扩散峰度成像在正常成人视通路中的应用研究

目的 应用扩散峰度成像(DKI)定量测量正常成人视通路各区域的平均峰度(MK)值、部分各向异性(FA)值和平均扩散率(MD), 探讨DKI技术在正常成人视通路研究中的应用价值。 方法 按区组随机化选择30名正常成人志愿者, 按年龄分为3组:20~39岁组、40~59岁组和60岁以上组, 每组10名, 均行常规颅脑MR和DKI序列扫描, 并测量视通路不同区域的MK值、FA值和MD, 采用SPSS15.0统计学软件分析MK值、FA值和MD的正常范围, 及其随年龄递增的变化规律。 结果 视神经、外侧膝状体、视放射和视皮层区域MK值与年龄呈负相关; 外侧膝状体、视放射区域FA值与年龄呈负相关; 视神经、外侧膝状体区域MD与年龄呈正相关。 结论 DKI所得参数可以无创性地反映正常成人视通路随年龄增长的微观结构的变化。     

DTI各向异性分数与椭球面积比在儿童特发性全面性癫痫中的比较研究

【摘要】目的：探讨DTI各向异性分数（FA）和椭球面积比（EAR）在特发性全面性癫痫（IGE）中的诊断价值。方法：根据脑电图对发作间期痫样放电（IED）的定侧结果,将33例IGE患儿分为3组,IGE-A组15例（双侧IED）,IGE-B组9例（左侧IED）,IGE-C组9例（右侧IED）。将32例健康志愿者纳入对照组（NC）,并根据年龄、性别分别与A、B、C组相匹配的方法,进一步分为NC-A组、NC-B组和NC-C组,显示阈值为50个体素（Px）。结果：IGE-A和NC-A组比较,FA和EAR异常分布最大区域为左侧半球额叶和颞叶脑白质,EAR异常还见于右中央颞区（222 Px）、顶叶（198 Px）、脑下回（126 Px）、中央后回（125 Px）等右侧大脑半球白质区域。与NC-B组比较,IGE-B组的FA和EAR异常分布区位于左侧大脑白质梭状回和枕叶,此外左额叶（65Px）白质内有少量EAR异常区域。IGE-C与NC-C组比较,FA和EAR异常改变均位于左侧大脑半球,EAR异常区的体素簇范围较FA体素簇大（169 vs. 50 Px）,EAR图还显示了左侧颞叶（123 Px）、左侧颞中回（112 Px）和颞上回（111 Px）等部位白质及灰质的异常改变。结论：EAR和FA均可反映IGE脑白质异常,EAR比FA更敏感,能发现更多白质异常区域,可用于人类脑部病变的研究。     

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。     

扩散峰度成像在小儿结节性硬化症中的应用

【摘要】目的：探讨扩散峰度成像（DKI）对小儿结节性硬化症（TSC）的诊断价值。方法：对32例在本院经临床诊断为TSC的患儿行脑部DKI检查（b值为0、1000和2000s/mm2,各有15个扩散方向）,测量患儿67个灰质结节及45个白质病变的平均扩散峰度（MK）、轴向峰度（AK）及径向峰度（RK）值,并与对侧正常区域进行对照分析。结果：灰质结节和对侧正常灰质的MK、AK及RK值分别为0.57±0.14、0.47±0.09、0.62±0.12和0.72±0.11、0.49±0.07、0.76±0.13;灰质结节的MK、RK值显著低于正常灰质,差异均有统计学意义（P<0.01）,而AK值的差异无统计学意义（P>0.05）。白质病变和对侧正常白质的MK、AK及RK值分别为0.63±0.16、0.54±0.09、0.66±0.14和0.78±0.11、0.60±0.11、0.86±0.12;白质病变的MK、RK值较对侧显著下降（P<0.001）,而AK值与对侧比较差异无统计学意义（P>0.05）。结论：DKI测量参数可反映TSC患者脑组织内细胞结构的变化,可为研究TSC的微观病理改变提供依据。     

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.     

弥散峰度成像对高级别脑胶质瘤和单发脑转移瘤的鉴别价值研究

目的 探讨弥散峰度成像(DKI)对鉴别高级别脑胶质瘤和单发脑转移瘤的临床应用价值.方法 搜集经病理或临床证实的33例脑肿瘤患者纳入研究,其中高级别胶质瘤18例,单发脑转移瘤15例,分别行常规磁共振平扫、DKI及常规增强扫描.经后处理分别得到DKI相关参量图,分别测量在肿瘤实性部分、瘤周水肿区域的各参数值.采用两样本t检验,分析高级别脑胶质瘤与单发脑转移瘤实质部分和瘤周水肿区域的各相对参数值平均弥散峰度(MK)、部分各向异性(FA)、平均扩散系数(MD),分析差异有无统计学意义.结果 在肿瘤实质部分,高级别脑胶质瘤和单发脑转移瘤MK、FA、MD各相对参数值比较,差异均无统计学意义(P值分别为0.529、0.645、0.84).在瘤周水肿区域,高级别胶质瘤和单发脑转移瘤MK、FA、MD各相对参数值比较,差异均有统计学意义(P值分别为0.002、0.003、0.04).结论 (1)DKI各相对参数MK、FA、MD在肿瘤实质部分对鉴别高级别脑胶质瘤和单发脑转移瘤没有明显价值.(2) DKI各相对参数MK、FA、MD在瘤周水肿区域对高级别脑胶质瘤和单发脑转移瘤有鉴别诊断价值.     

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<...     

扩散峰度成像对高级别胶质瘤及单发脑转移瘤的鉴别诊断价值

【摘要】目的：探讨磁共振扩散峰度成像（DKI）的多参数值对高级别胶质瘤（HGG）和单发脑转移瘤（SBM）的鉴别诊断价值。方法：搜集经手术病理或临床随访证实的19例HGG患者和14例SBM患者的病例资料,术前均行常规MRI扫描、DKI扫描及增强扫描。选取兴趣区（ROI）测定其DKI参数,并进行矫正处理得到各向异性分数（FA）、平均扩散（MD）及平均峰度（MK）值。应用独立样本t检验对两组间各参数值进行统计学分析,绘制ROC曲线计算敏感度、特异度及曲线下面积（AUC）。结果：两组肿瘤实质区DKI各参数值差异无统计学意义（P＞0.05）;而瘤周区的FA值、MD值及MK值在两组间的差异有统计学意义（P＜0.05）。ROC曲线分析显示,瘤周区的MK值鉴别两种肿瘤的敏感度和特异度较FA值和MD值高,曲线下面积最大。结论：瘤周区的FA值、MD值及MK值对HGG和SBM有良好的鉴别诊断价值,且瘤周区MK值诊断效能最高。     

扩散峰度成像在脊髓型颈椎病中的应用研究初探

目的探讨脊髓DKI序列在评估脊髓型颈椎病(CSM)应用价值。方法于2015年8月~2016年1月,选取20例成年健康志愿者作为对照组,20例经临床确诊的颈椎病患者作为实验组,采用3.0T MR进行DKI序列扫描,分别测定颈髓灰质和白质FA、MD、MK参数值。比较对照组各间盘层面FA、MD及MK参数值差异性,比较对照组和实验组FA、MD及MK参数值差异性。结果对照组各间盘层面DKI参数值未见显著性差异(P<0.05)。对照组与实验组之间FA-WM、MK-WM及MK-GM存在显著性差异(t值分别为-2.447、2.898、4.164;P<0.05)。结论 DKI能够反映出CSM患者的脊髓灰、白质微观结构的改变,MK在灰质评价方面优于FA。为临床的早期诊断、早期治疗及预后评估提供了参考。     

特发性全身性癫痫患者脑灰质结构基于体素的形态学测量的研究

目的 运用基于体素的形态学测量(VBM)方法分析特发性全身性癫痫患者(IGE)和正常人全脑灰质体积的差异.方法采用GE 3.0T HDX 超导型磁共振扫描仪对28例IGE患者和25例正常对照进行全脑高分辨解剖像扫描.在Matlab 7.0平台上采用SPM5软件包对图像进行处理.采用双样本t检验,将P< 0.005、像素簇大小＞200个体素的脑区作为有统计学差异的脑区.结果 与正常对照相比,IGE患者显示双侧大脑半球广泛脑区的灰质体积减少,包括双侧扣带回、双侧额中回、右侧额上回、右侧额叶直回、右楔叶、左侧尾状核头;与正常对照相比IGE患者灰质体积增加的脑区包括左侧颞上回、左侧屏状核、右侧豆状核.结论 VBM能揭示IGE患者存在广泛脑区灰质密度异常,灰质密度减低脑区多与认知功能相关,是引起癫痫患者认知功能下降的原因之一.     

扩散峰度成像在大鼠海人酸癫痫模型中的研究

目的：通过大鼠海人酸（KA）癫痫模型实验,探讨扩散峰度成像（DKI）应用于原发性癫痫研究的可行性。方法：将KA癫痫模型组（KA组）及正常对照组（NC组）各20只大鼠,在GE3．0T磁共振仪上行常规MRI、DKl及3D-MPRAGE等多序列扫描,在6个部位的灰质（基底节区、海马、杏仁核海马区、颞叶皮层、顶叶皮层、额叶皮层）和3个部位的白质（外囊区、前联合、胼胝体）内选取双侧对称部位的兴趣区（ROI）,手动测量各向异性分数（FA）、平均扩散率（MD）、平均峰度值（MK）并进行统计学分析。结果：在KA和NC组间,FA值（双侧均值）差异有统计学意义的部位为杏仁核海马区（分别为0．20±0．04和0．22±0．02,P=0．0337）、前联合（分别为0．22±0．04和0．28±0．06,P=0．002）及胼胝体区（分别为0．21±0．05和0．26±0．03,P=0．0002）;MD值（双侧均值）差异有统计学意义的部位为海马（分别为0．67±0．16和0．74±0．04,P=0．0275）;MK值（双侧均值）差异有统计学意义的部位为基底节区（分别为0．10±0．26和0．83±0．06,P=0．0098）、海马（分别为0．83±0．15和0．73±0．09,P=0．0499）及胼胝体区（分别为0．93±0．22和0．81±0．07,P=0．036）。结论：扩散峰度成像可用于原发性癫痫的研究,有望成为应用于人类癫痫研究的新的影像学方法。     

Regional values of diffusional kurtosis estimates in the healthy brain

Purpose:

To provide estimates of the diffusional kurtosis in the healthy brain in anatomically defined areas and list these along previously reported values in pathologies.

Materials and Methods:

Thirty‐six volunteers (mean age = 33.1 years; range, 19–64 years) underwent diffusional kurtosis imaging. Mean kurtosis (MK), radial kurtosis (RK), mean diffusivity (MD), radial diffusivity (RD), and fractional anisotropy (FA) were determined in 26 anatomical structures. Parameter estimates were assessed regarding age dependence.

Results:

MK varied from 1.38 in the splenium of the corpus callosum to 0.66 in the caudate head, MD varied from 0.68 to 0.62 μm²/ms and FA from 0.87 to 0.29. MK, and FA showed a strong positive correlation, RK and RD a strong negative correlation. Parameter estimates showed age correlation in some regions; also the average MK and RK for all WM and all GM areas, respectively, were negatively correlated with age.

Conclusion:

DKI parameter estimates MK and RK varied depending on the anatomical region and varied with age in pooled WM and GM data. MK estimates in the internal capsule, corpus callosum, and thalamus were consistent with previous studies. The range of values of MK and RK in healthy brain overlapped with that in pathologies. J. Magn. Reson. Imaging 2013;37:610–618. © 2012 Wiley Periodicals, Inc.     

MR diffusion kurtosis imaging predicts malignant potential and the histological type of meningioma

PurposeTo explore the value of Diffusion kurtosis imaging (DKI) metrics in the differential diagnosis of meningioma.MethodsFor this study, we retrospectively enrolled 35 patients of cerebral meningioma with DKI which included axial diffusion coefficient (AD), radial diffusion coefficient (RD), mean diffusion coefficient (MD), fractional anisotropy (FA), axial kurtosis (AK), radial kurtosis (RK) and mean kurtosis (MK). All of these metrics were normalized according to contralateral normal-appearing white matter (NAWMc). Patients were divided into two groups (benign and malignant meningioma) and were further analyzed using the independent sample t-test and receiver operating characteristic (ROC) curve. A one-way ANOVA analysis was used to analyze four groups divided according to pathological subtypes.ResultsThe metrics of AD, normalized AD, normalized MD, MK and normalized MK showed a significant difference between benign and malignant group, and MK showed relatively higher diagnostic ability with its cut-off value, area under the curve (AUC), sensitivity and specificity of 0.875, 0.780, 70% and 89%, respectively. The metrics of normalized MD, RD and normalized RD, FA and normalized FA, AK and normalized AK, and RK showed significant difference among four subtypes. MK and RK in meningioma were found to correlate positively with the Ki-67 labeling index (Ki-67 LI).ConclusionsDKI metrics may be used to differentiate benign from malignant meningioma, and also to distinguish some histological subtypes of meningioma. Moreover, DKI metrics may potentially reflect cellular proliferation.     

扩散峰度成像预估宫颈鳞癌病理分级的价值

目的：探讨扩散峰度成像(DKI)定量参数预估宫颈鳞状细胞癌(CSCC)病理分级的价值。方法回顾性分析45例CSCC患者的DKI图像,按照病理结果分为低分化组22例,高中分化组23例。由2位观察者分别测量2组病灶实质区DKI各参数值,包括平均扩散峰度值(MK)、平行扩散峰度值(Ka)、垂直扩散峰度值(Kr)、峰度各向异性分数(FAk)、平均扩散系数值(MD)、平行扩散系数值(Da)、垂直扩散系数值(Dr)及各向异性分数(FA)。采用组内相关系数(ICC)对2位观察者各参数测量结果一致性进行检验;采用两独立样本t检验比较2组各参数值;采用受试者工作特征曲线(ROC)评估各参数预估低分化 CSCC的效能,并找出相应界值。结果2位观察者测得2组病灶各参数值的一致性良好(ICC>0.75)。低分化组MK、Ka及Kr值大于高中分化组(P<0.05),低分化组 MD、Da及Dr值小于高中分化组(P<0.05),2组 FAk及 FA值间无差异(P>0.05)。MK、Ka、Kr、MD、Da、Dr值预估低分化CSCC的曲线下面积(AUC)分别为0.914、0.831、0.865、0.850、0.778、0.865,MK≥0.973、Ka≥1.075、Kr≥0.823、MD≤0.974μm2/ms、Da≤1.185μm2/ms、Dr≤0.762μm2/ms为预估低分化CSCC的界值。结论 DKI能够有效地预估CSCC的病理分级,有着很好的临床应用前景。     

磁共振扩散峰度成像诊断亚急性脑梗死进展性的价值

目的利用MR扩散峰度成像(DKI)研究亚急性期进展性脑梗死责任病灶,并结合NIHSS评分探讨其影像征象与临床相关性。方法前瞻性研究发病时间>72 h且在本影像中心行MRI扫描的亚急性期脑梗死病人79例,其中男45例,女34例,年龄43~88岁,平均(64.75±11.05)岁。根据NIHSS评分和病灶数目将其分为4组:单发脑梗死进展阴性组、多发脑梗死进展阴性组、单发脑梗死进展阳性组、多发脑梗死进展阳性组。对所有病人进行颅脑DKI及常规MRI扫描,获取MD和MK参数图,并于相应的参数图测量相应的参数值及病灶面积。多发性脑梗死病例在MD和MK图同一层面选取同一供血区内的2个独立病灶,分别将兴趣区设置于该缺血区的核心区(ROI 1)和周边区(ROI 2)。采用配对样本Wilcoxon符号秩检验比较MD图和MK图中病灶面积和信号的差异,采用散点图和信号变化百分比描述缺血灶的时间-信号变化。结果 (1)病灶面积。进展阴性组病人MD图与MK图中不同梗死灶的面积大小均相仿,其差异均无统计学意义(均P>0.05);进展阳性组MD图中不同梗死灶的面积均大于MK图(均P<0.05)。进展阴性组和阳性组的MD/MK不匹配区面积(显著的MD/MK不匹配区)百分比分别为0.2%和9.7%。(2)时间-信号散点图。a单发脑梗死组:与正常脑区相比,不同进展程度的单发脑梗死病人的病灶区均表现为MD值显著下降、MK值显著上升。进展阳性组病灶的信号恢复延迟,且MD、MK值偏离正常值的幅度大于进展阴性组。两组的MK值偏离正常值的幅度均大于MD值的变化幅度。b多发脑梗死组:多发性脑梗死进展阴性组病灶的MD和MK的时间-信号散点图与单发脑梗死进展阴性组相仿,ROI 1和ROI 2的时间-信号变化趋向一致性良好。多发性脑梗死进展阳性组ROI 1的MD和MK的时间-信号散点图与单发脑梗死进展阳性组相仿,而ROI 2的MD和MK的时间-信号散点图则呈无规律的杂乱曲线,表现出多病灶的异质性。结论脑梗死灶MK值恢复的延迟或多病灶的异质性均提示原发脑梗死病灶扩大及新发脑梗死,是亚急性脑梗死进展性诊断的重要征象。     

Age‐related non‐Gaussian diffusion patterns in the prefrontal brain

Purpose

To characterize age‐related MR diffusion patterns of the prefrontal brain cortex microstructure using a new method for investigating the non‐Gaussian behavior of water diffusion called diffusional kurtosis imaging (DKI).

Materials and Methods

Measures of mean diffusivity (MD), fractional anisotropy (FA) and mean kurtosis (MK) were compared in the prefrontal brain cortex of 24 healthy volunteers (adolescents, young adults, and elderly) ranging from age 13 to 85 years. A Mann‐Whitney test was used to compare subject groups with respect to the diffusion measures, and linear regression was used to characterize the change in each diffusion measure as a function of age.

Results

We found significant age‐related changes in the elderly adult group, with increase of MD and decrease of FA.

Conclusion

The current study demonstrates distinct mean kurtosis patterns for different age‐ranges, with significant age‐related correlation for mean kurtosis (MK) and MK peak position, showing that diffusional kurtosis is able to characterize and measure age‐related diffusion changes for both grey and white matter, in the developing and aging brain. J. Magn. Reson. Imaging 2008;28:1345–1350. © 2008 Wiley‐Liss, Inc.     

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.     

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.