Purpose: We aimed to develop a conversion formula between different calculations for testicular volume asymmetry.
Materials and methods: Male adolescents with varicoceles who underwent scrotal ultrasound were studied. Two formulas were analyzed: (1) testicular volume differential, TVDiff = (RTV - LTV)/(TTV), and (2) atrophy index, AI = (RTV - LTV)/(RTV). RTV, LTV, and TTV represent the right, left, and total testicular volume. Through transformations and regression a conversion formula between the calculations was derived.
Results: Based on 248 ultrasounds, a clear relationship between the two formulas was demonstrated: AI = ln[(1.97 × TVDiff) + 1], (p < 0.0001).
Conclusions: Differential testicular volumes can easily be converted from one formula to another with near-perfect accuracy. The formulas are essentially identical and interchangeable.
Keywords: Adolescents; Scrotal ultrasound; Testicular volume differential; Varicocele.
Published by Elsevier Ltd.