创伤后应激障碍患者扣带束及胼胝体纤维束FA值的初步研究

目的探讨创伤后应激障碍患者(PTSD)是否存在连合纤维束胼胝体及联络纤维扣带纤维束的超微结构异常。方法1.5T的MR成像仪下对12例PTSD患者及12名正常对照进行磁共振弥散张量成像(DTI),测量受试者胼胝体膝部、体部、压部、及双侧扣带水平部、后部等感兴趣区内主要白质纤维束的各向异性分数(FA)值,并进行组间比较。结果患者组双侧(左侧、右侧)扣带束水平部、胼胝体压部的FA值较对照组明显降低,差异均有统计学意义(t分别为3.26、-4.13、2.84,P均小于0.05)。结论PTSD患者的边缘系统纤维束可能存在结构异常。     

DTI tractography and white matter fiber tract characteristics in euthymic bipolar I patients and healthy control subjects

With the introduction of diffusion tensor imaging (DTI), structural differences in white matter (WM) architecture between psychiatric populations and healthy controls can be systematically observed and measured. In particular, DTI-tractography can be used to assess WM characteristics over the entire extent of WM tracts and aggregated fiber bundles. Using 64-direction DTI scanning in 27 participants with bipolar disorder (BD) and 26 age-and-gender-matched healthy control subjects, we compared relative length, density, and fractional anisotrophy (FA) of WM tracts involved in emotion regulation or theorized to be important neural components in BD neuropathology. We interactively isolated 22 known white matter tracts using region-of-interest placement (TrackVis software program) and then computed relative tract length, density, and integrity. BD subjects demonstrated significantly shorter WM tracts in the genu, body and splenium of the corpus callosum compared to healthy controls. Additionally, bipolar subjects exhibited reduced fiber density in the genu and body of the corpus callosum, and in the inferior longitudinal fasciculus bilaterally. In the left uncinate fasciculus, however, BD subjects exhibited significantly greater fiber density than healthy controls. There were no significant differences between groups in WM tract FA for those tracts that began and ended in the brain. The significance of differences in tract length and fiber density in BD is discussed.     

Neuropathological abnormalities of the corpus callosum in schizophrenia: a diffusion tensor imaging study

OBJECTIVES: Diffusion tensor imaging (DTI), a technique capable of examining water diffusion in different tissues and the organisation of white matter tracts, was used to investigate the neuropathology of the corpus callosum in vivo in patients with schizophrenia. METHODS: Diffusion tensor imaging was performed in 20 schizophrenic patients and 25 healthy controls. Two complementary measures, mean diffusivity and fractional anisotropy, which are considered to be sensitive indices of axonal integrity, were obtained from regions of interest in the genu (anterior) and splenium (posterior) of the corpus callosum. RESULTS: Mean diffusivity was significantly increased and fractional anisotropy significantly reduced in the splenium but not the genu of the corpus callosum in the schizophrenic group compared with controls. There were no significant sex differences in the DTI measures for either the schizophrenic or control group. Clinical variables such as age, duration of illness, dose of antipsychotic medication, and schizophrenic symptoms did not predict the DTI changes in the schizophrenic patients. CONCLUSIONS: The presence of DTI changes in the splenium but not the genu of the corpus callosum suggests that there may be a focal disruption of commisural connectivity in schizophrenia. However, these findings do not exclude the possibility of abnormalities in other areas of the corpus callosum or other regions of white matter and further research using different methods of analysis may enable us to clarify this. Diffusion tensor imaging is a valuable tool in investigating the structure of white matter in schizophrenia.     

Frontal Callosal Fiber Integrity Selectively Predicts Coordinated Psychomotor Performance in Chronic Alcoholism

Introduction  Quantitative fiber tracking with diffusion tensor imaging (DTI) provides a new approach for assessing deficits in the microstructural integrity of white matter circuits that may underlie cognitive deficits associated with conditions affecting white matter, including chronic alcoholism. Methods  Alcoholic men and women (n = 87) and healthy controls (n = 88) performed the Digit Symbol (DS) test and underwent structural and diffusion tensor imaging. Measures of fractional anisotropy (FA) of fibers passing through genu and splenium were computed, as were size of genu and splenium fiber target regions of interest (ROI). Results  Alcoholics scored lower than controls on the DS and had even greater deficits in genu than splenium fiber FA. In alcoholics, fiber FA of the genu selectively predicted DS scores after accounting for splenium FA. Neither fiber FA measure predicted incidental recall of the symbols used in the task. Size of genu and splenium ROI, although reduced in alcoholics, did not predict DS score or incidental recall. Conclusions  Quantitative tractography of frontal fibers connecting left and right hemispheres selectively predicted performance by alcoholics on a coordinated psychomotor task and provide support for frontally based systems in Digit Symbol performance, both of which are compromised in recovering alcoholics.     

A comparative diffusion tensor imaging study of corpus callosum subregion integrity in bipolar disorder and schizophrenia

Structural magnetic resonance imaging (MRI) studies have provided evidence for corpus callosum (CC) white matter abnormalities in bipolar disorder (BD) and schizophrenia (SZ). These findings include alterations in shape, volume, white matter intensity and structural integrity compared to healthy control populations. Although CC alterations are implicated in both SZ and BD, no study of which we are aware has investigated callosal subregion differences between these two patient populations. We used diffusion tensor imaging (DTI) to assess CC integrity in patients with BD (n=16), SZ (n=19) and healthy controls (HC) (n=24). Fractional anisotropy (FA) of CC subregions was measured using region of interest (ROI) analysis and compared in the three groups. Significant group differences of FA values were revealed in five CC subregions, including the anterior genu, middle genu, posterior genu, posterior body and anterior splenium. FA values of the same subregions were significantly reduced in patients with SZ compared with HC. FA values were also significantly reduced in patients with BD compared to the HC group in the same subregions, excepting the middle genu. No significant difference was found between patient groups in any region. Most of the alterations in CC subregions were present in both the BD and SZ groups. These results imply an overlap in potential pathology, possibly relating to risk factors common to both disorders. The one region that differed between patient groups, the middle genu area, may serve as an illness marker and is perhaps involved in the different cognitive impairments observed in BD and SZ.     

Abnormal frontal white matter tracts in bipolar disorder: a diffusion tensor imaging study

OBJECTIVES: Prefrontal white matter has been hypothesized to be integral to the pathophysiology of bipolar disorder. Recent morphometric studies however, have not observed changes in white matter in bipolar patients. We hypothesized that changes in prefrontal function in bipolar disorder, widely reported in the literature, may be related to a loss of white matter tract integrity with a resultant dysconnectivity syndrome. In this study we utilized diffusion tensor imaging (DTI) to examine prefrontal white matter in patients with bipolar disorder. METHODS: Nine patients with bipolar disorder and nine healthy controls were recruited. DTI and localizing anatomic data were acquired, and regions of interest (ROIs) identified in the prefrontal white matter at 15, 20, 25, and 30 mm superior to the anterior commissure (AC). Fractional anisotropy (FA) and trace apparent diffusion coefficient (TADC) were compared by ROI between study groups. RESULTS: The FA of ROIs 25 and 30 mm above the AC was significantly reduced in patients with bipolar disorder; FA of all ROIs showed high-medium to large effect sizes. No significant group differences were identified in TADC. CONCLUSIONS: Our findings suggest that a loss of bundle coherence is present in prefrontal white matter. This loss of coherence may contribute to prefrontal cortical pathology in patients with bipolar disorder.     

轻微型肝性脑病磁共振扩散加权成像和扩散张量成像的定量研究

目的通过磁共振扩散加权成像(DWI)和扩散张量成像(DTI)定量分析轻微型肝性脑病(MHE)患者脑功能的异常改变,探讨DWI和DTI在MHE中的应用价值。方法30例肝硬化患者经神经心理测试评分量表测试后,分为MHE组16例和无MHE单纯肝硬化组14例,同时选取15例健康志愿者为正常对照组。所有受试者均行DWI与DTI扫描,选取脑内8个部位为感兴趣区,计算各部位的表观扩散系数(ADC)值和各向异性分数(FA)值。结果18例肝硬化患者于T1WI图像上可见到双侧内囊、苍白球对称性高信号。额叶、枕叶白质、胼胝体膝部、胼胝体压部、内囊前肢、内囊后肢、尾状核头部由正常组、单纯肝硬化组至MHE组ADC值逐渐增加,且MHE组的ADC值较肝硬化组和正常组增加,差异有统计学意义(P<0.05);胼胝体膝部和压部的FA值由正常组、单纯肝硬化组至MHE组逐渐降低,差异有统计学意义(P<0.05)。结论DWI与DTI联合应用能够预测肝硬化患者MHE的进展程度,具有潜在的临床价值。     

弥漫性轴索损伤早期磁共振弥散张量成像检测与恢复期注意力障碍的相关性研究

目的应用磁共振弥散张量成像技术研究患者早期弥漫性轴索损伤(DAI)与恢复期时注意力障碍之间的关系。方法分别对12例DAI患者(伤后4.1±1.7d)和10例健康志愿者(正常对照组)进行MRI弥散张量成像(DTI)检查及神经心理测评量表评估。使用感兴趣区域方法对两组DTI图像的下纵束、上纵束、胼胝体膝部和胼胝体压部的FA值进行比较;分别对恢复期的DAI患者(20.9±7.3 M)与健康志愿者行认知量表评估,并对DAI组的FA值与神经心理测评量表的总分行pearson直线相关分析。结果与健康对照组相比,DAI患者全部感兴趣区的FA值显著降低(P<0.05)、注意力功能显著降低(P<0.05)。DAI患者中的上纵束和下纵束与注意力量表总分呈负性相关(P<0.05),胼胝体膝部和胼胝体压部与注意力量表总分无相关性(P>0.05)。结论利用DTI技术检测早期白质纤维束的损伤可以预测DAI患者在恢复期中的注意力功能障碍,为临床上DAI患者的认知障碍的诊断提供一定的科学依据。     

Diffusion tensor imaging of cocaine-treated rodents

Studies in cocaine-dependent human subjects have shown differences in white matter on diffusion tensor imaging (DTI) compared with non-drug-using controls. It is not known whether the differences in fractional anisotropy (FA) seen on DTI in white matter regions of cocaine-dependent humans result from a pre-existing predilection for drug use or purely from cocaine abuse. To study the effect of cocaine on brain white matter, DTI was performed on 24 rats after continuous infusion of cocaine or saline for 4 weeks, followed by brain histology. Voxel-based morphometry analysis showed an 18% FA decrease in the splenium of the corpus callosum (CC) in cocaine-treated animals relative to saline controls. On histology, significant increase in neurofilament expression (125%) and decrease in myelin basic protein (40%) were observed in the same region in cocaine-treated animals. This study supports the hypothesis that chronic cocaine use alters white matter integrity in human CC. Unlike humans, where the FA in the genu differed between cocaine users and non-users, the splenium was affected in rats. These differences between rodent and human findings could be due to several factors that include differences in the brain structure and function between species and/or the dose, timing, and duration of cocaine administration.     

Midlife measurements of white matter microstructure predict subsequent regional white matter atrophy in healthy adults

Objectives: Although age‐related brain changes are becoming better understood, midlife patterns of change are still in need of characterization, and longitudinal studies are lacking. The aim of this study was to determine if baseline fractional anisotropy (FA), obtained from diffusion tensor imaging (DTI) predicts volume change over a 4‐year interval. Experimental design: Forty‐four cognitively healthy middle‐age adults underwent baseline DTI and longitudinal T1‐weighted magnetic resonance imaging. Tensor‐based morphometry methods were used to evaluate volume change over time. FA values were extracted from regions of interest that included the cingulum, entorhinal white matter, and the genu and splenium of the corpus callosum. Baseline FA was used as a predictor variable, whereas gray and white matter atrophy rates as indexed by Tensor‐based morphometry were the dependent variables. Principal observations: Over a 4‐year period, participants showed significant contraction of white matter, especially in frontal, temporal, and cerebellar regions (P < 0.05, corrected for multiple comparisons). Baseline FA in entorhinal white matter, genu, and splenium was associated with longitudinal rates of atrophy in regions that included the superior longitudinal fasciculus, anterior corona radiata, temporal stem, and white matter of the inferior temporal gyrus (P < 0.001, uncorrected for multiple comparisons). Conclusions: Brain change with aging is characterized by extensive shrinkage of white matter. Baseline white matter microstructure as indexed by DTI was associated with some of the observed regional volume loss. The findings suggest that both white matter volume loss and microstructural alterations should be considered more prominently in models of aging and neurodegenerative diseases. Hum Brain Mapp 35:2044–2054, 2014. © 2013 Wiley Periodicals, Inc .     

Multivariate pattern analysis of DTI reveals differential white matter in individuals with obsessive‐compulsive disorder

Diffusion tensor imaging (DTI) studies have revealed group differences in white matter between patients with obsessive‐compulsive disorder (OCD) and healthy controls. However, the results of these studies were based on average differences between the two groups, and therefore had limited clinical applicability. The objective of this study was to investigate whether fractional anisotropy (FA) of white matter can be used to discriminate between patients with OCD and healthy controls at the level of the individual. DTI data were acquired from 28 OCD patients and 28 demographically matched healthy controls, scanned using a 3T MRI system. Differences in FA values of white matter between OCD and healthy controls were examined using a multivariate pattern classification technique known as support vector machine (SVM). SVM applied to FA images correctly identified OCD patients with a sensitivity of 86% and a specificity of 82% resulting in a statistically significant accuracy of 84% (P ≤ 0.001). This discrimination was based on a distributed network including bilateral prefrontal and temporal regions, inferior fronto‐occipital fasciculus, superior fronto‐parietal fasciculus, splenium of corpus callosum and left middle cingulum bundle. The present study demonstrates subtle and spatially distributed white matter abnormalities in individuals with OCD, and provides preliminary support for the suggestion that that these could be used to aid the identification of individuals with OCD in clinical practice. Hum Brain Mapp 35:2643–2651, 2014. © 2013 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. .     

A diffusion tensor imaging study of deep gray and white matter brain maturation differences between patients with spina bifida cystica and healthy controls

The aim of this study was to use diffusion tensor imaging (DTI) to identify differences in the maturation of deep gray matter (GM) and white matter (WM) between patients with spina bifida cystica (SBC) (n = 29) with normal-appearing brains on conventional MRI, and age-matched and sex-matched healthy control participants (n = 33). Changes in DTI metrics were calculated using a log–linear regression model. We observed increasing fractional anisotropy (FA) with age in the occipital, fornix, cingulum and middle cerebellar peduncles and decreasing FA with age in the genu and splenium of the corpus callosum (CC) and caudate nuclei in patients compared to controls. Increasing FA values in some of the WM structures probably represent faulty WM maturation, whereas decreasing FA values in the CC represents changes secondary to the affected WM fibers contributing to the CC. DTI changes in deep GM and WM in the absence of any abnormality on conventional MRI might provide the basis for cognitive decline in these patients.     

Reduced white matter fractional anisotropy and clinical symptoms in schizophrenia: a voxel-based diffusion tensor imaging study

Although not consistently replicated, diffusion tensor imaging (DTI) studies in schizophrenia have revealed lower fractional anisotropy (FA) in various white matter regions, a finding consistent with the disruption of white matter integrity. In this study, we used voxel-based DTI to investigate possible whole-brain differences in the white matter FA values between 58 schizophrenia patients and 58 healthy controls. We also explored the association between FA values and clinical symptoms in schizophrenia. Compared with the controls, the schizophrenia patients showed significant FA reductions in bilateral superior longitudinal fasciculus, bilateral inferior fronto-occipital fasciculus, and genu of right internal capsule. Furthermore, in the patient group, the FA value of the anterior part of the corpus callosum was negatively correlated with the avolition score on the Scale for the Assessment of Negative Symptoms. These findings suggest widespread disruption of white matter integrity in schizophrenia, which could partly explain the severity of negative symptomatology.     

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.     

White Matter Abnormalities in Schizophrenia and Schizotypal Personality Disorder

Prior diffusion tensor imaging (DTI) studies examining schizotypal personality disorder (SPD) and schizophrenia, separately have shown that compared with healthy controls (HCs), patients show frontotemporal white matter (WM) abnormalities. This is the first DTI study to directly compare WM tract coherence with tractography and fractional anisotropy (FA) across the schizophrenia spectrum in a large sample of demographically matched HCs (n = 55), medication-naive SPD patients (n = 49), and unmedicated/never-medicated schizophrenia patients (n = 22) to determine whether (a) frontal-striatal-temporal WM tract abnormalities in schizophrenia are similar to, or distinct from those observed in SPD; and (b) WM tract abnormalities are associated with clinical symptom severity indicating a common underlying pathology across the spectrum. Compared with both the HC and SPD groups, schizophrenia patients showed WM abnormalities, as indexed by lower FA in the temporal lobe (inferior longitudinal fasciculus) and cingulum regions. SPD patients showed lower FA in the corpus callosum genu compared with the HC group, but this regional abnormality was more widespread in schizophrenia patients. Across the schizophrenia spectrum, greater WM disruptions were associated with greater symptom severity. Overall, frontal-striatal-temporal WM dysconnectivity is attenuated in SPD compared with schizophrenia patients and may mitigate the emergence of psychosis.Key words: DTI, MRI, schizotypal personality disorder, schizophrenia, psychosis, white matter, genu, cingulum, inferior longitudinal fasciculus     

Diffusion tensor imaging studies of mild traumatic brain injury: a meta-analysis

Objectives To assess the possibility that diffusion tensor imaging (DTI) can detect white matter damage in mild traumatic brain injury (mTBI) patients via systematic review and meta-analysis. Methods DTI studies that compared mTBI patients and controls were searched using MEDLINE, Web of Science, and EMBASE, (1980 through April 2012). Results A comprehensive literature search identified 28 DTI studies, of which 13 independent DTI studies of mTBI patients were eligible for the meta-analysis. Random effect model demonstrated significant fractional anisotropy (FA) reduction in the corpus callosum (CC) (p=0.023, 95% CIs -0.466 to -0.035, 280 mTBIs and 244 controls) with no publication bias and minimum heterogeneity, and a significant increase in mean diffusivity (MD) (p=0.015, 95% CIs 0.062 to 0.581, 154 mTBIs and 100 controls). Meta-analyses of the subregions of the CC demonstrated in the splenium FA was significantly reduced (p=0.025, 95% CIs -0.689 to -0.046) and MD was significantly increased (p=0.013, 95% CIs 0.113 to 0.950). FA was marginally reduced in the midbody (p=0.099, 95% CIs -0.404 to 0.034), and no significant change in FA (p=0.421, 95% CIs -0.537 to 0.224) and MD (p=0.264, 95% CIs -0.120 to 0.438) in the genu of the CC. Conclusions Our meta-analysis revealed the posterior part of the CC was more vulnerable to mTBI compared with the anterior part, and suggested the potential utility of DTI to detect white matter damage in the CC of mTBI patients.     

Grey and white matter abnormalities in temporal lobe epilepsy with and without mesial temporal sclerosis

Temporal lobe epilepsy with (TLE-mts) and without (TLE-no) mesial temporal sclerosis display different patterns of cortical neuronal loss, suggesting that the distribution of white matter damage may also differ between the sub-groups. The purpose of this study was to examine patterns of white matter damage in TLE-mts and TLE-no and to determine if identified changes are related to neuronal loss at the presumed seizure focus. The 4 T diffusion tensor imaging (DTI) and T1-weighted data were acquired for 22 TLE-mts, 21 TLE-no and 31 healthy controls. Tract-based spatial statistics (TBSS) was used to compare fractional anisotropy (FA) maps and voxel-based morphometry (VBM) was used to identify grey matter (GM) volume atrophy. Correlation analysis was conducted between the FA maps and neuronal loss at the presumed seizure focus. In TLE-mts, reduced FA was identified in the genu, body and splenium of the corpus callosum, bilateral corona radiata, cingulum, external capsule, ipsilateral internal capsule and uncinate fasciculus. In TLE-no, FA decreases were identified in the genu, the body of the corpus callosum and ipsilateral anterior corona radiata. The FA positively correlated with ipsilateral hippocampal volume. Widespread extra-focal GM atrophy was associated with both sub-groups. Despite widespread and extensive GM atrophy displaying different anatomical patterns in both sub-groups, TLE-mts demonstrated more extensive FA abnormalities than TLE-no. The microstructural organization in the corpus callosum was related to hippocampal volume in both patients and healthy subjects demonstrating the association of these distal regions.     

A voxel-based diffusion tensor imaging study of temporal white matter in patients with schizophrenia

Diffusion tensor imaging (DTI) is a relatively new technique used to detect changes in the anisotropic diffusion of white matter. The study of the disruption of brain connectivity may increase our understanding of cognitive deficits associated with schizophrenia. Here we analysed DTI data in 25 patients with DSM-IV schizophrenia and 24 healthy controls. Two complementary measures, fractional anisotropy (FA) and the apparent diffusion coefficient (ADC), were considered and analysed using voxel-based morphometry. Declarative memory functions were also investigated and their associations with DTI data were analysed. FA was significantly reduced, and the ADC increased in the left sub-gyral white matter of the temporal lobe, which involves the posterior part of the fornix. In the schizophrenic group, females had lower FA than males in the genu of the corpus callosum. Memory functions correlate with FA values. These data provide further evidence for the disruption of white matter connectivity in the left medial temporal lobe, and for its contribution to the declarative memory deficit in schizophrenia.     

抑郁症患者脑白质变化初步研究

目的：利用能够提示脑白质纤维完整性的磁共振弥散张量成像（DTI）探讨首发和复发重性抑郁症患者脑白质纤维的变化及其差异。方法：20例重性抑郁症患者（首发9例，复发11例）和20名正常对照者均经常规磁共振成像（MRI）平扫，未发现异常者继续进行DTI和结构MRI（3D）扫描，基于像素的全脑分析技术对DTI数据进行分析。结果：与对照组相比较，抑郁症组白质纤维结构在双侧额中回、右顶下小叶及双侧脑岛等区域白质的各向异性值（FA）显著降低（各脑区P均〈0.001，cluster〉30像素）;与首发抑郁症患者相比较，复发抑郁症患者右侧额上回、右顶叶、中央前回、中央后回及右顶下小叶等区域FA值降低更为显著（各脑区P均〈0.001，cluster〉10像素）。结论：重性抑郁症患者存在脑白质异常，抑郁反复发作会导致脑白质损害进一步加重。     

Difference of the hippocampal and white matter microalterations in MCI patients according to the severity of subcortical vascular changes: neuropsychological correlates of diffusion tensor imaging

OBJECTIVES: Most imaging studies of mild cognitive impairment (MCI) have focused on gray matter alterations, although many MCI patients demonstrate subcortical vascular changes. We investigated the changes of the hippocampal area and various white matter areas in MCI patients with using diffusion tensor imaging (DTI), according to the severity of subcortical vascular changes, and we then correlated the DTI findings with the neuropsychological results. PATIENTS AND METHODS: Among the 40 MCI patients, the 21 non-vascular MCI (nvMCI) and 19 vascular MCI (vMCI) patients were subdivided according to Erkinjuntti's imaging criteria. The mean diffusivity (MD) and fractional anisotropy (FA) were compared in the bilateral temporal, frontal, parietal and occipital white matter regions, as well as in the bilateral hippocampi, centrum semiovale, and the midline genu and splenum of the corpus callosum among the nvMCI and vMCI patients and the 17 controls. The neuropsychological findings were also compared between the subgroups. RESULTS: All the MCI patients showed decreased FA and increased MD in all the regions except the occipital areas. In the parietal regions and centrum semiovale, the vMCI patients had a greater FA decrease than the nvMCI patients and controls. In the hippocampi, the FA was lowest in the nvMCI patients. The memory function in the nvMCI patients was more impaired than that in the vMCI patients. The vMCI patients showed impairment of the visuospatial and frontal executive functions. CONCLUSION: We were able to correlate the microstructural alterations with the neuropsychological findings in the MCI subgroups.