Figure 1: Main significant scrotal-related ultrasound and clinical parameters in relation to PI dimmer sDF. (a– c) Stepwise relationships among PI dimmer sDF and mean testis ultrasound volume, FSH and LH levels. The statistical analyses were performed using the mean testis volume, FSH or LH levels as continuous variables, although grouped here in quartiles for graphical purposes. Adjusted r (Adj. r) and P values derived from Table 3 , Model 2 (linear regression analysis) are reported. (d) Difference in PI dimmer sDF between subjects with or without epididymis tail inhomogeneity. P values derived from Table 3 , Model 2 (ANCOVA) are reported.