缺血性脑卒中患者功能磁共振研究

发布时间：2018-07-24 12:45

【摘要】：第一部分缺血性脑卒中核磁共振图像后处理相关问题探讨目的：探讨急性缺血性脑卒中患者脑内病变对于核磁图像数据处理过程中空间标准化结果的影响,比较在高分辨率T2WI/DWI上手工画病灶建立病灶模板(Lesion_Mask)以及采用不同的空间标准化算法对于空间标准化的结果,为后续功能数据分析寻找理论依据。方法：对5例发病一周内单侧发病的急性缺血性脑卒中患者功能数据在空间标准化过程中,分别对采用去除病灶(Lesion_Mask(+))/不去除病灶(Lesion_Mask(-))、不同空间标准化算法(分割法即unified models/不分割法即不经分割直接进行空间标准化)、高分辨空间T2WI/DWI上画病灶作为变量,通过计算病灶模板经空间标准化转换到MNI空间得到的病灶体积(MNI_Lesion_Auto)、重叠率和体积错误率来探讨以上三对因素对于空间标准的影响。结果： (1)比较几种方法(T2WI/DWI高分辨图像上设定Lesion_Mask、分割/不分割的标准化算法)MNI空间上自动获得的病灶图像(MNI_Lesion_Auto)、的体积,与手画病灶图像的体积错误率和病变重叠率,均得到的结果是去除病灶对于本组缺血性脑卒中患者的图像的空间标准化并没有明显统计学差别(P0.05)。 (2)在无论是否去病灶的情况下,病灶模板经不分割算法转换到MNI空间的病灶图像体积(MNI_Lesion_Auto)均大于分割算法获得的病灶体积,同时两种标准化算法所获得病灶的图像(MNI_Lesion_Auto)的病灶重叠率仅达到0.25±0.10,Landmark标注显示病灶、灰质及白质在空间的定位均存在差异,说明两种标准化算法差别显著。 (3)经分割方式/非分割法计算得到的病变重叠比率均显示DWI_Lesion_Mask优于T2WI_Lesion_Mask,具有明显的统计学差异(P0.05)。因此,在DWI高分辨空间上手动设定病灶mask明显优于T2WI。结论：(1)去病灶与否对于急性期脑卒中患者的空间标准化过程没有影响。(2)脑卒中急性期患者,在高分辨率DWI画病灶建立病灶模板优于T2WI。(3)采用不同的空间标准化算法(分割/不分割方法)对于病灶在MNI空间的位置及体积均有影响,对皮质及白质的空间位置也存在差异,我们推荐使用分割方法进行空间标准化。第二部分缺血性脑卒中患者经rTMS治疗前后运动功能连接改变目的：利用静息态功能磁共振成像技术观察缺血性脑卒中患者重复经颅磁刺激(rTMS)治疗前后病变侧初级运动皮质(M1)功能网络连接变化的特点,进而揭示脑功能重组的证据。方法：对5例发病一周内单侧发病的缺血性脑卒中患者在重复经颅磁刺激(rTMS)治疗前后各进行一次静息态功能磁共振(rs-fMRI)检查和临床功能评分。同时选取正常志愿者10例做为正常对照组,只进行一次rs-fMRI检查。通过分析rs-fMRI患者同侧初级运动皮质(M1)与全脑各体素之间的功能连接的变化,比较患者治疗前后组与正常对照组之间功能连接变化的差异。结果：(1)患者治疗前组两侧M1区功能连接值降低(z值=0.30±0.24),低于正常对照组(z值=0.70±0.21),治疗后连接值升高(z值=0.58±0.28),治疗前组与正常组之间的差异及治疗前后组的差异具有统计学意义(P0.05),但治疗后组与正常对照组两侧M1区功能连接值之间无统计学意义(P0.05)。 (2)与对照组相比,治疗前组病变同侧M1区与同侧颞下回、双侧小脑功能连接增强,而与病变对侧M1区、对侧辅助运动区功能连接减弱。然而,治疗后组病变同侧M1区与双侧小脑、同侧颞中回、对侧颞下回、对侧的额中回、对侧楔前叶功能连接增强,而与同侧运动前区、同侧M1区、对侧中央旁小叶、对侧M1区功能连接减弱。以上所有功能连接增强和减弱的区域均被投射到3维ICBM的模板上。与治疗前组相比,治疗后组病变同侧M1区与对侧额内侧回功能连接增强。 (3)与患者治疗前组相比,治疗后组患侧肢体NIHSS评分显著降低(P0.05)、患侧上肢FMA评分显著升高(P0.05)、患侧下肢FMA评分显著升高(P0.05)、BI评分显著升高(P0.05),提示患者治疗后功能改善。结论：通过静息态功能磁共振观察高频rTMS治疗前后患侧M1区功能连接的变化,为揭示rTMS改善运动功能提供了脑功能重组的依据。
[Abstract]:The first part is about the post-processing of magnetic resonance imaging in ischemic stroke.
Objective: To investigate the effect of intracerebral lesions on spatial standardization of NMR data processing in patients with acute ischemic stroke, to compare the focus template (Lesion_Mask) on high resolution T2WI/DWI, and to use different spatial standardization algorithms for spatial standardization, and for subsequent functional data. Analyze the theoretical basis for the analysis.
Methods: the functional data of 5 patients with unilateral acute ischemic stroke within one week of the onset of disease (Lesion_Mask (+)) / non removal of focus (Lesion_Mask (-)) and different spatial standardization algorithms (segmentation method, i.e. unified models/ non segmentation or non segmentation, were directly carried out in space standard). The focus of high resolution space T2WI/DWI is used as a variable. By calculating the focus volume (MNI_Lesion_Auto), overlap rate and volume error rate of the focus template converted to MNI space, the effects of the above three factors on space standards are discussed.
Result:
(1) compare several methods (T2WI/DWI high resolution image set Lesion_Mask, segmentation / non segmentation standardization algorithm) the MNI space automatically acquired focus image (MNI_Lesion_Auto), volume, volume error rate and lesion overlap rate of hand drawing focus images, all results are the removal of focus for ischemic stroke patients in this group There was no significant difference in spatial standardization of images (P0.05).
(2) the volume of focus (MNI_Lesion_Auto) of the focus image (MNI_Lesion_Auto) which the focus template is converted to MNI space is greater than that of the segmentation algorithm, and the focus overlap rate of the focus image (MNI_Lesion_Auto) obtained by the two standardized algorithms is only 0.25 + 0.10, and the Landmark tagging shows the disease. The location of foci, gray matter and white matter is different, indicating that the two standardization algorithms differ significantly.
(3) the overlap ratio calculated by the segmentation method / non segmentation method all showed that DWI_Lesion_Mask was superior to T2WI_Lesion_Mask and had obvious statistical difference (P0.05). Therefore, the manual setting of the focus mask on the DWI high resolution space was obviously superior to T2WI.
Conclusions: (1) there is no effect on the spatial standardization process of acute cerebral apoplexy patients. (2) in acute stroke patients, the establishment of focus templates in the high resolution DWI painting focus is superior to T2WI. (3) using different spatial standardization algorithms (segmentation / undivided square method) for the location and volume of the focus in MNI space, and The spatial position of cortex and white matter is also different. We recommend the use of segmentation method for spatial standardization.
The second part is the change of motor functional connectivity in patients with ischemic stroke before and after rTMS treatment.
Objective: To observe the characteristics of the changes in the functional network of the primary motor cortex (M1) in the ischemic stroke patients before and after the repeated transcranial magnetic stimulation (rTMS), and then reveal the evidence of the functional reorganization of the brain by using the resting state functional magnetic resonance imaging (fMRI).
Methods: 5 patients with unilateral ischemic stroke within one week were performed a resting state functional magnetic resonance (rs-fMRI) examination and clinical function score before and after repeated transcranial magnetic stimulation (rTMS). At the same time, 10 cases of normal volunteers were selected as the normal control group and only a rs-fMRI examination was performed. By analyzing the same of the rs-fMRI patients, The changes in the functional connection between the lateral primary motor cortex (M1) and the whole brain voxel were compared, and the difference of the functional connection between the patients before and after treatment and the normal control group was compared.
Results: (1) the value of functional connection of M1 area in both sides of the patients was lower (Z =0.30 + 0.24), lower than that of the normal control group (Z =0.70 0.21), and the connection value increased after treatment (Z value =0.58 + 0.28). The difference between the pre treatment group and the normal group and the difference of the group before and after treatment was statistically significant (P0.05), but the after treatment group and the normal control group were both M1 (P0.05). There was no statistical significance between the functional connectivity values (P0.05).
(2) compared with the control group, the ipsilateral M1 area and the ipsilateral temporal gyrus and bilateral cerebellar functional connection were enhanced, while the functional connection between the lateral M1 area and the contralateral auxiliary motor area was weakened. However, the posterior temporal gyrus, the contralateral temporal gyrus, the contralateral frontal gyrus, and the function connection to the lateral wedge increased in the ipsilateral M1 region and the bilateral cerebellum, the contralateral cerebellum, the lateral temporal gyrus, the lateral temporal gyrus, the contralateral lateral gyrus, the contralateral lateral frontal gyrus. Strong, with the ipsilateral premotor area, the ipsilateral M1 area, the contralateral paralateral lobule and the contralateral M1 area function connection weakened. All the areas with the enhanced and weakened function of all the functional connections were projected on the 3 dimensional ICBM template. Compared with the pre treatment group, the functional connection between the ipsilateral M1 region and the contralateral frontal lateral gyrus was enhanced in the post treatment group.
(3) compared with the pre treatment group, the NIHSS score of the affected limb was significantly lower (P0.05), the FMA score of the affected upper limb was significantly increased (P0.05), the FMA score of the lower extremities increased significantly (P0.05), and the BI score increased significantly (P0.05), suggesting that the patients were improved after treatment.
Conclusion: the changes of the functional connection of the M1 region in the affected side before and after the high frequency rTMS therapy are observed by resting state functional magnetic resonance (fMRI), which provides the basis for the revelation of the improvement of the function of the brain by rTMS.
【学位授予单位】：北京协和医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R743.3;R445.2

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