Statistical analysis
According to the normality of the data, the independent two-sample t-test, the paired t-test and one-way ANOVA were used to analyze data. Descriptive statistics included frequency (percentage) and mean ± standard deviation (Mean ± SD). To determine a diagnostic cut-off value of the ratio of C1 to C2 (C1/C2), we used the receiver operating characteristic (ROC) curve, calculated from the sonographic measurements of the patients. The significance level for all statistical analyses was set at 0.05.