Shear wave elastography (SWE) is reliable method for testicular spermatogenesis evaluation after torsion

This study aims to investigate effect of torsion on testicular stiffness alteration in affected and concomitant testis using improved ultrasound method of shear wave elastography (SWE). We compared the morphology of the testicular spermatogenesis assessed with Johansen's scale on histology specimens with a mean stiffness measured by SWE. A total of 18 New Zealand white male rabbits were divided into two groups (group A and group B), animals from group A were subjected to operation of right testicle torsion while left testicle remained intact. In group B both testicles were normal and right testicle was subjected to sham operation. The protocol of measurement for mean stiffness value was calculated from three elastographic images obtained from each testicle. Significant difference in mean stiffness value and Johnsen' scaling was observed in both groups (A and B), as well as for normal and torted testicle in group A. The mean stiffness positively correlated with histologic grade on both sided testicles in group B, and left sided testicles in group A (P=0.045, r=0.43; group B; P=0.001, r=0.98), while histologic grade negatively correlated with mean stiffness in the group A, torted testicle (torsion P=0.012, r=-0.76). In this study testicular torsion, with consequently higher mean stiffness value determined by SWE, has qualitatively and quantitatively decreased spermatogenesis. Gradual morphology change in testicle unaffected by torsion has not been previously reported. This study confirmed that quantitative change in testicular tissue stiffness as well as change in testicular spermatogenesis can be reliably evaluated with SWE.