慢性酒精依赖患者脑结构改变的DKI研究

目的：探讨慢性酒精依赖(CAD)患者大脑微结构异常与神经心理功能损害之间的关系。方法对19例 CAD 患者及17例健康志愿者行头部 T1 WI、T2 WI、FLAIR、DWI 及扩散峰度成像(DKI)扫描,对获得的2组图像进行对照分析。结果2组胼胝体体部、压部、左侧小脑半球、桥臂的平均扩散峰度(MK)值存在统计学差异(P <0.05),且 CAD 组差异脑区的 MK 值较健康组均减低;CAD 组左侧桥臂的 MK 值与蒙特利尔认知评估量表(MoCA)评分呈正相关。结论DKI 技术可早期发现 CAD 患者脑组织微结构的改变,MK 值与神经心理功能之间的相关性为临床早期诊疗提供了重要的依据。     

基于DKI技术对系统性红斑狼疮患者脑白质微结构改变的研究

目的 应用扩散峰度成像(DKI)技术中基于纤维束的空间统计分析方法(TBSS)探讨系统性红斑狼疮(SLE)患者脑白质结构的改变及其与神经精神量表的相关性。方法 选取41例女性SLE患者(SLE组)及45名与其年龄、性别及教育程度相匹配健康志愿者(HC组)进行DKI检查，测定有统计学差异脑区的各向异性分数(FA)、平均扩散系数(MD)、平均扩散峰度(MK)间的差异，并采用Spearman相关性分析来探讨差异脑区FA、MD及MK值与神经精神量表间的关系。结果 与HC组相比，SLE组患者在胼胝体(膝部、体部、压部)、双侧前、上放射冠、丘脑后辐射、外囊、上纵束及右侧后放射冠FA值均明显降低(P均<0.05);在胼胝体(膝部、体部、压部)、内囊膝支、双侧前、上、后放射冠、丘脑后辐射、上纵束及左侧外囊MD值均明显升高(P均<0.05),在胼胝体(膝部、体部、压部)、内囊后肢、双侧前、上放射冠、双侧丘脑后辐射、外囊、上纵束及右侧后放射冠MK值均明显降低(P均<0.05)。相关性分析发现，简易精神状态量表(MMSE)评分与胼胝体体部的FA、MK值呈正相关(r=0.5487,P<...     

轻度认知障碍患者海马的磁共振扩散峰度成像研究

目的 应用磁共振扩散峰度成像(DKI)研究轻度认知功能障碍(MCI)患者及正常老年人海马的差异.方法 搜集23例MCI患者为病例组(MCI组),23名健康志愿者为正常对照组(HC组),分别测量双侧海马的平均峰度(MK)值、轴向峰度(Ka)值、径向峰度(Kr)值、各向异性分数(FA)值、平均扩散(MD)值、轴向扩散(Da)以及径向扩散(Dr)值,使用两独立样本t检验对两组间所测DKI各参数进行分析;使用受试者工作特征曲线(ROC)曲线下面积(AUC)评价上述各参数值诊断MCI的能力;使用Pearson相关性分析对上述海马的DKI各参数值与MMSE评分的相关性进行分析.结果 与HC组相比,MCI组双侧海马的MK值、Kr值、FA值、Da值、Dr值减低,差异具有统计学意义(P＜0.05),双侧海马的MD值增加,差异具有统计学意义(P＜0.05),双侧海马的Ka值比较差异无统计学意义(P＞0.05);ROC曲线显示,左侧海马MD值的AUC最大,为0.765;Pearson相关性分析结果,双侧海马的MK值、Kr值、FA值、MD值、Da值、Dr值与简易精神状态检查量表(MMSE)评分均具有相关性(P＜0.05),海马的Ka值与MMSE评分无相关性(P＞0.05).结论 DKI技术能够敏感地探测到MCI患者海马的变化,为MCI患者和正常对照者的鉴别提供有效的影像学方法.     

脑瘫儿认知功能损害的3T多模态脑功能MR成像

目的:探索BOLD及DKI磁共振功能成像技术在认知功能损害脑瘫儿的应用。方法:选取伴有认知功能障碍脑瘫患儿(CP组)52例及正常小儿(CG组)50例,使用PhilipsIngenia3.0T多模态磁共振功能成像技术,在静息状态下行高分辨T1WI、BOLD及可行性DKI扫描,采集统计及分析MR功能数据。结果:CP组与CG组比较:①BOLD成像ALFF值:左丘脑、左壳核、左楔前回及右角回、右扣带回后部的ALFF值升高(P <0.05)。②ReHo值:左额上回、左岛叶皮质、左枕回、右额中回、右颞上回Reho值降低(P<0.05);左额叶白质、左顶下小叶、左丘脑、右额叶白质、右扣带回Reho值升高(P <0.05)。③DKI成像MK值:CP组双额叶、双顶叶、双枕叶MK值均低于CG组(P <0.05)。结论:RS-fMRI为无创性敏感研究认知功能障碍脑瘫儿脑灰白质功能、微观结构及病损的重要影像学方法。     

DKI对震颤型帕金森患者脑深部核团微结构变化的诊断价值

【摘要】目的：探讨扩散峰度成像（DKI）对震颤型（TD）帕金森病（PD）患者脑微观结构变化的诊断价值。方法：对40例TD型PD患者及34例健康志愿者（对照组）行常规序列及DKI序列MRI检查,对PD患者的运动和认知功能障碍进行评估。MRI原始扫描数据经后处理获得DKI各定量参数图,包括各向异性分数（FA）、平均扩散率（MD）、平均扩散峰度（MK）、横向峰度（Ka）、径向峰度（Kr）、横向扩散率（Da）和径向扩散率（Dr）,分别测量双侧红核、黑质致密带、黑质网状带、壳核、尾状核头、苍白球和丘脑的各项参数值,对各项参数值在两组间及患者左、右侧对称区域间的差异进行统计学分析。结果：①FA值：患者组症状侧及对侧红核的FA值与对照组的症状对侧比较,差异有统计学意义（P=0.013、0.036）;双侧尾状核头的FA值分别与对照组双侧对应部位比较,差异均有统计学意义（P=0.002、0.012、0.006和0.033）。②MD、Da、Dr、Ka值：双侧红核、壳核、黑质致密带、黑质网状带、苍白球、丘脑和尾状核头的各参数值分别与对照组双侧对应部位比较,差异均有统计学意义（P=0.000~0.030）。③MK值：患者组症状侧的黑质网状带、黑质致密带的MK值与对照组症状对侧之间的差异有统计学意义（P=0.043、0.042）;患者组双侧壳核的MK值分别与对照组双侧对应部位两两比较,差异均有统计学意义（P=0.046、0.006、0.008和0.001）;PD组中症状侧苍白球的MK值分别与对照组双侧对应部位比较,差异均有统计学意义（P=0.008、0.005））。④Kr值：患者组症状侧尾状核头的Kr值与对照组双侧对应部位比较,差异均有统计学意义（P=0.031、0.006）。结论：DKI在TD型PD患者亚临床期即可敏感的量化分析双侧各灰质核团微观结构的改变。     

扩散峰度成像对特发性全身性癫痫白质改变的研究

目的:探讨扩散峰度成像(DKI)对特发性全身性癫痫(IGE)患者脑白质细微结构的改变特征,并分析其与癫痫患者生活质量评分(QOLIE-31)的相关性。方法:招募20例IGE患者作为IGE组,19名性别、年龄及教育程度与IGE组相匹配的志愿者作为健康对照(HC)组,分别采集其全脑结构像3D T1WI、T2WI FLAIR和DKI数据,计算DKI各参数值:各向异性分数(FA)、平均扩散系数(MD)、轴向扩散系数(AD)、径向扩散系数(RD)、平均扩散峰度(MK)、轴向扩散峰度(AK)、径向扩散峰度(RK)、扩散峰度各向异性(FAK),采用两样本t检验比较组间DKI各参数差异。采用Pearson相关分析对差异有统计学意义的脑白质DKI参数与QOLIE-31评分进行相关性分析。结果:与HC组相比,IGE组左侧下纵束FAK升高(t=-2.31,P=0.032);左侧上辐射冠(t=-2.69,P=0.010)、左侧上额枕束(t=-2.85,P=0.007)、右侧上额枕束(t=-2.77,P=0.008)MD升高;右侧下纵束(t=2.04,P=0.048)、左侧前辐射冠(t=3.01,P=0.004)、左侧上辐射冠(t=2.58,P=0.014)、左侧上额枕束(t=2.29,P=0.027)、穹隆(t=3.39,P=0.001)AK值降低;左侧钩束(t=2.59,P=0.013)RK值降低;右侧上辐射冠(t=2.15,P=0.038)及左侧钩束(t=3.23,P=0.004)MK值降低。余扩散参数差异无统计学意义(P>0.05)。IGE患者穹隆的AK值与QOLIE-31评分呈正相关(r=0.46,P=0.044)。结论:采用DKI技术可以无创定量地发现IGE患者存在多个不对称脑白质纤维束细微结构的改变,有可能提供与癫痫电生理学互补或更丰富的信息。部分脑白质DKI参数与QOLIE-31评分具有相关性,提示脑白质微观结构的损伤对IGE患者的生活质量有一定影响。     

常规MRI阴性颞叶癫痫默认模式网络的fMRI研究

目的 利用静息态fMRI独立成分分析方法，探讨MRI阴性颞叶癫痫(TLE)患者默认模式网络(DMN)功能连接的改变，以提高其发病机制、病理生理的认识。方法 选取左侧MRI阴性TLE患者16例(阴性TLE组)、左侧内侧颞叶癫痫(MTLE)伴海马硬化(HS)患者26例(MTLE+HS组)、健康对照者24例(HC组)。对所有被试者采集一般资料及认知功能评估。对DMN脑区分析，并提取差异脑区功能连接值。并对三组一般临床资料、认知功能评估及功能连接值进行比较。结果 三组年龄、性别、教育年限及病程差异无统计学意义(P>0.05),三组蒙特利尔认知量表(MoCA)得分差异有统计学意义，MRI阴性TLE组和MTLE+HS组MoCA量表得分均低于HC组，MRI阴性TLE组与MTLE+HS组的MoCA量表得分差异无统计学意义。与HC组比较，MRI阴性TLE组和MTLE+HS组均在双侧楔前叶/后扣带回区域的功能连接减低；MRI阴性TLE组较MTLE+HS组在双侧楔前叶/后扣带回的功能连接减低体素减少。在左侧内侧前额叶和前扣带回的连接性减低，MRI阴性TLE组和MTLE+HS组较HC组在内侧前额叶功能连...     

扩散峰度与扩散张量成像对比评估兔周围神经急性挤压伤

目的:对比扩散峰度成像(DKI)与扩散张量成像(DTI)评估兔周围神经挤压伤的价值.方法:选取新西兰大白兔27只,于右后肢建立坐骨神经损伤与修复模型,左后肢为假手术侧.分别于术前、1、3天、1、2、4、6、8周行DTI及DKI扫描,测量各时间点定量参数,并于各时间点随机取2只兔子行电镜检查.结果:DKI参数中平均峰度(MK)值在损伤后第1天明显下降并在较低水平波动,自第2～8周逐渐上升,损伤侧与假手术侧MK值于2～8周差异均有统计学意义(P<0.05);损伤后1天各向异性分数(FADKI)值明显下降至最低点;3天～8周持续上升,各时间点差异均有统计学意义(P<0.005);径向峰度(RK)值仅在6周时双侧差异有统计学意义(P=0.018);而轴向峰度(AK)值于各时间点均无显著差异(P>0.05).DTI参数中FADTI与FADKI变化趋势一致且各时间点差异均有统计学意义(P<0.001);ADC值仅在第8周差异有统计学意义(P=0.038).结论:DKI可用于周围神经急性挤压伤的评估,但与DTI相比,DKI在评估急性周围神经损伤时可能并不能提供额外价值.     

扩散峰度成像评估多发性硬化患者脑结构网络拓扑属性改变及其微结构损伤

目的探讨多发性硬化(MS)患者脑结构网络拓扑属性改变及其微结构损伤, 并分析其与认知功能的相关性。方法回顾性分析2021年5月至2022年9月于重庆医科大学附属第一医院确诊为MS患者114例(MS组)的临床和影像资料。另招募同期71名志愿者作为健康对照组(HC组)。对所有受检者进行认知功能评估及3D-T1磁化准备快速梯度回波成像序列、3D液体衰减翻转恢复序列和扩散峰度成像(DKI)扫描。采用GRETNA软件获取网络拓扑属性, 全局属性包括全局效率、局部效率和小世界属性[聚类系数(Cp)、最短路径长度(Lp)、标准化Cp(γ)、标准化Lp和小世界指数(σ)]。局部属性包括节点介数(BC)、节点度(DC)、节点集聚系数(NCp)、节点效率、节点局部效率(NLe)和节点最短路径长度。采用后处理软件生成的DKI参数图, 提取脑结构网络局部属性异常脑区的DKI参数值。采用独立样本t检验或Mann-WhitneyU检验分析2组全局属性、局部属性差异及局部属性异常脑区DKI参数值[各向异性分数(KFA)、平均峰度(MK)、径向峰度(RK)和轴向峰度(AK)值]的差异, 并经错误发现率(FDR)校正。...     

扩散峰度成像与DWI在卵巢实性病灶良恶性鉴别诊断中的应用

目的:探讨扩散峰度成像(DKI)与DWI在卵巢实性病灶良恶性鉴别诊断中的应用价值。方法:回顾性分析87例卵巢实性病灶的临床及影像资料,患者均行卵巢MRI常规平扫、DWI、DKI检查,分别获取ADC值、平均扩散峰度(MK)和平均扩散率(MD),评估DWI、DKI对卵巢良恶性病变的鉴别诊断价值。结果:与卵巢恶性病变相比,卵巢良性病变的ADC值、MD明显升高,MK明显降低(均P<0.05)。ADC、MK、MD联合诊断卵巢良恶性病变的AUC较三者单独及MK联合MD诊断诊断的AUC大。结论:与DWI相比,DKI对卵巢良恶性病变鉴别诊断价值略高;DWI联合DKI可提高对卵巢良恶性病变鉴别诊断效能及卵巢实性病灶检出率。     

Characterization of Brain Microstructural Abnormalities in High Myopia Patients: A Preliminary Diffusion Kurtosis Imaging Study

ObjectiveTo evaluate microstructural damage in high myopia (HM) patients using 3T diffusion kurtosis imaging (DKI).Materials and MethodsThis prospective study included 30 HM patients and 33 age- and sex-matched healthy controls (HCs) with DKI. Kurtosis parameters including kurtosis fractional anisotropy (FA), mean kurtosis (MK), axial kurtosis (AK), and radial kurtosis (RK) as well as diffusion metrics including FA, mean diffusivity, axial diffusivity (AD), and radial diffusivity derived from DKI were obtained. Group differences in these metrics were compared using tract-based spatial statistics. Partial correlation analysis was used to evaluate correlations between microstructural changes and disease duration.ResultsCompared to HCs, HM patients showed significantly reduced AK, RK, MK, and FA and significantly increased AD, predominately in the bilateral corticospinal tract, right inferior longitudinal fasciculus, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and left thalamus (all p < 0.05, threshold-free cluster enhancement corrected). In addition, DKI-derived kurtosis parameters (AK, RK, and MK) had negative correlations (r = −0.448 to −0.376, all p < 0.05) and diffusion parameter (AD) had positive correlations (r = 0.372 to 0.409, all p < 0.05) with disease duration.ConclusionHM patients showed microstructural alterations in the brain regions responsible for motor conduction and vision-related functions. DKI is useful for detecting white matter abnormalities in HM patients, which might be helpful for exploring and monitoring the pathogenesis of the disease.     

Neuropsychiatric systemic lupus erythematosus: correlation of brain MR imaging, CT, and SPECT

Systemic lupus erythematosus (SLE) patients frequently present with neuropsychiatric symptoms. We conducted an imaging study with magnetic resonance (MR) imaging, computed tomography (CT), and single photon emission CT (SPECT) in 23 patients with SLE, 13 with major neuropsychiatric symptoms (NPSLE) and 10 without (non-NPSLE). The most frequent brain imaging findings were seen with MR imaging and were more prevalent in NPSLE: high signal intensity focal white matter lesions, infarcts in the cortex and pons, and basal ganglia lesions.     

阿尔茨海默病患者联络纤维的DTI诊断价值

目的采用磁共振扩散张量成像(diffusion tensor imaging,DTI)观察阿尔茨海默病(Alzheimer’s disease,AD)患者联络纤维的改变情况。资料与方法对10例轻中度AD患者和18名健康老年人(对照组)行常规MRI[(T1WI、T2WI、T2液体衰减反转恢复序列(FLAIR)]及DTI检查,DTI测量双侧扣带束、上纵束Ⅱ、钩束及额枕下束8个感兴趣区(ROI)的部分各向异性分数(FA)值。采用简易精神状态量表(MMSE)和蒙特利尔认知评估量表(MoCA)对AD患者的认知功能进行测定。结果与对照组相比,AD组MMSE评分和MoCA评分较对照组明显下降(P<0.05),AD组常规MRI上ROI白质信号无明显变化,ROI部位的FA值均显著下降(P<0.05),且上纵束Ⅱ的FA值与MMSE(右侧r=0.672,P=0.033,左侧r=0.919,P<0.01)和MoCA(右侧r=0,747,P=0.013;左侧r=0.679,P=0.031)评分呈正相关。结论轻中度AD患者存在联络纤维损害且上纵束Ⅱ的损害程度与认知功能密切相关。     

Neurometabolism of active neuropsychiatric lupus determined with proton MR spectroscopy.

PURPOSETo determine the neurometabolism of patients with active neuropsychiatric systemic lupus erythematosus (NPSLE) by using proton MR spectroscopy.METHODSThirty-six patients with SLE and eight control subjects were studied with proton MR spectroscopy to measure brain metabolites. Peaks from N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and at 1.3 parts per million (ppm) lipid, macromolecules, and lactate were measured. Patients were classified as having major NPSLE (seizures, psychosis, major cognitive dysfunction, delirium, stroke, or coma) (n = 15) or minor NPSLE (headache, minor affective disorder, or minor cognitive disorder) (n = 21). Patients with major NPSLE were severely ill and hospitalized.RESULTSSLE patients had lower NAA and increased metabolites at 1.3 ppm than did control subjects (NAA/Cr(SLE) = 1.90 +/- 0.35, NAA/Cr(Control) = 2.16 +/- 0.26; 1.3 ppm/Cr(SLE) = 0.49 +/- 0.41, 1.3 ppm/Cr(Control) = 0.27 +/- 0.05). NAA/Cr in patients with current or prior major NPSLE was lower than in patients without major NPSLE. Increased peaks at 1.3 ppm were present in all SLE subgroups, but particularly in patients with major NPSLE. These resonances were not evident at an echo time of 136, indicating that these signals were not lactate.CONCLUSIONMajor NPSLE, past or present, is associated with decreased levels of NAA. Elevated peaks around 1.3 ppm do not represent lactate even in severely ill patients, indicating that global ischemia is not characteristic of NPSLE. Neurochemical markers determined by MR spectroscopy may be useful for determining activity and degree of brain injury in NPSLE.     

基于fMRI的脑网络节点灵活度在血管性认知障碍患者中的研究

目的运用图论分析方法研究(vascular congnifive impairment,VCI)患者与正常者之间的脑网络节点灵活度差异,并将脑网络节点灵活度与临床认知评分进行相关性分析,探讨VCI患者认知功能改变的神经机制。方法纳入28例VCI患者作为病例组,纳入30例认知功能正常者作为对照组。两组均构建静息态脑网络,采用两独立样本t检验对比两组脑网络节点灵活度的差异。在控制性别、年龄、受教育程度的情况下,采用Pearson偏相关分析对VCI组的脑网络节点灵活度与MoCA评分作相关性分析。结果与对照组相比,VCI组在右侧顶内沟、左侧后扣带回、左侧颞叶、左小脑下部的节点灵活度显著降低,右侧枕叶节点灵活度显著升高,P值均<0.05。在控制性别、年龄、受教育程度等情况下,VCI组在右背外侧前额叶皮层及右枕叶后部的节点灵活度(r=-0.399,P=0.035)、(r=-0.387,P=0.042)与MoCA评分呈负相关;在左侧顶内沟区节点灵活度(r=0.393,P=0.039)与MoCA评分存在呈正相关。结论脑网络节点灵活度可以在一定程度上作为反映VCI的影像学标志,为VCI的早期诊断、病程监测、动态观察及预后评估提供依据。     

轻微型肝性脑病患者后扣带回与双侧海马间功能连接静息态功能MRI研究

目的：探讨轻微型肝性脑病（MHE）患者静息态下后扣带回（PCC）与双侧海马间功能连接（FC）的改变情况。方法：采用静息态功能磁共振成像（rs-fMRI）技术，分析17例 MHE患者（MHE组）和17例健康对照者（HC组）静息态下脑功能活动，观察 MHE患者静息态下PCC与双侧海马间的功能连接情况，并与数字-符号试验（DST）和数字连接试验-A （NCT-A）评分进行相关分析。结果：与 HC组相比，MHE组 PCC 与右侧海马间 FC 减低（P＜0．05，K≥10体素）；MHE组PCC和右侧海马FC分数与DST评分呈显著正相关，与NCT-A评分呈显著负相关（P＜0．05，K≥体素）。结论：MHE患者脑功能存在损伤，海马与后扣带回间连接强度可以提示 MH E患者的认知功能状态。     

Brain diffusivity in patients with neuropsychiatric systemic lupus erythematosus with new acute neurological symptoms

PURPOSE: To investigate the source of significant difference in apparent diffusion coefficient (ADC) between patients with acute symptoms of neuropsychiatric (NP) systematic lupus erythematosus (SLE) (NPSLE) and normal controls. MATERIALS AND METHODS: Diffusion-weighted echo-planar imaging was performed on 1.5-T scanners in 17 female and four male NPSLE patients with acute neurological symptoms (23-76 years, mean = 42.7 years), and in 21 aged-matched healthy controls (16 female, five male, 26-63 years, mean = 41.1 years). ADC histograms were calculated for whole brain, gray matter tissue, and white matter tissue. RESULTS: Of the 17 NPSLE patients, 13 (72%) had abnormal findings on MR imaging. The NPSLE patients had a mean ADC value of (1105.1 +/- 23.6) x 10(-6) mm(2)/second and the control had a mean ADC value of (1012.5 +/- 9.4) x 10(-6) mm(2)/second (P < or = 0.0012). Significant differences were also found in white matter (P < or = 0.0020) and gray matter (P < or = 0.0022). CONCLUSION: ADC histogram analysis demonstrated increased general diffusivity in the brain in NPSLE patients with acute symptoms compared with healthy normal controls. This finding suggests that in the brain parenchyma of NPSLE patients a loss of tissue integrity occurs facilitating motility of free-water protons.     

A preliminary diffusional kurtosis imaging study of Parkinson disease: comparison with conventional diffusion tensor imaging

Introduction

Diffusional kurtosis imaging (DKI) is a more sensitive technique than conventional diffusion tensor imaging (DTI) for assessing tissue microstructure. In particular, it quantifies the microstructural integrity of white matter, even in the presence of crossing fibers. The aim of this preliminary study was to compare how DKI and DTI show white matter alterations in Parkinson disease (PD).

Methods

DKI scans were obtained with a 3-T magnetic resonance imager from 12 patients with PD and 10 healthy controls matched by age and sex. Tract-based spatial statistics were used to compare the mean kurtosis (MK), mean diffusivity (MD), and fractional anisotropy (FA) maps of the PD patient group and the control group. In addition, a region-of-interest analysis was performed for the area of the posterior corona radiata and superior longitudinal fasciculus (SLF) fiber crossing.

Results

FA values in the frontal white matter were significantly lower in PD patients than in healthy controls. Reductions in MK occurred more extensively throughout the brain: in addition to frontal white matter, MK was lower in the parietal, occipital, and right temporal white matter. The MK value of the area of the posterior corona radiata and SLF fiber crossing was also lower in the PD group.

Conclusion

DKI detects changes in the cerebral white matter of PD patients more sensitively than conventional DTI. In addition, DKI is useful for evaluating crossing fibers. By providing a sensitive index of brain pathology in PD, DKI may enable improved monitoring of disease progression.