Diagnostic accuracy of classical radiological measurements for basilar invagination of type B at MRI
To evaluate the diagnostic accuracy of classical measurements for basilar invagination (BI) of type B at MRI.
This study used head MRIs from 31 participants with BI type B and 96 controls. The radiological criterion for BI was the odontoid process invagination using the obex as reference. It based on the independent prospective reading of two neuroradiologists. Concordance between the two neuroradiologists was analysed through the KAPPA index, and the discrepancy was resolved in a consensus meeting. A third examiner measured in two occasions (double blind) the distance of the odontoid apex to Chamberlain’s line (DOCL) and McGregor’s line (DOMG), clivus canal angle (CCA), Welcker’s basal angle (WBA), and Boogaard’s angle (BOA). Intra-examiner reproducibility of the measurements was evaluated with the intraclass correlation coefficient and the diagnostic accuracy by ROC curve. All analyses were at 95% confidence interval.
Agreement between the two neuroradiologists was statistically relevant (KAPPA = .91; P = .0001). The intra-examiner reproducibilities were .98 (DOCL), .97 (DOMG), .96 (CCA), .94 (WBA), and .95 (BOA) (P < .05). The areas under the ROC curve were .963 (DOCL), .940 (DOMG), .880 (CCA), .867 (WBA), and .951 (BOA) (P < .05). The cut-off criteria were ≥ 7 mm (DOCL), ≥ 8 mm (DOMG), ≤ 145° (CCA), ≥ 142° (WBA), and ≥ 136° (BOA). The diagnostic accuracies were .904 (DOCL), .870 (DOMG), .844 (CCA), .810 (WBA), and .899 (BOA).
The DOCL and BOA presented the highest diagnostic accuracy for BI type B.
KeywordsBasilar invagination Chamberlain line Boogaard’s angle Diagnostic accuracy Roc curve
Apex distance of the odontoid to Chamberlain’s line
Apex distance of the odontoid to McGregor’s line
Clivus canal angle
Welcker’s basal angle
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee.
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.
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