【作者】 刘婷；

【导师】 伍建林；

【作者基本信息】 大连医科大学 ， 影像医学与核医学， 2008， 硕士

【摘要】 目的:应用磁敏感加权成像(Susceptibility Weighted Imaging, SWI)技术相对定量分析不同年龄段正常人脑深部灰质核团(主要包括黑质、红核、苍白球、壳核、尾状核)的脑铁分布及含量,同时探讨不同年龄段脑铁变化规律以及铁沉积与年龄的相关关系,为评价病变作参考。材料与方法:选择171例经临床及磁共振检查除外精神神经疾患病史的健康志愿者行头部SWI扫描。年龄范围20~69岁(中位年龄为44.26岁),其中男86例,女85例。所有志愿者按年龄分以下五组:20~29岁、30~39岁、40~49岁、50~59岁、60~69岁,每组分别为31、33、35、40、32例,每组男女比例基本均衡。应用美国GE Signa HD1.5T echospeed MRI磁共振扫描仪扫描,首先行轴位T2加权图像,用于解剖定位及除外神经系统疾患,扫描参数为:TR 4000 ms,TE 102 ms,层厚2.0mm,层间距0mm。视野为24cm,NEX为1,带宽为10.42;然后采用三维SWI序列成像,定位线与常规扫描一致,扫描参数为:TR 50ms,TE 45ms,层厚3.0mm,间隔0mm,视野为24cm,矩阵为320×320,NEX为0.75,带宽为31.25,翻转角30°,总采集时间388s。SWI采集的原始数据离线在GE Advantage workstation4.3工作站进行后处理,得到较正的相位图像(Corrected Phase)以及重建的SWI影像。使用GE Advantage workstation 4.3工作站的多边形及椭圆形测量工具,分别在SWI图像上测量黑质、红核、苍白球、壳、尾状核头部的SWI信号值(分别测量三次取平均值)。对所有测量数据应用统计软件包(statistics package for social science, SPSS)11.0版进行统计学分析。各年龄组黑质、红核、苍白球、壳、尾状核头双侧SWI信号值,经统计学检验无显著性差异后,将它们分别合并为一组,均采用均数±标准差(Mean±SD)进行分析,用单因素方差分析(ANOVA)评价脑组织不同年龄阶段的SWI信号值的差异显著性,分析不同年龄阶段对SWI信号值的影响。每一深部灰质核团按年龄分组进行SWI信号值与年龄的相关回归分析,列出r值,并对r值进行t检验。所有统计结果以P<0.05为有统计学意义。结果:1.在同一年龄组以深部灰质核团SWI信号值为最低;2.诸深部灰质核团SWI信号值男女性别之间均无显著性差异(P>0.05)。3.不同年龄阶段所测量得到的尾状核头、壳核、苍白球、黑质、红核SWI信号值之间存在显著性差异(P<0.001)。不同年龄组尾状核头、壳核、苍白球、黑质、红核SWI信号值有一定的变化规律:在20~39岁年龄组,SWI信号值分别为黑质、苍白球、红核较低,尾状核头部相对较高、壳核最高;而在40~69年龄组,黑质、红核、苍白球SWI信号值较低,壳核相对较高、尾状核头部最高。在不同年龄组同一部位核团比较中,尾状核、苍白球SWI信号值于20~39岁变化基本平稳,诸深部灰质核团SWI信号值均于40岁随年龄的增长而快速下降(以红核及壳核为著),黑质、红核SWI信号值60岁后基本趋于平缓。4.不同部位脑深部灰质核团按年龄分组进行SWI信号值与年龄的相关回归分析:黑质、红核、壳、尾状核头SWI信号值均与年龄呈明显负相关(r黑质=-0.759, r红核=-0.875, r壳核=-0.880, r尾状核头=-0.524,P<0.001);苍白球SWI信号值与年龄存在弱相关(r =-0.211,P=0.042)。结论:通过对171例健康志愿者行头部SWI扫描研究,得出初步结论如下:1.不同年龄阶段所测量得到的尾状核头、壳核、苍白球、黑质、红核SWI信号值之间存在显著性差异(P<0.001)。不同年龄组尾状核头、壳核、苍白球、黑质、红核SWI信号值以40岁为界限呈现不同的变化规律。2.同一部位不同性别间SWI信号值不存在统计学差异;黑质、红核、壳、尾状核头SWI信号值均与年龄呈明显负相关;苍白球SWI信号值与年龄存在弱相关。3.本研究通过对不同年龄组健康志愿者进行SWI信号值的测量比较,证明了SWI技术可定量研究脑内正常铁沉积的变化,为正常人脑铁含量研究提供了一个新的非损伤性的方法。SWI信号值可以反映脑铁分布区域性和随年龄变化的规律,这对于观察正常成人脑与某些神经功能障碍性脑铁过度沉积性疾病提供了相对定量的标准。更多还原

【Abstract】 Purposes: To study the correlation of Susceptibility Weighted Imaging (SWI) signal values of deep brain gray nucleus (including substan- tia nigra, red nucleus, globus pallidus, putamen, caudate nucleus) and age in normal human brains and to evaluate the brain iron changes with advancing age on SWI signal values.Materials and methods: 171 cases of healthy adults(86 males and 85 females) were selected to perform MR examination, in which, none of the subjects had the history of neurological and psychotic diseases according to MRI and clinical results. Each subject gave a written consent for participation before the experiment. All of volunteers ranged from 20 to 69 years (mean 44.26 years), which were divided into five age groups in term of ten years: 20~29(31 cases)、30~39(33 cases)、40~49(35 cases)、50~59(40 cases)、60~69(32 cases).MRI Experiment scanning: GE Signa 1.5T echospeed MR/i scanner and 8-channel head coil were used. Firstly,transecting T2 WI was perfomed and its scan parameter included TR 4000ms,TE 102ms, slice thickness 2.0mm, no interval, matrix 256×160, fields of view 24 cm, NEX 1. During the experiment period, the SWI were performed using a both magnitude and phase images from a high-resolution, three-dimensional, fully velocity compensated gradient echo sequence, and its scan parameter: TR 50ms, TE 45ms, slice thickness 3.0mm, intervals 0mm, fields of view 24 cm, matrix 320×320, NEX 0.75, Bandwidth 31.25, Flip Angle:30°,Scan time: 338s. And then, raw data of SWI for every volunteer was sent to GE Advantage workstation 4.3 workshop and“Corrected phase”and“SWI-Negative Mask”images were reconstructed. The signal values of substantia nigra, red nucleus, globus pallidus, putamen, caudate nucleus on SWI were measured by manual measuring tools. The measurement was taken three times with variable oval areas. All the statistical data were displayed as Mean±SD. Different age groups SWI signal values were compared by using the one-way ANOVA. The relationship between SWI signal values of deep brain gray nucleus and age use linear correlation model. P value less than 0.05 indicated a statistically significant difference.Results:1. In 171 cases, the signal values of deep brain gray nucleus of SWI was lower than them in the deep gray matter in the same age group .2. SWI signal values of deep brain gray nucleus were no statistical difference beween male and female (P>0.05).3. In the 20~39 group, SWI signal values the low - to - high order were as follows: substantia nigra, globus pallidus, red nucleus, caudate nucleus, putamen. In the 40~69 group, SWI signal values the low - to - high order were as follows: substantia nigra, red nucleus, globus pallidus, putamen, caudate nucleus.The speed of brain iron deposit become slower during the period of 20~39 years, and increase rapidly after 40 years (especially red nucleus and putamen), while iron depoisit in substantia nigra and red nucleus became slower again after 60 years. 4. Obviously negative correlations between age and SWI signal values were shown in substantia nigra(r=-0.759), red nucleus(r=-0.875), putamen (r=-0.880) and caudate nucleus(r=-0.524), while weakly negative linear correlation was displayed in globus pallidus (r =-0.211).Conclusion:1. SWI intensity decreased with age in all deep gray matter areas. And the speed of brain iron deposit seemed to divided by 40 years old.2. There is no statistical difference beween male and female in the SWI signal values of all deep gray nucleus. Negative correlations were measured between SWI signal values and age in these gray nuleus.3. SWI have provided a new method to detect brain iron, and can quantitatively measure the anatomical localization and age-related iron concentration changes.更多还原