Figure 1.
Figure of the posterior neck muscles and diagram demonstrating how the measurement plane was selected.
A. Non-contrast T1-weighted MR of transverse plane of the neck at mid-infero-superior-C2 level. B. Outline diagram showing the neck muscles whose cross-sectional areas were measured. C. Outline diagram demonstrating how measurement plane is selected with an example C2 height of 42 mm.
Figure 2.
Flowchart summarizing method to measure craniad muscles cross-sectional areas.
Figure 3.
Diagram summarizing the methods for the four studies.
Table 1.
Intra-class correlation coefficients for the second technique trialled in the feasibility study (Study 1).
Figure 4.
Plot of MR slice chosen as representing the mid-point of C2 for both raters.
Table 2.
Mean cross-sectional areas (CSAs) as measured by each rater summed for left and right, together with absolute mean difference and mean difference as percentage of CSA between raters (Study 2).
Table 3.
Intra-class correlation coefficients with 95% confidence intervals for the reliability study (Study 2).
Figure 5.
Bland-Altman plots for total neck muscle CSA and SCM+combined CSA measured by 2 raters.
Bias of measurement between 2 different raters (mean of the ordinate) and limits of agreement (2sd) are represented by a solid and two dashed lines respectively. A. Bland-Altman plot for measurements of total neck muscle CSA by 2 different raters. B. Bland-Altman plot for measurements of SCM+combined CSA by 2 different raters.
Table 4.
Coefficients of variation (%) with 95% CI and Levene's significance test between the two raters (Study 2).
Table 5.
Between scanner intra-class correlation coefficients for the repeatability study (Study 3).
Table 6.
Within scanner intra-class correlation coefficients for the repeatability study (Study 3).
Figure 6.
Bland-Altman plots for total neck muscle CSA measured on 3 different MRI scanners.
Bias of measurement between different MRI scanners (mean of the ordinate) and limits of agreement (2sd) are represented by a solid and two dashed lines respectively. A. Bland-Altman plot for total neck muscle CSA measured on the Aberdeen and Edinburgh MR images. B. Bland-Altman plot for total neck muscle CSA measured on the Edinburgh and Glasgow MR images. C. Bland-Altman plot for total neck muscle CSA measured on the Glasgow and Aberdeen MR images.
Table 7.
Coefficients of variation (%) with 95% CI and Levene's significance test between the three MRI scanners (Study 3).