Ultrasound measurements of testicular volume: Comparing the three common formulas with the true testicular volume determined by water displacement

Abstract

Objective: To determine the accuracy of various ultrasound formulas for measuring the testicular volume in humans by comparing the resultant measurements with the actual testicular volume. Subjects and methods: The testicular volume of 121 testes from 62 patients with prostate cancer (mean age 72.7 ± 9.4) was measured using ultrasonography before therapeutic bilateral orchidectomy. The ultrasound measurements of the testicular volume were calculated using the following three formulas: (a) length (L)× width (W) × height (H) × 0.52; (b) L × W² × 0.52 and (c) L × W × H × 0.71. The actual testicular volume was determined by water displacement of the testis. Results: The mean actual testicular volume was 10.6 ± 3.5 ml. A strong correlation was found between the actual testicular volume and the volume calculated by the three-ultrasound formulas (r = 0.853–0.871, p = 0.0001). The smallest mean difference from the actual testicular volume was observed with the formula L × W × H × 0.71, which underestimated the actual volume by 0.4 ml (3.9%). Conclusion: The results of this study show that ultrasonography and the formula L × W × H × 0.71 are the most accurate method for the calculation of the testicular volume.

Keywords: Testicular volume; Measurement; Ultrasound; Water displacement

African Journal of Urology (2013) 19, 69–73