MRI和CT在测评退行性颈椎滑脱关节突关节矢状位不对称角中可靠性的比较

目的确定MRI和CT评估退行性颈椎滑脱关节突关节矢状位不对称角的可靠性。方法利用4度评估法,3个评估者对60位病人的76个关节突关节矢状位角的不对称程度在轴向位MRI和CT上进行单盲和随机测评,结果用Kappa系数进行统计分析。结果当评估颈椎关节突关节矢状位角的不对称性时,CT和MRI的一致性为0.76(加权K值,P0.001),一致率为82%(62 vs 76),可认为方法间有比较好的一致性,三个测评者在MRI和CT中的k值范围分别为0.61~0.74和0.65~0.81,可认为测评者间用MRI测评时的信度为比较可靠,用CT测评时为比较可靠到非常可靠,但测评者内的信度无论是MRI还是CT都比测评者间的信度要高。结论 MRI和CT在评估关节突关节矢状位角的不对称性时无论是方法间的一致性,还是组间或组内的信度,都有较好的一致性,这表明MRI用于测评关节突关节矢状位角度的不对称性是比较可靠的。因此,用MRI测评时没有必要再增加额外的CT扫描。

Comparison of the reliability of computed tomography and magnetic resonance imaging in the evaluation of facet tropism in degenerative cervical spondylolisthesis

Objectives 　To determine the reliability of MRI and CT in the assessment of facet tropism of spondylolisthesis levels in degenerative cervical spondylolisthesis.　Methods　Using a 4-point scale, 3 reviewers blindly and independently graded the severity of facet tropism of 76 cervical facet joints on axial T2-weighted and sagittal T1- and T2-weighted turbo spin echo images and separately on the corresponding axial MRI and CT scans. All results were subjected to the kappa coefficient statistic for strength of agreement.　Results　When assessing the severity of facet tropism, the weighted kappa coefficients for agreement between MRI and CT grading were 0.76 (P<0.001), MRI grading of facet tropism was identical to the CT grading in 62 of 76 joints (82%), with substantial intermethod concordance. The inter-rater reliability of three reviewer in MRI and CT were 0.61~0.74 and 0.65~0.81 (range k), respectively. CT performed better, with substantial to very good inter-rater reliability than MRI, which had substantial inter-rater reliability. Intra-rater reliability was higher than inter-rater reliability for both CT and MRI.　Conclusion　When using MRI and CT to assess facet tropism, they all performed excellent, with substantial to very good agreement for both intermethod agreement and inter-rater reliability or intra-rater reliability. This indicates that MRI can reliably determine the presence or degree of facet tropism. Therefore, for comprehensive assessment of facet tropism, an MR scan should not be performed in addition to a CT.