Objectives

This study aims to determine the reliability of the radiological tests used in the diagnosis of basilar invagination (BI).

Methods

Patients diagnosed with type B basilar invagination, who had both magnetic resonance (MR) and computed tomography (CT) imaging between January 2014 and November 2019 were included in this retrospective reliability study. In this study, distance from odontoid apex to Chamberlain’s line (OA-CL) was accepted as a reference method for the diagnosis. Forty-two BI cases and 79 controls were included. Three radiologists with different levels of experience individually evaluated OA-CL, Boogard’s angle (BoA), clivo-axial angle (CXA), clivo-dens angle (CDA), and clivo-palate angle (CPA) on midsagittal CT and MR images. Statistical analysis was made with the intraclass correlation coefficient (ICC), t-test, and receiver operating characteristic (ROC) curve.

Results

The ICC for CT and MR were; 0.977−0.973 (OA-CL), 0.912−0.882 (BoA), 0.845−0.846 (CXA), 0.862−0.864 (CDA), and 0.762−0.747 (CPA) respectively (P < 0.001). The areas under the ROC curve were 0.977 (BoA), 0.832 (CXA), 0.852 (CDA), and 0.719 (CPA) (P < 0.001). The cut-off measures were ≥137.84° (BoA), ≤149.25° (CXA), ≤129.58° (CDA), and ≤61.83° (CPA). The diagnostic accuracies were 0.954 (BoA), 0.664 (CXA), 0.704 (CDA), 0.438 (CPA) (P < 0.001).

Conclusions

OA-CL and BoA express excellent inter-rater agreement than CXA, CDA, and CPA, which are limited due to morphological variations and head spatial position. BoA is the second most reliable diagnostic test. CXA, CDA, should only be used for complementary information. CPA was found inadequate for the diagnosis of BI.

中文翻译：

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B 型基底陷陷的放射学方法：可靠性和准确性

目标

本研究旨在确定用于诊断基底动脉内陷 (BI) 的放射学检查的可靠性。

方法

这项回顾性可靠性研究纳入了在 2014 年 1 月至 2019 年 11 月期间进行磁共振 (MR) 和计算机断层扫描 (CT) 成像的 B 型基底动脉内陷患者。在本研究中，齿状突尖到张伯伦线的距离（OA-CL）被接受作为诊断的参考方法。包括 42 例 BI 病例和 79 例对照。三位具有不同经验水平的放射科医师分别评估了正中矢状 CT 和 MR 图像上的 OA-CL、Boogard 角 (BoA)、顶轴角 (CXA)、顶角 (CDA) 和顶腭角 (CPA)。采用组内相关系数（ICC）、t检验和受试者工作特征（ROC）曲线进行统计分析。

结果

CT和MR的ICC是；分别为 0.977-0.973 (OA-CL)、0.912-0.882 (BoA)、0.845-0.846 (CXA)、0.862-0.864 (CDA) 和 0.762-0.747 (CPA) (P < 0.001)。ROC曲线下面积分别为0.977（BoA）、0.832（CXA）、0.852（CDA）和0.719（CPA）（P < 0.001）。截止测量值为 ≥137.84° (BoA)、≤149.25° (CXA)、≤129.58° (CDA) 和 ≤61.83° (CPA)。诊断准确率分别为 0.954 (BoA)、0.664 (CXA)、0.704 (CDA)、0.438 (CPA) (P < 0.001)。

结论

OA-CL 和 BoA 比 CXA、CDA 和 CPA 表现出出色的评分者间一致性，但由于形态变化和头部空间位置而受到限制。BoA 是第二可靠的诊断测试。CXA、CDA 只能用于补充信息。CPA被发现不足以诊断BI。