急性脑梗死的DKI与血流状态研究

发布时间：2018-04-15 03:09

本文选题：扩散峰度成像 + 脑梗死　；参考：《天津医科大学》2017年硕士论文

【摘要】：目的:观察扩散峰度成像(diffusion kurtosis imaging,DKI)在脑梗死急性期的变化特点,对比DKI与扩散加权成像(diffusion weighted imaging,DWI)评价梗死核心区的能力,探索DKI与DWI不同表现区域的血流灌注情况,从而揭示DKI在急性脑梗死患者早期诊断及评估预后中的价值,并探讨其可能机制。对象与方法:(1)选取急性脑梗死患者共60例,所有患者除常规MRI扫描外,还进行DWI、DKI、MRA、DSC-PWI(dynamic susceptibility contrast enhanced perfusion weighted imaging,DSC-PWI)扫描。分别获得ADC、平均扩散系数(mean diffusivity,MD)、平均峰度系数(mean kurtosis,MK)、轴向峰度系数(axial kurtosis,AK)和径向峰度系数(radial kurtosis,RK)参数图,测量患侧与健侧相应的参数值,并计算各参数值的变化率。(2)其中37例急性脑梗死患者完成纵向随访研究,MRI检查时间分别为24小时内、5-7天、30天后,将所有病灶按照大小分为小病灶(Dmax1cm)和大病灶(Dmax≥1cm)两组,小病灶组进行计数比较,大病组测量病灶的体积大小。(3)其中25例急性脑梗死患者,共包含32个大病灶,根据MD与MK参数图所示异常范围的一致程度,分为MD/MK匹配与MD/MK错配两组,错配组病灶由内向外依次分为病灶中心区、错配区及边缘区,而匹配组无错配区,由内向外依次为病灶中心区、边缘区,分别测量两组患者不同区域脑组织内各灌注血流动力学参数值(MTT、TTP、CBF、CBV值),以对侧脑组织作为正常对照。统计学分析采用SPSS 19.0软件包:分析脑梗死急性期各扩散、峰度参数值患侧与健侧的差异,并比较各参数值变化率间的差异;分析大病灶组急性期各扩散、峰度参数图所示病灶体积的差异,并比较急性期各参数图病灶体积与随访最终体积的相关性,分析小病灶组急性期各参数图与随访最终阳性病灶数目的一致性;分析急性期脑梗死患者MD/MK匹配与错配两组间不同区域各灌注血流动力学参数值的差异,并比较各组内不同区域间各灌注参数值间的差异。结果:(1)急性期脑梗死患者病灶内各扩散参数ADC、MD值减低,而各峰度参数MK、AK、RK值增高(P值均0.001),且各峰度参数的变化率大于各扩散参数的变化率(P值均0.001),同类参数的变化率相比,扩散参数ADC与MD值的变化率无统计学差异,峰度参数除AK与RK之间具有统计学差异(P0.005),余峰度参数之间差异均无统计学意义。大病灶组急性期各扩散、峰度参数图所示的病灶体积无统计学差异(H=8.506,P0.05),复查T2WI显示的病灶体积与急性期各扩散、峰度参数显示的病灶体积均呈正相关(P值均0.001),其中与扩散参数ADC、MD图的体积呈中度相关,相关系数r分别为0.761、0.775,与峰度参数MK、AK、RK图的体积呈高度相关,相关系数分别为0.880、0.869、0.870;小病灶组急性期各峰度参数图较各扩散参数图与最终T2WI图显示的阳性病灶数具有更好的一致性,前者无统计学差异(P值均0.05)。(3)急性期MD、MK异常范围划分的不同区域的脑组织较对侧均表现为MTT、TTP值延长,CBF、CBV值减低(P值均0.05),病灶中心区与错配区之间,仅CBF值存在差异,表现为前者较后者减低(P值0.05);病灶中心区与边缘区之间,TTP、CBF、CBV值均存在差异,分别表现为前者较后者延长、减低、减低(P值均0.05);病灶错配区与边缘区之间,仅CBV值存在差异,表现为前者较后者减低(P值0.05)。结论:急性脑梗死患者DKI较传统DWI可以提供更丰富的病灶信息,有助于对病灶的早期诊断,尤其是MK参数图;急性脑梗死患者峰度参数较扩散参数能更准确的评价梗死核心区,更易于脑梗死早期预测病灶的最终转变;急性脑梗死患者MD异常范围内,MK异常的中心区较MK正常的错配区具有更低的CBF值,提示MK可以分级MD内部处于不同代谢状态的组织结构改变,为DKI能够准确地评价梗死核心区提供了依据,同时也为IP的准确定义提供了补充。
[Abstract]:Objective: To observe the diffusion kurtosis imaging (diffusion kurtosis, imaging, DKI) changes in patients with acute cerebral infarction, compared with DKI and diffusion weighted imaging (diffusion weighted, imaging, DWI) to evaluate the ability of the infarct core area, explore the perfusion of DKI and DWI showed different areas, so as to reveal the diagnosis and evaluation of prognosis of DKI in patients with early acute the value of cerebral infarction, and to explore its possible mechanism. Subjects and methods: (1) from patients with acute cerebral infarction were 60 cases, all patients in addition to routine MRI scan, but also DWI, DKI, MRA, DSC-PWI (dynamic susceptibility contrast enhanced perfusion weighted imaging, DSC-PWI). ADC scan respectively, average diffusion coefficient (mean diffusivity, MD), the average coefficient of kurtosis (mean kurtosis, MK (axial), axial kurtosis coefficient kurtosis, AK) and radial (radial kurtosis, RK kurtosis parameter) map, measure the ipsilateral and The parameters of the corresponding contralateral values, and calculate the parameter values of the rate of change. (2) including 37 cases of acute cerebral infarction patients completed longitudinal follow-up study, MRI examination time was 24 hours, 5-7 days, 30 days later, all lesions were small lesions according to size (Dmax1cm) and large lesions (Dmax = 1cm two) group, small size group were counted, the volume of illness group lesion. (3) including 25 cases of acute cerebral infarction patients, including 32 lesions, according to the degree of uniform MD and MK parameters shown abnormal range, divided into MD/MK, MD/MK and mismatch mismatch group two groups. Focus from the inside to the outside is divided into the central area of the lesion, the mismatch area and the edge area, and the match was no mismatch, from inside to outside for the center of the lesion area, the edge area, respectively. The brain tissue was measured in two groups in different regions of the perfusion hemodynamic parameters (MTT, TTP, CBF, CBV) the contralateral brain tissue. As the normal control group. Statistical analysis using SPSS 19 software: analysis of the diffusion of acute cerebral infarction, the difference and the contralateral side of the kurtosis parameter values, and compare the difference between the parameter values of the diffusion rate; analysis of large lesion group in acute stage, the difference shown in the kurtosis parameter of lesion, and to compare the correlation between acute the parameter maps of lesion volume and follow-up final volume, consistency analysis of minor lesions in acute stage of map and follow-up parameters eventually positive number of lesions; analysis of MD/MK patients in acute stage of cerebral infarction, the difference between the two groups in different regions of the perfusion blood flow mechanics parameters and mismatch, and compare the perfusion parameters in different regions the difference between the values between the groups. Results: (1) in patients with acute cerebral infarction lesions by diffusion parameters ADC, MD value decreased, and the kurtosis parameter MK, AK, RK value increased (P 0.001), and the change rate of large kurtosis parameter The change in the rate of diffusion parameter (P value 0.001), change the same parameters than on the rate of diffusion parameters ADC and MD value was no significant difference, except the kurtosis parameter with statistical difference between AK and RK (P0.005), the difference between more than peak parameters were not statistically significant. The diffusion of large lesion group in acute period, there was no significant difference in kurtosis parameters shown in the lesion volume (H=8.506, P0.05), the diffusion lesion volume and acute phase T2WI scan show, the kurtosis parameter display the lesion volume were positively correlated (P = 0.001), and the diffusion parameters ADC, MD graph volume showed a moderate correlation, correlation the coefficient of R were 0.761,0.775, AK, MK and kurtosis parameters, RK was highly correlated with graph volume, the correlation coefficient was 0.880,0.869,0.870; the number of positive lesions in small lesions in acute stage of the kurtosis parameter map is the diffusion parameter map and final T2WI display has better Consistency, no significant difference between the former (P 0.05). (3) the acute phase of MD, MK anomaly range in different regions of the brain than the other side are represented as MTT, CBF, TTP value increased, CBV value decreased (P = 0.05), between the center of the lesion area and the mismatch area. There is only the difference in CBF value is lower in the former than in the latter (P = 0.05); between the center of the lesion area and the edge area of TTP, CBF, CBV values were different, respectively for the performance of the former than the latter to extend, reduce, decrease (P 0.05); mismatch between the lesion area and the edge area, there are only the difference in CBV value is lower in the former than in the latter (P = 0.05). Conclusion: DKI in patients with acute cerebral infarction than conventional DWI can provide more abundant information focus, is helpful to early diagnosis of the lesions, especially MK parameters; acute cerebral infarction with diffusion parameters kurtosis parameters can be more accurate assessment of infarct core area indeed, more prone to cerebral infarction early The final change measuring lesions in patients with acute cerebral infarction; MD anomaly range, central area of abnormal MK than in normal MK mismatch region with lower CBF values, suggesting that MK may be classified in MD internal changes of tissue structure of different metabolic state, DKI can accurately estimate the infarct core area provides the basis, but also provides the supplement for the accurate definition of IP.

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R445.2;R743.33

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