Reference values for testicular volume, epididymal head size and peak systolic velocity of the testicular artery in adult males measured by ultrasonography.

PURPOSE: To obtain ultrasonography-based reference values for testicular volume, epididymal head size and peak systolic velocity (PSV) of the testicular artery in adult males of all ages.

MATERIALS AND

METHODS

Between 2009 and 2011, 306 Caucasian adult males (median age: 51 years; range: 18-88 years) without scrotal pathology underwent prospective scrotal ultrasonography. The testicular volume was calculated from the length (L), width (W), and height (H) using three formulas: a) 0.52 × L × W × H, b) 0.52 × L × W², and c) 0.71 × L × W × H. Thickness and height of the epididymal head and PSV of the testicular artery were measured.

RESULTS

The median testicular volumes on the right (left) side were 13.9 (12.7) ml, 18.1 (16.5) ml, and 18.9 (17.3) ml for formula a), b), and c) respectively, and thus significantly different (p < 0.01 for all). The left testes were significantly smaller than the right testes (p < 0.01). The thickness and height of the right (left) epididymal head measured 7.5 (7.7) mm and 11.6 (11.3) mm, respectively. Median PSV of the right (left) testicular artery was 8.7 (8.6) cm/sec. No significant side-specific differences were documented with respect to epididymal size and PSV.

CONCLUSION

It was possible to obtain virtually age-independent reference values for testicular volume, epididymal head size and PSV of the testicular artery in adults. With regard to testicular volumetry, it is essential to consider which formula has been used, since the calculated volumes differ significantly from formula to formula.