Statistical analysis
All data were analyzed using IBM SPSS software version 22.0 for Windows and a p value of less than 0.05 was considered statistically significant. Data were reported as means with standard deviations (SDs) or medians with interquartile ranges (IQRs). The Mann-Whitney U test was used to compare non-parametric variables. For parametric data, Student’st test was used. Correlations between ultrasound parameters and clinical/echographic scores were assessed with Spearman’s rank correlation coefficient.