胎儿脊髓腰骶膨大发育宫内及标本MRI研究

发布时间：2018-09-17 14:57

【摘要】：目的：依据不同孕周胎儿标本与宫内胎儿MR扫描图像,寻找脊髓圆锥末端位置、腰骶膨大左右径、前后径及相应层面椎管左右径及前后径随孕周变化的规律,对比标本图像与宫内图像的差异。了解胎儿腰骶膨大发育状况及脊髓移行过程与孕周的关系,从而,制定各孕周胎儿脊髓腰骶膨大发育及脊髓移行生长曲线及参考值,对评估胎儿发育及早期发现先天脊椎发育畸形及椎管内病变提供可靠、直观的影像数据及图谱。材料和方法： 1.胎儿标本选择与MR数据获取本课题共筛选了29例脊椎发育正常的胎儿标本作为研究对象,胎龄大小范围自17孕周至39孕周,所有研究对象均接受3.0TMR(general electric, GE)脊椎扫描,以腰椎为中心,获取标准横、矢、冠三方位断层图像。扫描序列为T2WI (TR:11000ms, TE:93ms)。观察及测量内容： (1)结合全脊椎椎体特点确定腰椎； (2)在矢状位上确定腰骶膨大及圆锥末端位置与腰椎的位置关系； (3)结合横轴位、矢状位及冠状位测得腰骶膨大左右及前后最大径线、最大横断面积,同时测得同一水平椎管面积,得出腰骶膨大与椎管面积之比； (4)用回归分析处理所得数据与孕周间的关系。 2.宫内胎儿数据获取从500例超声检查显示脊椎及脊髓发育正常的胎儿中,随机选取142例为研究组,行宫内胎儿腰椎MRI检查,孕周范围为20孕周～38孕周。成像使用1.5TMR(GE Echo speed)扫描仪,采用2D FIESTA序列(TR：3.6-4.2ms,TE：1.0-1.8ms),以L2椎体为中心行横、矢、冠三方位扫描。观察及测量内容： (1)结合脊椎全长不同椎体特点确定腰椎序列； (2)以腰椎矢状位为参考,确定腰骶膨大中心位置及圆锥末端位置； (3)结合横轴位、矢状位及冠状位测得腰骶膨大左右及前后最大径线、最大横断面积,同时测得同一水平椎管面积,得出腰骶膨大与椎管面积之比； (4)对所得数据行回归分析,得到与孕周间的关系。结果：胎儿标本及宫内胎儿均显示：脊髓腰膨大及相应层面椎管前后径及左右径线随孕周呈线性增长关系。脊髓圆锥末端位置的移行规律为：随孕周增长脊髓圆锥末端位置亦呈上升趋势,但个体差异明显,这种上升并非一直持续到出生,而是在孕中期即已快速上升至相对稳定位置即第L1-2椎体水平。标本数据显示：在21孕周及之前,脊髓圆锥末端均位于L3腰椎以下水平,22～30孕周其变化范围最大位于L1～L4水平,第31～40孕周位于L1～L2水平,因此,如果31孕周以后脊髓圆锥末端仍位于L2水平以下,可以认为是异常低位。与标本数据不同,宫内胎儿在26孕周时,脊髓圆锥末端位置即达第二腰椎水平,较标本时间段前移,但在之后时间段内两种检测数据仍表现出较好一致性。标本图像更稳定,获得层厚更小、结构更清晰、数据更准确。结论：宫内胎儿MRI真实反应自然状态下胎儿脊髓腰骶膨大的发育变化规律及圆锥位置,但,对椎体骨化中心、椎间盘及脊髓信号显示欠佳；标本图像能清晰显示椎体、椎间盘形态及脊髓信号改变,两种方法同时研究,能更科学的获取胎儿脊椎发育的参考值并描述其生长曲线,对判断胎儿脊椎生长发育状况及疾病诊断提供影像数据及图像参考。
[Abstract]:Objective:
According to the MR scanning images of fetal specimens and intrauterine fetuses at different gestational weeks, the position of the end of conus medullaris, the left and right diameters of lumbosacral enlargement, the anterior and posterior diameters of spinal canal and the corresponding layers were found out. Thus, the development of lumbosacral enlargement and spinal cord transitional growth curves and reference values of fetuses at each gestational week can provide reliable and intuitive image data and maps for evaluating fetal development and early detection of congenital vertebral malformations and intraspinal lesions.
Materials and methods:
1. Fetal specimens were selected and MR data were obtained. Twenty-nine fetal specimens with normal vertebral development were selected as the subjects. The gestational age ranged from 17 weeks to 39 weeks. All the subjects underwent 3.0TMR (general electric, GE) spinal scan. The standard transverse, sagittal and coronal three-dimensional tomograms were obtained with the lumbar spine as the center. Listed as T2WI (TR:11000ms, TE:93ms). Observations and measurements:
(1) determine the lumbar spine with the characteristics of the entire vertebral body.
(2) determine sagittal position of the lumbosacral enlargement and the position of the conus end with the position of the lumbar spine.
(3) Combined with transverse axis, sagittal and coronal position, the maximum diameter and cross-sectional area of lumbosacral enlargement were measured, and the ratio of lumbosacral enlargement to spinal canal area was obtained.
(4) regression analysis was used to deal with the relationship between the data and gestational age.
2. intrauterine fetal data acquisition
Among 500 fetuses with normal vertebral and spinal cord development, 142 cases were randomly selected as the study group and examined by intrauterine fetal lumbar MRI, ranging from 20 to 38 gestational weeks. Azimuth scanning.
Observation and measurement contents:
(1) determine the lumbar vertebrae sequence according to the characteristics of different vertebrae.
(2) to determine the location of the lumbosacral enlargement and the position of the conus end, based on the sagittal sagittal position of the lumbar spine.
(3) Combined with transverse axis, sagittal and coronal position, the maximum diameter and cross-sectional area of lumbosacral enlargement were measured, and the ratio of lumbosacral enlargement to spinal canal area was obtained.
(4) regression analysis of the data was carried out to get the relationship with gestational age.
Result:
Fetal specimens and intrauterine fetuses showed that the anterior and posterior diameters and the left and right diameters of the spinal canal linearly increased with gestational age. Sample data show that the end of the conus medullaris is located below the L3 lumbar vertebrae at and before 21 weeks of gestation. The maximum range of change is at the L1-L4 level at 22-30 weeks of gestation and the L1-L2 level at 31-40 weeks of gestation. Therefore, if the end of the conus medullaris medullaris is located after 31 weeks of gestation. Unlike the original data, the end of the conus medullaris reached the level of the second lumbar vertebra at 26 gestational weeks and moved forward compared with the specimen time, but the two data showed good consistency in the subsequent period. Clearer and more accurate data.
Conclusion:
The development and cone position of lumbosacral enlargement of fetal spinal cord in natural state are reflected by intrauterine fetal MRI, but the signal of ossification center of vertebral body, intervertebral disc and spinal cord is not well displayed; the image of specimen can clearly show the change of vertebral body, the shape of intervertebral disc and the signal of spinal cord. The two methods can be studied simultaneously to obtain the fetal vertebral column more scientifically. The development reference value and the growth curve are described to provide the image data and the image reference for judging the fetal vertebral growth and the disease diagnosis.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R714.5;R445.2

【参考文献】