正常脑老化中脑白质改变的MRI研究

发布时间：2018-06-18 19:02

本文选题：磁共振成像 + 脑老化　；参考：《河北医科大学》2014年硕士论文

【摘要】：目的：通过VBM技术研究正常脑老化过程中白质体积发生年龄相关性改变的规律及性别差异性。方法：自2013年8月-2013年11月招募健康成年志愿者，均行常规颅脑核磁共振成像（magnetic resonance imaging, MRI）和T1加权3D快速场回波（T1weighted image Fast Field Echo, T1-FFE）序列检查。共选出187例符合纳入标准的受检者，其中男性92例，女性95例，年龄范围20-78岁，平均年龄47.2岁，中位年龄47岁。将所有被试按性别和年龄分为青年组、中年组和老年组。采用基于体素的形态测量法(Voxel-basedmorphometry, VBM)，对脑结构图像T1-FFE序列进行预处理，分割平滑后得到全脑白质体积数据进行统计分析。采用两样本t检验比较男女性别之间全脑白质体积有无差异。采用方差分析方法对不同性别、年龄组间白质体积的变化进行分析。采用回归分析检测所有研究对象全脑白质体积与年龄相关性进行分析。视P0.05的脑区为差异有统计学意义。同时采用回归分析检测各感兴趣区白质体积与年龄的相关关系。结果： 1全脑白质体积性别差异分析：调整颅内总体积后，，女性较男性具有更大的白质体积，差别具有统计学意义（t=3.79, P=0.0001, FDR校正）。局部白质体积在女性较大的脑区主要位于：延髓、脑桥、两侧大脑脚、两侧颞叶内侧回、两侧小脑前叶、左侧枕叶、两侧额上回、左侧额叶眶回、两侧顶叶、扣带回膝部。局部白质体积在男性较大的区域主要位于两侧小脑后叶、两侧岛叶外囊、两侧额叶直回，以及在两侧顶叶和左侧枕叶局部脑区。 2不同年龄组之间白质体积改变的分析：使用双因素方差分析分别比较三组之间的脑白质体积差异，发现每两组之间白质体积均存在显著的年龄主效应(P0.05, FDR校正)。中年组与青年组比较，白质体积表现为增加的脑区位于两侧额叶直回、两侧中央前回、两侧放射冠、两侧内囊前肢、右侧外囊、右侧小脑中脚、两侧颞叶钩回、两侧豆状核、右侧枕叶。老年组和青年组比较显示局部白质体积减少的脑区主要位于两侧额叶、两侧大脑脚、两侧内囊后肢、左侧内囊前肢、胼胝体压部、两侧枕叶、左侧颞叶、前扣带回。老年组和中年组比较显示局部白质体积萎缩的脑区主要位于两侧颞叶内侧回、两侧颞下回、左侧颞上回、两侧大脑脚、两侧丘脑、两侧额中回、左侧额下回、两侧放射冠、胼胝体体部和膝部、两侧扣带回、左侧顶叶、两侧海马旁回、右侧楔前叶及两侧小脑部分脑区。另外，青年组和中年组比较时，若不采用多重对比校正(P0.001,未校正)，部分脑区表现为女性的相对保护，主要位于两侧小脑半球、脑桥前部、延髓、左侧放射冠、左侧枕叶等。同样老年组和青年组比较时，若不采用多重对比校正(P0.001,未校正)可观察到部分脑区，如两侧放射冠、两侧海马、左侧外囊、左侧内囊后肢等，表现为女性对上述脑区的相对保护作用。青年组、中年组及中年组三组中各两组之间均未发现显著的年龄×性别交互效应(P0.05, FDR校正)。 3脑白质体积与年龄的相关性分析：全脑白质体积与年龄呈非线性、二次方式倒“U”型变化趋势，R2=0.124, P＜0.000。将各感兴趣区白质体积作为应变量进行回归分析，结果显示额叶为年龄相关性最强的脑区，R2=0.13，P0.001。而枕叶出现年龄相关性萎缩的时间最晚。两侧小脑半球、中脑、脑桥及延髓与年龄间未见显著相关性。结论： 1在调整颅内总体积的情况下，全脑白质体积分布存在性别的差异，在大部分脑区女性具有更大白质体积，并且在老化过程中，部分脑区（如两侧放射冠、两侧海马旁回、左侧枕叶、左侧大脑脚及左侧内囊等）女性表现为相对保护作用。 2在正常老化过程中，全脑白质体积与年龄呈现为二次方式、倒“U”型相关性改变，约在50岁达到最大值，之后逐渐减少。但是不同脑区一般以“后进先出”的规律呈现不同模式，额叶年龄相关性最强，枕叶受年龄影响时间较晚。 3两侧小脑半球、中脑、脑桥及延髓随年龄并未表现出显著相关性。
[Abstract]:Objective : To study the changes of age - related changes in white matter volume during normal brain aging by VBM technique .

Methods : Healthy adult volunteers were recruited from August 2013 to November 2013 . 187 cases were selected according to normal brain nuclear magnetic resonance imaging ( MRI ) and T1 weighted 3D fast field echo ( T1 - FFE ) sequence .

Results :

1 Whole brain white matter volume sex difference analysis : after adjusting the total volume of intracranial volume , the female had greater white matter volume than the male , and the difference had statistical significance ( t = 3.79 , P = 0.0001 ) . The local white matter volume is mainly located in the medulla , the brain bridge , the cerebral feet on both sides , the medial gyrus of the temporal lobe on both sides , the frontal lobe of the left frontal lobe , the left occipital lobe , the frontal gyrus of the left frontal lobe , the left frontal lobe , the parietal lobe on both sides , and the back knee .

2 . Analysis of the change of white matter volume between different age groups : A two - factor variance analysis was used to compare the difference of brain white matter volume between the three groups . It was found that there was a significant age - dominant effect between the two groups ( P0.05 ) . In the aged group and the middle - aged group , the brain areas with reduced local white matter volume were mainly located on the medial gyrus , the left parietal lobe , the left superior cerebellar peduncle , the left temporal lobe , the left occipital lobe , the right occipital lobe , the left temporal lobe and the left occipital lobe . The relative protective effects of female on the above - mentioned brain regions were observed in the left inner capsule hind limbs , etc . There were no significant differences in age and sex between the young group , middle - aged group and middle - aged group ( P0.05 ) .

The relationship between brain white matter volume and age was analyzed : the whole brain white matter volume and age were non - linear , the quadratic form inverted " U " type change trend , R2 = 0.124 , P < 0.000 . The white matter volume of each region of interest was analyzed by regression analysis . The results showed that the frontal lobe was the most age - related brain region , R2 = 0.13 , P0.001 .

Conclusion :

1 . In the case of adjusting the total intracranial volume , there is a gender difference in the whole brain white matter volume distribution , and in most brain regions , women have a greater white matter volume , and in the aging process , women in some brain regions ( such as bilateral radiation crowns , parahippocampal gyrus , left occipital lobe , left brain foot , left side inner capsule , etc . ) behave as a relative protection function .

2 . In the course of normal aging , the whole brain white matter volume and age were presented in the second way , the " U " type correlation was changed , the maximum was reached at the age of 50 years , and then decreased gradually . However , the different brain regions generally showed different patterns with the laws of " LIFO " , the correlation between frontal and leaf age was strongest , and the age of the occipital lobe was relatively late .

There was no significant correlation between the cerebellum hemisphere , midbrain , brain bridge and medulla with age on both sides .
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R338;R445.2

【引证文献】