磁共振弥散张量成像对良 恶性脑膜瘤诊断的初探

目的运用磁共振弥散张量成像(DTI)测量脑膜瘤表现弥散系数(ADC)值、FA值和白质纤维走行图,探讨其对良、恶性脑膜瘤的诊断价值。方法对23例良性脑膜瘤,4例恶性脑膜瘤行弥散张量成像,分别测量肿瘤实质区、瘤周水肿区和瘤周白质区的ADC值和FA值,并根据原始图像重建双侧白质纤维走行图。结果①良、恶性脑膜瘤肿瘤实质区ADC值比较差异有统计学意义;良、恶性脑膜瘤瘤周白质FA值差异有统计学意义。②良性脑膜瘤瘤周白质表现为纤维束受压移位或无明显变化;恶性脑膜瘤瘤周水肿区、瘤周白质均出现较明显的纤维束缺失。结论ADC值和FA值有助于脑膜瘤良、恶性的鉴别;白质纤维走行图能清晰显示肿瘤与白质纤维束的关系。     

磁共振弥散张量成像在脑胶质瘤手术前后的临床应用研究

目的查看MRI弥散张量成像（DTI）在脑胶质瘤的诊断价值。方法对我院34例脑胶质瘤患者进行MRI及DTI检查。测定脑胶质瘤及周围组织的平均弥散系数（MD值）、各向异性指数图（FA值）。观察肿瘤与相邻脑白质纤维束的解剖关系。并患者对手术前后临床症状进行评价。结果 24例确诊为低级别脑胶质瘤（Ⅰ-Ⅱ级）。胶质瘤推移相邻白质纤维束。手术切除充分临床症状缓解明显;10例确诊高级别脑胶质瘤（Ⅲ-Ⅳ级）。胶质瘤浸润破坏相邻白质纤维束。脑白质纤维束缺失及中断。手术切除后临床症状改善不明显;瘤床区MD值显著高于正常白质区,差异有统计学意义（P〈0.05）。瘤周水肿区显著高于正常白质区,差异有统计学意义（P〈0.05）。而瘤床区MD值稍高于瘤周水肿区,差异无统计学意义（P〉0.05）;3个区域FA值比较差异均有统计学意义（P〈0.05）。结论磁共振DTI技术可区分高级别脑胶质瘤瘤床区与周围组织的关系。同时对选择治疗方案有重要价值。对评估手术风险和预后也有重要临床意义。     

磁共振弥散张量成像在功能区胶质瘤手术中的应用研究

目的：探讨研究磁共振弥散张量成像（DTI）在功能区胶质瘤手术中的应用。方法选取符合标准的45例功能区胶质瘤患者,根据WHO的评级将45例患者分为低度恶性组（ n ＝21）与高度恶性组（ n ＝24）。2组患者均采用DTI对感兴趣区进行诊断,比较各感兴趣区表面扩散系数（ ADC）值与各向异性分数（ FA）值的差异,以及低度恶性组与高度恶性组ADC值与FA值的差异。结果肿瘤强化区、脑脊液区以及对侧正常大脑白质ADC值均与水肿区差异有统计学意义（ P ＜0?．05）。脑脊液与对侧正常大脑白质ADC值均与肿瘤强化区差异有统计学意义（ P ＜0．05）。脑脊液与对侧正常大脑白质FA值与水肿区和肿瘤强化区均差异有统计学意义（ P ＜0．05）。低度恶性组的肿瘤强化区与水肿区的ADC值均显著性高于高度恶性组（ P ＜0．05）。低度恶性组与高度恶性组肿瘤强化区与水肿区的FA值差异无统计学意义（ P ＞0．05）。结论通过DTI,能够明确功能区胶质瘤与正常白质之间的关系,为进一步的治疗以及手术提供一定的指导。     

核磁共振弥散张量成像在脑胶质瘤诊断中的应用研究

目的 探讨MRI弥散张量成像（DTI）技术显示胶质瘤与相邻脑白质纤维束解剖关系在脑胶质瘤诊断中的意义.方法 23例脑胶质瘤患者接受术前常规头颅MRI序列检查的同时进行DTI序列扫描,应用Functool软件进行图像分析处理,分别获得各自的部分各向异性图（FA图）、彩色编码张量图及脑白质纤维束图;并测定胶质瘤肿瘤病灶区、灶周水肿区及正常白质区的平均弥散系数（MD值）、各向异性图;进行FA图像信号强度及对比度的分析研究,分析脑胶质瘤与相邻脑白质纤维束的解剖关系.结果 所有病例均成功实现包括DTI序列扫描以及FA图像生成.脑白质纤维束显示为显著的高信号结构,灰质显示为等信号,脑脊液显示为低信号,脑内肿瘤呈类圆形等低信号,灶肿瘤周围间质水肿区白质纤维束仍能在DTI的FA图上显像,DTI的FA图像对于脑白质纤维束显影的信号对比度明显优于常规的T1W图像.肿瘤病灶区和灶周水肿区与正常白质区的MD值比较差异均有统计学意义（均P＜0.05）,而肿瘤病灶区与灶周水肿区的MD值比较差异无统计学意义（P＞0.05）;3个区域的FA值比较差异均有统计学意义（均P＜0.05＝.结论 磁共振DTI技术可在活体清晰、无创、直观地显示脑胶质瘤与周围脑白质纤维束的关系,结合其他序列的MRI应用于脑胶质瘤的术前诊断,可以准确判断肿瘤和周围脑白质纤维束的毗邻关系,对脑胶质瘤术前诊断、手术方案设计以及术后神经功能障碍的预测与预防具有重要意义.     

脑深部肿瘤白质纤维束弥散特征的变化

目的探讨弥散张量成像在脑深部肿瘤白质纤维束弥散特征变化的应用价值。方法20例脑深部肿瘤患者,术前常规行MRI、DTI检查,构建各向异性分数（FA）图和表观弥散系数（ADC）图,测量肿瘤邻近区白质纤维束和其相对应正常脑白质纤维束的FA值、ADC值。结果肿瘤邻近白质纤维束区、相对应正常脑白质纤维束区之间FA、ADC均值的差异有显著统计学意义。结论脑深部肿瘤白质纤维束弥散特征的变化对为深部脑肿瘤的治疗计划提供了重要的信息。     

弥散张量成像在痉挛型脑性瘫痪中的应用

目的：通过头颅磁共振弥散张量成像技术（DTI）并结合脑性瘫痪（CP）患儿粗大运动评估（GMFM）的测定来探讨其对脑瘫患儿运动功能转归的应用价值。方法选取痉挛型脑瘫患儿65例作为研究组,正常儿童16例作为对照组,应用GMFM评价患儿粗大运动功能。对受试儿童进行DTI检查,测量各组患儿主要白质纤维束部分各向异性（ FA）。结果各个部位的FA值与GMFM-88值存在正相关性,均存在统计学意义,其中内囊后肢相关性明显（r＝0．455）。结论粗大运动功能障碍与脑内广泛白质纤维束损伤有关,以内囊后肢部位最明显。 FA值的高低一定程度上反映运动功能的发育情况,DTI在评价痉挛性脑瘫运动功能方面有较高的应用价值。     

脑星形细胞瘤近瘤周远瘤周白质区的扩散张量成像参数分析

目的旨在探讨脑星形细胞瘤近瘤周、远瘤周白质区的扩散张量成像(DTI)特征。方法 37例脑星形细胞瘤术前行DTI扫描,其中Ⅰ级6例,Ⅱ级12例,Ⅲ级10例,Ⅳ级9例。重建FA图和FA编码彩色图,评价FA图像中近瘤周(IPR)白质、远瘤周(DPR)白质及对侧正常脑白质区的信号特点,并测定相应平均称散率(MD)值及各向异性分数(FA)值。结果Ⅳ级星形细胞瘤IPR白质的MD值高于其他三组(P<0.05),Ⅲ级星形细胞瘤IPR白质的FA值低于Ⅰ、Ⅱ级星形细胞瘤组(P<0.05)。Ⅳ级星形细胞瘤IPR、DPR的白质FA值低于Ⅰ、Ⅱ、Ⅲ级星形细胞瘤组(P<0.05)。结论 DTI能够较为直观的、准确地反映IPR及DPR白质区受肿瘤侵犯的情况。     

磁共振弥散张量在脑振荡患者中的应用价值

目的探讨磁共振弥漫张量成像在脑振荡患者中的应用价值。方法应用CT、常规磁共振扫描及磁共振弥散张量成像(DTI)对88例头部轻微伤、临床诊断为脑振荡的患者和15名健康志愿者(对照组)进行检查。行DTI图像后处理得到不同兴趣区(ROI)和各向异性分数(FA),包括两侧内囊和外囊、额叶、枕叶和颞下回部的FA值。将对照组相应部位的DTI值计算出均值和标准差作为常模,将88例观察组与之比较。结果与对照组比较,实验组中有65(73.86%)例的ROI的FA值均下降,另23(26.13%)例和对照组比较没有差异。结论 DTI技术对白质纤维损伤较为敏感,能准确定位、定量分析损伤程度,可为临床诊断脑振荡提供客观依据。     

顶、颞、枕叶白质在帕金森患者认知障碍发病中的测定价值

目的探讨顶白质，颞白质，枕白质在帕金森患者认知障碍发病中的测定价值，为帕金森患者认知障碍的防治提供科学理论。方法选取我院收治的帕金森病患者72例，并依照认知障碍评定量表（MoCA）判定为认知障碍的36例帕金森患者为帕金森认知障碍组（PDD组），判定为无认知障碍的36例帕金森患者为帕金森未发认知障碍组（PD．CogNL组），观察2组顶白质，颞白质、枕白质的FA（部分各异性）值。结果PPD组颞叶白质、枕叶白质FA值均低于PD—CogNL组，差异均有统计学意义（P〈0．05）。2组顶叶白质FA值比较差异无统计学意义（P〉0．05）。结论顶白质结构变化与帕金森患者认知障碍无显著相关，而颞白质、枕白质结构变化与帕金森患者认知障碍发病具有显著相关性，因此颞白质和枕白质很可能能作为测定帕金森患者是否并发认知障碍的参照指标，值的临床进一步探讨。     

脑膜瘤肌腱蛋白的表达对肿瘤血管形成侵袭和瘤周水肿的影响

目的 肌腱蛋白（tenascin,TN）在肿瘤血管形成、肿瘤侵袭及恶性转化、转移过程起重要调节作用。本研究探讨了脑膜瘤中TN的表达和临床病理学意义。方法 应用免疫组织化学SP法检测52例脑膜瘤组织中TN、第Ⅷ因子相关抗原的表达情况,并结合临床病理参数进行综合分析。结果 TN的表达和脑膜瘤病理分级、微血管密度（MVD）、侵袭行为、瘤周水肿显著相关（P〈0．05）,而和肿瘤切除范围、肿瘤分型、肿瘤部位、肿瘤形状、大小无关（P〉0．05）。结论 TN在肿瘤血管形成、恶性转化和浸润、瘤周水肿等方面起着重要作用。检测脑膜瘤TN的表达对进一步了解脑膜瘤生物学行为、临床表现和判断预后有重要价值。     

不同年龄人群脑白质纤维弥散张量成像研究

目的应用磁共振（纤维）弥散张量成像（DTI）技术对不同年龄人群正常脑白质纤维进行研究,探讨其变化规律。方法将40名健康志愿者按年龄分为青年组及老年组各20名进行3．0T磁共振DTI扫描,对比分析其各向异性分数（FA）值变化规律。结果老年组部分脑区域FA值明显低于青年组。结论老年人脑白质纤维完整性较青年人有较为明显的降低,对疾病患者脑白质纤维完整性进行研究的同时要注意年龄的影响因素。     

磁共振弥散张量成像评估早期创伤性轴索损伤的价值

目的探讨磁共振弥散张量成像(DTI)对早期创伤性脑损伤(TBI)患者轴索损伤的临床应用价值。方法对21例TBI早期(伤后10d内)患者(TBI组)及10例正常志愿者(对照组)行DTI检查,分别测量两侧大脑半球6个感兴趣区(胼胝体膝部、胼胝体压部、内囊前肢、内囊后肢、外囊及背侧丘脑)的部分各向异性(FA)值,并构建上述部位三维弥散张量纤维束成像(3D-DTT)图。比较以上两组感兴趣区平均FA值的差异,并对TBI组的FA值与临床GCS评分进行相关性分析。结果 FA图像上可以清楚观察到呈高信号的脑白质纤维束,损伤局部呈低信号。TBI组平均FA值为0.562±0.042,明显低于对照组的0.609±0.045(P<0.01)。TBI患者FA值与GCS评分呈正相关(r=0.508,P<0.05)。3D-DTT图可以直观显示胼胝体、内外囊等白质纤维束的损伤情况。结论 FA值的变化反应了TBI患者脑白质纤维束水分子各向异性程度的变化,对评估伤情及判断预后有重要意义。     

Brain macrostructural and microstructural abnormalities in cocaine dependence

RATIONALE: Two previous studies have utilized diffusion tensor imaging (DTI) to examine microstructural integrity in cocaine abuse and found evidence of brain abnormalities in white matter. OBJECTIVE: Using anatomical magnetic resonance imaging (MRI), DTI, and clinical evaluation, the macrostructural and microstructural correlates of cocaine abuse were investigated. METHODS: Twenty-one men and women (mean age 42.5 and mean 18.9 years of cocaine use) and 21 age/gender-matched controls were included. Fractional anisotropy (FA) was measured in frontal white matter ROIs. Gray and white matter volumes in superior and inferior frontal regions were compared. RESULTS: DTI data revealed that cocaine users had lower FA than controls, specifically in inferior frontal white matter. FA differences were not seen in other areas. Significant volumetric differences were not seen, but both gray and white matter inferior frontal volumes trended toward smaller in the cocaine group. The data suggested that duration of use was associated with decreased gray and white matter volumes. FA and gray matter volume were correlated in cocaine users. CONCLUSIONS: Both macrostructural and microstructural abnormalities were seen in a group of cocaine abusers. Length of cocaine use was associated with severity of the brain abnormalities. Future studies of white matter tissue integrity are warranted including examination of the relationship between DTI measures and traditional volumetric measures.     

White matter disruptions in patients with bipolar disorder

Bipolar disorder (BD) patients show aberrant white matter microstructure compared to healthy controls but little is known about the relation with clinical characteristics. We therefore investigated the relation of white matter microstructure with the main pharmacological treatments as well its relation with IQ. Patients with BD (N = 257) and controls (N = 167) underwent diffusion tensor imaging (DTI) and comprehensive clinically assessments including IQ estimates. DTI images were analyzed using tract-based spatial statistics. Fractional anisotropy (FA) and Mean Diffusivity (MD) were determined. Patients had significantly lower FA and higher MD values throughout the white matter skeleton compared to controls. Within the BD patients, lithium use was associated with higher FA and lower MD. Antipsychotic medication use in the BD patients was not associated with FA but, in contrast to lithium, was associated with higher MD. IQ was significantly positively correlated with FA and negatively with MD in patients as well as in controls. In this large DTI study we found evidence for marked differences in FA and MD particularly in (but not restricted to) corpus callosum, between BD patients and controls. This effect was most pronounced in lithium-free patients, implicating that lithium affects white matter microstructure and attenuates differences associated with bipolar disorder. Effects of antipsychotic medication intake were absent in FA and only subtle in MD relative to those of lithium. The abnormal white matter microstructure was associated with IQ but not specifically for either group.     

1．5T西门子磁共振弥散张量成像儿童脑白质的研究

目的探讨磁共振弥散张量成像技术在检NJL童脑白质发展情况中的应用。方法随机选择32名不同年龄的儿童,分为五组。运用弥散张量成像技术,检测不同部位脑白质的FA与ADC值,并进行分析比较。结果左右两侧大脑各感兴趣区的FA值与ADC值相比,结果无统计学意义（P〉0．05）。不同年龄不同部位大脑白质ADC值与FA值有明显的差异,具体表现为,各部位大脑白质的ADC值均随着年龄的增加而减少,FA值均随年龄增加而增加,且相同年龄不同部位的参数值有明显差异,结果均具有统计学意义（P〈0．05）。结论运用弥散张量成像技术可以有效反映脑白质的发育情况,对检测及预防其病变有重要的意义。     

Disruption of brain white matter microstructure by excessive intracellular and extracellular fluid in alcoholism: evidence from diffusion tensor imaging.

Magnetic resonance diffusion tensor imaging (DTI) has revealed the disruption of brain white matter microstructure in normal aging and alcoholism undetectable with conventional structural MR imaging. The metrics of DTI can be useful in establishing the nature of the observed microstructural aberrations. Abnormally low fractional anisotropy (FA), a measure of diffusion orientation and coherence, may result from increased intracellular or extracellular fluid, which would be reflected in complementary high apparent diffusion coefficients (bulk mean diffusivity) and low FA, or from disorganization of fiber structure, which would be reflected in low FA but with a lack of the inverse FA and diffusivity relationship. To test these competing possibilities, we examined 15 alcoholic men and 31 control men with DTI to quantify diffusivity in the genu and splenium of the corpus callosum and centrum semiovale. In addition to the previously observed FA deficits in all the three brain regions, the alcoholics had abnormally high white matter diffusivity values in the genu and centrum. Further, inverse correlations between FA and diffusivity were significant in the genu (r=-0.52, p<0.05) and centrum (r=-0.92, p=0.0001). Multiple regression analyses examining diffusivity and age as predictors of FA identified diffusivity as a significant unique contributor to FA in both regions. These results suggest that decreased orientational coherence of brain white matter in alcoholism is attributable, at least in part, to the accumulation of intracellular and extracellular fluid in excess of that occurring in aging, and that the differential influence of these fluid compartments can vary across brain regions.