磁共振波谱分析在颅脑胶质瘤分级中的应用研究

目的分析脑胶质瘤的氢质子磁共振波谱(proton magnetic resonance spectroscopy,~1H-MRS)表现及其临床意义;探讨脑胶质瘤的1H-MRS特点与其病理级别相关性。方法搜集经临床手术、病理证实的脑胶质瘤病例49例,按照WHO诊断标准分成两组:低级别脑胶质瘤组、高级别脑胶质瘤组。所有患者在术前行~1H-MRS检查,均在MR非增强成像的基础上获得。使用Philips Achieva 1.5T超导磁共振扫描仪,单体素或多体素扫描,点分辨法,检测不同区域代谢物变化。结果脑胶质瘤的~1H-MRS表现:肌酸(Cr)轻度下降,N-乙酰天门冬氨酸(NAA)显著下降,胆碱(Cho)显著增高。低、高级别脑胶质瘤的肿瘤组织与对侧正常脑组织的NAA、Cho、NAA/Cr、NAA/Cho值存在显著性差异(P0.05);低级别和高级别脑胶质瘤的肿瘤组织的NAA/Cr、NAA/Cho值存在显著性差异(P0.05)。脑胶质瘤的NAA/Cho、Cho/Cr、NAA/Cr值与病理级别相关,其中NAA/Cho和NAA/Cr值反映肿瘤级别较稳定;NAA/Cr、NAA/Cho值呈负相关关系,Cho/Cr值呈正相关关系。结论 :~1H-MRS结合MRI能提高脑胶质瘤术前诊断的准确性。~1H-MRS能对胶质瘤进行分级,反映胶质瘤代谢特性以及肿瘤生长潜能。     

质子磁共振波谱分析在颅内病变诊断中的应用

目的:探讨氢质子磁共振波谱(MRS)检查技术在颅内占位性病变诊断中的临床应用价值.方法:对40例经立体定向活检确诊的颅内占位性病变病例行常规MRI检查,同时行MRS检查,并计算病变区Cho/Cr,NAA/Cr,Cho/NAA值,分别依据单纯常规MRI和MRI结合MRS作出术前诊断,最后再与病理结果比较.结果:不同的疾病有不同的波谱特征;与病理诊断比较,常规MRI诊断正确率为37.5% (15/40),而MRI结合MRS诊断正确率为80%(32/40),二者相比差异有统计学意义(P＜0.05).结论:MRS可提供组织生化和代谢方面的信息,可以提供比常规MRI之外更多的信息,对颅内占位性病变的诊断提供帮助.     

2D1H-MRS与PWI技术相结合在评价胶质瘤中的应用

目的探讨胶质瘤内含胆碱化合物(Cho),肌酸(Cr)、脂质(Lip)、乳酸(Lac)含量与肿瘤相对性脑血流容积(rCBV)间的相关性,间接评价胶质瘤细胞增殖、缺氧与坏死及血管生成情况。方法采用二维质子磁共振波谱分析技术(2D ~1H-MRS)与灌注成像技术(PWI),分别定量测量40例胶质瘤代谢物(Cho/Cr、Lac、Lip)与rCBV,并采用统计学分析探讨不同级别胶质瘤代谢物含量变化及代谢物含量与rCBV的相关性。结果经MRI影像诊断的40例胶质瘤术后病理证实为星形细胞瘤20例,间变性星形细胞瘤12例,胶质母细胞瘤8例。t检验表明,rCBV、Cho/Cr、Lip-Lac在低级别组(星形细胞瘤20例)和高级别组(包括间变性星形细胞瘤12例和胶质母细胞瘤8例)间均有非常显著的差异(t=3.29,p<0.01;t=6.73,p<0.01;t=28.9,p<0.01)。相关性分析表明,rCBV与Cho/Cr具有非常显著的正相关(r=0.635,p<0.01),rCBV与Lip-Lac具有显著正相关(r=0.554,p<0.05)。结论2D ~1H-MRS与PWI技术相结合可用于胶质瘤恶性度分级,对胶质瘤临床诊断和治疗方案选择具有一定的指导作用。     

磁共振波谱分析联合荧光素钠导航手术在幕上高级别胶质瘤患者中的实施效果

目的 探究磁共振波谱分析(MRS)联合荧光素钠(FL)导航手术在幕上高级别胶质瘤患者中的效果.方法 随机选94例幕上高级别胶质瘤患者分为对照组(行常规显微外科手术)和观察组(行MRS+FL导航手术),每组47例,对比治疗效果.结果 观察组肿瘤全切率为95.74％较对照组的72.34％高,KPS评分表明、肿瘤无进展生存时...     

奇异值分解在磁共振波谱成像中的应用

目的:磁共振波谱成像有7类快速方法,它们都来自快速MRI成像方法.本文提出的奇异值分解波谱成像不同这7类快速方法,它是把MRI中任意轨迹图像重建方法用于波谱成像,这将有利于设计出速度更快的波谱成像数据采集脉冲序列.     

弥散加权成像联合磁共振波谱分析在脑梗死中的应用研究

目的探讨脑梗死弥散加权成像(DWI)和磁共振波谱分析(MRS)的特点和影响因素,及二者对评估脑梗死的临床价值。方法采用Philips Achieva 1.5T双梯度超导磁共振扫描仪,对72例临床疑是脑梗死患者行常规T1WI、T2WI、FLAIR、DWI、MRS检查,在工作站上测定梗死核心区、内缘区、外缘区、周围区和镜像区的ADC值和代谢物Lac、NAA、Cr、Cho、NAA/Cr、Lac/Cr、Lac/NAA值。结果 DWI显示的梗死灶范围较常规MRI像更加准确、清晰;超急性期、急性期、亚急性期和慢性期梗死核心区的Lac/Cr值和Lac/NAA值高于对侧镜像区,ADC值和NAA/Cr值低于对侧镜像区,存在统计学差异(P<0.05);DWI的影响因素有b值、扩散系数、T2穿透效应和各向异性等,MRS的影响因素有磁场均匀性、压水压脂性能、体素、TE与TR、组织代谢物浓度和波谱采集链等。结论 DWI结合MRS能更加全面地评估缺血半暗带,更精确地对脑梗死进行分期和定位。     

磁共振波谱（MRS）对胶质瘤切除程度评估的初步研究

目的　探讨术前后MRS在胶质瘤手术切除程度评估的应用价值。 方法　对16例胶质瘤患者术前术后行常规MRI和3D多体素MRS检查,计算术前后的Cho/Cr和Cho/NAA的比值,寻找相等或相近的Cho/Cr和Cho/NAA比值,结合体素所在层面的位置,建立对应关系,从而评价术后切除到达范围。同时术中收集“瘤周组织”作病理检查,评估切除程度,与3D多体素MRS评估结果相比较。 结果　16例病人收集到完整的影像学和病理学资料有11例,病理评估为3例全切除,8例为大部分切除;3D多体素MRS 评估为2例全切除,9例为大部分切除,评估结果与术后病理评估结果无显著性差异（P>0.05）。 结论　无创性评估胶质瘤切除程度是MRS的一项新应用,具有良好的发展前景。     

二维颅脑质子磁共振成像法的代谢的含量的测定方法

该方法用于自动分析和测定ＭＲＩ得到的人体颅脑代谢物的质子谱，能自动校正谱线的相，基线和线型，能准确地分析各代谢物的参量，能避免由于人为因素所造成的分析误差。该方法能对ＮＡＡ、Ｌａｃｔａｔｅ，Ｃｈｏｌｉｎｅ，Ｃｒｅａｔｉｎｅ等代谢物的含量进行分析，从而能提高对某些脑病变的诊断率。     

二维颅脑质子磁共振谱成像法的代谢物含量的测定方法

该方法用于自动分析和测定ＭＲＳＩ得到的人体颅脑代谢物的质子谱，能自动校正谱线的相、基线和线型，能准确地分析各代谢物的参量，能避免由于人为因素所造成的分析误差。该方法能对ＮＡＡ、Ｌａｃｔａｔｅ、Ｃｈｏｌｉｎｅ、Ｃｒｅａｔｉｎｅ等代谢物的含量进行分析，从而能提高对某些颅脑病变的诊断率。     

磁共振波谱成像(MRSI)的数据重建及波谱量化分析软件系统

采用交互式数据语言开发了基于PC机的磁共振波谱成像数据重建和波谱量化分析的软件系统.它可以实现临床MRSI原始数据和图像数据读入、代谢物种类设计、数字幻影模型生成、k-空间采样轨迹设计、k-空间原始数据生成、数据重建、波谱定量分析以及代谢物图像生成等功能.该系统有助于学习和开发新的MRSI采样轨迹,数据重建方法和波谱量化分析方法,在国内还未见前例.     

瘤周区多体素磁共振波谱在脑肿瘤鉴别诊断中的应用

目的评价脑肿瘤周围区域多体素氢质子磁共振波谱(1H-MRS)在脑肿瘤诊断及鉴别诊断中的应用价值。方法搜集行常规MRI及多体素1H-MRS检查的脑肿瘤病变患者38例,包括胶质瘤15例、转移瘤9例、脑膜瘤14例(均为良性)。再根据WHO2000年分类标准,将脑胶质瘤分为低级别组(Ⅰ～Ⅱ级)8例,高级别组(Ⅲ～Ⅳ级)7例。所有患者检查前均未接受过化疗或放疗,没有脑外伤或/和脑手术史。常规扫描后增强前采用定点分辨磁共振波谱序列(PRESS)扫描,根据病灶的特征选定感兴趣区(ROI),ROI的大小既要包括肿瘤实质区、肿瘤周围区,也要尽可能涵盖对侧正常脑组织,又要避开骨骼、脑室、血管、坏死、囊变、出血、气体及钙化等区域。后处理应用MR机附带的波谱分析软件自动完成。计算脑胶质瘤、转移瘤及脑膜瘤实质区、周围区及对侧正常脑组织区代谢产物比值的平均值,进行组内、组间比较。P<0.05有统计学意义。结果多体素1H-MRS显示不同脑肿瘤的肿瘤实质区NAA/Cr、Cho/Cr和NAA/Cho平均值与对侧正常脑组织区比较有显著性差异(P<0.05);脑胶质瘤周围区与脑膜瘤、转移瘤的周围区以及高、低级别胶质瘤肿瘤周围区域多组代谢物比值具统计学差异(P<0.05)),高级别与低级别脑胶质瘤肿瘤周围区Glx/Cr的比值有显著性差异(P<0.05)。结论多体素1H-MRS技术可无创观察脑肿瘤患者脑代谢改变,有助于脑肿瘤的诊断、鉴别诊断、预测侵袭性病变的浸润范围以及脑胶质瘤的分级诊断等。     

人脑胶质瘤中肝癌衍生生长因子及细胞周期素D1的表达及意义

目的探讨肝癌衍生生长因子（hepatoma—derived growth factor,HDGF）与细胞周期素D1（cyclin D1）在人脑胶质瘤中的表达及意义。方法采用免疫组织化学法检测9例脑外伤内减压切除的正常脑组织和55例不同级别脑胶质瘤组织中HDGF和cyclin D1的表达强度。结果在55例胶质瘤组织中,HDGF及eyclin D1的表达阳性率分别为74．5％（41／55）和63．6％（35／55）,显著高于正常对照脑组织中的表达水平（3／9和2／9,P=0．008和P=0．024）。胶质瘤组织恶性程度越高,HDGF及cyclin D1表达越强（P=0．006和P〈0．001）。胶质瘤组织中HDGF与cyclin D1的表达水平呈正相关性（r=0．728,P〈0．001）。结论HDGF与cyclin D1蛋白在脑胶质瘤的发生发展中起重要作用。     

Metabolite alterations in autistic children: a 1H MR spectroscopy study

PurposeThe purpose of this study was to assess the role of proton magnetic resonance spectroscopy (1H MRS) in the detection of changes in cerebral metabolite levels in autistic children.Material and methodsStudy group consisted of 12 children, aged 8–15 years, who were under the care of Pediatric Neurology Department and Pediatric Rehabilitation Department of Medical University of Bialystok. The diagnosis of autism was established by neurologist, psychiatrist and psychologist in every case. All patients matched the clinical criteria of the disease according to International Statistical Classification of Diseases and Related Health Problems (ICD-10). The control group included 16 healthy children aged 7–17. ¹H MRS was performed with a single-voxel method (TE-36, TR-1500, NEX-192). The volume of interest (VOI) was located in the frontal lobe regions, separately on each side.ResultsWe showed lower N-acetylaspartate/creatine (NAA/Cr), γ-aminobutyric acid /creatine (GABA/Cr) and glutamate/creatine (Glx/Cr) in the frontal lobes in the study group comparing with healthy controls. The ratio of myoinositol/creatine (mI/Cr) was increased in autistic children. No differences in choline/creatine (Cho/Cr) ratio in study group and controls were found. There was a correlation between age and NAA/Cr in autistic children (R=0.593 p=0.041). No significant differences in metabolite ratios between right and left hemisphere in ASD and controls were found.Conclusions¹H MRS can provide important information regarding abnormal brain metabolism. Differences in NAA/Cr, GABA/Cr, Glx/Cr and mI/Cr may contribute to the pathogenesis of autism.     

Reduced Brain GABA in Primary Insomnia: Preliminary Data from 4T Proton Magnetic Resonance Spectroscopy (1H-MRS)

Study Objectives:

Both basic and clinical data suggest a potential significant role for GABA in the etiology and maintenance of primary insomnia (PI). Proton magnetic resonance spectroscopy (1H-MRS) can non-invasively determine GABA levels in human brain. Our objective was to assess GABA levels in unmedicated individuals with PI, using 1H-MRS.

Design and Setting:

Matched-groups, cross-sectional study conducted at two university-based hospitals.

Participants:

Sixteen non-medicated individuals (8 women) with PI (mean age = 37.3 +/− 8.1) and 16 (7 women) well-screened normal sleepers (mean age = 37.6 +/− 4.5).

Methods and Measurements:

PI was established with an unstructured clinical interview, a Structured Clinical Interview for DSM-IV (SCID), sleep diary, actigraphy and polysomnography (PSG). 1H-MRS data were collected on a Varian 4 Tesla magnetic resonance imaging/spectroscopy scanner. Global brain GABA levels were averaged from samples in the basal ganglia, thalamus, and temporal, parietal, and occipital white-matter and cortex.

Results:

Average brain GABA levels were nearly 30% lower in patients with PI (.18 +/− .06) compared to controls (.25 +/− .11). GABA levels were negatively correlated with wake after sleep onset (WASO) on two independent PSGs (r = −0.71, p = 0.0024 and −0.70, p = 0.0048).

Conclusions:

Our preliminary finding of a global reduction in GABA in non-medicated individuals with PI is the first demonstration of a neurochemical difference in the brains of those with PI compared to normal sleeping controls. 1H-MRS is a valuable tool to assess GABA in vivo, and may provide a means to shed further light on the neurobiology of insomnia.

Citation:

Winkelman JW; Buxton OM; Jensen JE; Benson KL; O''Connor SP; Wang W; Renshaw PF. Reduced brain GABA in primary insomnia: preliminary data from 4T proton magnetic resonance spectroscopy (1H-MRS). SLEEP 2008;31(11):1499–1506.     

Morphogenesis of Lateral Choroid Plexus During Human Embryonic Period

The morphological and histological changes of the choroid plexus (CP) during Carnegie stage (CS) 18 and CS23 were presented, based on magnetic resonance imaging data and histological serial section of human embryos from the Kyoto Collection of Human Embryos. The primordium of the CP was initially detected as a small lump at CS19 that grew caudally, so that the CP became crescent shaped. It developed in all directions after CS21, as the dorsal and frontal growth also became prominent. The CP formed a number of undulating surfaces at CS20, irregular bulges at CS21, and then three large clusters with two deep fissures on the caudal surface at CS23. The mean volume of the CP was 0.282±0.141 mm³ at CS19; it reached 16.8±8.77 mm³ at CS23. Additionally, the histology was different depending on the regions of the CP at all stages after CS20. The epithelium and angioblasts in the center of the stroma were proliferated in the proximal region, whereas the epithelium was differentiated and lobulated in the distal region where the blood vascular system was organized. The histological differentiation was mapped on the CP reconstructed from histological serial sections. The data suggested the correlation between morphological information obtained from magnetic resonance data sets and distribution of the differentiation. With the help of morphological analysis and histological findings, we have been able to categorize each CP into specific stages. These findings will be useful in clinical evaluation of development during the embryonic period. Anat Rec, 296:692–700, 2013. © 2013 Wiley Periodicals, Inc.     

The relationship between the expression of tumor matrix-metalloproteinase and the characteristics of magnetic resonance imaging of human gliomas

Objective

To investigate the relationship between the expression level of matrix-metalloproteinases (MMPs) with the pathological grades and MRI characteristics of human gliomas.

Methods

Prior pre- and post-contrast enhancement MRI was performed on 31 patients with gliomas, which were confirmed by post-operational pathology. The expression of MMP-2 and MMP-9 were determined by immunohistochemical staining in both a low grading group (grades I and II, n = 20) and high grading group (grades III and IV, n = 11).

Results

Compared to the low grading group, the expression levels of MMP-2, MMP-9, as well as the tumor edema index (EI), enhanced percentage (EP) and maximum diameters were significantly greater in the high grading group. MMP-2 and MMP-9 expression were correlated with the tumor EI, EP and the maximum diameters. There were no differences in MMP-2 and MMP-9 expression between the unclear border definition group and the clear border definition group, whereas the MMPs expression levels were greater in the heterogeneous signal group than in the homogeneous signal group.

Conclusion

The expression level of MMPs is correlated with the invasion ability of human gliomas. The MRI parameters, such as tumor EI, EP, maximum diameter, and signal heterogeneity technically reflect the expression level of MMPs, and can be used to estimate the tumor''s malignant behavior, thus providing the guidance for clinical therapies.     

Evaluation of treatment effects in Alzheimer's and other neurodegenerative diseases by MRI and MRS

Neurodegeneration refers to a large clinically and pathologically heterogeneous disease entity associated with slowly progressive neuronal loss in different anatomical and functional systems of the brain. Neurodegenerative diseases often affect cognition, e.g. Alzheimer's disease (AD), dementia with Lewy bodies and vascular dementia, or different aspects of the motor system, e.g., amyotrophic lateral sclerosis, Parkinson's disease and ataxic disorders. Owing to increasing knowledge about the mechanisms leading to neurodegeneration, the development of treatments able to modify the neurodegenerative process becomes possible for the first time. Currently, clinical outcome measures are used to assess the efficacy of such treatments. However, most clinical outcome measures have a low test-retest reliability and thus considerable measurement variance. Therefore, large patient populations and long observation times are needed to detect treatment effects. Furthermore, clinical outcome measures cannot distinguish between symptomatic and disease-modifying treatment effects. Therefore, alternative biomarkers including neuroimaging may take on a more important role in this process. Because MR scanners are widely available and allow for non-invasive detection and quantification of changes in brain structure and metabolism, there is increasing interest in the use of MRI/MRS to monitor objectively treatment effects in clinical trials of neurodegenerative diseases. Particularly volumetric MRI has been used to measure atrophy rates in treatment trials of AD because the relationship between atrophic changes and neuron loss is well established and correlates well with clinical measures. More research is needed to determine the value of other MR modalities, i.e. diffusion, perfusion and functional MRI and MR spectroscopy, for clinical trials with neuroprotective drugs.     

Serial proton spectroscopy,magnetization transfer ratio and T 2 relaxation in pseudotumoral demyelinating lesions

In some rare cases, demyelinating plaques appear on contrast-enhanced T1-weighted images as pseudotumoral, cyst-like lesions (hypointense, ring enhancing). Serial proton MR spectroscopy, T2 relaxometry and magnetization transfer ratios (MTR) were performed on three pseudotumoral demyelinating lesions to obtain information about their pathological basis. Baseline and 1-month MTR and T2 values were similar to those of cerebrospinal fluid, while spectra showed lactate, lipids and choline. Three-month and 1 year exams showed recovery of MTR, T2 and N-acetylaspartate, approaching the contralateral values, while creatine and choline were normal or surpassed contralateral values. Lipids and lactate gradually disappeared. These results suggest that pseudotumoral, cyst-like, ring-enhancing lesions may be characterized by an accumulation of oedema in the extracellular space with an almost complete absence of cells. Reduction of the oedema allows restoration of the tissue to its original location, indicating that cellular destruction was less important than was expected after the first exam. Thus, the evolution of this kind of lesion should be kept in mind when considering lesion volume from T1-weighted images as a marker of disability or irreversible cellular destruction in MS.