Statistics

All continuous parameters are reported as mean ± standard deviation. Differences in parameters between subject groups were assessed using the standardized t-test (two-sample, unequal variance) for normal distributions and Wilcoxon rank sum test otherwise [29]. We computed Pearson’s correlation coefficient R to assess relationships between torsion, age, and EF, a correlation with p < 0.05 was considered significant. Inter-observer variability and scan-rescan reproducibility were analyzed using Bland-Altman plots and by calculating mean differences and limits of agreement (mean ± 1.96xSD of the differences).