Occipital glucose metabolic reduction was greater in the hemisphere contralateral to the side of the body affected initially or more severely in PD. There was an inverse correlation between side-to-side asymmetries in finger-tapping performance and occipital glucose metabolic reduction (r = -0.45, p < 0.05; n = 28). The correlation was strongest in patients with a relatively early stage of PD with more unilateral motor impairment (Hoehn and Yahr stage I, r = -0.74, p < 0.01; n = 10). CONCLUSION: The results indicate a pathophysiologic association between nigrostriatal dysfunction and occipital glucose metabolic reduction in PD.     

~(11)C-PIBPET和~(18)F-FDGPET显像诊断阿尔茨海默病与遗忘型轻度认知损害的临床价值

目的应用11C-PIB PET和18F-FDG PET显像研究阿尔茨海默病和遗忘型轻度认知损害患者β-淀粉样蛋白(Aβ)沉积与葡萄糖代谢之间的关系,联合载脂蛋白E(ApoE)基因型进一步探讨遗忘型轻度认知损害与阿尔茨海默病的相关性。方法利用PET显像对阿尔茨海默病(14例)、遗忘型轻度认知损害(10例)和正常对照者(5例)脑组织Aβ沉积和葡萄糖代谢变化进行分析,采用聚合酶链反应-限制性片段长度多态性方法对ApoE基因型进行分析。结果阿尔茨海默病组患者11C-PIB标准化摄取比值在下顶叶、颞叶外侧、额叶、后扣带回皮质和楔前叶、枕叶和纹状体均高于正常对照组(P0.05);遗忘型轻度认知损害组患者脑组织11C-PIB结合水平呈双峰形。11C-PIB+aMCI亚组与阿尔茨海默病组、11C-PIB-aMCI亚组与正常对照组之间11C-PIB标准化摄取比值差异均无统计学意义(P0.05)。18F-FDG PET显像显示,3/5例11C-PIB+aMCI亚组患者双侧顶叶、颞叶和楔前叶代谢减低,其中2例ApoEε4等位基因携带者随访期间进展至阿尔茨海默病;3/5例11C-PIB-aMCI亚组患者双侧额叶和前扣带回代谢减低。结论11C-PIB PET显像是筛查具有阿尔茨海默病病理特点的遗忘型轻度认知损害患者的有效工具。具有阿尔茨海默病病理特征的遗忘型轻度认知损害患者可伴有顶叶、颞叶外侧皮质和楔前叶代谢减低,其中ApoEε4等位基因携带者更易进展至阿尔茨海默病痴呆。     

局灶性难治性颞叶癫痫全脑葡萄糖代谢特点

目的 探讨局灶性难治性颞叶癫痫全脑葡萄糖代谢特点。方法 回顾性分析2017年1~12月行发作间期18FDG-PET/CT检查的23例局灶性难治性颞叶癫痫的影像学资料。将PET图像导入MIM neuro软件,软件自动分析癫痫病人葡萄糖代谢水平与正常人群葡萄糖代谢的差异,各脑区差异结果以Z-Score值显示,分析颞叶癫痫病人全脑葡萄糖代谢特点。结果 术后病理为脑皮质发育不良22例,节细胞胶质瘤1例;病灶位于左侧颞叶16例,右侧颞叶7例。除颞叶呈葡萄糖低代谢改变外,还存在同侧海马、海马旁回、岛叶、杏仁核、颞叶岛盖以及双侧小脑半球葡萄糖代谢不同程度减低;对侧颞叶、额叶、顶叶、顶上小叶以及角回葡萄糖代谢不同程度增高。结论 颞叶癫痫具有一定葡萄糖代谢特点,其特定的葡萄糖代谢特点有助于更加精准的癫痫术前定位及其病理特征的分析。     

正常人安静和催眠状态下脑葡萄糖代谢的自身对照研究

目的 研究健康正常人催眠静息状态和清醒安静状态下脑内葡萄糖代谢的差异,初步探索催眠状态的神经生理基础。方法 正常人在清醒安静状态下行^18F—FDG PET扫描。隔日后,采用凝视法将受试者诱导进入催眠状态,再次行^18F—FDG PET扫描。两种状态皆应采用3D模式进行PET脑显像,应用SPM分析对催眠静息状态和清醒安静状态^18F—FDG PET图像进行组间体元统计,统计所得到的一系列数值构成了统计参数地图（SPM）。比较催眠静息状态和清醒安静状态脑局部糖代谢的变化,根据变化差异显著（P〈0．001）区域的Talariach坐标值确定其部位。结果 SPM分析显示催眠静息状态较清醒安静状态右侧枕叶（BA17,18）、左侧枕叶（BA17,18）、左侧顶叶（BA40,）、左侧颞上回（BA22）、右侧尾状核、右侧小脑后叶、右侧额叶（BA6）、左侧额中回（BA8,9）和右侧丘脑葡萄糖代谢明显降低（P〈0．001）。结论 催眠静息状态脑葡萄糖代谢不同于清醒安静状态,催眠静息状态存在神经生理基础。     

进行性核上性麻痹与多系统萎缩的头部MRI和FDG-PET比较

目的对比研究进行性核上性麻痹(PSP)与多系统萎缩(MSA)的脑干MRI表现和头部葡萄糖代谢特征。方法对11例PSP患者、37例MSA患者和43例健康对照进行头部MRI平扫检查,并计算MRI正中矢状面T1加权像上中脑截面面积,其中5例PSP和19例MSA进行了18F-FDG PET检查。结果(1)MRI:11例PSP正中矢状位T1加权像均可见中脑上缘平坦或凹陷表现,呈"蜂鸟征",而MSA患者和健康对照组未见上述表现。37例MSA患者中有34例轴位T2加权像桥脑可见"十字征"样长T2异常信号。PSP患者正中矢状位T1加权像上中脑截面面积分别低于MSA组和健康对照组(P<0.01)。(2)PET:PSP组主要表现为对称性额叶低代谢;MSA组主要表现为额、顶、颞叶普遍低代谢,纹状体对称性代谢降低,丘脑代谢高于纹状体。结论PSP中脑MRI特征和头部葡萄糖代谢特征与MSA和健康对照有明确差异,有助于PSP与MSA的鉴别诊断。     

Regional correlation between resting state FDG PET and pCASL perfusion MRI

To determine how arterial spin labeling (ASL) measured perfusion relates to baseline metabolism, we compared resting state cerebral perfusion using pseudo-continuous ASL and cerebral glucose metabolism using ¹⁸F-FDG PET in 20 normal volunteers. Greater regional metabolism relative to perfusion was observed in the putamen, orbitofrontal and temporal lobes, whereas perfusion was relatively higher in the hippocampus and insula. In a region of interest analysis limited to gray matter, the overall mean correlation between perfusion and metabolism across voxels was r=0.43 with considerable regional variability. Cross-voxel correlations between relative perfusion and metabolism in mean ASL and PET images of all 20 subjects were the highest in the striatum (caudate: r=0.78; putamen: r=0.81), and the lowest in medial temporal structures (amygdala: r=0.087; hippocampus: r=−0.26). Correlations between mean relative perfusion and metabolism across 20 subjects were the highest in the striatum (caudate: r=0.76; putamen: r=0.58), temporal lobe (r=0.59), and frontal lobe (r=0.52), but very poor in all other structures (r<0.3), particularly in caudal structures such as the hippocampus (r=−0.0026), amygdala (r=0.18), and insula (r=0.14). Although there was good overall correlation between perfusion and glucose metabolism, regional variability should be considered when using either ASL or ¹⁸F-FDG PET as surrogate markers for neural activity.     

Ischemic lesions of the occipital cortex and optic radiations: positron emission tomography

We used 18-F-fluoro-2-deoxyglucose positron emission tomography (PET) and computed tomography (CT) to study eight patients with homonymous hemianopias or quadrantanopias due to ischemic lesions of the visual pathways. Four patients with ischemic damage to all or part of the occipital lobe had decreased glucose metabolism in the affected region. Three patients with ischemic damage limited to the optic radiations had decreased glucose metabolism in the portion of striate cortex appropriate for the visual field defect. Changes in glucose metabolism frequently occurred in the undamaged ipsilateral thalamus and visual association areas.     

Region-specific corpus callosum atrophy correlates with the regional pattern of cortical glucose metabolism in Alzheimer disease

BACKGROUND: Positron emission tomographic studies of patients with Alzheimer disease (AD) suggest a loss of metabolic functional interactions between different cortical regions. Atrophy of the corpus callosum as the major tract of intracortical connective fibers may reflect decreased cortical functional integration in AD. OBJECTIVES: To investigate whether regional atrophy of the corpus callosum is correlated with regional reductions of cortical glucose metabolism, as shown by positron emission tomography, and whether primary white matter degeneration is a possible cofactor of corpus callosum atrophy in AD. PATIENTS AND METHODS: We measured total and regional cross-sectional areas of the corpus callosum on midsagittal magnetic resonance imaging scans from 12 patients with AD and 15 age-matched control subjects. Regional cerebral metabolic rates for glucose in cortical lobes were measured by positron emission tomography using fludeoxyglucose F 18. White matter hyperintensities were rated in T2-weighted magnetic resonance imaging scans. RESULTS: The total cross-sectional area of corpus callosum was significantly reduced in patients with AD, with the most prominent changes in the rostrum and splenium and relative sparing of the body of the corpus callosum. Frontal and parietal lobe metabolism was correlated with the truncal area of the corpus callosum in AD. The ratios of frontal to parietal and of frontal to occipital metabolism were correlated with the ratio of anterior to posterior corpus callosum area in the group with AD. White matter hyperintensities did not correlate with corpus callosum atrophy in the patients with AD. CONCLUSION: The regional pattern of corpus callosum atrophy correlated with reduced regional glucose metabolism independently of primary white matter degeneration in the patients with AD.     

Recovery of vision after ischemic lesions: positron emission tomography

We used [18F]fluoro-2-deoxyglucose positron emission tomography (PET) to study serial changes in the local cerebral metabolic rate of glucose in 5 patients with ischemic lesions of the posterior afferent visual system causing homonymous visual field defects. All 5 patients had striking impairment of glucose metabolism in the striate cortex shortly after ictus. In 2 patients, visual field defects abated, and repeat PET scans showed reduced size of the metabolic lesion and improvement of striate metabolism. Three patients did not recover vision, and repeat PET scans did not show improvement. Patients who recovered vision had ischemic lesions outside the occipital lobe, while those who did not experience improvement had primary damage to the occipital lobe itself.     

~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍患者脑葡萄糖代谢特点的研究

目的探讨~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍(iRBD)患者脑葡萄糖代谢改变和iRBD脑葡萄糖代谢改变与病程间的相关性。方法纳入多导睡眠监测(PSG)确诊的iRBD患者20例(iRBD组)和年龄、性别匹配的健康对照者19例(对照组)。两组均行~(18)F-FDG PET脑显像。基于自动解剖标记模板将大脑划分为90个左右对称的脑区,计算各脑区葡萄糖代谢半定量值。对iRBD组和对照组各脑区葡萄糖代谢半定量值进行独立样本t检验;并对iRBD组脑葡萄糖代谢改变与病程行Pearson相关分析。结果 (1)与对照组比较,iRBD组的双侧背外侧额上回、双侧眶部额上回、双侧眶部额中回、双侧海马、双侧海马旁回、双侧杏仁核、左侧眶部额下回、左侧岛叶、左侧内侧与旁扣带脑回、左侧中央旁小叶、左侧苍白球的葡萄糖代谢半定量值均增高(P0.05);双侧距状裂周围皮质、双侧楔叶、双侧舌回、双侧枕上回、双侧枕中回、双侧枕下回、双侧角回、双侧颞上回、双侧颞中回、右侧颞横回的葡萄糖代谢半定量值均降低(P0.05)。Pearson相关分析结果,iRBD组双侧杏仁核、双侧颞上回、右侧楔叶、右侧枕上回、右侧颞横回、左侧海马、左侧颞中回的葡萄糖代谢半定量值与病程呈正相关(P0.05);而双侧眶部额上回、双侧眶部额中回、左侧中央旁小叶、左侧眶部额下回、左侧内侧和旁扣带回、右侧背外侧额上回、右侧海马旁回的葡萄糖代谢半定量值与病程呈负相关(P0.05)。结论 iRBD患者脑内存在疾病相关的葡萄糖代谢水平改变,有助于客观评估iRBD病情的变化。     

~(11)C-CFT PET显像评价帕金森病与多系统萎缩P型患者脑内多巴胺转运体分布特点的研究

目的基于~(11)C-CFT正电子发射计算机断层(PET)显像评价帕金森病(PD)与多系统萎缩P型(MSA-P)患者脑内多巴胺转运体(DAT)分布特点,评估~(11)C-CFT PET显像在PD与MSA-P鉴别诊断中的价值。方法回顾性分析年龄、性别和疾病严重程度匹配的32例MSA-P患者(MSA-P组)和56例PD患者(PD组)的临床资料以及~(11)C-CFT PET影像资料;另选择年龄匹配的健康对照者20例为对照组。应用感兴趣区技术获得3组研究对象的尾状核、前壳核和后壳核的DAT分布半定量值,对各感兴趣区的DAT分布半定量值、相互比值和不对称性进行对比研究。建立受试者工作特征曲线(ROL),利用曲线下面积评估基于~(11)C-CFT PET显像所得相关参数对PD和MSA-P的鉴别能力。结果与PD组比较,MSA-P组患者病程更短、进展速度更快(P0.000 1)。与对照组比较,PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值均显著减低(P0.000 1),且后壳核降低最为显著。PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值及其不对称指数比较均差异无显著性。PD组和MSA-P组纹状体各感兴趣区DAT分布半定量值中,前壳核/尾状核比值(AP/C)、后壳核/前壳核比值(PP/AP)均差异无显著性;但MSA-P组后壳核/尾状核比值(PP/C)PD组(P0.05),两组PP/C比值的ROL曲线下面积为0.696(P=0.002);以0.611作为PP/C比值的临界值,其对MSA-P和PD鉴别诊断的灵敏度和特异度分别为71.9%和62.5%。结论 ~(11)C-CFT PET显像可以精准显示MSA-P及PD患者脑内多巴胺能神经元的突触前功能损害,但尚不能有效鉴别两种疾病。     

Functional imaging for disorders of basal ganglia]

The nigrostriatal dopaminergic function and regional glucose metabolism were evaluated in patients suffering from various disorders of basal ganglia by using positron emission tomography with 18F-dopa and 18F-FDG, respectively. The 18F-dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The 18F-dopa uptake in the striatum also decreased in cases of multiple system atrophy and progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral cortices and the striatum: this finding was also different from those of Parkinson's disease. A normal 18F-dopa uptake with a markedly decreased striatal glucose metabolism was observed in cases of Huntington's disease. The 18F-dopa uptake increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of 18F-dopa uptake and glucose metabolism were thus observed in the various disorders of basal ganglia. These results suggest that the measurements of the 18F-dopa uptake and glucose metabolism would be useful for evaluating the function of the basal ganglia in various disorders of basal ganglia.     

Striatal dopa and glucose metabolism in PD patients with freezing of gait.

In Parkinson's disease (PD), freezing suggests sudden and transient blocks of motor behavior during initiating or continuous repetitive movements. Its underlying pathophysiology remains unclear. The objective of this study is to compare striatal dopamine metabolism and cerebral glucose metabolism between PD patients with and without freezing of gait (FOG). A total of 10 PD patients with FOG at off and 7 PD patients without FOG underwent brain positron emission tomography with (18)[F]-6-fluoro-levodopa (FDOPA) and (18)[F]-fluordesoxyglucose (FDG). Striatum decarboxylase activity was expressed by metabolic influx constants of the striatum related to the occipital lobe (Kocc). FDG uptake in caudate and putamen was normalized to global FDG uptake. Region of interest (ROI) analysis of striatal regions was used, as well as voxel-based analysis by statistical parametric mapping (SPM). ROI analysis did not reveal differences in striatal FDOPA and FDG uptake between the groups. SPM showed lower putaminal FDOPA uptake (P = 0.05 uncorrected) with increased FDG uptake (P = 0.01 uncorrected) in freezing PD, whereas caudate uptake of the two tracers was reduced. Freezing-related cortical FDG decrease was found in (right) parietal regions. In conclusion, in freezing PD, caudate uptake of FDG and FDOPA was reduced, whereas putamen FDOPA decrease was associated with FDG increase. Right hemisphere circuitry seemed to be more affected in freezing patients.