Non-invasive evaluation of testicular torsion using ultrasound shear wave elastography: an experimental study

Abstract

Purpose: The goal of this study was to examine changes in testicular stiffness at various intervals after the induction of testicular torsion, as well as to assess the predictive value of testicular stiffness for testicular spermatogenesis after torsion.Methods: Sixty healthy male rabbits were randomly assigned to one of three groups: complete testicular torsion, incomplete testicular torsion, or control. All rabbits underwent preoperative and postoperative scrotal ultrasonography, including shear wave elastography (SWE), at predetermined intervals. Changes in SWE values were analyzed and compared using repeatedmeasures analysis of variance. To assess the diagnostic performance of SWE in determining the degree of spermatogenic function impairment, the areas under the receiver operating characteristic curves (AUCs) were calculated.Results: SWE measurements in both central and peripheral zones of the testicular parenchyma affected by torsion demonstrated significant negative correlations with spermatogenesis, with coefficients of r=-0.759 (P<0.001) and r=-0.696 (P<0.001), respectively. The AUCs of SWE measurements in the central or peripheral zones of the torsed testicular parenchyma were 0.886 (sensitivity, 83.3%; specificity, 100%) and 0.824 (sensitivity, 83.3%; specificity, 73.3%) for distinguishing between hypospermatogenesis and spermatogenic arrest, respectively (P=0.451, DeLong test).Conclusion: Variations in the stiffness of both central and peripheral regions of the testicular parenchyma correlate with the extent and duration of torsion, exhibiting a specific pattern. The "stiff ring sign" is the characteristic SWE finding associated with testicular torsion. SWE appears to aid in the non-invasive determination of the extent of spermatogenic damage in torsed testes.