MRI定量分析胎儿后颅窝结构的临床价值

发布时间：2018-01-13 02:05

  本文关键词：MRI定量分析胎儿后颅窝结构的临床价值　出处：《宁夏医科大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 胎儿 磁共振 正中矢状面 后颅窝畸形

【摘要】：目的:应用MRI获得通过胎儿蚓部的正中矢状面,观察胎儿后颅窝结构,测量胎儿小脑蚓部上下径、前后径、面积及BV角、BT角,研究其随孕周进展的变化规律,为MRI评估胎儿后颅窝结构的发育提供影像学参考标准。分析常见后颅窝畸形胎儿的上述测值与正常胎儿的差异性,探讨胎儿颅脑MRI正中矢状面后颅窝测值在常见后颅窝畸形诊断及鉴别诊断中的临床应用价值。方法:选择2013年1月至2016年12月在我院行胎儿产前超声筛查及MRI检查,未发现中枢神经系统异常或仅侧脑室轻度扩张,追踪至分娩后无明显异常的中晚孕周胎儿123例。应用胎儿颅脑MRI观察后颅窝结构及相邻结构间的毗邻关系,将原始MRI图像传至随机后处理工作站ADW4.4,选择通过蚓部的正中矢状面,利用测量工具手动描绘并分别测量胎儿小脑蚓部上下径、前后径、面积及BV角、BT角,分析以上测量指标与孕周的关系。选择同期产前超声及MRI检查,拟诊为后颅窝畸形(包括DWM、IVH、MCM)的中晚孕胎儿25例。应用相同方法观察后颅窝结构和测量后颅窝各观察指标,同时注意观察是否合并其他畸形,分别与正常组后颅窝测量值对比观察。结果:1.正常组胎儿颅脑MRI后颅窝结构示:小脑蚓部连接两侧小脑半球,覆盖第四脑室,正中矢状面上几乎与脑干平行,外形饱满、略呈“心”形,第四脑室顶部呈锐角,小脑蚓部原裂显示清晰,大致位于正中矢状面蚓部2点钟位置,次裂在25周后见,较原裂显示清晰度差,约在正中矢状面蚓部5点钟位置,在孕30周后小脑蚓部各分叶清晰可见,原裂、次裂及其它小裂隙可辨。2.123例正常胎儿颅脑MRI正中矢状面上小脑蚓部各观察指标(上下径、前后径及面积)的测值与孕周呈高度正相关(R2=0.911、0.839、0.947,P均0.01),正常胎儿BV角、BT角平均值分别为5.77°±2.73°、28.58°±6.60°,BV角及BT角的测值与孕周均不相关(R2=0.011、0.043,P均0.05)。3.异常组25例,其中DWM胎儿3例(全部引产)、IVH胎儿7例(6例引产、1例出生后1岁随访智力低下)和MCM胎儿15例(出生后3个月至2岁随访正常)。3例DWM胎儿的小脑蚓部各测量指标的Z分数均小于-5,BV角的Z分数均大于10,BT角的Z分数均大于2;7例IVH胎儿的小脑蚓部各测量指标的Z分数均小于-3,BV角的Z分数均大于5,BT角的Z分数均1.96;15例MCM胎儿的后颅窝各测量指标(上下径、前后径、面积、BV角及BT角)的Z分数在-1.96~1.96之间。结论:1.胎儿颅脑MRI获得的正中矢状面能清晰显示小脑蚓部、第四脑室、后颅窝池的大小、形态及脑干、小脑幕与小脑蚓部的毗邻关系,为后颅窝畸形的诊断提供更多直接征象。2.正常胎儿小脑蚓部各观察指标随孕周增长而增大,测量这些指标并建立孕周参考值,可帮助定量评估胎儿后颅窝小脑蚓部的发育状况。正常胎儿BV角、BT角平均值分别为5.77°±2.73°、28.58°±6.60°,BV角11.12°时可以认为小脑蚓部上旋,BT角41.51°时可以认为小脑幕上抬。3.DWM胎儿颅脑MRI正中矢状面后颅窝各观察指标测值提示小脑蚓部发育不良程度重,小脑蚓部上旋严重,小脑幕轻度上抬;IVH胎儿颅脑MRI正中矢状面后颅窝各观察指标测值提示小脑蚓部发育不良程度较轻,小脑蚓部轻度上旋,小脑幕上抬不明显;MCM胎儿颅脑MRI正中矢状面后颅窝各观察指标测值提示小脑蚓部发育、小脑蚓部及小脑幕位置与正常组无显著差异。4.在胎儿颅脑MRI正中矢状面上仔细观察后颅窝结构及相邻结构间的毗邻关系,测量胎儿后颅窝各观察指标可帮助定量评估小脑蚓部的发育情况,用于常见后颅窝畸形的诊断与鉴别诊断。
[Abstract]:Objective: the application of MRI obtained by fetal vermis median sagittal plane, fetal posterior fossa structures, measurement of fetal cerebellar vermis on diameter, anteroposterior diameter, area and BV angle, BT angle, the research progress of its changes with gestational weeks, MRI assessment of fetal posterior fossa structures for development the imaging reference standard. The measured value of normal fetal sex differences and analysis of common posterior fossa malformations of the fetus, fetal brain MRI on the median sagittal plane of posterior fossa measurements in common posterior fossa malformations in diagnosis and differential diagnosis of clinical value. Methods: from January 2013 to December 2016 in our hospital for prenatal ultrasonography and MRI examination, no central nervous system abnormalities or only mild ventriculomegaly, to track after delivery with no obvious abnormality in the late gestation fetal 123 cases. Application of fetal brain MRI observation of posterior fossa structure and adjacent relationship between two adjacent structures, the The original MRI images were randomly selected by ADW4.4 postprocessing workstation, vermis of the midsagittal plane, manual and description of fetal cerebellar vermis on diameter and anteroposterior diameter were measured using measurement tools, area and BV angle, BT angle, analysis the above measurement index relationship with gestational age. Selected prenatal ultrasound and MRI, diagnosed as posterior fossa malformations (including DWM, IVH, MCM) in 25 cases of late pregnancy fetus. To observe the application of the same method of posterior fossa and posterior fossa structure measurement of the observed indicators, and observe whether associated with other malformations, compared with normal posterior fossa measurements were compared. Results: 1. fetal brain MRI group of posterior fossa structures in the cerebellar vermis cerebellum connected, covering the fourth ventricle, the median sagittal plane almost parallel with the brain stem, plump shape, slightly "heart shaped", at the top of the fourth ventricle was acute, cerebellar vermis primary fissure shows clear, large 鑷翠綅浜庢�ｄ腑鐭㈢姸闈㈣殦閮�2鐐归挓浣嶇疆,娆¤�傚湥�

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