腰椎后缘软骨结节的CT和MRI诊断价值

目的　分析腰椎后缘软骨结节的ＣＴ和ＭＲＩ表现，探讨其发病机理及其与椎间盘突出的关系。材料和方法４９例ＬＰＭＮ行ＣＴ检查，其中１９例行ＭＲＩ检查，均经手术证实。结果　本组好发年龄２０～４０岁，以Ｓ１和Ｌ５后上缘最常见。软骨结节的形态以类圆形最多见，多有硬化边缘；裂隙形或边缘无硬化者可能为本病早期改变。软骨结节下多形成骨性突起，造成椎管矢状径变小。软骨结节常使椎体终板变形后膨，导致椎体侧隐窝狭窄。结论　ＣＴ是较好的检查手段，能清楚显示软骨结节和其后骨块的形态及大小。软骨结节与邻近椎间盘相连续且信号变化一致，是ＭＲＩ的特征表现。本病可能是在椎体终板发育相对薄弱的基础上，加上扭曲外力使椎间盘疝入椎体终板内而形成。

CT and MRI Study of Lumbar Posterior Marginal Intraosseous Node

Purpose To study the CT and MRI manifestation, pathogeny of lumbar posterior marginal intraosseous cartilaginous node(LPMN)and relationship between LPMN and herniation of intervertebral discs. Materials and methods. 49 cases of LPMN were examined by CT in which 19 cases were examined by MRI. All cases were confirmed by surgical operation. Results Most of LPMN come on in 20-40 years and the posterior superior margins of S1 and L5 were the commonest sites. The shapes of the intraosseous cartilaginous nodes were paracircle mostly and most of its edges were scleroid. The shape of rift and no hardmargin probably were the manifestations of LPMN at the early stage. Bony protrusions below the intraosseous cartilaginous node were often formed and resulted in the sagittal diameter of the vertebral tube being changed narrow. LPMN often made the vertebral plate be out of shape and expand backwards and led to vertebral lateral crypts narrowed. Conclusion The best way to diagnose LPMN was CT examination. The characteristic MRI appearances were that the intraosseous cartilaginous nodes linked up to the adjacent intervertebral discs and their signals changed identically. The pathogeny probably was that while the wrench strength acted on the dysplastic vertebral plate,the intervertebral disc herniated into the vertebral plate. LPMN and the herniation of intervertebral discs helped each other forward.