运用CT三维重建测量重度先天性脊柱侧凸Cobb角的临床应用

The Value of Three-dimensional CT Reconstruction Imaging in Measuring the Cobb Angle in Severe Congenital Scoliosis

目的:评价在CT三维重建上测量重度先天性脊柱侧凸Cobb角度的可重复性和可靠性。方法:收集在我院诊治的重度先天性脊柱侧凸病人的CT三维重建和脊柱全长X线片,共计67例。由五名不同测量者对CT三维重建脊柱畸形冠状面主弯Cobb角测量两次,两次间隔在三周以上,并测量脊柱全长X线片脊柱畸形冠状面主弯Cobb角一次,运用组内相关系数分析测量结果之间的可重复性和可靠性。结果:同一测量者两次测量结果之间的差值平均为4.5°。同一测量者两次测量结果之间的组内相关系数为0.969,不同测量者之间测量结果的组内相关系数为0.913。取五名测量者在CT三维重建上第一次测量的Cobb角度,其平均值为(110.5±23.5)°,五名测量者在X线片上测量结果的平均值为(103.1±22.0)°,对两组数据进行Mann-Whitney非参数检验差异有统计学意义(Z=-2.86,P=0.004)。结论:在CT三维重建上测量重度先天性脊柱侧凸的Cobb角,可以减小测量的误差,提高测量的可重复性和可靠性,是一种相对准确的测量方法。

Objective： To assess the accuracy as well as the intra- and interobserver of measuing Cobb angle of the patient with severe congenital scoliosis on three-dimensional CT reconstruction imagings. Methods： Sixty-seven three-dimensional CT reconstruction imagings and standard standing posteroanterior whole-spine radiographs of the patients with severe congenital scoliosis treated in our hospital were reviewed. Each curve was measured twice by five different obsevers with varying experience in curve measurement on three-dimensional CT reconstruction imaging, with an interval of at least three weeks between the two measurements, and one time on standard standing posteroanterior whole-spine radiographs on two separate occasions. The observers were blinded to the dates on which the radiographs were made, the patients＇ identities, and any other previous measurement. Only one curve per radiograph was measured. The end vertebrae were not preselected. SPSS 17.0 software was used for statistical analyses. Both intraobsever and interobserver reliability for each measure were assessed with the intraclass correlation coefficient （ICC）. Results： The mean intraobserver variance was 4.5° measured on three-dimensional CT reconstruction imaging. The interobserver and intraobserver Cobb angle measurements had high reliability on three-dimensional CT reconstruction imaging. The ICC of intraobserver reliability was 0.969, and the ICC of interobserver reliability was 0.913 on three-dimensional CT reconstruction imaging. The mean of the first measured Cobb angles on three-dimensional CT reconstruction imaging was （110.5± 23.5）° . And the mean measured Cobb angles on standard standing posteroanterior whole-spine radiographs was （103.1 ± 22.0）° . Compared these two goups with Mann-Whitney test, there was notable statistical difference the Cobb angle （Z=-2.86, P=0.004）. Conclusions： Measurement on three-dimensional CT reconstruction imaging for severe congenital scoliosis may not only help to minimize measurement discrepancies, but also improve the reliability and reproducibility. The way to measure the Cobb angle of severe congenital scoliosis in three-dimensional CT reconstruction imaging was a reliable, accurate measurement tool.