磁共振弥散张量成像在脑高级别星形细胞瘤和转移瘤瘤周实质区的诊断价值

目的 探讨磁共振弥散张量成像(diffusion tensor imaging,DTI)在高级别星形细胞瘤和单发脑转移瘤诊断中的价值.方法 25例脑高级别星形细胞瘤和16例单发脑转移瘤,术前行DTI扫描,测定瘤周脑实质区及对侧正常脑实质的平均弥散系数(MD)值及各向异性分数(FA)值,并重建白质纤维示踪图,观察病灶与白质纤维束的关系.结果 高级别星形细胞瘤与脑转移瘤瘤周实质区的FA值分别为0.227±0.05、0.169±0.07,两者存在统计学差异(P＜0.05).DTI白质纤维示踪图可以较为准确地反映病灶与白质纤维束的关系.结论瘤周实质区FA值有助于高级别脑星形细胞瘤与转移瘤的鉴别.     

腰椎间盘突出受压神经的DTI参数与神经根疼痛的相关性研究

目的：探讨DTI对腰椎间盘突出受压神经损伤情况的诊断价值,并分析DTI参数与神经根疼痛的相关性。方法：选取经临床诊断及MRI平扫显示为单侧神经根受压的腰椎间盘突出症患者73例,均行DTI检查,测量各向异性分数(FA)值、ADC值、神经纤维束长度及密度指数,并采用视觉模拟评分法(VAS)进行疼痛分级;比较腰椎间盘突出L₄～S₁神经根受压侧与健侧之间上述各参数的差异;分析受压侧DTI参数与VAS评分的相关性。结果：73例患者中,受压侧神经根与健侧对应神经根FA值、纤维束长度及密度指数比较,差异均有统计学意义(均P<0.05);ADC值比较,差异无统计学意义(P> 0.05)。VAS评分：27例为轻度,38例为中度,8例为重度,轻、中、重度患者的FA值、神经根纤维束长度及密度指数差异均有统计学意义(均P<0.05),ADC值差异无统计学意义(P> 0.05)。FA值、受压神经根纤维束长度及密度指数均与VAS评分均呈负相关(r=-0.881,-0.540,-0.803;均P<0.05);ADC值与VAS评分无相关性(r=...     

DTI评估实验性自身免疫性神经炎兔坐骨神经损伤的可行性研究

目的 探讨弥散张量成像（DTI）在兔坐骨神经实验性自身免疫性神经炎（EAN）诊断中的可行性。方法 选取大耳白兔20只，实验组10只建立EAN动物模型，对照组10只。分别于0、14、18、20天行DTI扫描，进行纤维束示踪成像；并于各时间点测量并比较FA值和ADC值。结果 DTI示踪成像显示EAN实验组坐骨神经较正常组边缘不光整，纤维数量减少。兔坐骨神经各时间点纤维束FA值实验组低于对照组，ADC值实验组高于对照组，差异有统计学意义。结论 应用DTI活体纤维束示踪EAN动物模型坐骨神经损伤的形态变化，定量评价神经损伤是可行的。     

DCE-MRI定量参数预测高强度超声消融术治疗症状性子宫肌瘤首次体积消融率价值

目的 探讨DCE-MRI定量渗透性与T1灌注分析预测高强度超声消融术(HIFU)治疗子宫肌瘤首次体积消融率价值.方法 搜集本院29例症状性子宫肌瘤行HIFU消融治疗患者(36个肌瘤,直径3.1 ～9.2 cm),治疗前、后3天内分别行DCE-MRI和常规MRI检查,术前测量子宫肌瘤DCE-MRI定量参数值(Ktrans、Kep、Ve、Vp、BF、BV),术后测量肌瘤首次体积消融率,根据体积消融率划分为消融70％以上组(H组)和70％以下组(L组),回顾性分析这两组病例术前渗透性与T1灌注定量参数值有无差别及其与体积消融率的相关性,然后采用ROC曲线评价各参数值的预测价值,寻找术前预测首次体积消融率的最佳临界值.结果 (1)H组(n=20)Ktrans、Kep、Ve、BF低于L组(n=16),差异有统计学意义(P值均＜0.05),余两组各参数间无统计学差异.(2)Ktrans、BF、BV与首次体积消融率呈负相关(r分别为-0.471、-0.452、-0.396,P值均＜0.05).(3)Ktrans、BF、BV值预测首次体积消融率ROC曲线下面积(AUC)分别为0.803、0.809、0.750(P值均＜0.05).以体积消融率70％分界,均获得较高的敏感性和特异性.结论 不同消融率组之间术前Ktrans、Kep、Ve、BF存在差异,Ktrans、BF、BV与首次体积消融率呈负相关,即术前Ktrans、BF、BV值越高,首次体积消融率越低,这三种参数中BF预测效能最好,Ktrans次之.术前DCE-MRI定量参数值可用于预测瘤灶的首次体积消融率,为HIFU消融治疗子宫肌瘤病例筛选和初步判断疗效提供依据.     

视放射DTI、DTT改变与视野缺损对照研究

目的 探讨视放射异常磁共振弥散张量成像(diffusion tensor imaging,DTI)、弥散张量纤维束追踪成像(diffusion tensor tractography,DTT)改变与视野缺损间的关系.方法 对37例脑内病变累及视放射的患者及20例正常对照组行3.0T磁共振DTI、DTT及视野检查,分析DTI的各向异性(FA)值、表观扩散系数(ADC)值与视野的平均光敏感度(MS)值及平均缺损(MD)值间的关系及视放射纤维束形态改变与视野缺损间的关系.结果 与对照组比较,病变组FA值降低,ADC值升高,差异均有统计学意义(P＜0.001);病变组FA值与MS值呈正相关(r=0.718),与MD值呈负相关(r=0.694);ADC值与MS值呈负相关(r=-0.625),与MD值呈正相关(r=0.538).9例视放射腹束受损表现为双侧视野同上象限偏盲,7例背束及侧束受损表现为双侧视野同下象限偏盲;21例视放射广泛受损表现为双侧视野对称性或不对称性同向偏盲.结论视放射DTI及DTT检查与视野检查结果有高度相关性,可成为评价视放射功能及形态改变的客观指标.     

磁共振扩散张量成像在评估帕金森病脑内白质改变中的应用

目的 利用磁共振扩散张量成像技术(diffusion tensor imaging,DTI)评价帕金森病患者脑白质纤维束与正常老年组间的差异.方法 对23例临床诊断为原发性帕金森病(Parkinson's disease, PD)患者和相匹配的22例正常老年人行DTI成像,采用人工勾画感兴趣区(region of interest,ROI)的方法在DTI参数图,包括部分各向异性图(fractional anisotropy,FA)和平均扩散系数图(mean diffusivity,MD)上测量脑内主要白质纤维束的FA值及MD值,采用t检验的方法进行组间比较.结果 PD组双侧钩束、后扣带束及上纵束的FA值低于对照组(P＜0.05),双侧后扣带束及右侧上纵束的MD值高于正常组(P＜0.05).结论 PD的病理改变不仅存在于黑质纹状体系统,也累及白质纤维.     

1.5 T MR兔坐骨神经在体扩散张量纤维束示踪的可行性研究

目的探讨1.5 T MR兔坐骨神经在体扩散张量成像(diffusion tensor imaging,DTI)纤维束示踪的可行性及优化参数。材料与方法采用400 s/mm2、1000 s/mm2、1400 s/mm2 3个不同b值对10只健康新西兰大白兔在1.5 T MR上行32方向DTI及纤维束示踪,测量并比较在不同b值下纤维束数量、平均长度、总像素、各向异性分数(FA)、表观扩散系数(ADC)、最大本征向量(λ1)、图像的信噪比(SNR)。结果 b=1000 s/mm2时神经纤维束得以较好显示,纤维束走行与兔坐骨神经解剖一致。b=1000 s/mm2时纤时维束数量、平均长度和总像素数量均高于其他两个b值,差异有统计学意义(P=0.000);3个b值下纤维束FA无显著性差异;ADC、λ1和SNR随b值的升高而下降。结论 1.5 T MR兔坐骨神经在体DTI纤维束示踪是可行的,b=1000 s/mm2时纤维束示踪图像质量最高。     

基于纤维束示踪的空间统计分析在帕金森病扩散张量成像中的应用研究

目的 通过磁共振扩散张量成像(DTI)的基于纤维束示踪的空间统计分析(TBSS)技术研究帕金森病(PD)脑白质微结构的损害.方法 PD患者31例和健康对照组34名行磁共振检查,扫描序列包括常规磁共振平扫和DTI,通过TBSS技术比较PD组与对照组白质纤维束的各向异性分数(FA)值,寻找FA值有显著性差异的脑白质纤维束,并分析PD组白质纤维束损伤与MoCA、MMSE、HAMD、ADL和UPDRSIII评分的相关性.结果 PD组有多个纤维束FA值明显低于健康对照组,主要包括胼胝体、上纵束、扣带束、视辐射、额叶及颞叶皮层下弓形纤维、脑干及内囊的白质束.其中胼胝体压部、左上纵束、右上纵束、小脑中脚FA值与MMSE评分呈正相关;右上纵束、左皮质脊髓束、左小脑上脚、右皮质脊髓束和小脑中脚FA值与HAMD评分呈负相关;胼胝体压部、左上纵束、右上纵束FA值与ADL评分呈负相关.结论 磁共振DTI的TBSS技术能够发现PD患者白质微结构的损害及其与认知和抑郁之间的关系,有助于研究PD患者认知功能障碍和抑郁的发生机制.     

脑高级别星形细胞瘤瘤周DTI参数的测定及分析

目的：应用弥散张量成像（DTI）技术探讨脑高级别星形细胞瘤瘤周弥散各向异性特点。方法：25例脑高级别星形细胞瘤术前行DTI扫描,测定瘤周脑实质区及对侧正常脑实质的平均弥散系数（MD）值及各向异性分数（FA）值。并通过弥散张量纤维束成像（DTT）观察病灶与白质纤维束的关系。结果：高级别星形细胞瘤瘤周MD值为1．610±0．23,高于对侧正常脑实质（P〈0．01）。FA值为0．236±0．06,低于对侧正常脑实质（P〈0．01）。结论：DTI能够准确反应脑星形细胞瘤瘤周各向异性特点,DTT能够较为准确显示病灶与白质纤维束的关系。     

基于TBSS的急性CO中毒患者脑白质微细结构损伤研究

目的应用扩散张量成像(DTI)观察急性CO中毒患者脑白质结构的改变,应用影像技术量化脑白质损害程度,推测急性CO中毒迟发性脑病相关机制。方法对25例急性CO中毒患者和25例性别与年龄相匹配的健康志愿者进行头部磁共振DTI扫描,采用基于纤维束示踪的空间统计方法(TBSS),分析急性CO中毒患者脑白质平均扩散系数(MD)、各向异性分数(FA)的变化,探讨其与患者认知功能障碍间的相关性。结果与健康对照组对比,急性CO中毒患者组的放射冠、胼胝体的MD增高而FA降低(P<0.05);双侧上纵束,内、外囊,丘脑和脑干的MD增加但无FA改变(P<0.05)。与临床量表分数相关性比较发现,差异脑区FA值与MMSE评分呈一定正相关(P<0.05),差异脑区MD值与MMSE评分呈一定负相关(P<0.05)。结论DTI准确反映急性CO中毒导致脑内白质广泛的血管源性水肿以及脑白质纤维束完整性损害,可能量化反应病情缺氧脑损伤程度、预测迟发性脑病,同时DTI参数的改变还可以一定程度反映患者认知障碍情况。     

子宫肌瘤磁共振扩散张量成像特征的初步研究

目的：分析子宫肌瘤和正常子宫肌层磁共振扩散张量成像(DTI)的影像特征,探讨 DTI 在评估子宫肌瘤结构的应用价值。方法研究对象为经手术病理证实的44例子宫肌瘤患者,DTI 采用双梯度 GE HDxt 3.0T 和 HD Cardiac 线圈,应用 GE AW4.5工作站进行数据处理。记录子宫肌瘤和正常子宫肌层的表观扩散系数(ADC)、各向异性分数(FA)值、容积比各向异性(VRA)值和 T2-weighted trace 值,绘制扩散张量的纤维示踪图像(DTT)。对比不同感兴趣区(ROI)的成像指标差异。结果正常子宫肌层和子宫肌瘤的 ADC、FA、VRA、T2-weighted trace 平均值分别为(1.65±0.32)×10-9 mm2/s 和(1.21±0.97)×10-9 mm2/s、0.20±0.08和0.28±0.08、0.05±0.05 和0.09±0.07、344.22±66.19和318.97±98.48。正常子宫肌层 ADC 值高于子宫肌瘤(P =0.009)。正常子宫肌层的 FA 和 VRA 低于子宫肌瘤(P =0.000、P =0.005)。2组的 T2-weighted trace 值差异无统计学意义(P =0.174)。DTI 纤维示踪图显示正常子宫肌层和子宫肌瘤的纤维方向、排列和数量存在明显的差异。结论 DTI 能够反映出正常子宫肌层和子宫肌瘤的微观结构差异,有助于提高 MRI 对子宫肌瘤的影像学评估的应用价值。     

复发-缓解型多发性硬化边缘系统白质纤维束定量DTI改变

目的 探讨复发-缓解型多发性硬化(relapsing remitting multiple sclerosis,RRMS)患者边缘系统白质纤维束定量弥散张量的改变.方法 RRMS患者24例,年龄和性别相匹配的健康志愿者24例为对照进行MRI扫描,获取常规MRI图像和弥散张量成像(DTI)图像,经GE工作站处理后进行测量分析,比较2组边缘系统主要纤维束(扣带束、穹窿束和终纹束)不同部分各向异性指数(FA)值和平均弥散系数(MD)值的变化.结果 在考虑年龄和性别因素的影响后.RRMS组患者穹窿柬(F=15.605,P=0.000135)、右侧穹窿/终纹束(F=15.772,P=0.000127)、左侧穹窿/终纹束(F=8.53,P=0.004)的FA值较健康对照组明显降低; RRMS组患者穹窿束(F=13.28,P=0.0004)、右侧终纹柬(F=10.943,P= 0.002)、右侧穹窿/终纹束(F= 7.326,P=0.008)的MD值较健康对照组明显增高;RRMS组患者左/右侧的前、后扣带束、右侧终纹束(F= 0.986, P=0.326)、左侧终纹束的FA和对照组比较无明显差异,RRMS组患者左/右侧的前、后扣带束、左侧终纹束、左侧穹窿/终纹束的MD值较健康对照比较差异均无统计学意义.结论 DTI可作为反映RRMS边缘系统纤维束病理性改变的较敏感的检测方法.     

Assessment of corticospinal tract (CST) damage in acute stroke patients: Comparison of tract‐specific analysis versus segmentation of a CST template

Purpose:

To compare two techniques to assess corticospinal tract (CST) damage in stroke patients: tract‐specific analysis by probabilistic tractography and segmentation using a CST template.

Materials and Methods:

We extracted fractional anisotropy (FA) values, the FA ratio, and mean diffusivity (MD) in 18 stroke patients and 21 healthy volunteers matched for age and sex. We compared the two methods in order to determine their ability to detect 1) differences between diffusion tensor imaging (DTI) parameters of healthy volunteers and stroke patients, 2) the correlation between DTI parameters and clinical scores, and 3) the correlation between DTI parameters and blood oxygen level‐dependent (BOLD) signals in a fist‐closure task.

Results:

FA values were higher with the tractography approach than with the segmentation method, but differences between the ipsilesional CST and the homologous region in healthy subjects were detected using both methods. In patients, clinical scores were significantly correlated with FA values and FA ratios with both methods. The BOLD signal was positively correlated with FA values for CST with the segmentation but not with the tractography approach.

Conclusion:

CST damage in stroke patients can be assessed by either probabilistic tractography or segmentation of a CST template. Although each method has advantages and limitations, both are sensitive enough to detect differences among stroke patients and identify specific correlations with clinical scores. J. Magn. Reson. Imaging 2013;37:836–845. © 2012 Wiley Periodicals, Inc.     

Quantitative diffusion tensor fiber tracking of age-related changes in the limbic system

Cerebral white matter is known to undergo degradation with aging, and diffusion tensor imaging (DTI) is capable of revealing the white matter integrity. We assessed age-related changes of quantitative diffusivity parameters and fiber characteristics within the fornix and the cingulum. Thirty-eight healthy subjects aged 18–88 years were examined at 3 Tesla using a 1.9-mm isotropic DTI sequence. Quantitative fiber tracking was performed for 3D-segmentation of the fornix and the cingulum to determine fractional anisotropy (FA), mean diffusivity (MD), eigenvalues (λ₁, λ₂, and λ₃), number of fibers (NoF), and mean NoF/voxel (FpV). In the fornix, all diffusivity parameters (FA, MD, and eigenvalues) were moderately correlated with age. Strong and moderate negative correlations for NoF and FpV were found, respectively. In the cingulum, no correlation was observed between FA and age, and only weak correlations for the other quantitative parameters. Differences in correlations between the fornix and the cingulum were significant for all diffusivity parameters and for NoF, but not for FpV. The strongest relative changes per decade of age were found in the fornix: FA −2.1%, MD 4.2%, NoF −10.6%, and FpV −4.6%. Our quantitative 3D fiber tracking approach shows that the cingulum is resistant to aging while the fornix is not.     

Changes in fiber integrity, diffusivity, and metabolism of the pyramidal tract adjacent to gliomas: a quantitative diffusion tensor fiber tracking and MR spectroscopic imaging study

BACKGROUND AND PURPOSE: The underlying changes in the neuronal connectivity adjacent to brain tumors cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative sensorimotor deficits are associated with impairment in pyramidal fiber bundles. Hence, we investigated the potential of combined quantitative diffusion tensor (DT) fiber tracking and MR spectroscopic imaging (MRSI) to determine changes in the pyramidal tract adjacent to gliomas. MATERIALS AND METHODS: Quantitative DT fiber tracking and proton MRSI were performed in 20 patients with gliomas with WHO grades II-IV. Eight patients experienced preoperative sensorimotor deficits. Mean diffusivity (MD), fractional anisotropy (FA), and number of fibers per voxel (FpV) were calculated for the pyramidal tract of the ipsilateral and contralateral hemisphere. Metabolite concentrations for choline-containing compounds (Cho), creatine (Cr), and N-acetylaspartate (NAA) were computed, using LCModel, for all voxels located at the pyramidal tracts. RESULTS: For the whole pyramidal tract, quantitative DT fiber tracking resulted in significantly lower FpV and FA values (P < .001), but not MD values, for the ipsilateral hemisphere. For the section of the fiber bundle closest to the lesion, we found significantly decreased FpV and FA (P < .001) and increased MD (P = .002). MRSI showed, for the same volumes of interest, significantly decreased NAA (P = .001), increased Cho (P = .034) and Cho/NAA (P = .001) for the ipsilateral pyramidal tract. In patients suffering sensorimotor deficits, we found significantly lower FA (P = .022) and higher MD values (P = .026) and a strongly negative correlation between FA and MD (R = -0.710, P = .024) but no correlation in patients without deficits (R = 0.078, ns). CONCLUSION: Quantitative DTI was able to show significant differences in diffusivity of the pyramidal tract in patients with sensorimotor deficits in relation to patients without them. The additional use of proton MRSI may be helpful to discern whether these diffusivity changes in fiber tracts are caused by tumor infiltration or peritumoral edema.     

Early postnatal development of corpus callosum and corticospinal white matter assessed with quantitative tractography

BACKGROUND AND PURPOSE: The early postnatal period is perhaps the most dynamic phase of white matter development. We hypothesized that the early postnatal development of the corpus callosum and corticospinal tracts could be studied in unsedated healthy neonates by using novel approaches to diffusion tensor imaging (DTI) and quantitative tractography. MATERIALS AND METHODS: Isotropic 2 x 2 x 2 mm(3) DTI and structural images were acquired from 47 healthy neonates. DTI and structural images were coregistered and fractional anisotropy (FA), mean diffusivity (MD), and normalized T1-weighted (T1W) and T2-weighted (T2W) signal intensities were determined in central midline and peripheral cortical regions of the white matter tracts of the genu and splenium of the corpus callosum and the central midbrain and peripheral cortical regions of the corticospinal tracts by using quantitative tractography. RESULTS: We observed that central regions exhibited lower MD, higher FA values, higher T1W intensity, and lower T2W intensity than peripheral cortical regions. As expected, MD decreased, FA increased, and T2W signal intensity decreased with increasing age in the genu and corticospinal tract, whereas there was no significant change in T1W signal intensity. The central midline region of the splenium fiber tract has a unique pattern, with no change in MD, FA, or T2W signal intensity with age, suggesting different growth trajectory compared with the other tracts. FA seems to be more dependent on tract organization, whereas MD seems to be more sensitive to myelination. CONCLUSIONS: Our novel approach may detect small regional differences and age-related changes in the corpus callosum and corticospinal white matter tracts in unsedated healthy neonates and may be used for future studies of pediatric brain disorders that affect developing white matter.     

3T MRI腰骶部脊神经根扩散张量成像在腰椎间盘突出症中的应用价值

目的 探索扩散张量成像(diffusion tensor imaging,DTI)和纤维示踪成像(fibre tracking,FT)显示腰骶脊神经根的可行性,并评估椎间盘突出症患者L4及L5脊神经根各向异性分数(fractional anisotropy,FA)和表观扩散系数(apparent diffusion coefficient,ADC)值的差别.方法 20例由于后外侧或椎间孔椎间盘突出引起单侧坐骨神经痛的患者和20例健康志愿者纳入研究.所有检查均在Philips Achieve 3.0 T TX MRI上进行,纤维示踪成像参数:FA阈值＝0.15;最小纤维束长度=10mm;最大角度=27°.应用横轴位T2解剖融合图像序列评估重建图像的相关性.对所有被检者的L4、L5和S1脊神经根行扩散张量和纤维示踪成像,并在FA图和ADC图上测量L4和L5脊神经根的平均FA值和ADC值.结果 腰椎间盘突出症患者和健康志愿者腰骶部脊神经根纤维束成像在T2解剖融合图像上完全匹配.在纤维示踪图像上可以清晰地辨别腰骶部脊神经根受压位置.所有患者和健康志愿者的FA值和ADC值可以从FA图和ADC图上获得.受压侧脊神经根的FA值显著低于对侧神经根(P＜0.01)和健康志愿者的(P＜0.01); ADC值显著高于对侧神经根(P＜0.01)和健康志愿者的(P＜0.01).结论 3T MRI腰骶部脊神经根扩散张量和纤维示踪成像是可行的.腰椎间盘突出症患者受压L4和L5脊神经根的FA值和ADC值有显著性的变化.     

复发-缓解型多发性硬化投射纤维束定量DTI

目的：探讨复发-缓解型多发性硬化（RRMS）患者投射纤维定量扩散张量改变.方法：20例RRMS患者及年龄和性别相匹配的20例健康志愿者（对照组）行MRI扫描,获取常规MRI及DTI图像,分别进行测量分析,比较2组投射纤维的部分各向异性指数（FA）和平均扩散系数（MD）值的变化.主要纤维束包括丘脑前辐射（atr）、丘脑上辐射（str）、丘脑后辐射（ptr）、皮质延髓束（cpt）、皮质脊髓束（cst）等.结果：RRMS组患者与健康对照组的FA值比较：ptr（左侧：0.541±0.141 vs 0.628±0.153;右侧：0.512±0.079 vs 0.560±0.102）、cpt/atr（左侧：0.421±0.118 vs 0.503±0.104;右侧：0.437±0.064 vs 0.512±0.102）、cpt/ptr（左侧：0.405±0.056 vs 0.500±0.078;右侧：0.427±0.057 vs 0.496±0.083）、cpt/cst/str（左侧：0.476±0.115 vs 0.554±0.056;右侧：0.462±0.095 vs 0.520±0.074）,RRMS组的FA值均较健康对照组低,2组间差异有统计学意义（P〈0.05）;RRMS组患者atr的FA值（左侧：0.538±0.103,右侧：0.542±0.092）与对照组（左侧：0.564±0.087;右侧0.568±0.116）比较,差异无统计学意义（P〉0.05）.RRMS组患者与健康对照组的MD值比较：cpt/ptr（左侧：0.928±0.102 vs 0.853±0.105;右侧：0.949±0.165 vs 0.859±0.141）、cpt/cst/str（左侧：0.811±0.137 vs 0.772±0.093;右侧：0.868±0.167 vs 0.784±0.128）的MD值差异有统计学意义（P〈0.05）,RRMS组的MD值较健康对照组增高;RRMS组患者atr（左侧：0.898±0.143 vs 0.868±0.118;右侧：0.850±0.164 vs0.835±0.074）、ptr（左侧：0.874±0.203 vs 0.829±0.103;右侧：0.847±0.172 vs 0.802±0.075）、cpt/atr（左侧：0.856±0.187 vs 0.805±0.161;右侧：0.829±0.246 vs 0.820±0.093）的MD值和健康对照比较差异均无统计学意义（P〉0.05）.结论：多发性硬化患者双侧ptr、cpt/atr、cpt/ptr、cpt/cst/str存在FA值减小,双侧cpt/ptr、cpt/cst/str存在MD值的增高,提示在投射纤维中上述白质纤维束存在结构改变,DTI可以作为反映RRMS投射纤维微观病理改变的敏感检查指标.