皮质下缺血性血管性痴呆患者脑白质损害的磁共振弥散张量成像研究

目的:应用磁共振弥散张量成像技术(DTI)观察皮质下缺血性血管性痴呆(SIVD)患者脑白质损害程度,探讨DTI对SIVD白质损害的评估及与阿尔茨海默病(AD)鉴别诊断价值。方法:研究对象分为3组,分别是健康老年人(NC)、皮质下缺血性血管性痴呆(SIVD)患者、AD患者,每组各20例。行常规MR I和DTI扫描后,测定相同感兴趣区(RO I)的各向异性分数(FA)值和表观扩散系数(ADC)值进行比较。结果:SIVD组下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位FA值下降,ADC值升高,与NC、AD组比较差异有统计学意义(P<0.05)。与NC组比较,AD组前额叶、颞叶、海马、下额枕束、胼胝体膝部和扣带束等部位FA值降低,颞叶、海马等部位ADC值升高,两组差异具有显著性(P<0.05);结论:DTI可以用来评估痴呆患者白质损害的程度,SIVD患者以下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位受累为主,可作为与AD鉴别的客观指标。     

弥散张量成像技术预测遗忘型轻度认知障碍患者向老年性痴呆转化的随访研究

目的:探讨弥散张量成像技术(diffusion tensor imaging,DTI)对遗忘型轻度认知功能障碍(aMCI)向老年性痴呆(AD)转化的预测作用。方法:41例aMCI患者(aMCI组)常规予核磁共振(MRI)和DTI扫描,测定感兴趣区的各向异性分数(fractional anisotropy,FA)和表观扩散系数(apparent diffusion coefficient,ADC),以20名老年健康志愿者作为对照(正常对照组)并随访1~3年。结果:与正常对照组比较,aMCI组41例患者中有22例扣带束FA基线值偏低(P0.05),随访1~3年后,其中有19例转化为AD;另外19例扣带束FA值正常的aMCI患者只有2例转化为AD。与非转化AD者比较,AD转化者前额叶、颞叶、海马、下额枕束、胼胝体膝部和扣带束等部位FA值降低(P均0.01),颞叶、海马等部位ADC值升高(P均0.05)。结论:DTI技术具有预测aMCI向AD转化的作用,aMCI患者扣带束FA值低可能是aMCI向AD转化的敏感指标。     

皮质下缺血性血管病患者联络纤维的扩散张量成像分析和认知功能相关研究

【摘要】 目的 运用磁共振成像（magnetic resonance imaging,MRI）基于白质地图的扩散张量成像（diffusion tensor imaging,DTI）技术研究皮质下缺血性血管病（subcortical ischemic vascular disease,SIVD）患者联络纤维的超微结构改变,并分析DTI参数与认知功能的关系。 方法 连续入选40例SIVD患者,分为血管性认知障碍组18例,无认知障碍组22例,另设立20例正常老年人为对照组。对三组进行MRI检查并对其白质改变进行评分,对联络纤维进行基于白质地图分析（atlase based analysis,ABA）DTI成像,比较组间部分各向异性指数（fractional anisotrophy,FA）、平均扩散率（mean diffusivity,MD）差异,并对SIVD患者DTI参数与蒙特利尔认知评估量表（Montreal Cognitive Assessment,MoCA）得分进行相关性分析。 结果 无认知障碍组较正常组在右侧矢状层（下纵束/下额枕束）、右侧扣带（海马部）及左侧上额枕束的FA值减低;认知障碍组较正常组存在广泛的联络纤维FA值降低,差异均具有显著性。无认知障碍组与正常组比较,仅左侧扣带海马部及左侧上纵束MD值无显著差异,余联络纤维的MD值均显著增高;认知障碍组较正常组存在广泛的联络纤维MD值增高,差异均具有显著性。与无认知功能障碍组比较,认知功能障碍组在双侧矢状层（下纵束/下额枕束）、双侧扣带扣带回部、海马部、双侧上纵束、双侧上额枕束及双侧钩束的FA值减低,MD值增高,差异具有显著性。SIVD患者双侧矢状层（下纵束/下额枕束）、扣带扣带回部、上纵束、上额枕束及钩束和左侧扣带海马部的FA值与MoCA评分呈正相关,MD值与MoCA评分呈负相关。 结论 SIVD患者联络纤维的FA值减低,MD值增高,且DTI参数与其认知功能密切相关。     

磁共振弥散张量成像对预测皮质下缺血性血管性痴呆患者认知功能障碍的价值

目的应用磁共振弥散张量成像(DTI)技术,探讨皮质下缺血性血管性痴呆(SIVD)患者不同联络纤维感兴趣区弥散张量参数改变与认知功能的关系。方法对60例SIVD患者和40例年龄匹配的非痴呆对照者,采用测定感兴趣区弥散张量参数的方法,比较其纤维束完整性差异及与神经心理学量表的关系。结果 (1)与对照组比较,SIVD组双侧下额枕束、双侧扣带束、左侧上纵束和胼胝体膝部的FA值显著下降及ADC值显著升高;(2)双侧额叶前部皮质下白质FA值与MMSE及Mo CA评分呈明显正相关;(3)双侧海马区、双侧扣带束的FA值与MMSE评分呈明显正相关。结论不同脑区的弥散张量参数变化特点有助于SIVD患者认知功能障碍的早期预测。     

皮质下缺血性血管性痴呆患者大脑联络纤维弥散张量成像研究

目的应用磁共振弥散张量成像(DTI)技术,研究皮质下缺血性血管性痴呆(SIVD)患者脑白质联络纤维变化的特点,以探讨弥散张量成像在诊断SIVD患者中的诊断价值。方法对60例SIVD患者和45例年龄匹配的非痴呆对照者,应用简易智能状态检查量表(MMSE)、蒙特利尔认知测评量表(Mo CA)及临床痴呆量表(CDR)进行认知功能评估;用全脑磁共振DTI技术,测量上纵束、下额枕束(额部、额颞部和颞部)、胼胝体膝部和压部和扣带束多个感兴趣区的各向异性分数(FA)值和表观弥散系数(ADC)值。结果与对照组比较,SIVD组双侧下额枕束、双侧扣带束、左侧上额枕束和胼胝体膝部FA值明显下降,ADC值明显升高,差异有统计学意义(均P<0.05),右侧上额枕束和胼胝体压部的FA值和ADC值差异无统计学意义(P>0.05)。结论 SIVD患者多个感兴趣区的DTI改变证明联络纤维损伤明显;全脑DTI研究是SIVD患者敏感可靠的技术方法,有助于理解SIVD患者的认知功能与联络纤维损害的关系。     

颞叶内侧结构弥散张量成像及白质纤维束成像在颞叶癫痫诊断中的应用价值

目的 通过磁共振弥散张量成像(DTI)及白质纤维束示踪(DTT)技术定量分析颞叶癫痫患者双侧颞叶内侧结构弥散参数值及局部纤维束变化特点,评价DTI技术对颞叶癫痫的诊断价值.方法 对广州医学院第二附属医院自2010年12月至2011年2月临床诊断为颞叶癫痫的16例患者和20例健康志愿者进行常规MRI及DTI扫描,测量双侧颞叶杏仁体、海马及颞叶皮质的部分各向异性(FA)、相对各向异性(RA)、表观弥散系数(ADC)等数值并进行统计学分析,同时应用DTT技术观察癫痫患者局部纤维束与正常对照者的差异.结果 正常对照者双侧颞叶内侧各结构FA、RA、ADC值比较差异均无统计学意义(P＞0.05).颞叶癫痫患侧、对侧与正常对照者颞叶内侧各结构FA、RA、ADC值比较差异均有统计学意义(P＜0.05),其中ADC值呈颞叶癫痫患侧＞颞叶癫痫对侧＞正常对照者的变化趋势,以海马尾部变化最为显著;而FA、RA值呈颞叶癫痫患侧＜颞叶癫痫对侧＜正常对照者的变化趋势,并且杏仁体、海马体部变化较海马尾部更显著.结论 DTI技术能充分了解癫痫患者颞叶内侧结构的弥散参数值及纤维束变化特点,有助于癫痫病灶定位的准确诊断,同时加深对颞叶内侧结构整体变化的了解亦有助于术前的整体评估及提高手术疗效.     

DTI在诊断中枢神经系统疾病的应用研究

目的评价DTI诊断中枢神经系统疾病的应用价值,对比不同疾病的FA、ADC值,总结诊断经验。方法选取2015-02—2016-02于我院神经内科接受常规MRI检查的中枢神经系统疾病患者34例,选择同期健康的同龄体检者34例为对照组,进行DTI检查。结果阿尔茨海默病组扣带束、扣带束后部、上纵束、顶叶白质FA值及扣带束后部、上纵束ADC值与对照组存比较差异均有统计学意义(P0.05);脑梗死、轻度创伤性脑损伤表现与阿尔茨海默病组相类似,与正常人群相比,脑梗死、轻度创伤性脑损伤患者部分脑白质区域FA显著下降,上纵束、内囊、额叶等均有分布,与受创、梗死部位等关系密切,部分白质纤维束MD值显著上升;通过脑白质FA、ADC诊断中枢神经系统疾病敏感性97.06%(33/34),特异度88.23%(30/34),阳性符合率92.65%(63/68),高于常规MRI诊断,差异有统计学意义(P0.05)。结论 DTI可弥补常规MRI不足,通过分析脑白质FA等指标变化,诊断中枢神经系统疾病。     

阿尔茨海默病颞干纤维束扩散张量成像研究

目的应用扩散张量成像(DTI)研究阿尔茨海默病和遗忘型轻度认知损害患者白质和颞干纤维束部分各向异性(FA)值变化特点,探讨颞干纤维束损伤机制及其对阿尔茨海默病和遗忘型轻度认知损害的诊断与鉴别诊断价值。方法应用常规MRI和DTI测量阿尔茨海默病(10例)、遗忘型轻度认知损害(10例)和正常对照者(10例)颞干纤维束(包括前连合、钩束、额枕下束)及前额叶、颞叶、顶叶、枕叶白质FA值,比较各组受试者左右侧对称部位白质和颞干纤维束FA值变化。结果各组受试者左右侧对称部位白质和颞干纤维束FA值差异无统计学意义(均P0.05),但其前连合、钩束、额枕下束及前额叶白质FA值差异具有统计学意义(均P0.05)。其中,阿尔茨海默病组前连合、钩束、额枕下束FA值低于遗忘型轻度认知损害组(均P0.05),前连合、钩束、额枕下束及前额叶、顶叶白质FA值低于正常对照组(均P0.05);而遗忘型轻度认知损害组与正常对照组前连合、钩束、额枕下束及前额叶白质FA值差异无统计学意义(均P0.05)。结论阿尔茨海默病和遗忘型轻度认知损害患者与正常老年人颞干纤维束FA值存在显著差异,提示颞干纤维束在阿尔茨海默病患者白质损伤中具有重要意义,DTI检查有助于阿尔茨海默病与遗忘型轻度认知损害和正常老龄化的鉴别诊断。阿尔茨海默病前连合、钩束、额枕下束及前额叶、顶叶白质FA值异常具有良好的临床诊断价值。     

皮质下缺血性血管性痴呆患者认知功能与脑白质弥散张量成像的关系

目的探讨皮质下缺血性血管性痴呆(SIVD)患者认知功能与脑白质弥散张量成像(DTI)的关系。方法采用MMSE、蒙特利尔认知测评量表(Mo CA)及临床痴呆量表(CDR)评价60例SIVD患者(SIVD组)和45名正常对照者(正常对照组)。应用DTI技术测量患者脑白质不同感兴趣区(ROI)各向异性分数(FA)和表观弥散系数(ADC)。SIVD组用常规头颅MRI采用年龄相关白质改变(ARWMC)评分方法对侧脑室周围脑白质高信号严重程度进行评分。结果与SIVD组比较,正常对照组MMSE及Mo CA评分显著增高,CDR评分显著降低(均P0.01)。与正常对照组比较,SIVD组双侧额叶前部、双侧侧脑室前角区及后角区的FA值显著下降,ADC值显著升高(P0.05~0.01)。其余各区FA及ADC值差异无统计学意义。SIVD组ARWMC评分为1分11例(18.3%),2分31例(51.7%),3分18例(30.0%)。正常对照组中5人(11.1%)为1分。Spearman相关性分析显示,SIVD组ARWMC评分与双侧侧脑室前角区及后角区FA值呈负相关(r=-0.912,P0.01),与ADC值呈正相关(r=0.891,P0.01)。双侧额叶前部皮质下白质及海马区FA值与MMSE及Mo CA评分呈正相关(P0.05~0.01)。结论 SIVD患者多个ROI的FA值降低及ADC值的增高程度,可以反映认知功能障碍的程度。     

首发精神分裂症阳性症状为主型患者脑弥散张量成像研究

目的 探讨首发精神分裂症阳性症状为主型患者主要脑区白质纤维束有无异常.方法 对未系统使用过精神药物治疗的20例首发精神分裂症阳性症状为主型患者和20名正常对照进行磁共振弥散张量成像(DTI)扫描,测量胼胝体膝部、压部、双侧额叶白质、双侧扣带束前部和双侧海马头部分各向异性(FA)值.结果 ①患者组及对照组组内比较,左右侧FA值差异均无统计学意义(P>0.05).②患者组左侧海马头和胼胝体压部FA值[(0.17±0.03),(0.73±0.09)]显著低于对照组[(0.20±0.02),(0.79±0.05)],差异均有统计学意义(P<0.05);③患者组左右侧扣带束前部FA值[(0.28±0.06),(0.29±0.05)]低于对照组[(0.43±0.07),(0.38±0.08)],差异均有统计学意义(P<0.01).结论 首发精神分裂症阳性症状为主型患者双侧扣带束前部、胼胝体压部及左侧海马头的白质纤维束完整性受损,提示其可能存在脑神经发育连接异常.     

Multimodal imaging in diagnosis of Alzheimer's disease and amnestic mild cognitive impairment: value of magnetic resonance spectroscopy, perfusion, and diffusion tensor imaging of the posterior cingulate region

The purpose of this study was to assess metabolic, perfusion, and microstructural changes within the posterior cingulate area in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) using advanced MR techniques such as: spectroscopy (MRS), perfusion weighted imaging (PWI), and diffusion tensor imaging (DTI). Thirty patients with AD (mean age 71.5 y, MMSE 18), 23 with aMCI (mean age 66 y, MMSE 27.4), and 15 age-matched normal controls (mean age 69 y, MMSE 29.5) underwent conventional MRI followed by MRS, PWI, and DTI on 1.5 Tesla MR unit. Several metabolite ratios (N-acetylaspartate [NAA]/creatine [Cr], choline [Ch]/Cr, myoinositol [mI]/Cr, mI/NAA, mI/Cho) as well as parameters of cerebral blood volume relative to cerebellum and fractional anisotropy were obtained in the posterior cingulate region. The above parameters were correlated with the results of neuropsychological tests. AD patients showed significant abnormalities in all evaluated parameters while subjects with aMCI showed only perfusion and diffusion changes in the posterior cingulate area. Only PWI and DTI measurements revealed significant differences among the three evaluated subject groups. DTI, PWI, and MRS results showed significant correlations with neuropsychological tests. DTI changes correlated with both PWI and MRS abnormalities. Of neuroimaging methods, DTI revealed the highest accuracy in diagnosis of AD and aMCI (0.95, 0.79) followed by PWI (0.87, 0.67) and MRS (0.82, 0.47), respectively. In conclusion, AD is a complex pathology regarding both grey and white matter. DTI seems to be the most useful imaging modality to distinguish between AD, aMCI, and control group, followed by PWI and MRS.     

Discriminating subcortical ischemic vascular disease and Alzheimer's disease by diffusion kurtosis imaging in segregated thalamic regions

Differentiating between subcortical ischemic vascular disease (SIVD), Alzheimer''s disease (AD), and normal cognition (NC) remains a challenge, and reliable neuroimaging biomarkers are needed. The current study, therefore, investigated the discriminative ability of diffusion kurtosis imaging (DKI) metrics in segregated thalamic regions and compare with diffusion tensor imaging (DTI) metrics. Twenty‐three SIVD patients, 30 AD patients, and 24 NC participants underwent brain magnetic resonance imaging. The DKI metrics including mean kurtosis (MK), axial kurtosis (K _axial) and radial kurtosis (K _radial) and the DTI metrics including diffusivity and fractional anisotropy (FA) were measured within the whole thalamus and segregated thalamic subregions. Strategic correlations by group, thalamo‐frontal connectivity, and canonical discriminant analysis (CDA) were used to demonstrate the discriminative ability of DKI for SIVD, AD, and NC. Whole and segregated thalamus analysis suggested that DKI metrics are less affected by white matter hyperintensities compared to DTI metrics. Segregated thalamic analysis showed that MK and K _radial were notably different between SIVD and AD/NC. The correlation analysis between K _axial and MK showed a nonsignificant relationship in SIVD group, a trend of negative relationship in AD group, and a significant positive relationship in NC group. A wider spatial distribution of thalamo‐frontal connectivity differences across groups was shown by MK compared to FA. CDA showed a discriminant power of 97.4% correct classification using all DKI metrics. Our findings support that DKI metrics could be more sensitive than DTI metrics to reflect microstructural changes within the gray matter, hence providing complementary information for currently outlined pathogenesis of SIVD and AD.     

Uncinate fasciculus-correlated cognition in Alzheimer's disease: a diffusion tensor imaging study by tractography

Background: Neuroimaging studies show increased diffusivity and decreased anisotropy in Alzheimer's disease (AD) patients by diffusion tensor imaging (DTI). Previous reports have analyzed a correlation with cognitive function and DTI parameters, but their results are inconsistent. A reason for this might be a region of interest (ROI) method, used to calculate parameters for DTI, because this method has various usages of how to place a ROI and includes summations of values for various neuronal fiber tracts, resulting in contamination of unintended fibers. To improve the instability with ROI placement, a tractography‐based method might be useful. Our coworker reported decreased fractional anisotropy (FA) and increased apparent diffusion coefficient (ADC) of uncinate fasciculus (UF) in patients with AD by tractography. To confirm whether DTI parameter values are related to severity of cognitive function in patients with AD, we measured mean diffusion anisotropy and diffusivity of coregistered voxels along the tracking lines (i.e. tract of interest) of UF. Methods: The subjects were 30 patients with probable AD (NINCDS‐ADRDA criteria). Assessment of cognitive function was carried out according to the Mini‐Mental State Examination (MMSE) and the Alzheimer's Disease Assessment Scale‐cognitive component‐Japanese version (ADAS‐Jcog). A 1.5‐T clinical magnetic resonance unit was used to obtain diffusion tensor images. Diffusion tensors were computed and fiber‐tract maps were created using ‘dTV II’ DTI software developed by Masutani et al. We measured mean FA and ADC values along the bilateral UF. Results: FA values were positively correlated with MMSE score (r= 0.67) and were negatively correlated with ADAS‐Jcog score (r=?0.62), while ADC values were negatively correlated with MMSE score (r=?0.58) and were positively correlated with ADAS‐Jcog score (r= 0.59). Conclusion: FA and ADC values might reflect the severity of cognitive dysfunction. The tract‐of‐interest method might be a useful tool for objectively evaluating DTI parameters in AD.     

In vivo parahippocampal white matter pathology as a biomarker of disease progression to Alzheimer's disease

Noninvasive diagnostic tests for Alzheimer's disease (AD) are limited. Postmortem diagnosis is based on density and distribution of neurofibrillary tangles (NFTs) and amyloid‐rich neuritic plaques. In preclinical stages of AD, the cells of origin for the perforant pathway within the entorhinal cortex are among the first to display NFTs, indicating its compromise in early stages of AD. We used diffusion tensor imaging (DTI) to assess the integrity of the parahippocampal white matter in mild cognitive impairment (MCI) and AD, as a first step in developing a noninvasive tool for early diagnosis. Subjects with AD (N = 9), MCI (N = 8), or no cognitive impairment (NCI; N = 20) underwent DTI‐MRI. Fractional anisotropy (FA) and mean (MD) and radial (RD) diffusivity measured from the parahippocampal white matter in AD and NCI subjects differed greatly. Discriminant analysis in the MCI cases assigned statistical membership of 38% of MCI subjects to the AD group. Preliminary data 1 year later showed that all MCI cases assigned to the AD group either met the diagnostic criteria for probable AD or showed significant cognitive decline. Voxelwise analysis in the parahippocampal white matter revealed a progressive change in the DTI patterns in MCI and AD subjects: whereas converted MCI cases showed structural changes restricted to the anterior portions of this region, in AD the pathology was generalized along the entire anterior–posterior axis. The use of DTI for in vivo assessment of the parahippocampal white matter may be useful for identifying individuals with MCI at highest risk for conversion to AD and for assessing disease progression. J. Comp. Neurol. 521:4300–4317, 2013. © 2013 Wiley Periodicals, Inc.     

Analysis of high-voltage electrical spinal cord injury using diffusion tensor imaging

The aim of this study was to investigate spinal cord injury (SCI) on the basis of diffusion tensor imaging (DTI) in patients with high-voltage electrical injury. We recruited eight high-voltage electrical injury patients and eight healthy subjects matched for age and sex. DTI and central motor conduction time were acquired in both the patient and control groups. We obtained DTI indices according to the spinal cord levels (from C2 to C7) and cross-section locations (anterior, lateral, and posterior). Fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were compared between the two groups; additionally, they were compared in relation to spinal cord level and cross-section location. In the patient group relative to the control group, the FA value decreased and the MD and RD values increased in all of the regions of interest (ROI) with statistical significance (p < 0.05). In the patient group, particularly in the ROIs of the anterior spinal cord compared with the lateral and posterior spinal cords, the FA value decreased with statistical significance (p < 0.05). The DTI indices did not differ by level. DTI revealed the change of diffusion in the spinal cords of patients with high-voltage electrical injury, and corroborated the pathophysiology, myelinopathy and typical anterior spinal cord location of high-voltage electrical SCI already reported in the literature.     

White matter integrity linked to functional impairments in aging and early Alzheimer's disease

BackgroundAlzheimer's disease (AD) is associated with changes in cerebral white matter (WM), but the functional significance of such findings is not yet established. We hypothesized that diffusion tensor imaging (DTI) might reveal links between regional WM changes and specific neuropsychologically and psychophysically defined impairments in early AD.MethodsOlder adult control subjects (OA, n = 18) and mildly impaired AD patients (n = 14) underwent neuropsychological and visual perceptual testing along with DTI of cerebral WM. DTI yielded factional anisotropy (FA) and mean diffusivity (〈D〉) maps for nine regions of interest in three brain regions that were then compared with the performance measures.ResultsAD patients exhibited nonsignificant trends toward lower FAs in the posterior region's callosal and subcortical regions of interest. However, posterior callosal FA was significantly correlated with verbal fluency and figural memory impairments, whereas posterior subcortical FA was correlated with delayed verbal memory, figural memory, and optic flow perceptual impairments.ConclusionsWM changes in early AD are concentrated in posterior cerebral areas, with distributions that correspond to specific functional impairments. DTI can be used to assess regional pathology related to individual's deficits in early AD.     

运用磁共振弥散张量成像观察显微血管减压术后三叉神经的结构变化

目的：利用磁共振弥散张量成像（DTI）序列,观察显微血管减压术（MVD）后,三叉神经痛（TN）患者三叉神经的微观结构改变。方法9例原发性 TN 患者术前及术后行 DTI 扫描,测算两侧三叉神经向异性分数（FA）、平均弥散率（MD）、轴向弥散率（AD）、垂直弥散率（RD）和两侧各弥散参数差值比。按手术疗效分为治愈和未治愈两组,分析两组患者在手术前后,两侧三叉神经各 DTI 参数及两侧间各弥散参数差值比的变化。结果男性6例,女性3例;平均年龄52．1岁,平均病程5．1年。于术后第一次复查（平均12．3个月）时行 DTI ,术后疗效随访平均66个月。治愈组6例,均有明显的血管压迫,三叉神经有受压变形;未治愈组3例,2例有血管压迫,1例患者仅有严重的蛛网膜粘连而无血管压迫。治愈组术前患侧明显下降的 FA 值及明显上升的 MD 、RD 值,术后复查时均恢复。而未治愈组的各弥散参数及差值比则在手术前后无明显变化。结论 MVD 术后疼痛消失的患者,患侧三叉神经的脱髓鞘变恢复正常。然而术后疼痛仍然存在的患者,神经的脱髓鞘变依然存在。三叉神经的脱髓鞘变与 TN 关系密切。     

Diffusion tensor imaging in early Alzheimer's disease

Our aim was to investigate the extent of white matter tissue damage in patients with early Alzheimer disease (AD) using diffusion tensor magnetic resonance imaging (DTI). Although AD pathology mainly affects cortical grey matter, previous magnetic resonance imaging (MRI) studies showed that changes also exist in the white matter (WM). However, the nature of AD-associated WM damage is still unclear. Conventional and DTI examinations (b=1000 s/mm(2), 25 directions) were obtained from 12 patients with early AD (Mini Mental State Examination [MMSE] score=27, Grober and Buschke test score=33.2, digit span score=5.6) and 12 sex- and age-matched volunteers. The right and left mean diffusivity (MD) and fractional anisotropy (FA) of several WM regions were pooled in each patient and control, and compared between the two groups. Volumes of the whole brain and degree of atrophy of the temporal lobe were compared between the two groups. In AD, MD was increased in the splenium of the corpus callosum and in the WM in the frontal and parietal lobes. FA was bilaterally decreased in the WM of the temporal lobe, the frontal lobe and the splenium compared with corresponding regions in controls. Values in other areas (occipital area, superior temporal area, cingulum, internal capsule, and genu of the corpus callosum) were not different between patients and controls. No correlations were found between the MMSE score and the anisotropy indices. Findings of DTI reveal abnormalities in the frontal and temporal WM in early AD patients. These changes are compatible with early temporal-to-frontal disconnections.