成人下腰椎神经根与椎板骨窗之间CT容积再现技术成像特点与意义

The characteristic and significance of normal human lower lumbar nerve root and vertabral interlaminar space under CT volume rendering technique

中文关键词:  下腰椎  神经根  CT容积再现技术  完全内窥镜技术  影像测量

英文关键词:Lower lumbar  Nerve root  CT volume rendering technique  Full-endoscopic technique  Image measurement

中文摘要:

  【摘要】 目的：观察正常成人下腰椎神经根与对应椎板骨窗之间CT容积再现技术（volume rendering technique，VRT）成像的影像学特点，为完全内窥镜下经椎板间隙入路技术的安全应用提供依据。方法：从2011年9月～11月在我院体检人群中选取60例正常成人的下腰椎CT片，男32例，女28例，年龄20～59岁，平均40岁。将64排螺旋CT平扫下腰椎的三维重建数据传至工作站，在多平面重建技术下获得矢状面、冠状面及横断面成像，确定神经根起始点位置，在前后位上以神经根起始点为参照，与对应椎板骨窗之间进行VRT成像，测量以下参数：椎板骨窗的上下径及左右径，神经根起始点与相应椎板骨窗的椎板上缘及上下关节突内侧缘（椎板骨窗的外侧缘）垂直距离，神经根起始点与相应椎弓根上缘垂直距离，神经根与硬膜囊夹角（根囊角），以及神经根起始点至相应椎弓根下缘的直线距离和垂直距离，并进行统计学分析。结果： 60例均获得了下腰椎神经根起始点与椎板骨窗对应的清晰图像。根据神经根起始点与椎板骨窗位置对应关系分为四型：即上缘内型、上缘外型、下缘内型和下缘外型。各相邻节段神经根测量参数比较均有统计学意义（P<0.05），即椎板窗的上下及左右径均逐渐增大，L4~S1的神经根起始点至椎板上缘的距离逐渐增大，与上下关节突内侧缘的距离逐渐增大，根囊角逐渐减小，神经根在椎管内的直线投影距离逐渐增长，神经根起始点至椎弓根上、下缘的距离逐渐增长。结论：VRT技术可快速、直观显示下腰椎神经根与对应椎板骨窗之间的空间关系，能为完全内窥镜下经椎板间隙入路技术应用提供指导。

英文摘要:

  【Abstract】 Objectives:　To investigate the characteristic of the normal human lower lumbar nerve root and interlaminar space under CT volume rendering technique, and to provide the basis for safe practice of the full-endoscopic technique. Methods: From September 2011 to November 2011, CT volume rendering technique was performed on lumbar nerve root and interlaminar space of 60 healthy population. There were 32 males and 28 females with a mean age of 40(20-59) years old. Three-dimensional reconstruction data of lower lumbar spine under 64-slice spiral CT were transferred into working station, multi-planar reconstruction(MPR) technique was used to obtain the sagittal, coronal and cross sectional imaging, the starting point of nerve root was determined, then the imaging of lower lumbar nerve root and vertabral interlaminar space was obtained under CT volume rendering technique(VRT). Index included: the vertical diameter(VD) and longitude diameter(LD) of interlaminar space; the vertical distance from nerve root to the superior edge of pedicle(PSRD), the vertical distance from nerve root to the inferior edge of pedicle(PIRD); the vertical distance from nerve root to the superior edge of vertebral lamina(LSRD), the vertical distance from nerve root to medial edge of the facet(LMRD); the straight distance from nerve root to the inferior edge of pedicle(RSD); the angle between nerve root and dura mater(RA). Each parameter was statistically analyzed. Results: All images of lower lumbar nerve root and vertebral interlaminar space from 60 cases were obtained under CT volume rendering technique. Four types were determined according to the position of nerve root and interlaminar space: superior edge and medial, superior edge and outside, inferior edge and medial, inferior edge and outside. However, there was statistical significance with adjacent segment parameters(P<0.05). The values of VD, LD,　PSRD,　PIRD,　LSRD,　LMRD and RSD increased gradually from L4 to S1; on the contrary, the RA decreased gradually from L4 to S1, and the length of nerve root in the spinal canal increased gradually. Conclusions: The morphology of the lower lumbar nerve root and interlaminar space can be accurately detected by CT volume rendering technique, which can be used for the surgical treatment of lumbar disc herniation under full-endoscopic technique.