螺旋CT测量颈椎椎体间隙准确性的验证

Accuracy verification of measuring cervical intervertebral space with multi-spiral CT

[目的]验证螺旋CT测量颈椎椎体间隙的准确性,为螺旋CT测量颈椎椎体间隙提供理论依据。[方法]选取8具男性(30～52岁,平均年龄37.7岁)新鲜尸体,排除先天畸形,创伤,肿瘤及明显退行性变,取其头颈部标本。在颈椎生理曲度下,螺旋CT扫描标本,三维重建图像,测量颈椎椎体间隙的前后径,左右径,正中矢状面上的前缘,中点及后缘的高度。将颈椎标本固定于相同的生理曲度。在C型臂X线机透视引导下,以外固定支架固定颈椎标本,刮除干净各间隙椎间盘和软骨终板,在间隙内灌注硅胶,待硅胶凝固后,松开外固定支架,取出硅胶模型,修剪模型边缘至光滑。应用激光三维扫描仪创作硅胶模型的三维图像。测量其各项径线。[结果]将CT扫描的测量值与硅胶模型的测量值进行配对t检验。P值范围为0.058～0.893,均大于0.05,CT扫描与硅胶模型的测量值不存在显著差异。[结论]螺旋CT测量颈椎椎体间隙结果准确,可以作为测量较大样本量颈椎标本的可信方法。硅胶塑形法与螺旋CT扫描法相结合,能更好地为符合国人解剖特点的仿生型颈椎椎体间融合器的研发工作提供形态学依据。

[ Objective] To verify the accuracy of measuring cervical intervertebral space with multi -spiral CT scanning. [ Methods ] Eight male （30 - 52 years, average 37.7 years） fresh cadavers＇ head - neck specimens were selected, excluding those with tumor, malformation, trauma, and obvious degeneration. CT images were obtained from each specimen maintaining physical curve. The 3D reconstructions were used to measure the anteroposterior diameter and the transverse diameter of the cervi- cal intervertebral space as well as the heights of anterior margin, middle and posterior margin on mid - sagital plane. External fixations were performed under C - arm guiding to retain the physical curve of cervical spine. The intervertebral discs and carti- laginous endplates were removed from the cervical spine, and the intervertebral space was filled with silica gel. The external fixa- tion was disassembled after solidification, and the silica gel models of cervical intervertebral spaces were modified and meas- ured. The 3 - dimensional images were established based on the silica models and statistical analyses were carried out. [ Re- suits] There was no significant difference between CT scan images and silica gel models in comparison of corresponding diame- ters （P 〉0.05, by paired t- test ） . [ Conclusion] The parameters of cervical intervertebral spaces acquired from 3 -D CT images were accurate compared with corresponding disc models. CT scanning is a reliable method of measuring cervical interver- tebral spaces.