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.     

二维磁共振波谱分析在评价颅内胶质瘤中的临床应用

目的探讨脑胶质瘤二维磁共振波谱分析(2D 1H-MRS)表现及其主要代谢物含量变化。方法选择120例幕上脑胶质瘤行常规MRI及2D-1H-MRS检查并定量检测其主要代谢物N-乙酰天门冬胺酸(NAA)、含胆碱化合物(Cho)、肌酸(Cr)、乳酸(Lac)和脂质(Lip)含量。采用t检验进一步探讨各级别胶质瘤代谢物含量的差异。结果120例接受常规MRI和2D-1H-MRS检查的病例按术后病理结果分为三组:星形细胞瘤(AS)40例,间变性星形细胞瘤(AA)40例,胶质母细胞瘤(GM)40例。随胶质瘤恶性程度的增加,NAA呈下降趋势,Cho呈上升趋势,Cr变化不明显或轻度下降,Lip-Lac呈升高趋势。在AS与AA、AS与GM、AA与GM间NAA含量差异显著(p<0.01)。在AS与GM间Cr含量差异显著(P<0.05),在AS与AA、GM间Cho含量差异显著(p<0.01)。在AS与AA、AS与GM、AA与GM间Cho/cr比值差异显著(p<0.01);在AS与AA、GM间及AA与GM间NAA/Cho比值差异显著(p<0.01,P<0.05);在AS与AA、GM间Lip/lac比值差异显著(p<0.01)。结论胶质瘤2D1H-MRS表现及其代谢物定量研究有助于胶质瘤临床诊断与肿瘤恶性度分级。     

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。     

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。     

磁共振波谱联合MRI常规多参数扫描方案在前列腺癌中的诊断价值

目的 探讨磁共振波谱(MRS)联合磁共振成像常规多参数扫描(MP-MRI)方案在前列腺癌(PCa)中的诊断价值.方法 将104例疑诊PCa患者作为研究对象,均给予MRS联合MP-MRI检查,比较二者诊断价值和Cho/Cit和(Cho+Cre)/Cit水平.结果 病理结果显示,52例为前列腺增生,52例为PCa.MRS联...     

快速磁共振波谱成像的研究进展

传统磁共振波谱成像时间太长 ,不能应用到临床。发展快速波谱成像方法是必然的。目前有 7类快速波谱成像方法 ,它们都来自快速 MRI成像方法。本文对传统波谱成像和 7类快速方法分别作了介绍 ,并且展望如果把 MRI中任意轨迹图像重建方法用于波谱成像 ,将能够设计出速度更快的波谱成像数据采集脉冲序列。     

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.     

磁共振波谱成像技术在中枢神经系统疾病中的临床应用

磁共振波谱成像（magnetic resonance spectroscopy imaging,MRSI）是生物医学研究进入分子水平的重要检测工具之一,是分子医学、基因疗法等医学前沿的首选监控技术[1],它可以在疾病发生的早期,对人体的生化环境、组织代谢等进行无创定量分析。一、磁共振波谱（MRS）分析原理MRS是一种可以观察活体细胞代谢的无创伤性检测手段,化学位移和自旋耦合现象是它的关键,这两种现象形成了频谱的精细结构。波谱的水平轴代表共振频率,用每百万单位（ppm）表示,波峰高度或峰下面积与受检原子核数量呈正比。     

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.     

磁共振波谱成像技术的研究现状及发展趋势

磁共振波谱成像是21世纪生物医学研究进入分子水平的重要检测工具之一,它对各种严重疾病具有早期诊断和疗效监控能力。本文介绍了磁共振波谱成像在成像技术与数据重建、波谱量化和临床研究等方面的研究现状,并探讨了其发展趋势。     

Ultrastructural and Morphometric Investigation of Human Brain Capillaries in Normal and Peritumoral Tissues

Capillaries of peritumoral and normal brain tissues were ultrastructurally and morphometrically investigated to evaluate the changes in peritumoral capillaries connected with the tumor-associated vasogenic edema. The endothelial cells of peritumoral capillaries showed varying thickness, electron-lucent cytoplasm, and structurally normal tight junctions. The basal lamina was thickened, rarefied, and vacuolated. The pericytes were provided with pinocytotic vesicles and phagocytic bodies. The astrocytic glia appeared empty or swollen, with few glycogen granules and a disarranged cytoskeleton; well-preserved glia was occasionally observed. The brain tissue was slightly edematous. No statistically significant differences were observed between normal and peritumoral capillaries as regards diameter, wall thickness, endothelial thickness, and endothelial vesicle density. Instead, the peritumoral capillaries displayed three times as many endothelial surface-connected vesicles, a markedly thicker basal lamina, and significantly reduced extension of pericytic and glial investments. The kind and severity of the vascular modifications, compared with the slight edematous appearance of the nervous tissue, strengthen the hypothesis that peritumoral capillaries could be involved in the edema resolution process.     

皮质下缺血性脑血管病的磁共振波谱研究

目的:检测皮质下缺血性脑血管病(SIVD)患者和正常对照组不同脑区脑组织的代谢水平,探讨其与认知功能损害的关系。方法:采用多体素磁共振波谱(1 H-MRS)技术评测SIVD患者(SIVD组,n=32例)和体检健康人(对照组,n=21)额叶及顶叶皮质、白质的代谢物N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr);计算有关比值NAA/Cr、Cho/Cr,分析有无认知功能损害SIVD患者上述比值的变化。结果:(1)SIVD组额叶皮质、白质及顶叶皮质、白质各体素NAA/Cr比值明显低于对照组(P0.01);(2)SIVD组顶叶皮质及白质的Cho/Cr比值明显高于对照组(P0.01);(3)SIVD组有认知功能损害患者的额叶皮质和顶叶皮质、白质NAA/Cr比值显著低于无认知功能损害者(P值分别0.01、0.01、0.05),Cho/Cr比值的两者间差异无统计学意义(P0.05)。结论:SIVD患者脑组织存在NAA/Cr、Cho/Cr比值改变,且额叶皮质和顶叶皮质、白质NAA/Cr的下降与认知损害有关。     

The Action Sites of Propofol in the Normal Human Brain Revealed by Functional Magnetic Resonance Imaging

Propofol has been used for many years but its functional target in the intact brain remains unclear. In the present study, we used functional magnetic resonance imaging to demonstrate blood oxygen level dependence signal changes in the normal human brain during propofol anesthesia and explored the possible action targets of propofol. Ten healthy subjects were enrolled in two experimental sessions. In session 1, the Observer's Assessment of Alertness/Sedation Scale was performed to evaluate asleep to awake/alert status. In session 2, images with blood oxygen level dependence contrast were obtained with echo‐planar imaging on a 1.5‐T Philips Gyroscan Magnetic Resonance System and analyzed. In both sessions, subjects were intravenously administered with saline (for 3 min) and then propofol (for 1.5 min) and saline again (for 10.5 min) with a constant speed infusion pump. Observer's Assessment of Alertness/Sedation Scale scoring showed that the subjects experienced conscious–sedative–unconscious–analepsia, which correlated well with the signal decreases in the anesthesia states. Propofol induced significant signal decreases in hypothalamus (18.2% ± 3.6%), frontal lobe (68.5% ± 11.2%), and temporal lobe (34.7% ± 6.1%). Additionally, the signals at these three sites were fulminant and changed synchronously. While in the thalamus, the signal decrease was observed in 5 of 10 of the subjects and the magnitude of decrease was 3.9% ± 1.6%. These results suggest that there is most significant inhibition in hypothalamus, frontal lobe, and temporal in propofol anesthesia and moderate inhibition in thalamus. These brain regions might be the targets of propofol anesthesia in human brain. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

MRS在鉴别颅脑原发性肿瘤及转移瘤中的探讨

目的 探究颅脑原发性肿瘤与转移瘤鉴别中应用磁共振波谱的临床价值。方法 回顾性分析2012年1月~2018年5月在我院接受治疗的颅脑原发性肿瘤患者32例以及颅脑转移瘤患者25例的临床资料,分别记为甲组与乙组,诊断时均行MRS检查,计算并比较两组Cho/Cr、NAA/Cr、Cho/NAA。结果 经MRS诊断,甲组Cho/Cr、Cho/NAA分别为(3.12±1.02)、(3.18±1.05),乙组分别为(1.96±0.53)、(2.03±0.65),甲组高于乙组,差异有统计学意义（P＜0.05）,甲组NAA/Cr为(1.12±0.31),乙组为(1.47±0.37),甲组低于乙组,差异有统计学意义（P＜0.05）。结论 颅脑原发性肿瘤与转移瘤实质区代谢物相对浓度存在较大差异,临床中可使用MRS诊断对其进行鉴别,协助诊断,为治疗提供科学依据。     

A Review of the Automated Detection of Change in Serial Imaging Studies of the Brain

Serial imaging is frequently performed on patients with diseases of the brain, to track and observe changes. Magnetic resonance imaging provides very detailed and rich information, and is therefore used frequently for this application. The data provided by MR can be so plentiful; however, that it obfuscates the information the radiologist seeks. A system which could reduce the large quantity of primitive data to a smaller and more informative subset of data, emphasizing change, would be useful. This article discusses motivating factors for the production of an automated process to this effect, and reviews the approaches of previous authors. The discussion is focused on brain tumors and multiple sclerosis, but many of the ideas are applicable to other disease processes, as well.     

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.     

针灸人体穴位对应脑部区域特征代谢改变规律的研究方法探讨

随着国内外对针灸作用机制及理论的研究深入,明确针灸治疗脑部疾病的物理、化学和生物学效应突显重要。本文在分析针刺相关穴位对相关脑结构具有区域特异性的基础上,创造性地提出了研究脑部相关特异性区域中的相关代谢物定量表征的两种方法,进一步探讨了利用这种表征手段来研究针刺部位、手法、时间等参数作用于相关部位产生代谢改变状况的优越性。     

基于磁共振图像与波谱的专家辅助诊断系统的设计

神经系统疾病是影响人类寿命和生存质量的常见疾病,磁共振图像(MRI)和磁共振波谱(MRS)分别提供了病变结构像和代谢物含量改变信息。综合分析MRI和MRS信息有助于医生更好地诊断疾病和制定治疗方案,因此磁共振数据共享与辅助诊断平台的建设受到广泛关注。基于MRI和MRS的专家辅助诊断系统以脑肿瘤、阿尔茨海默症、轻度认知障碍为重点,以DICOM格式标准的MR图像和LCModel量化后的MRS结果为数据基础,使用MySQL建立后台数据库存储和管理医学数据,并采用Java进行系统的后台和前端开发。该系统提供了病人信息查询、MRI及其属性标签查看与下载、MRS量化结果显示与下载、MRS与MRI的位置配准及其空间可视化等功能,为医生、研究人员、管理员等提供不同权限的需要。该系统的建立为医生的病情诊断和科研人员实施研究提供了极大帮助,推进了远程资料共享和自动化诊断的进程,并促进临床和科研的学术交流。     

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。