Hemispheric Regional Based Analysis of Diffusion Tensor Imaging and Diffusion Tensor Tractography in Patients with Temporal Lobe Epilepsy and Correlation with Patient outcomes
Hemispheric Regional Based Analysis of Diffusion Tensor Imaging and Diffusion Tensor Tractography in Patients with Temporal Lobe Epilepsy and Correlation with Patient outcomes
复制标题
DOI：
10.1038/s41598-018-36818-x
复制
发表时间：
2019-01-18
影响因子：
4.6
通讯作者：
Sharan, Ashwini
中科院分区：
文献类型：
--
作者：
Alizadeh, Mahdi;Kozlowski, Lauren;Sharan, Ashwini
癫痫外科领域的成像仍然是一个重要的工具，因为它能够识别癫痫灶可能作为可切除区域存在的区域。然而，在许多情况下，一个明显的结构异常是看不到的。这为癫痫领域的新方法和成像创新创造了机会，例如扩散张量成像（DTI）和扩散张量纤维束成像（DTT）。在这项研究中，我们的目的是评估使用DTI和DTT作为癫痫领域的预测模型，特别是颞叶癫痫（TLE），并将其临床意义与术后结果相关联。一个半球为基础的分析被用来比较束密度，以及从病理半球的特定区域的感兴趣的TLE患者的健康半球的DTI指数。共22例TLE患者（12例男性，10例女性，22-57岁）接受了开颅术、前颞叶切除术（ATL）或微创方法选择性激光杏仁核切除术（SLAH），并使用3.0 T Philips Achieva MR扫描仪进行成像。在参与者中，12人接受了SLAH，10人接受了ATL。这项研究得到了托马斯杰斐逊大学医院机构审查委员会的批准。获得所有患者的知情同意书。根据标准临床标准，所有患者均诊断为TLE。DTI图像采集轴向在相同的解剖位置规定的T1加权图像。首先对由扩散体积组成的原始数据集进行涡流失真和运动伪影校正。计算各向异性分数（FA）、平均扩散率（MD）、径向扩散率（RD）和轴向扩散率（AD）等DTI指标，并与freesurfer获得的脑分区图进行配准。由功能神经外科医生选择16个强化的皮质和皮质下区域作为感兴趣区域（ROI），计算每个ROI的DTI值并与对侧半球的相应ROI进行比较。此外，使用基于纤维取向分布（FOD）的确定性纤维追踪生成68个白色物质包裹的轨迹密度成像（TDI），并与每个癫痫组的对侧大脑进行比较：左侧内侧颞叶硬化（LMTS）和右侧MTS（RMTS））。在LMTS患者中，与右侧海马相比，左侧海马的MD和RD值使用双尾t检验显著降低（分别为p = 0.03和p = 0.01）。此外，RD显示左杏仁核轻微显著降低（p = 0.05）。LMTS中的DTT分析显示左侧白色物质边缘上包裹略微显著减少（p = 0.05）。在RMTS患者中，FA在同侧内侧颞叶（p = 0.02）、海马旁区（p = 0.03）和丘脑（p = 0.006）中显著降低。
Imaging in the field of epilepsy surgery remains an essential tool in terms of its ability to identify regions where the seizure focus might present as a resectable area. However, in many instances, an obvious structural abnormality is not visualized. This has created the opportunity for new approaches and imaging innovation in the field of epilepsy, such as with Diffusion Tensor Imaging (DTI) and Diffusion Tensor Tractography (DTT). In this study, we aim to evaluate the use of DTI and DTT as a predictive model in the field of epilepsy, specifically Temporal Lobe Epilepsy (TLE), and correlate their clinical significance with respect to postsurgical outcomes. A hemispheric based analysis was used to compare the tract density, as well as DTI indices of the specific regions of interest from the pathologic hemisphere to the healthy hemisphere in TLE patients. A total of 22 patients with TLE (12 males, 10 females, 22-57 age range) underwent either a craniotomy, Anterior Temporal Lobectomy (ATL), or a less invasive method of Selective Laser Amygdalohippocampectomy (SLAH) and were imaged using 3.0 T Philips Achieva MR scanner. Of the participants, 12 underwent SLAH while 10 underwent ATL. The study was approved by the institutional review board of Thomas Jefferson University Hospital. Informed consent was obtained from all patients. All patients had a diagnosis of TLE according to standard clinical criteria. DTI images were acquired axially in the same anatomical location prescribed for the T1-weighted images. The raw data set consisting of diffusion volumes were first corrected for eddy current distortions and motion artifacts. Various DTI indices such as Fractional Anisotropy (FA), Mean Diffusivity (MD), Radial Diffusivity (RD) and Axial Diffusivity (AD) were estimated and co-registered to the brain parcellation map obtained by freesurfer. 16 consolidated cortical and subcortical regions were selected as regions of interest (ROIs) by a functional neurosurgeon and DTI values for each ROI were calculated and compared with the corresponding ROI in the opposite hemisphere. Also, track density imaging (TDI) of 68 white matter parcels were generated using fiber orientation distribution (FOD) based deterministic fiber tracking and compared with contralateral side of the brain in each epileptic group: left mesial temporal sclerosis (LMTS) and right MTS (RMTS)). In patients with LMTS, MD and RD values of the left hippocampus decreased significantly using two-tailed t-test (p = 0.03 and p = 0.01 respectively) compared to the right hippocampus. Also, RD showed a marginally significant decrease in left amygdala (p = 0.05). DTT analysis in LMTS shows a marginally significant decrease in the left white matter supramarginal parcel (p = 0.05). In patients with RMTS, FA showed a significant decrease in the ipsilateral mesial temporal lobe (p = 0.02), parahippocampal area (p = 0.03) and thalamus (p = 0.006).