Study Design: 

Retrospective radiographic study.

Objective: 

To evaluate cervical sagittal alignment measurement reliability and correlation between upright radiographs and magnetic resonance imaging (MRI).

Summary of Background Data: 

Cervical sagittal alignment (CSA) helps determine the surgical technique employed to treat cervical spondylotic myelopathy. Traditionally, upright lateral radiographs are used to measure CSA, but obtaining adequate imaging can be challenging. Utilizing MRI to evaluate sagittal parameters has been explored; however, the impact of positional change on these parameters has not been determined.

Methods: 

One hundred seventeen adult patients were identified who underwent laminoplasty or laminectomy and fusion for cervical spondylotic myelopathy from 2017 to 2019. Two clinicians independently measured the C2–C7 sagittal angle, C2–C7 sagittal vertical axis (SVA), and the T1 tilt. Interobserver and intraobserver reliability were assessed by intraclass correlation coefficient.

Results: 

Intraobserver and interobserver reliabilities were highly correlated, with correlations greater than 0.85 across all permutations; intraclass correlation coefficients were highest with MRI measurements. The C2–C7 sagittal angle was highly correlated between x-ray and MRI at 0.76 with no significant difference (P=0.46). There was a weaker correlation with regard to C2–C7 SVA (0.48) and T1 tilt (0.62) with significant differences observed in the mean values between the 2 modalities (P<0.01).

Conclusions: 

The C2–C7 sagittal angle is highly correlated and not significantly different between upright x-ray and supine MRIs. However, cervical SVA and T1 tilt change with patient position. Since MRI does not accurately reflect the CSA in the upright position, upright lateral radiographs should be obtained to assess global sagittal alignment when planning a posterior-based cervical procedure.

中文翻译：

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磁共振成像不足以评估颈椎矢状排列参数

学习规划： 

回顾性射线照相研究。

客观的： 

评估颈椎矢状位测量的可靠性以及正位 X 线片和磁共振成像 (MRI) 之间的相关性。

背景数据摘要： 

颈椎矢状面排列 (CSA) 有助于确定用于治疗脊髓型颈椎病的手术技术。传统上，直立侧位 X 光片用于测量 CSA，但获得足够的成像可能具有挑战性。已经探索了利用 MRI 评估矢状面参数；然而，位置变化对这些参数的影响尚未确定。

方法： 

确定了 117 名在 2017 年至 2019 年间因脊髓型颈椎病接受了椎板成形术或椎板切除术和融合术的成年患者。两名临床医生独立测量了 C2-C7 矢状角、C2-C7 矢状垂直轴 (SVA) 和 T1 倾斜度。通过组内相关系数评估观察者间和观察者内的可靠性。

结果： 

观察者内和观察者间的可靠性高度相关，所有排列的相关性均大于 0.85；MRI 测量的组内相关系数最高。C2-C7 矢状角在 X 线和 MRI 之间高度相关，为 0.76，无显着差异（P = 0.46）。C2-C7 SVA (0.48) 和 T1 倾斜度 (0.62) 的相关性较弱，两种模式之间的平均值存在显着差异 ( P <0.01)。

结论： 

C2-C7 矢状角高度相关，并且在直立 X 射线和仰卧位 MRI 之间没有显着差异。然而，颈椎 SVA 和 T1 倾斜会随着患者体位的变化而变化。由于 MRI 不能准确反映直立位的 CSA，因此在计划基于后路的颈椎手术时，应获得直立侧位 X 线片以评估整体矢状位对齐。