儿童脊柱正常MRI与胎儿脊柱骨发育  

Normal MR imaging of spine in children and bone development in fetal spine

作　　者：王云钊[1] 刘薇[1] 程晓光[1] 

机构地区：[1]北京大学积水潭医院放射科,北京100035

出　　处：《放射学实践》2004年第8期558-562,共5页Radiologic Practice

摘　　要：目的 :探讨胎儿椎体和椎间盘的组织学结构以及儿童脊柱的正常X线和MRI表现。方法 :44周胎儿X线平片 1例 ;儿童脊柱正常椎体MRI 13例 ;胎儿脊柱标本 2 6例 ,全部标本经固定、水冲洗、分批脱水、火棉胶包埋后制成脊柱标本整体切片 ,HE染色。结果 :44周胎儿脊柱每个椎体前面X线表现均有“V”字形凹陷。 13例儿童脊柱正常椎体MRI ,共分析了110个椎体的信号变化 ,其T1WI和T2 WI表现 :44 %的椎体前面“V”形凹陷呈高信号 ,63 %的椎体后面“V”形凹陷 ;16.4%的椎体前后面均凹陷 ;47%的椎体中心有雪花样高信号 ;13例中有 9例各椎体内均有双层低信号生长线。 2 6例胎儿脊柱椎体的组织学结构 :① 12周和 15周胎儿 ,椎体软骨内血管数量较多 ;②胎儿椎体前、后面中部凹陷 ,以膜内成骨形成“V”字形骨皮 ,不同病例椎体前面或后面均可见凹陷 ,出现率 9.6%～ 2 7.1% ,有 2例在椎体前面“V”字骨皮内形成松质骨小梁 ,并有骨髓形成 ;③椎体骨化中心有红髓和血管 :椎体后面“V”字骨皮内的大静脉窦与骨化中心静脉窦相通 ;④椎间盘 :只见于 12周的胎儿椎间盘内有血管 ,2例紧贴椎间盘的软骨椎体内见无细胞区 ,且部分髓核物突入椎体软骨内。结论 :4～Objective:To reassess the normal radiographic and MRI manifestations of vertebral bodies in children and to explain their signal intensity changes based on the histologic findings in fetal vertebral bodies and intervertebral disks.Methods:Radiographs of a fetus of 44 weeks of gestation and MR images of normal vertebrae in 13 children were used for study.Specimens of 26 fetuses with 12～44 weeks of gestation were used for study.All the specimens were processed in a conventional manner and block section of whole spine and HE stain were performed.Results:In the fetus of 44 weeks of gestation ”V” shaped indentation was seen in the anterior aspect of every vertebral body.On MRI of 13 cases of normal vertebrae ”V”shaped indentation was seen in anterior aspect of the vertebral body in 48 (44%) showing high signal intensity on T 1WI and T 2WI;indentation in posterior aspect was seen in 69 (53%),in both anterior and posterior aspects in 18 (16.4%).Snowflake-like high signal intensity was found at the center of the vertebral body in 52 (47%).Double layered low signal intensities of growth lines were found in the vertebral body in 9 of the 13 cases.Histologic findings:①In fetuses of 12 and 15 weeks,vertebral intrachondral blood vessels were plentiful. ②In the anterior and posterior aspects of the fetal vertebral body,”V”shaped bone bark indentation was formed by intramembranous ossification.③ There were bone marrow and blood vessels in the ossification center of the vertebral body.while the venous sinuses in the posterior aspect of the vertebral body were continuous with that in the ossification center .④Intervertebral disk: Blood vessels were found merely in the intervertebral disks in 2 fetuses of 12 weeks of gestation.Certain amount of neucleus pulposus was protruded into the cartilaginous vertebral body.Conclusion:MRI manifestation of normal vertebral body in children with 4～11 years of age maintains the corresponding histologic characteristics of fetal vertebral bone development. The ”V�

关 键 词：儿童 脊柱 MRI 胎儿 脊柱骨发育 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]