帕金森病早期诊断的影像技术应用

帕金森病(Parkinson disease,PD)是一种常见于中老年人的慢性进行性神经变性疾病,其早期诊断对延缓病情发展及改善预后尤为重要。近些年,SPECT、PET、MRS、SWI、f MRI、经颅超声等医学影像技术的快速发展,加深了人们对PD脑形态结构、脑血流、代谢、神经递质、转运体和受体改变、黑质回声改变等的认识,也在PD的早期诊断中显示出较大潜力。     

几种新型的中枢多巴胺转运蛋白显像剂

中枢多巴胺转运蛋白显像剂123I-β-CIT(2β-carbomethoxy-3β-[4-iodophenyl]-tropane)在帕金森病诊断和鉴别诊断以及病情严重程度的评估的显像研究中已取得成功,但由于123I-β-CIT对多巴胺转运蛋白选择性较低,最佳显像时间在注射后20h,限制了其临床应用。近年来,人们又设计合成了几种新型的中枢多巴胺转运蛋白显像剂,使中枢多巴胺转运蛋白显像特性得到了明显的改善。     

锰中毒的神经影像学研究进展

近二十年来,医学影像学对临床医学的影响非常深刻,在疾病的诊断和治疗中的作用是具革命性的。核磁共振成像(MRI)、正电子发射断层摄影(PET)和单光子发射断层摄影(SPECT)等神经影像学方法在最近十年中已应用于锰中毒和其神经毒理学研究。MRI T1加权图像信号强度增加会反映锰的沉积,功能神经影像学如:PET、SPECT,能早期发现黑质纹状体多巴胺系统的异常,因此MRI、PET、SPECT对于锰中毒的诊断非常重要。     

DWI联合PET/CT对转移性骨肿瘤的影像学表现分析

目的 分析转移性骨肿瘤患者单独应用MRDWI、PET/CT以及二者联合应用的影像学诊断价值。方法 选取145例本院接诊的转移性骨肿瘤患者,采取MRDWI、PET/CT单独应用以及两种技术联合应用的诊断方案,对比不同b值下MRDWI技术诊断转移性骨肿瘤的差异,对比不同诊断方案的准确率以及诊断效能指标。结果 1)相比于b=50 s/mm²,b=400 s/mm²、b=800 s/mm²时的信号质量指数、信噪比、信号强度均明显更低,且b=400 s/mm²低于b=800 s/mm²时的数值(P<0.05);2)实质区在b=800 s/mm²时的ADC值明显低于坏死区(P<0.05);3)病理诊断结果显示145例患者共有150个病灶,混合型骨转移、成骨型骨转移病灶分别为110个、40个,MRDWI联合PET/CT检测以及MRDWI单独检测不同转移性骨肿瘤病灶的准确率均明显高于PET/CT单独检测,且联合检测高于MRDWI单独检测准确率,MRDWI的检测...     

99m Tc-MIBI SPECT对脑肿瘤恶性程度的诊断价值

目的:对99mTc-MIBI脑肿瘤SPECT同病理分级之问的关系进行研究.材料和方法:28例怀疑为脑肿瘤患者和5例脑转移瘤患者(平均年龄50.2±15.6岁)行99mTc-MIBI SPECT显像.根据术后病理诊断分组:良性或低度恶性病变组和高度恶性肿瘤组.结果:良性或低度恶性肿瘤组和高度恶性肿瘤组的早期相99mTc-MIBI摄取率分别为3.17±3.00、4.90±2.85,P=0.136;两组的延迟相99mTc-MIBI摄取率分别为2.75±2.49、6.81±4.18,经统计学检验两者P=0.011;两组滞留率分别为-0.42±0.65、1.91±2.30,经统计学检验两者P=0.006;两组滞留指数分别为-8.2%±21.3%,39.4%±51.1%,P=0.011.结论:99mTc-MIBI脑肿瘤SPECT可对了解脑肿瘤良、恶性提供一定帮助.滞留率和滞留指数由于反映的是脑肿瘤细胞内示踪剂的动态过程,因此具有较高的鉴别价值,尤以滞留率更佳.99mTc-MIBI脑肿瘤SPECT可在术前同CT或MRI影像学检查起到互补作用.     

99m Tc-MIBI心肌显像对冠状动脉病变的定位研究

目的：探讨９９ｍＴｃ－ＭＩＢＩ心肌显像在检出冠心病病变心肌节段和病变血管定位上的价值。方法：对照分析２０例冠心病和５例对照组冠状动脉造影与９９ｍＴｃ－ＭＩＢＩ单光子发射断层显像（ＳＰＥＣＴ）的结果。结果：潘生丁负荷ＳＰＥＣＴ检出冠心病、病变血管和病变心肌节段的敏感性分别为９５．００％、６３．６４％和４３．６８％明显高于静息相的６０．００％、４２．４２％和２７．５９％（Ｐ＜０．０１）。与静息相比较,潘生丁负荷ＳＰＥＣＴ多发现３３．３３％的病变血管和３６．８４％的病变心肌节段。对病变血管的敏感性,ＬＡＤ高于ＲＣＡ和ＬＣＸ;对于病变心肌节段检测敏感性ＲＣＡ支配节段高于ＬＡＤ和ＬＣＸ,特异性均较高。结论：潘生丁ＳＰＥＣＴ能显著提高冠心病的检出,有效估计病变心肌范围和病变冠状动脉     

功能影像学在癫痫灶定位诊断中的应用

外科手术已成为治疗药物难治性癫痫的有效手段,对于控制和治愈难治性癫痫,将致痫灶切除是最有效的方法,而术前精确定位致痫灶则是手术成功的关键。近年来,功能影像学在癫痫灶定位诊断中发挥越来越重要的作用。SPECT、PET及功能性磁共振(fMRI)在癫痫灶定位诊断中均有各自的优点,同时也存在各自的局限性,因此临床要根据患者实际情况选择检查方法。     

部分癫痫的神经影像学诊断

功能影像研究在部分癫痫综合征的评价中非常重要。磁共振波谱分析（MRS）有助于发现脑代谢物和一些神经递质，当没发现脑结构异常时，各种代谢物水平的下降具有判断预后的参考价值。PET可以显示葡萄糖代谢下降的区域。这些区域是致癫灶的标志，且通常大于结构异常区。PET对颞叶癫痫的定侧有用，然而对源于颞叶外的癫痫灶没有大的帮助，对此具有前景的是苯二氮彭咚受体配体显像，因为此配体显像的稀疏区的分布更局限，这将对来源于颞叶外的致癫灶的定位更有帮助。临近癫痫发作前后的SPECT可以显示脑血流的增加，且对于MRI正常的患者的癫痫发作的定侧和定位很有帮助。     

应用SPECT评价高压氧对新生儿缺氧缺血性脑病的疗效及其治疗机制的研究

目的　应用ＳＰＥＣＴ评价高压氧（ＨＢＯ）对新生儿缺氧缺血性脑病（ＨＩＥ）的疗效并探讨其治疗机制。方法　研究对象为３４ 例新生儿,分为正常新生儿组３ 例,ＨＢＯ 组ＨＩＥ患儿２０ 例和对照组ＨＩＥ患儿１１例。正常新生儿在出生后５～８ 天内进行１次ＳＰＥＣＴ检查作为比较。两组ＨＩＥ患儿分别在治疗前和治疗后各接受一次ＳＰＥＣＴ检查。结果　治疗前３１ 例ＨＩＥ患儿ＳＰＥＣＴ示有４６ 个大小不同的局灶性血流灌注低下区和功能缺损。ＨＢＯ组ＨＩＥ患儿经１～２ 个疗程的ＨＢＯ治疗后,脑内原有局灶性血流灌注低下区和功能缺损缩小或消失。对照组的ＨＩＥ患儿虽也有一定好转,但恢复程度不及ＨＢＯ组,两组之间的疗效有非常显著性差异（Ｐ＜ ０．０１）。结论　ＨＢＯ治疗ＨＩＥ患儿疗效显著,其机制可能主要是通过增加脑组织局部血流灌注和含氧量,改善脑细胞的缺氧状态,激发脑细胞的活性,促进损伤脑细胞的修复     

帕金森病的影像学诊断进展

帕金森病(PD)是中老年人最常见的神经退行性疾病之一,是一种以运动迟缓、强直和静止性震颤为主要临床症状的神经变性疾病。2005年,北京、西安和上海3个大城市的流行病学调查发现,PD在65岁以上人群中的发病率为1.7%,已经接近发达国家的发病率[1],发病人数保守估计超过170万。由于PD致残率高,病程长,严重影响了中老年人的生活质量。神经影像及尸检结果显示,在退行性神经病变的早期进行神     

Thallium-201 SPECT with triple-headed gamma camera for differential diagnosis of small pulmonary nodular lesion 20 mm in diameter or smaller

AIM: Although thallium-201 (201Tl) has been used for the diagnosis of lung cancer, its detectability of small pulmonary nodules is not known. The aim of this study was to evaluate the ability of 201Tl SPECT for the differential diagnosis for the pulmonary nodules 20 mm in diameter or smaller. METHODS: 201Tl SPECT was performed in 31 patients suspected of having primary lung cancer. The final diagnosis was established by histology, and tumor size was 10 to 20 mm in diameter. Twenty of 31 patients had malignant tumors, including squamous cell lung cancer (n = 5), adenocarcinoma (n = 14) and small cell lung cancer (n = 1), but in none of them was there mediastinal lymphnode involvement. RESULTS: Ten of 20 malignant tumors and 1 of 11 benign lesions demonstrated significant 201Tl uptake, so that the positive predictive value, negative predictive value, sensitivity and specificity for the diagnosis of lung cancer were 90.9% (10/11), 50.0% (10/20), 50.0% (10/20) and 90.9% (10/11), respectively. CONCLUSION: These data suggest that sensitivity for detecting lung cancer 20 mm or less in diameter may be insufficient, but even in patients with small pulmonary nodules, a positive 201Tl result is highly predictive of lung cancer.     

Unexpected accumulation of thallium-201 in bilateral thalamic venous infarction induced by arteriovenous fistula in the posterior fossa: Report of a case

We encountered unexpected accumulation of thallium-201 in a patient with thalamic dementia resulting from bithalamic venous infarction induced by arteriovenous fistula in the posterior fossa The site and degree of abnormal accumulation varied between early and delayed thallium-201 SPECT images. This unexpected and complicated accumulation of thallium-201 appeared to depend on not only breakdown of the blood-brain barrier but also on the hemodynamics of this type of venous infarction.     

统计参数图在PET和SPECT脑功能显像中的应用

感兴趣区(ROI)法是脑功能显像资料常用的分析方法,但由于其主观性强、重复性差等缺点使脑功能研究的精确性及效率显著降低,统计参数图(SPM)法是为解决这一问题而开发的以像素为基础的自动分析软件,该法将多种数理模型应用到针对全脑的像素统计推断中。本文介绍了该法的简单原理、主要应用模块组成和实际应用。该方法对认知领域、神经生物学和神经药理学的研究将起到一定的推动作用,必将随着脑科学进展的需要得到更广泛的应用。     

放射性肝损伤的早期影像学评价实验研究

目的:探讨早期放射性肝脏损伤的99mTc-Phytate显像和超顺磁性氧化铁(SPIO)增强MRI表现。方法:12只成年家兔,左侧半肝X线照射后第3、4天,行99mTc-Phytate显像SPECT和SPIO增强MRI检查,并进行病理分析。结果:99mTc-Phytate肝显像,家兔肝脏照射区核素摄取减弱呈放射性稀疏区;SPIO增强早期MRI,家兔肝脏照射区较未照射区呈高信号;特异性铁颗粒染色肝脏照射区吞噬SPIO颗粒的Kupffer细胞数量下降。结论:99mTc-Phytate肝显像与SPIO增强MRI均可敏感地检出肝脏照射后早期出现的网状内皮系统损伤,SPIO增强MRI对早期诊断有很好的应用潜力。     

Applications of SPECT imaging of dopaminergic neurotransmission in neuropsychiatric disorders

Single photon emission computed tomography (SPECT) tracers selective for pre- and post-synaptic targets have allowed measurements of several aspects of dopaminergic (DA) neurotransmission. In this article, we will first review our DA transporter imaging in Parkinson's disease. We have developed the in vivo dopamine transporter (DAT) imaging with [123I]beta-CIT ((1R)-2beta-Carbomethoxy-3beta-(4-iodophenyl)tropane). This method showed that patients with Parkinson's disease have markedly reduced DAT levels in striatum, which correlated with disease severity and disease progression. Second, we applied DA imaging techniques in patients with schizophrenia. Using amphetamine as a releaser of DA, we observed the enhanced DA release, which was measured by imaging D2 receptors with [123I]IBZM (iodobenzamide), in schizophrenics. Further we developed the measurement of basal synaptic DA levels by AMPT (alpha-methyl-paratyrosine)-induced unmasking of D2 receptors. Finally, we expanded our techniques to the measurement of extrastriatal DA receptors using [123I]epidepride. The findings suggest that SPECT is a useful technique to measure DA transmission in human brain and may further our understanding of the pathophysiology of neuropsychiatric disorders.     

Comparison of FDG-PET and IMP-SPECT in patients with dementia with Lewy bodies

OBJECTIVES: To investigate regional differences in cerebral glucose metabolism and blood flow of dementia with Lewy bodies (DLB), we studied 7 subjects with DLB and 20 normal controls using F-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET) and then examined the same 7 subjects and 20 other normal controls with I-123 iodoamphetamine (IMP) and single photon emission computed tomography (SPECT). METHODS: The anatomically standardized images were produced with NEUROSTAT and the regional relative metabolic and perfusional values were calculated. RESULTS: The mean reduction ratios of FDG uptake in the DLB group relative to the mean normal controls in the parietal lobe and occipital lobe were 0.72 and 0.83, respectively, while the corresponding mean reduction ratios of IMP uptake were 0.81 and 0.88, respectively. In the DLB group, parietal FDG uptake was significantly lower than parietal IMP uptake (p < 0.05), occipital FDG uptake was significantly lower than occipital IMP uptake (p < 0.05), and parietal IMP uptake was significantly lower than occipital IMP uptake (p < 0.01), but there was no difference between parietal and occipital FDG uptake. CONCLUSIONS: Our findings suggest that parietal metabolism and perfusion are severely affected in DLB patients, though the occipital metabolic and perfusional reduction is thought to be a feature of DLB. FDG-PET is thought to be superior to IMP-SPECT in detecting functional changes in the DLB brain.     

Technical and analytical advances in pulmonary ventilation SPECT with xenon-133 gas and Tc-99m-Technegas

This paper describes the recent advances in technical and analytical methods in pulmonary ventilation SPECT studies, including a respiratory-gated image acquisition of Technetium-99m (99mTc)-labeled Technegas SPECT, a fusion image between Technegas SPECT and chest CT images created by a fully automatic image registration algorithm, and a three-dimensional (3D). display of xenon-133 (133Xe) gas SPECT data, and new analytical approaches by means of fractal analysis or the coefficient of variations of the pixel counts for Technegas SPECT data. The respiratory-gated image acquisition can partly eliminate problematic effects of the SPECT images obtained during non-breath-hold. The fusion image is available for routine clinical use, and provides complementary information on function and anatomy. The 3D displays of dynamic 133Xe SPECT data are helpful for accurate perception of the anatomic extent and locations of impaired ventilation, and the assessment of the severity of ventilation abnormalities. The new analytical approaches facilitate the objective assessment of the degrees of ventilation abnormalities.     

Accuracy and reproducibility of co-registration techniques based on mutual information and normalized mutual information for MRI and SPECT brain images

We implemented a 3D co-registration technique based on mutual information (MI) including 2D image matching as a coarse pre-registration. The 2D coarse pre-registration was performed in the transverse, sagittal and coronal planes sequentially, and all six parameters were then optimized as fine registration. Normalized mutual information (NMI) was also examined as another entropy-based measure that was invariant to the overlapped area of two images. In order to compare accuracy and precision of the present method with a conventional two-level multiresolution approach, simulation was performed by 100 trials with the random initial mismatch of +/-10 degrees and +/-17.92 mm (Type-I) and +/-20 degrees and +/-40.32 mm (Type-II). For Type-I, no significant differences were found between registration errors of the multiresolution approach and the present method with the MI criterion. No biases were observed (< or =0.13 degrees and < or =0.57 mm for the multiresolution approach; < or =0.12 degrees and < or =0.57 mm for the present method) and the SDs were very small (< or =0.18 degrees and < or =0.12 mm for the multiresolution approach; < or =0.11 degrees and < or =0.11 mm for the present method). For Type-II, SDs for the multiresolution approach (< or =1.8 degrees and < or =0.88 mm) were markedly larger than those for the present method (< or =0.64 degrees and < or =0.20 mm) with MI. Success rate for the present method was 99.9%, which was higher than 97.6% for the multiresolution approach. Simulation also revealed that MI and NMI performance were almost equivalent. The choice of optimization strategy more affected accuracy and reproducibility than the choice of the registration criterion (MI or NMI) in our simulation condition. The present method is sufficiently accurate and reproducible for MRI-SPECT registration in clinical use.     

Assessment of anatomic relation between pulmonary perfusion and morphology in pulmonary emphysema with breath-hold SPECT-CT fusion images

OBJECTIVE: Anatomic relation between pulmonary perfusion and morphology in pulmonary emphysema was assessed on deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images. METHODS: Subjects were 38 patients with pulmonary emphysema and 11 non-smoker controls, who successfully underwent DIBrH and non-BrH perfusion SPECT using a dual-headed SPECT system during the period between January 2004 and June 2006. DIBrH SPECT was three-dimensionally co-registered with DIBrH CT to comprehend the relationship between lung perfusion defects and CT low attenuation areas (LAA). By comparing the appearance of lung perfusion on DIBrH with non-BrH SPECT, the correlation with the rate constant for the alveolar-capillary transfer of carbon monoxide (DLCO/VA) was compared between perfusion abnormalities on these SPECTs and LAA on CT. RESULTS: DIBrH SPECT provided fairly uniform perfusion in controls, but significantly enhanced perfusion heterogeneity when compared with non-BrH SPECT in pulmonary emphysema patients (P < 0.001). The reliable DIBrH SPECT-CT fusion images confirmed more extended perfusion defects than LAA on CT in majority (73%) of patients. Perfusion abnormalities on DIBrH SPECT were more closely correlated with DLCO/VA than LAA on CT (P < 0.05). CONCLUSIONS: DIBrH SPECT identifies affected lungs with perfusion abnormality better than does non-BrH SPECT in pulmonary emphysema. DIBrH SPECT-CT fusion images are useful for more accurately localizing affected lungs than morphologic CT alone in this disease.     

Relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism: assessment with breath-hold SPECT-CT pulmonary angiography fusion images

PURPOSE: The relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism (PTE) was comprehensively assessed on deep-inspiratory breath-hold (DIBrH) perfusion SPECT-computed tomographic pulmonary angiography (CTPA) fusion images. MATERIALS AND METHODS: Subjects were 34 acute PTE patients, who had successfully performed DIBrH perfusion SPECT using a dual-headed SPECT and a respiratory tracking system. Automated DIBrH SPECT-CTPA fusion images were used to assess the relation between lung perfusion defects and intravascular clots detected by CTPA. RESULTS: DIBrH SPECT visualized 175 lobar/segmental or subsegmental defects in 34 patients, and CTPA visualized 61 intravascular clots at variable locations in 30 (88%) patients, but no clots in four (12%) patients. In 30 patients with clots, the fusion images confirmed that 69 (41%) perfusion defects (20 segmental, 45 subsegmental and 4 lobar defects) of total 166 defects were located in lung territories without clots, although the remaining 97 (58%) defects were located in lung territories with clots. Perfusion defect was absent in lung territories with clots (one lobar branch and three segmental branches) in four (12%) of these patients. In four patients without clots, nine perfusion defects including four segmental ones were present. CONCLUSION: Because of unexpected dissociation between intravascular clots and lung perfusion defects, the present fusion images will be a useful adjunct to CTPA in the diagnosis of acute PTE.