下腰椎椎管CT图像辅助计算机测量分析

The Assisted Computer Measurement Analysis on the CT Image of the Spinal Canal

目的 探讨CT 图像几何学测量的不同方法和指标对腰椎管狭窄症的诊断价值。方法 以正常人群和腰椎管狭窄症患者各100 例的下腰段CT 图像为样本,应用计算机图像分析系统,测量了椎管矢径、横径、椎管面积和椎管内切圆面积等项指标。结果 在正常组和狭窄组之间,狭窄组内不同的病程段之间进行比较,各项指标的差异均具有显著性意义(P< 0 .05 或P< 0 .001)。在几种测量方法中,椎管面积和内切圆面积的测量对狭窄组的诊断符合率分别为86.75 % 和92 .17 % 。结论 椎管面积测量较之径线测量更能准确地反映出椎管容积的变化,作者自行设计的椎管内切圆面积测量法不仅能反映中央椎管的大小。

Objective To study the diagnosis value of different geometrical methods of measurements and indices on CT images in lumbar spinal stenosis(LSS). Methods Two hundred cases of CT images were selected as samples in which 100 cases were normal and the others had LSS. Computer image analysis system was used to carry out the geometrical measurements and calculation including the sagittal, transverse diameters, the areas of the spinal canal as well as the internal tangential circular areas(TCA) of the spinal canal. Results Comparing the indices between the two groups, the difference between them is highly significant(P < 0.05 or P< 0.001). When the lower limit of the two indices, the cross sectional area of the canal(CAC) and the TCA of the normal group, were taken as standard, the rate of diagnostic accuracy reached 86.75% and 92.17% respectively. Conclusion The CAC is more accurate to show the spinal canal volume than the diameter line measurement methods. TCA not only shows the central spinal volume, but also helps to distinguish the changes of the spinal canal morphology.