Can multi-positional magnetic resonance imaging be used to evaluate angular parameters in cervical spine? A...

To test the reliability and validity of the multi-positional magnetic resonance imaging (MRI) in measuring cervical angular parameter using the standard dynamic cervical X-ray as a reference.

All patients who underwent both cervical dynamic plain radiograph and multi-positional MRI on the same day between 2010 and 2016 were included in this study. The C2-7 angle and the segmental angles of the C2-3 to C6-7 segments were measured in all three positions (neutral, flexion, and extension) using multi-positional MRI and dynamic radiograph. The Pearson's correlation coefficients and linear regression analysis were used for statistical analysis.

46 patients were enrolled in this study. All angular parameters showed significant positive correlation between multi-positional MRI and dynamic X-ray (p < 0.05). The angle of C2-7 showed significantly positive correlation between multi-positional MRI and X-ray (r = 0.552-0.756). All segmental angles from C2-3 to C6-7 showed moderate correlation (r = 0.401-0.636). The linear regression analysis showed that C2-7 angles and all angular parameters had significant correlation between multi-positional MRI and dynamic X-ray (p < 0.05, R ² = 0.107-0.571).

The C2-7 angle and segmental cervical angles measured by multi-positional MRI were valid, and reliability substituted the dynamic X-ray measurement within the acceptable range of error. Multi-positional MRI can be used as a reliable tool for angular parameter measurement and detection of angular instability in the cervical spine.