CT扫描层厚度对椎弓根钉道参数测量结果的影响

目的探讨CT扫描层厚度不同对椎弓根钉道参数CT测量结果影响的程度。方法将椎骨标本摆放为不同的倾斜角度，分别采用2．5mm和0．625mm层厚进行CT扫描重建，由两位测量者分别对椎弓根钉道参数进行测量，每人测量两次。对相同倾斜角度、不同CT层厚间的椎弓根钉道各CT参数分别进行配对t检验。结果2．5mm与0．625mm层厚组的部分长度和角度测量结果（t9〉0．05）在统计学上没有显著性的差异，而椎弓根钉道的宽度测量结果（P〈0．05）在统计学上存在显著性的差异。结论与0．625mm层厚相比，采用2．5mm层厚进行CT扫描时不会引起CT测量误差的增加，其中椎弓根钉道的宽度除外。

To Evaluate CT Thickness Effection to the Accuracy of the Pedicle Screw Parameters

Objective To evaluate CT thickness effection to the accuracy of the pedicle screw param- eters. Methods A vertebra located in different rotational angles was scanned twice with the CT thickness of 2.5 mm and 0. 625 mm. Two observers measured twice the pedicle screw parameters double-blindedly. The data from the 2.5 mm and 0. 625 mm groups were analyzed with SPSS10.0 （ Paired-Samples T- Test）. Results The measuring data of seme distances and angels （P 〉 0.05） from the 2.5mm and 0. 625 mm groups were not significantly different statistically. The width of the pedicle screw measuring data（P 〈 0.05） from the 2.5mm and 0. 625 mm groups were significantly different statistically. Conclusion There is not more error increased in the pedicle screw CT parameters from the 2.5 mm group than from the 0. 625 mm group except the width of the pedicle screw.