PURPOSE CT myelography has been used since 1976 to diagnose neural compression in the axial skeleton. With the advent of routine MRI, its role in accurately diagnosing neural compression has been questioned as its normal appearances are not defined in the study. In this study, we examine a series of CT myelograms to define the normal appearances of the neural elements of the spine. METHODS The CT myelograms of patients with unilateral symptoms were examined by four independent physicians. The lateral extent of contrast was examined and recorded. Concordance between the recorded extents was assessed using kappa scores. RESULTS Thirty-six scans were reviewed. Kappa analysis shows that there is a fair agreement in the lateral extent of contrast at L1, L3 and L4. At L2 and L5, agreement is slight. CONCLUSION The interpretation of CT myelography shows significant interobserver variability. As a result, the usefulness of this diagnostic tool can be questioned, and if misinterpreted, it could lead to questionable diagnoses and inadvertently erroneous management if used in isolation. These slides can be retrieved under Electronic Supplementary Material.

中文翻译：

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CT脊髓造影的正常外观。

自从1976年以来，目的CT脊髓造影已被用于诊断轴向骨骼的神经压迫。随着常规MRI的出现，人们对它在准确诊断神经压迫中的作用提出了质疑，因为该研究未定义其正常外观。在这项研究中，我们检查了一系列CT脊髓造影，以定义脊柱神经元的正常外观。方法由四名独立医师检查单侧症状患者的CT脊髓造影。检查并记录横向对比。使用kappa评分评估记录范围之间的一致性。结果进行了36次扫描。Kappa分析表明，在L1，L3和L4处，横向对比度的范围相当一致。在L2和L5，一致性很小。结论CT脊髓造影的解释显示观察者之间存在显着差异。结果，该诊断工具的实用性可能会受到质疑，如果误解了，如果单独使用它可能会导致可疑的诊断和错误的管理。这些幻灯片可以在电子补充材料下找到。